Future Energy eNews   IntegrityResearchInstitute.org      Oct. 28, 2008       

1) Advanced Aerodynamic Air Turbine Engine - Trial run is "flawless" even though engine is unbelievable 
2) Gas Hydrates - a 'Clean' Energy Source?? - Journalist for hire deftly avoids obvious CO2 emissions with her story
3) Renewable Energy: Electric Dreams - Special New Scientist series addressing issues about 100% renewable energy 
4) Renewable Energy: Will the Lights Stay On? - Dynamic demand and smart meters help renewables with ties to grid
5) Renewable Energy: Anywhere the Wind Blows - 75-meter 10 MW wind turbines now and 130-meter 20 MW by 2020
6) Renewable Energy: The Tide is Turning - Tidal wave power is growing worldwide - 8GW and 15 GW units planned
7) Renewable Energy: Power Beneath our Feet - Good review of geothermal power, heat too far down, 22 GWh so far
8) Renewable Energy: From Deam to Reality - Overview of the countries achieving 60% to 100% renewable energy!

1) The Advanced Aerodynamic Air Turbine Engine

Editorial, July 2008 (as printed in The American's Bulletin July Issue), http://www.airturbineengine.com/

The future has arrived with the solution to our world's energy needs. The Aerodynamic Air Turbine Engine (AATE), aptly named "The Crystal Ion", will be the energy revolution we have been waiting for. Clean energy utilizing the force of nature to create powerful and sustainable motion with no detrimental environmental impact is here. The air we breathe is the same air that drives the AATE; no wind required. This is not a perpetual motion machine. When I first learned of Rockwell Scientific Research L.L.C. (RSR) and the AATE, I was very skeptical. The more I thought about it the more my feelings mixed. Can this be real? My thoughts torn between my disbelief and belief. I became more exhilarated as the myriad of potential uses flooded my neuron pathways; an engine that runs on ambient air, without any air tanks, combustion or fuel cells, producing no exhaust. The thoughts thrilled me to no end. I just had to see the engine for myself.

I will forever remember the day I actually saw the engine running with my own eyes. As unbelievable as it first appeared my skepticism quickly turned to enthusiasm that was so totally overwhelming I nearly wet myself. Here was the future, right before me. The engine hummed along at 30k plus RPM without any fuel or exhaust. The clear design of the casing afforded a detailed view of the interior. There were no electronics inside except for the LEDs. As the throttle revved the engine up and down it was clear to me that this was genuine and not a hoax.

What really boggled my mind was the fact that there were no investors beating down the door to become a part of this new energy revolution. Here was the absolute answer to the energy crisis we are currently facing. What is wrong with Americans today? Why would everyone be so willing to continue down the pathway paved by oil, coal and nuclear technologies when that path results in torturing common citizens, reaching deep into their pockets? Why are so many of our fine young men and women dying needlessly for the right to oil? Why are billions of dollars being spent trading Carbon Credits and where is all that cash going? Are people really concerned about their living environment? Politicians are quick to blame industries for what is really political failure.

So how was the AATE re-born? In late April 2005 Ron Rockwell, of RSR, was invited to meet with inventor Haskell Karl who claimed to have built an engine powered only by air. Ron met with Haskell in person and after reviewing all his material (consisting only of photographs, drawings and sketches) and detailed phone discussions. Ron decided to rebuild the engine using current technology. I am sure that skepticism reigned high. However, Ron believed this technology had substantial merit and invited his trusted colleague, friend and fellow machinist Cliff Cruz, to join his team in re-creating the engine. Through twelve years of research and development of various devices in the high tech industry, RSR has developed the AATE.

In the early 1960's, Haskell took the original engine he built for testing to Wyle Testing Laboratory. They could not figure out how it worked and requested that he leave it with them so they could further analyze the engine. Haskell refused and headed home with the invention. The AATE was scheduled to be presented to President Kennedy at a special meeting. Before this presentation could take place, the people who worked with Mr. Karl on the engine mysteriously disappeared. Shortly thereafter, the engine also disappeared. There was also talk that China was willing to pay 100 billion dollars for the engine but the deal fell through when a key individual died from a massive heart attack. Haskell Karl went into hiding, keeping with him the documents, original drawings, and numerous photos of how he built the engine. Now 40 some years later, the engine is re-born.

Although the concept and science behind the engine (Vortex Air Implosion Technology) was not fully understood at that time, the determination was made that a new prototype based on discussions, drawings and photos, could be built. The task was undertaken.

The machine shop of RSR started the initial construction in May of 2005. Work was arduous. Unique parts needed to be manufactured. In order to do so, new tools also needed to be machined in order to manufacture these parts. There was no manual, guidebook or instructions. Instead Ron and his team had to rely on their knowledge, ingenuity and creativity to build the engine. With the latest technology available today, Ron was able to redesign and improve things that could not be done back in the 60's. Through trial and error (not much of the latter) and 3 million dollars later, they finally completed the first functioning prototype in the fall of 2006.

Ecstatic with the results, arrangements were made to travel to Washington DC to present the engine to the Department of Energy in hopes that they would embrace this unprecedented technology. Unfortunately, Mr. Rockwell and Dr. Beverly were met with bureaucratic indifference. Need more be said? The people needed to know that a solution to the world's energy was available and a press release was issued in November to over 200 newspapers and magazines. Again there was huge indifference by the press who were more focused on news of the war and elections. Case in point. That day in Washington at Fox News Channel 5, they spoke with a woman named Sheila who said "unless [they] had a story about the Iraq war or the upcoming elections that Fox probably wouldn't run a story on it", "those [are] the 2 most pressing issues that people wanted to hear about". Unbelievable! It is this kind of attitude and indifference towards true solutions for peace and clean energy that have prevented this country and our world from realizing its full potential.

As with any technology that promises huge gains, security is an issue. There have been several security breaches over the course of development. Thankfully, they were discovered early enough to thwart them. One lengthy breach occurred in the summer of 2007 when 2 individuals (referred to as "vultures") attempted to "take-over the technology". They began contacting Haskell, eventually coercing him to denounce Mr. Rockwell and promising him quick profit. They also contacted Ron's chief machinist and met with him several times to engage him in assisting them to develop the engine without Ron. Despite knowing that they were being videotaped, they continued their discussion with Cliff to bring him on board and away from RSR and the engine project. These individuals are under criminal investigation. The result of this breach caused a serious delay in the completion of the engine. Security is now tighter than ever.

A number of individuals came forward claiming to be investors, venture capitalists and personally wealthy. Many of these individuals were not investors but brokers, agents or individuals that knew someone who wanted to invest and really had nothing to offer. This was also a source of lost time.

The purpose of seeking investment was to develop, market and support innovative cost-effective clean energy devices, products and services; especially those made available through its proprietary technology designs. RSR will offer the Ultimate Solution to the growing world energy problem. The end of fossil fuel use, preserving natural resources, create low cost clean energy (zero emissions), create independence from foreign oil use, non-degenerative and non-destructive energy forces from the technology use, while creating worldwide demand for this Ultimate Solution.

Ron and his team made some substantial technical discoveries and potential problems with the current design and proceeded to re-build the AATE with new specifications. Noise level was substantially reduced and overheating was no longer any concern. Haskell met the improvements in the design with great joy. What remains to be done is more testing and validation from a government source (Wyle Testing Laboratory) that the AATE performs as described and is sustainable.

In early 2008 there had been an invitation by a government department to apply for a number of grants that were available only for new energy projects. Sounded more promising than the first encounter with the government. The applications were arduous and requested very specific and detailed specifications of the engine. It was not acceptable to provide the government with those specifications. Another individual with high status in the Mexican Government offered to set up a meeting with the President of Mexico. At first it sounded very good to Ron. As the time approached, the meeting was postponed and Ron began to feel something was not right. This trip did not happen either. As it turned out, this individual was in a financial bind and planned no introduction to President of Mexico. The promised trip to Washington was actually a scheduled NAFTA meeting not a special meeting for Ron.

So what exactly is the AATE? It is a mechanical device built to spin at high revolutions without the need for any fuel, combustion or compressed air. This device is a sophisticated application of a simple scientific principle long known in the alternative energy field, Vortex Implosion Air Technology (VIAT). Viktor Schauberger first discovered the principle of the Vortex and developed technology for moving water more efficiently. The same principle can be applied to airflow. The RSR AATE runs on ambient air; the very air we breathe, using no air tanks and no other power source other than air. A tornado is created in the engine that implodes on itself which actually speeds up and sustains the airflow back into the tornado.

We see what is wrong with our energy policies every time we go to the pump, buy groceries, pay our bills and of course all the news that bombards us daily. Perhaps it is a good thing that huge caverns (many times the size of the Grand Canyon) are being created beneath the earth surface. When the current trend of melting glaciers and icebergs continues, the land will cave in and fill those caverns. We will not have to worry about flooding the land we live on.

Enough is enough America. Take the time to contact your politicians and let them know that you know the time for positive change is now. Forget those hybrid cars, wind generators and solar cells. The costs of implementing these technologies will never be recovered in your lifetime but you and your children will be paying for them without any true benefit.

Anton Bernhardt
July 1, 2008
For info on the Aerodynamic Air Turbine Engine contact:
Dr. Bob Beverly 702-715-3996 drbobbeverly@hotmail.com

2) Looking for an Endless, Clean Fuel Source?

--- Warning: This article deceives the public by failing to mention the CO2 emissions that hydrates create. - Ed Note ---

Elizabeth H. Casey/Tech Beat/For the Times-Standard, Article Launched: 10/09/2008 http://www.times-standard.com/ci_10676201?IADID=Search-www.times-standard.com-www.times-standard.com

 Most of us don't have an appreciation for sea slime, (AKA sea floor sediment), but we should.

Why? At certain depths and temperatures, much of the sediment on the bottom of the world's oceans becomes rife with a substance called gas hydrate, which is a fascinating material that could potentially power many of our planet's crucial systems. Research into this naturally occurring phenomenon could yield bountiful alternative power solutions.

Gas hydrate, also known as gas clathrate, is crystalline structures, resembling ice, found in sediment and formed by a mixture of low-temperature, pressurized water and various low-weight natural gasses, most commonly methane. The water molecules form a type of “cage” around the gas, trapping it in pockets of sediment. Gas hydrate is believed to form when natural gasses escape from fault lines throughout the ocean and mix with the sediment and cold, pressurized ocean water. When the hydrate material is burned, little residue is left behind other than faintly salty water, so it's considered a much cleaner potential fuel than currently extracted fuels in use today.

In many places, the ocean floor, at approximately 1600 feet in depth, contains astronomically large areas of gas hydrate that spreads out for miles and includes large mounds, pockets, veins, and layers of the material. Gas hydrate is also found in land locations with permafrost, but the greatest concentrations are in the sea floor. Because sea sediment changes viscosity when gas hydrate is present, studying the phenomenon might also answer questions about other sea floor technologies, such as drilling, bridge design, wells, and pipelines.

So, how much gas hydrate is there? The TAMU Oceanography Web site states that, “Estimates of the total energy reserves trapped ... vary considerably, but ... the resource potential of methane in gas hydrate exceeds the combined worldwide reserves of conventional oil and gas reservoirs, coal, and oil shale by a wide margin.”

And, from the Science Daily Web site, “USGS estimates that the nation's gas hydrate deposits contain 200,000 trillion cubic feet (Tcf) of natural gas. Compare this with a known recoverable natural gas resource of approximately 1,500 Tcf. If just 1 percent of the gas hydrate resource could be rendered producible, our nation's natural gas resource base would more than double.”

The real challenge is in harvesting (or manufacturing) the hydrates. Because gas hydrate degrades into its base components -- gas and water -- and disperses when brought up from the depths, special containers are required to get the material to the surface for study. And, experiments to create the hydrate have resulted in molecularly similar compounds, but none as ingenious as the real stuff. The laboratory grown hydrate never reaches the correct consistency and texture.

Growing hydrates in ocean settings have yielded some success, but again, getting the material to a point where it can be preserved long enough to wring fuel from it is the challenge. Up to this point, no real-world, practical method has been developed to stabilize gas hydrate so that the substance can be converted into usable, liquid fuel. The research goes on.

Much of the sediment on the bottom of the world's oceans contains vast deposits of gas hydrate, which with further study and testing, could yield an alternative energy solution for our power-hungry species.

Studying and testing the phenomenon is the charter of several prominent institutions, such as the Monterey Bay Aquarium Research Institute (MBARI), the TAMU Oceanography organization, and the U.S. Geological Survey, among many others. Initial studies indicate that gas hydrates are an exceptional source of clean fuel and leave little residue behind once burned. This could potentially provide a much cleaner, greener fuel for use in all kinds of applications.

Liz Casey of ButterFat Writing Services, Inc.(www.butterfatwriting.com) provides robust copy and technical writing for clients who want their written collateral to effectively communicate and make them money. She is a member of the Redwood Technology Consortium (www.redwoodtech.org). 

3) Renewable Energy: Electric Dreams

Helen Knight, New Scientist, Oct 11, 2008, http://environment.newscientist.com/channel/earth/mg20026771.500-renewable-energy-electric-dreams.html

SMOKESTACKS, cooling towers, reactor domes and gas installations are defining features of our modern landscape. Each is a key component in electricity generation, but perhaps not for much longer.

Sprinkled over every continent are the totems of a new era of power: wind turbines and solar energy collectors. So far they are few and far between, but that's about to change. Plans for huge solar power plants have been drawn up in the US, Spain and Portugal, and it seems barely a month goes by without a new wind farm springing up.

In the past decade, the amount of electricity generated from renewables worldwide almost doubled, according to the International Energy Agency, and by 2006 they accounted for 2.3 per cent of the 19 million gigawatt-hours of electrical energy the world produced.

This is set to rise even further in the next few years. In January, the European Union set targets for its member states that would require 20 per cent of its electricity to come from renewable sources by 2020. China plans to reach 15 per cent by the same year. Some US states have introduced similar targets.

On paper, the amount of recoverable renewable energy available globally could serve our needs several times over (see Earth, wind and fire). So could we meet all of our energy needs from renewable sources?

It's a tricky question. One problem is that the more energy provided by renewables, the more unstable national electricity grids become. Unlike nuclear, coal or gas-fired power plants, renewable generators only produce electricity intermittently: when the wind is blowing or the sun is shining. So as things stand we will either have to accept more frequent outages, or have to rely on back-up from fossil-fuel or nuclear generators.

With up to 20 per cent from renewables, the problem is manageable - operators already keep back-up plants running to smooth out such fluctuations. It is easily affordable too. Meeting this target with wind alone would add just 50 cents per month to the average US household bill, states a report from the Department of Energy, published in May.

Going beyond this brings more challenges. "At around 30 per cent penetration of renewables it will start causing problems for the utility grids," says Georgianne Peek, an energy researcher at Sandia National Laboratories in Albuquerque, New Mexico. And the further you go, the worse it gets. "We are used to being able to flick the switch and having the lights come on," Peek says. "That won't happen with 100 per cent renewables."

So to make a high level of renewables workable, you need to do more than just install wind turbines and solar panels. Something will also have to be done by the consumer. We are already seeing hints of how this will work in fridges and aircon units that switch themselves off when the electricity supply is overstretched. Similarly, smart metering can dynamically change the price of electricity to encourage people to use power-hungry devices at times when demand is low (see Will the lights stay on?).

Renewable sources can also generate excess power when demand is low. Finding efficient ways to smooth out the peaks and troughs is a top priority (see Saving up for a windless day). Finally, high-voltage direct-current "supergrids" linking areas with significant renewable resources across thousands of miles could shift power more efficiently to regions that need it (see Edison's revenge).

Put all these together, and there is no technical reason that we could not get close to 100 per cent of our electricity from renewables, says Samir Succar, at the Princeton Environmental Institute at Princeton University, who studies energy storage and transmission systems. "I don't see intermittency as an insurmountable obstacle."

Some communities have already managed to make the switch (see From dream to reality). Isn't it time the rest of us followed suit?

* * *

Read all the articles in our special issue on renewable energy:

Renewable energy: Will the lights stay on?

Renewable energy: Anywhere the wind blows

Renewable energy: The tide is turning

Renewable energy: Power beneath our feet

Renewable energy: Dreams become reality


Saving up for a windless day

Edison's revenge: The return of direct current

Catching the waves

Sunny side up: New forms of solar power

Power plants: Can we harness plant waste?

Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.

What's a watt worth?

A watt is a measure of power - the rate of flow of energy. A typical TV set has a power consumption of 150 watts, so for an hour's viewing it will consume 150 watt-hours of energy. A large, 10-megawatt wind turbine should produce at least 10,000 megawatt-hours of energy in a year, enough to meet the needs of 1000 average American homes.

From issue 2677 of New Scientist magazine, 08 October 2008, page 28-29

4) Renewable Energy: Will the Lights Stay On?
Helen Knight, New Scientist, Oct 11, 2008

IN A laboratory in Italy, 100 fridges sit quietly monitoring their electricity supply. It's an odd thing for fridges to do, but these are no ordinary fridges. They are part of an experiment that, if successful, could transform the reliability of supplying electricity from renewable sources.

One of the key problems with renewables is their intermittent availability. You can only generate energy from the wind when it is blowing, or from the sun when it's shining. Critics argue this is why we will never be able to rely on renewables for the majority of our electricity generation. But that criticism may soon be silenced. Researchers are developing new ways to balance supply and demand so that interruptions to the supply at a power station are unnoticeable to the consumer.

For example, the idea behind the fridge experiment exploits the peculiar way the power grid responds when demand exceeds supply. In Europe, the frequency of the alternating current on the grid hovers close to 50 hertz, in North America it is 60 hertz. If demand increases, or the supply drops - as might happen, for example, if the wind stops blowing at a large wind farm - the frequency will dip below this level by up to 1 hertz as the remaining generators struggle to keep up. If it dips further, to around 48.8 hertz in Europe, the grid operators must shed some of the load, and parts of the country are disconnected from the grid and blacked out.

The Italian fridges are connected to a network that simulates this kind of power crisis, but instead of relying on a central control room to switch out the load, it is the fridges themselves that respond. As the frequency drops, a built-in controller in each fridge detects the change, checks the temperature of the fridge, and calculates how long it can stay chilled without drawing any power. It then switches the fridge off for as long as is safe. A similar system, developed by the the US Department of Energy's Pacific Northwest National Laboratory in Richland, Washington, was successfully tested last year in 150 specially modified tumble-dryers.

If the technology, called dynamic demand, were fitted to enough fridges and air-conditioning units it could go a long way to smoothing out the fluctuations caused by the intermittent nature of renewable energy supplies. A report last year by the UK's Department for Business, Enterprise and Regulatory Reform said the dynamic demand controllers would cost no more than £4 per appliance, a cost easily offset by the market value of the balancing services each fridge provides, estimated at around £30 over its lifetime. Fitting all the UK's 30 million domestic fridges with dynamic demand controllers would slice 2 gigawatts off peak demand, which could mean that two fewer coal-fired power station would be needed, according to Andrew Howe, CEO of RLTec, the London-based company that developed the dynamic demand software being tested in the Italian fridges. If industrial and commercial fridges were also included, dynamic demand could compensate for the sort of fluctuations expected if 20 per cent of the UK's electricity were supplied from renewables, Howe says.

Dynamic demand is not the only way to tackle these fluctuations. In a contrasting approach, known as smart grid systems, an operating system run by the utility company is in two-way communication with controllers in consumers' appliances. Using information fed in by the appliances, combined with predictions of renewable power output based on local short-term weather forecasts, the operating system can balance demand to match supply by telling non-essential appliances to switch themselves off. "We can turn off a compressor in somebody's air-conditioning system for 15 minutes, and the temperature really won't change in the house," says Karl Lewis, chief operating officer of GridPoint in Arlington, Virginia, a company that designs smart grids.

By providing homes with smart meters to monitor their energy use, such systems can also help smooth out demand by encouraging consumers to set their washing machines for cheaper, off-peak times, for example.

GridPoint is working with Minnesota-based Xcel Energy to test the technology on a city-wide basis in Boulder, Colorado. In August, Xcel began equipping homes in the city with smart meters and remotely controlled devices. Next year, it plans to introduce solar and wind energy generators onto the grid. The hope is that the project will pave the way for cities of the future to be powered largely by electricity from renewables.

Read all the articles in our special issue on renewable energy

Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.

Saving up for a windless day

Keeping the electricity flowing will take a battery the likes of which you've never seen

When you need it there's not enough, and when you don't there's too much. All too often, that's the story with renewable energy. So finding a way of storing the excess generated when demand is low and releasing it for use at peak times is a priority if renewable electricity is ever going to be as reliable as fossil fuels.

At the moment, the preferred option for handling peak demand is to turn on gas-turbine generators, something that can be done at almost a moment's notice. But as gas has become more expensive, electricity companies have become increasingly interested in energy storage as a way of dealing with the peaks, says Dan Rastler, an energy storage specialist at the Electric Power Research Institute (EPRI) in Palo Alto, California.

To store the quantities of electrical energy needed to keep the grid supplied, conventional batteries like the lead-acid cells used in cars just will not do. One of the alternatives being developed is the sodium sulphur battery. Another option is the vanadium flow battery, which can store large amounts of energy in chemical form in electrolyte solutions stored in large tanks. When fed into the battery proper, the electrolyte's chemical energy is converted into electricity, and the spent solution is passed onto a holding tank. Then, when surplus power is available, the process can be reversed to regenerate the electrolyte. A 2-megawatt (MW) vanadium flow battery with an energy capacity of 12 megawatt-hours (MWh) is due to be installed next year at the Sorne Hill wind farm at Buncrana in County Donegal, Ireland. It will cost $6.3 million.

Another promising alternative is to use spare capacity when demand is low to store compressed air. Electricity from a wind generator, for example, is used to compress the air, which is stored underground in aquifers or salt domes. When electricity is needed, the compressed air is released and fed into a gas turbine.

The turbine is fuelled with natural gas, so the process is not emissions-free, but because a large proportion of the fuel consumed typically goes into compressing the air before it is mixed with the gas for combustion, the turbine will use up to 50 per cent less fuel. This results in carbon dioxide emissions of 86.5 kilograms per megawatt-hour, compared with 222 kg/MWh for a conventional gas turbine. "It is one of the few options we have for storing large amounts of energy, and acting like a shock absorber on the system," says Rastler.

EPRI plans to build a 300-MW demonstrator plant, and estimates that compressed-air energy storage (CAES) plants like this will cost around $600 or $750 per installed kilowatt to build, compared with $1850 to $2150 per kilowatt for sodium sulphur batteries. Coal-fired power stations cost $476 per kilowatt to build, while more efficient, integrated gasification combined cycle plants, in which coal is converted into synthetic gas and impurities are removed before combustion, cost a whopping $3593 per kilowatt.

A group of municipal utility companies in Iowa is planning to build a $214 million, 268-MW CAES facility that will be used to store electricity from a 75-MW wind farm. It should be operating within five years. The technology is not new - a CAES plant was first built in Huntorf, Germany, in 1979. But unlike the Huntorf plant, the Iowa installation will capture exhaust heat from the turbine and use it to preheat the compressed air before combustion, increasing efficiency.

Meanwhile, a project funded by the European Commission is developing an advanced CAES plant which will not consume any natural gas, and so emit no CO2. When air is compressed it releases heat, and in CAES plants like that in Iowa, this heat is lost to the environment. In the European system, the heat will be stored in a honeycomb of ceramic bricks. To recover the energy, the compressed air is passed over the bricks to absorb heat, and then used to drive a modified steam turbine.

Helen Knight

5) Renewable Energy: Anywhere the Wind Blows

Rob Edwards, New Scientist, 08 October 2008 http://environment.newscientist.com/channel/earth/mg20026771.700-renewable-energy-anywhere-the-wind-blows.html

PETER HOPE'S job is to break the blades of wind turbines. Standing in a huge shed on the coast of north-east England, he describes how he uses a set of heavy-duty winches to bend them until they snap with a loud bang. He tests the designs to breaking point to ensure they can withstand the wildest gales. Once he tugged the tip of a 42.5-metre blade 11 metres off its axis - bending it by 15 degrees - before it failed. "We've broken every blade we've tested," he says

Hope is head of one of the world's most advanced turbine blade testing facilities, run by the UK New and Renewable Energy Centre (NaREC) in Blyth, near Newcastle. Next year he is looking forward to starting tests on what will be the longest blade yet made - a 75-metre monster being developed by the California wind power company Clipper, http://www.clipperwind.com/, designed to generate 10 megawatts (MW) of electricity.

After that, the blades are likely to get even bigger. The European Union is funding research into 20-MW machines, which could have 130-metre blades. In theory blades could be larger still but economic factors and the practical problems of construction and installation will come into play long before that limit is reached.

The time and money being spent on wind power is perhaps not surprising when you consider that, based on global average annual wind speeds, worldwide there is the potential to generate 106 million gigawatt-hours of electricity per year from wind - five times the total amount of electricity generated globally today. Recent estimates put the cost of generating electricity from wind at €0.04 to 0.08 per kilowatt-hour, comparable with nuclear power, and electricity from gas turbines with natural gas at today's prices.

The dramatic increase in the length of turbine blades - mostly for offshore wind farms - mirrors the rapid expansion of wind farms worldwide. Between 2006 and 2007 global capacity leapt by over 25 per cent to 94 gigawatts (GW) - equivalent to around 90 average-sized coal-fired power stations - that's a ninefold increase on the 10.2 GW generated from wind just 10 years ago. By comparison, total global electricty generation from all sources increased by just 30 per cent.

All indications are that this booming growth in wind energy capacity will continue. The Global Wind Energy Council (GWEC), based in Brussels, Belgium, predicts that the global wind market will grow by over 15 per cent from its current size to reach 240 GW of total installed capacity by the year 2012. By then, wind energy will be producing more than half a million gigawatt-hours of electricity a year, pushing its share of the global total from 1 per cent in 2007 to 3 per cent. How has wind gone from being a quaint afterthought to such a significant contributor to global electricity generation in such a short space of time?

The biggest influence on wind generation has been the huge investment in a few key European countries that are rich in wind resource and driven by ambitious targets to cut CO2 emissions. Germany leads the world, with 19,460 turbines in 2007 capable of generating 22.25 GW, which can supply 7 per cent of the country's electricity. To encourage the shift to renewables, all suppliers of electricity from renewable sources are paid a premium "feed-in" tariff for the first five years they supply power to the grid.

But Germany may soon be toppled from its wind power throne. The GWEC predicts that in 2009 the US will overtake it and become the world's biggest producer of wind-powered electricity. China, which has succeeded in doubling its capacity every year since 2004, is not far behind. The Chinese Renewable Energy Industry Association forecasts it will reach around 50 GW by 2015.

A leading US expert on wind power, Walt Musial from the National Renewable Energy Laboratory in Golden, Colorado, compares the state of wind technology today to that of the car industry in 1940. There are many ways to improve the technology, he says, which could make turbines even more efficient, more reliable and more powerful.

But he warns that these improvements come at a cost. For example, using carbon fibre to make lighter turbine blades would mean turbine makers having to compete with aircraft makers for the raw material. Making the blades longer will make torque on the drivetrains among the largest of any piece of rotating equipment ever constructed, putting immense strain on the materials used.

Clipper's answer to the torque problem has been to develop a gearing system it claims reduces the load from the blades to one-quarter that of an equivalent conventional turbine.

To identify and overcome potential pitfalls for the next generation of giant 10-megawatt turbines, in 2006 the European Union launched a five-year €22.3 million research project involving over 40 partners from 14 countries. Known as UpWind, it has already come up with some useful ideas.

A team led by Martin Kühn, from the University of Stuttgart in Germany, has suggested attaching big turbines to the seabed via tripods at depths of between 35 and 50 metres. For water deeper than 50 metres, they suggest floating turbines on platforms anchored to the seabed.

Another group, led by aerospace engineer Harald Bersee from the Delft University of Technology in the Netherlands, has been investigating "smart blades". Inspired by research into helicopter rotors, he envisages sensors controlling a series of wing flaps along the trailing edges of turbine blades that would unfold in light winds to expand the blade's surface area and so improve its performance.

UpWind researchers are also studying the possibility of a 20-MW turbine. They have concluded that although technological barriers could be overcome, it is doubtful whether such large machines are economically viable. This is because of what wind engineers call the "square cube law".

A turbine's power output is proportional to the square of the length of its blades, making it attractive to lengthen them. But its volume and weight are proportional to the cube of its dimensions, meaning the price of a turbine climbs faster than its power output as its size increases. This suggests there will be an optimum size for a wind turbine, though so far no one has calculated what that will be.

There are those who believe size isn't everything. Peter Jamieson from the wind consultants Garrad Hassan in Glasgow, UK, says the advantage of scaling up has "rarely been demonstrated". Instead, he suggests it would be more economic to build lots of small cheap, lower-power turbines. There is also growing interest in high-altitude wind power in which kites attached to winches tap the higher wind speeds available up there.

But Jamieson is in a minority. For now, when it comes to turbines, bigger is broadly accepted as better. Back in Blyth's big shed that is certainly the way Peter Hope expects things to go. He's clearly looking forward to bending 100-metre blades until they break. "They'll make a big bang," he says.

Read all the articles in our special issue on renewable energy

Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.

From issue 2677 of New Scientist magazine, 08 October 2008, page 32-35

6) Renewable Energy: The Tide is Turning
Jason Palmer, New Scientist, Oct. 8, 2008 http://environment.newscientist.com/article/mg20026771.800
WELCOME to the Bay of Fundy in eastern Canada, home to the highest tides in the world. Here, 100 billion tonnes of Atlantic seawater flow in and out of the 270-kilometre-long bay every day. The sea level at Fundy rises by an average of 11 metres, reaching a maximum of 17 metres at the narrowest point, twice a day without fail, thanks to the moon's gravitational pull. Could this tidal movement be used to generate power?

The unwavering predictability and scale of the tides in some parts of the world make them an attractive renewable energy source. The World Energy Council estimates that Fundy's tides alone could generate 17,000 gigawatt-hours (GWh) of energy per year. Some estimates put the energy in the world's tides at as much as 1 million GWh per year, or about 5 per cent of the electricity generated worldwide, though only a fraction of this is likely to be exploited due to practical constraints.

With so much to gain, it is little wonder that in recent years interest in tidal power has risen and investment has flowed in. Yet it is an enterprise fraught with engineering and environmental challenges. In addition, tidal energy is unevenly distributed across regions and countries, with local geography determining whether it will be economically viable in any given area. Still, there are plenty of researchers, small companies and would-be entrepreneurs vying to harvest the ocean's bounty of "blue energy".

One method for harvesting tidal energy is the use of barrages - dams across a bay or river mouth that are opened as the tide comes in, allowing the bay to fill with water. At high tide the barrages are closed and later the water empties out through hydroelectric turbines, generating electricity. The roughly 12-hour tidal cycle ensures that this process occurs without fail twice a day.

The poster child for tidal energy is in Brittany, France, where a tidal barrage sits astride the Rance estuary. In operation since 1966, the La Rance plant provides 70 megawatts (MW) of power on average and has long since paid for itself. According to French electricity company EDF, which runs the plant as well as other power stations, La Rance's tidal energy costs ¬0.20 per kilowatt-hour, which is less than the company's average cost.

Similar barrages are in operation in Canada, Russia and China, albeit on a much smaller scale. Meanwhile, South Korea is building the world's largest tidal power plant at Sihwa Lake, 25 kilometres south-west of Seoul. Scheduled for completion next year, the plant will have a capacity of 254 MW, enough to power the nearby city of Ansan.

La Rance and Sihwa Lake will look like puddles if two ambitious projects proposed by Russia are realised. Engineers are planning to build a 15-GW barrage at Mezenski Bay on the White Sea and an 8-GW plant in Tugurski Bay in the far east of the country, to help power nearby industry.

The barrage approach has many detractors, however. Environmentalists claim that the water trapped in the bay or estuary by the barrage floods tidal plains and mudflats, displacing wildlife such as the shorebirds which rely on them for food. Barrages could also have more far-reaching effects. Computer models of the Bay of Fundy have shown that a large barrage would affect the tides as far away as Boston, 500 kilometres to the south.

However, studies at La Rance reveal that the area now has greater biodiversity than before the barrage was installed. It also draws a quarter of a million tourists every year, helping to boost the local economy.

Barrages draw the most fire, though, because they are huge infrastructure projects that require many years of work and enormous investment before they produce any juice. For example, the Severn estuary in the UK enjoys the world's third-highest tidal range with an average of 7 metres, rising to over 14 metres, which could provide up to 17,000 GWh of electrical energy per year. Proposed Severn barrage schemes have met with resistance, though, because they would cost upwards of £15 billion and require decades to complete.

There is a potentially cheaper way to exploit tidal energy that is also kinder to the marine environment: use currents to drive turbines. In essence it is the same idea as a wind farm, but under water. This approach has already been shown to work, having provided energy to the northern Norwegian town of Hammerfest since 2003. In the US, Verdant Power has provided energy from a small tidal-current project in the East River, New York, to a supermarket and parking garage since 2006.

Recent months have seen a spurt of activity on a grander scale. In August, UK company Marine Current Technology used tidal currents in Strangford Lough, Northern Ireland, to provide power to the national grid. The firm hopes the scheme will be at its full 1.2-MW capacity by next month. In March, Lunar Energy, another UK company, signed a £500 million deal to build a 300-turbine farm off the South Korean coast - the largest of its kind yet proposed. In New Zealand and India, small pockets of interest are slowly developing into prototypes and tentative energy-production deals.

The idea is not limited to tidal estuaries. Currents in large rivers and the open ocean could also do the job. Frederick Driscoll's team at Florida Atlantic University, Dania Beach, is spearheading an effort to capture energy from the Gulf Stream as the tide passes through a narrow channel off the Florida coast. The team is using a prototype 20-kilowatt turbine.

Estimates for the eventual cost of electricity from these tidal current schemes vary widely, primarily because the technology is unproven on a large scale. A report commissioned by the Carbon Trust, an organisation set up to help UK businesses develop low-carbon technologies, puts the cost of energy generated by tidal currents at between 12 and 15 pence per kilowatt-hour, making it four times as expensive as large wind farms.

However, Roger Bedard of California's Electric Power Research Institute believes that the cost will fall steeply as more turbines are installed. The tidal current industry shares so much technical know-how with the wind industry, the innovation costs should also fall.

So can tidal energy provide us with boundless clean energy? Perhaps. It could meet a substantial chunk of a country's electricity demands but, as it depends on geography, only for a lucky few.

Read all the articles in our special issue on renewable energy

Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.

Catching the waves

There's energy aplenty in the oceans' waves - taming them is the tricky part

Moored 5 kilometres off the coast of northern Portugal is the world's first wave farm. Built by UK company Pelamis Wave Power (PWP), the farm comprises three enormous floating cylinders connected by articulated joints. As the articulated structures bend with the waves, they drive hydraulic pistons which in turn operate turbines capable of generating up to 2.25 megawatts (MW) of power.

Worldwide, waves could provide anything from 1000 to 10,000 gigawatts of power, according to the World Energy Council. This means that waves could provide far more energy than the tides. Harvesting that energy is the tough part.

There are widely varying designs among the 60 or so proposed solutions to the wave power challenge, says Stephen Wyatt, an expert in marine energy at the UK's Carbon Trust. "What we haven't seen yet are any clear winners." Unlike with wind and tidal power, there has been no convergence of technology and it doesn't look like happening any time soon. Many seemingly good ideas haven't gone much further than the bar napkins on which they were conceived.

Some trends are emerging, however. Articulated structures like the PWP machines are one option. Another approach uses an oscillating water column, in which a cylinder tethered to the seabed is fitted with a piston connected to a buoy floating at the surface. As the buoy rises and falls with the waves, it moves the piston up and down, which drives water through turbines, generating power.

Vancouver-based company Finavera Renewables plans to use this approach to build a demonstration wave machine in Humboldt county, California. The company has signed a deal with California utilities giant Pacific Gas and Electric to provide a 2-MW wave plant that will plug into the grid in 2012.

Other approaches simply collect water from waves crashing over them. As the water flows back towards the sea it is channelled through turbines that generate power. A Danish company called Wave Dragon has successfully trialled prototype devices.

The trouble with waves is that their height and frequency vary hugely depending on the weather and geography. A technology designed to work best for metre-high waves arriving every few seconds will be inefficient for smaller, more frequent ones. What's more, wave farms have to withstand storms and freak, giant waves, and this makes them expensive to build. Like tidal power, location is paramount.

Jason Palmer

7) Renewable Energy: Going Underground
Julian Smith, New Scientist, Oct. 8, 2008 http://environment.newscientist.com/article/mg20026771.900
AT FIRST glance, geothermal energy seems almost too good to be true. It's clean, inexhaustible, provides predictable 24-hour power and you can get it just about anywhere. A 2006 report by researchers at the Massachusetts Institute of Technology estimated that there is enough geothermal energy in the US alone to meet the country's energy needs 2000 times over. According to the Geothermal Energy Association (GEA), based in Washington DC, the best sites can generate electricity for as little as 5.5 cents per kilowatt-hour, compared with 8 or 9 cents per kilowatt-hour for natural gas plants.

There is a snag, however. Outside of geologically blessed places like Iceland, Japan and New Zealand, where volcanically active rocks are close to the surface, the Earth's heat is locked away under several kilometres of rock. Now, though, new developments are making these depths easier and more cost-effective to reach, and the world is beginning to realise the potential of geothermal energy.

The key to tapping this resource is a relatively recent technology called enhanced geothermal systems (EGS), which can create a geothermal hotspot pretty much anywhere. The process involves fracturing hot rocks, then injecting water, which heats up as it circulates through them. It is then pumped back to the surface and passed through a heat exchanger, which drives a turbine, generating electricity.

A number of EGS projects have recently come online. The world's first commercial plant in Landau, Germany, was commissioned in 2007 and already produces 22 gigawatt-hours of electricity per year. A 1.5-megawatt (MW) pilot plant in Soultz, France, began operating this June and a test plant at Groß Schönebeck, Germany, should be online by the end of next year. In southern Australia, a 1-MW demonstration plant should be producing electricity by January.

In the US, meanwhile, the Department of Energy has invested over $5 million to add an EGS system to a conventional geothermal well - where water is pumped through naturally hot rocks - east of Reno, Nevada, in the hope of increasing its productivity.

Sites like these are proving to be worthwhile investments, but that's mainly because, as existing oil, gas or conventional geothermal sites, their geology was already well understood. Some even had boreholes that could be adapted for EGS. Elsewhere, though, the costs of finding and tapping geothermal energy remain high.

Drilling, in particular, is costly - at Soultz it ate up 60 per cent of the investment. Clearly it is more cost-effective to drill where hot rocks are shallowest, but a lack of survey data means that these places are hard to find. "What they're mostly doing now is blind drilling where we see hot water coming out of the ground. It's the equivalent of the oil industry in the 1800s," says Karl Gawell of the GEA.

In fact, rocks at the necessary temperatures of between 150 and 250 °C are often 3 kilometres down or more. "The deeper you go, the more expensive it gets," says Jared Potter of California-based Potter Drilling. So, together with Jefferson Tester of MIT, Potter is developing a hydrothermal drill to try to change that equation.

The team has designed a system that replaces conventional drill bits with a high-pressure jet of steam at 800 °C. There is no solid cutting edge, so there is very little wear on the equipment. That means longer uninterrupted drilling times, fewer delays and significant savings. At the moment it costs up to $100 million to drill past 9 kilometres, says Potter. A 2006 study by Tester and colleagues estimated that reaching the same depth using the new drill could be up to an order of magnitude cheaper. "If these savings can be realised, EGS would become viable basically everywhere," Potter says. Even a savings factor of 2 or 3 could make it more widely workable. Potter and Tester hope to have a prototype ready for field testing next year.

Not everyone is convinced, however. "Our wells are more expensive than oil and gas wells because the product we're getting out isn't very valuable until we get a lot of it, and all at once," says Susan Petty of EGS development company AltaRock. The prices of the steel and cement used in well casings are soaring, she adds. "A new drill bit isn't necessarily going to fix this."

There are other ideas to make EGS projects more efficient. One is to replace the water sent through an EGS reservoir with "supercritical" carbon dioxide - CO2 at a temperature and pressure high enough to give it the properties of both gas and liquid. CO2 becomes sequestered in the rock in the process. The idea, developed by Donald Brown at Los Alamos National Laboratory, New Mexico, in the 1990s, would increase heat outputs because supercritical CO2 can move faster and more easily through the system than water. According to models this could increase heat extraction rates by 50 per cent and would sequester about 3.6 tonnes of CO2 for every megawatt-hour of electricity it produced. A state-of-the-art coal power plant produces around 0.8 tonnes of CO2 per megawatt-hour.

As well as financial considerations, there are practical obstacles to overcome before EGS is ready to go mainstream. For a start, injecting fluid into hot, dry rocks occasionally triggers earthquakes. An EGS project in Basel, Switzerland, was suspended in 2006 after it triggered a 3.4-magnitude quake. Researchers are trying to understand what exactly causes these quakes and how to prevent them.

In Iceland, by contrast, the viability of geothermal energy isn't a problem - over half the country's energy comes from geothermal sources. Even so, one project is hoping to prove that there's no such thing as too much green energy. The Iceland Deep Drilling Project (IDDP), which began in 2000, aims to take geothermal beyond steam by drilling into a reservoir of water which has been heated to 450 °C by a magma chamber below and is in a supercritical state. It's tricky stuff to handle - generally geothermal engineers try to avoid these reservoirs as they can cause dangerous and expensive blow-outs. "Supercritical fluids are not very predictable - there is the risk of explosion," says Ragnar Asmundsson, coordinator of the HITI project, a spin-off of the IDDP that is currently drilling towards one of these unusual reservoirs. The risk may well be worth it, though. If they can tame the fluid, the wells could each produce an order of magnitude more power than a conventional geothermal borehole.

Similarly explosive geothermal conditions can be found in underground reservoirs where gas-saturated liquids are trapped in deep sedimentary formations. These "geopressured" reservoirs could yield not only heat from the fluid itself, but also chemical energy from the dissolved natural gas, and hydraulic energy from the extreme pressure. Germany and Australia are currently looking into ways to exploit these resources.

Interest in geothermal is at an all-time high, but while there is no shortage of heat, the same can't be said for funds. A healthy injection of investment - and government subsidies - is desperately needed if geothermal power is to achieve its potential. In the US, the Department of Energy has proposed the creation of a national geothermal database to help interested parties strike heat. This August, Google.org, the charitable arm of the internet giant, announced a $10 million funding package for projects to map geothermal resources or make drilling more cost-effective. There's still a way to go, but according to Dan Reicher, director of climate and energy initiatives at Google.org, geothermal - and EGS in particular - is going to be big. "[It] could be the 'killer app' of the energy world," he says.

Read all the articles in our special issue on renewable energy

Sunny side up

There's much more to solar power than photovoltaic cells

Photovoltaic cells are currently the fastest growing energy technology, with production increasing by around 48 per cent each year. By 2015 the price of electricity from PV cells is expected to match that of conventional energy generators. (For a detailed account of the state of the art in photovoltaic cells see New Scientist, 8 December 2007, p 32.)

But photovoltaic cells aren't the only way to capture the power of the sun. Large-scale concentrating solar power (CSP) systems are all the rage in the energy-hungry US. Last June, the 64-megawatt (MW) Nevada Solar One CSP plant switched on near Boulder City. Since then, over 1.6 gigawatts of new CSP capacity have been announced in neighbouring California.

In the past year or so, the US Bureau of Land Management has received more than 30 planning requests to develop large-scale CSP plants across the US. The situation is similar in Europe, where around a dozen plants are under construction with at least 24 more proposed in Spain alone.

Sound economics lie behind this enthusiasm. At the moment, electricity generated by large-scale solar concentrator systems costs around 12 US cents per kilowatt-hour. Though this is around four times the price of electricity from a coal-fired power station, it's half the price of electricity produced by photovoltaic cells. What's more, this technology offers an advantage that could prove decisive in the longer term: the ability to store energy for hours or days at a stretch.

Rather than converting sunlight directly into electricity, a CSP system uses arrays of mirrors to focus sunlight onto tubes filled with water or oil. The fluid is heated under pressure to around 400 °C and is then circulated to a steam turbine to generate electricity. By replacing the water or oil with molten salts, typically a mix of sodium nitrate (NaNO3) and potassium nitrate (KNO3), and storing this hot mixture in insulated tanks, it is possible to use energy collected during daylight hours to generate electricity at times of peak demand - day or night.

"With this system you can make electricity when you want," says Massimo Falchetta, an engineer at the Italian National Agency for New Technologies, Energy and the Environment, in Rome. That means the energy can be sold for a higher price than stuff from wind generators or PV cells.

Solar concentrators are nothing new. The Solar Energy Generating Systems (SEGS) plant has been operating in California's Mojave desert since 1985. Made up of nine energy farms capable of generating a total of 354 MW, SEGS is the largest solar concentrator system in the world.

During the 1980s and 1990s, US engineers tested various designs, including power towers - mirrors arranged around a vertical pipe system - and systems with molten salts. However, the US Department of Energy halted research in 2000 after the US National Research Council suggested that any further gains in performance would be insignificant.

Development continued in Europe, and later this year the first commercial molten salt-based solar collector system is due to be switched on at Guadix in Andalusia, Spain. Andasol-1 has over 500,000 square metres of parabolic mirrors and will generate 50 MW of power. With large storage tanks for the salt solution, it will be able to continue generating electricity for more than 7 hours after sunset.

In April, the Electric Power Research Institute in California released a report suggesting that adding up to 9 hours of energy storage with molten salts to a solar concentrator plant can reduce the cost of its electricity by up to 13 per cent.

This cost could fall further if new experimental fluids containing nanoparticles outperform salts, says Mark Mehos, who manages the solar thermal power programme at the National Renewable Energy Lab in Golden, Colorado. "It's early days but this has the potential to be revolutionary," he says.

Ben Crystall

Power plants

With so much plant waste around, it should be easy to bring biomass into the mainstream. So what's the problem?

Biomass is plentiful enough. You can burn wood, manure and more or less any other kind of plant material. Indeed, it provides around 11 per cent of the world's energy, mainly as heat, although in most industrialised nations it yields just 1 or 2 per cent of their electricity at best. And despite a growing enthusiasm for all things green, biopower faces some distinct challenges if it is to move from the margins to mainstream production.

The problem is, biomass doesn't actually yield much energy. Felled trees and energy crops are only a quarter as energy dense as bituminous coal - biomass generally yields around 7 gigajoules per tonne - so right now biopower is struggling to break even economically. In Sweden, which generates around 4 per cent of its electricity from biomass, the break-even figure for willow plantations is 12 to 16 tonnes of dry wood biomass per hectare each year. A recent study at Lund University suggests that only along its wet western coast can Sweden exceed this, with annual yields of up to 17 tonnes per hectare.

Yet biomass does have some advantages. For example, Canada's forestry industry faces a serious threat from the mountain pine beetle, a pest that has already devastated more than 130,000 square kilometres of Canadian forests (New Scientist, 18 December 2004, p 16). Beetle-infested timber is useless as lumber, but it could be good news for biopower, argues Amit Kumar at the University of Alberta in Edmonton. The infested wood could support three 300-megawatt (MW) power stations, providing around 1 per cent of Canada's electricity needs.

It's telling that Canada, with over 400 million wooded hectares, has no healthy forest to devote to biopower. The lumber and paper industries monopolise it and, as Kumar suggests, biopower can succeed only by feeding on their scraps. This problem is even more apparent elsewhere. In the US, biopower has become the single largest provider of renewable electricity, thanks primarily to waste biomass from the paper industry. That resource is now fully exploited, though, and the US Department of Energy estimates that future biopower growth will slow, providing around 1.7 per cent of the country's electricity by 2030.

So where can we find biomass to feed the power stations? Fortunately, untapped resources exist in many parts of the world, including waste from sugar-cane processing in Brazil and waste palm oil and rice hulls in Asia. In the US, livestock produce over 1 billion tonnes of manure annually, most of which is left to rot. Why not collect the stuff, convert it to methane in anaerobic digesters and use it in power stations? Michael Webber at the University of Texas in Austin calculates that US manure could generate 68 million megawatt-hours each year - almost 2 per cent of the annual US electricity demand (Environmental Research Letters, vol 3, p 034002). The infrastructure to collect and transport manure would incur its own costs, so local-scale operations might be key to maximising profits.

With that in mind, plans by Finnish company Wärtsilä to build small combined heat and power plants attached to two breweries in the north of England could be a sign of things to come. Using spent grain from the brewing process to generate power, their output will be modest - around 3.1 MW of electricity each. That's plenty to power the breweries' operations, though, and any excess will be sold to the grid.

Colin Barras

Edison's revenge

When electricity has to travel thousands of miles you need a different kind of grid

Sometimes newest isn't best. A technology dismissed as obsolete a century ago could turn out to be the key to building a power grid fit for delivering electricity generated from renewable sources.

Nearly all of the world's power lines carry alternating current (AC). The reasons for this go back to an epic argument in the late 19th century between two of the biggest names in the history of electricity: Thomas Edison, the inventor of the light bulb, and the engineer Nikola Tesla. Edison argued that direct current (DC) was the right way to transmit power over long distances, because with AC this can only be done if the voltage is stepped up to lethal levels. He even built the first electric chair to demonstrate his point. Edison lost the "war of currents" because Tesla's AC transmission system proved more practical, and so it remained through the 20th century.

But Edison may yet be vindicated. Unlike conventional power plants, which can be built close to where their electricity is needed, renewable energy sources are not always near population centres, so this power must be transmitted over long distances. Over a distance of 1000 kilometres, AC transmission lines become increasingly inefficient, losing over 10 per cent of the energy pumped into them, whereas a high-voltage DC line would lose just 3 per cent. When you factor in conversion from DC to the AC supply that consumers need, the additional losses are 0.6 per cent at most. In all, at distances of about 800 kilometres and above, DC transmission becomes cheaper than AC.

This has led supporters of renewables to call for a new generation of high-voltage DC "supergrids" linking regions rich in wind, solar or other renewable energy sources with populated areas thousands of miles away.

In May, the environmentalist Robert Kennedy Jr called on the next US president to build a high-voltage DC grid to transport electricity from the "wind corridor" that stretches from the Texas panhandle to North Dakota, and solar power plants in the Southwest, to all major US cities.

In Europe, Gregor Czisch, an energy systems expert at the University of Kassel in Germany, has calculated the costs and benefits of a supergrid stretching from western Siberia to Senegal and providing 1.1 billion Europeans with 4 million gigawatt-hours of electricity a year from renewables. The grid would link onshore and offshore wind farms, hydropower resources and solar concentrator power plants with major European cities. The sheer extent of a grid like this would do a lot to smooth out the energy supply, Czisch says.

Not only would the electricity this provides be clean, it would also be reasonably cheap. At 2007 prices, a European supergrid would deliver wholesale electricity at a cost of ¤0.047 per kilowatt-hour, says Czisch, compared with ¤0.06 to ¤0.07 per kilowatt-hour for electricity from gas-fired power plants.

Helen Knight

From issue 2677 of New Scientist magazine, 08 October 2008, page 37-40

8) Renewable Energy: From Dream to Reality
Phil McKenna , New Scientist, Oct. 8, 2008 http://environment.newscientist.com/article/mg20026772.000
WHAT do a small Italian village, a community of millionaires in Oregon and a town in Austria have in common? Nearly all of their electricity needs are supplied by renewable energy. They are by no means the only ones. A growing number of communities are working towards using only electricity generated by renewables.

At the same time, many of the largest cities around the world have set themselves ambitious targets to cut carbon dioxide emissions to less than half present levels in the coming decades, and they will be relying heavily on renewable energy sources to do this. For example, London aims to cut its emissions by 60 per cent of 1990 levels by 2025 with the help of renewables. While no country - except geothermally blessed Iceland - gets all of its electricity from renewables, some resource-rich, sparsely populated countries, including Austria, Sweden and Norway, aim to get between 60 and 90 per cent of their electricity from renewables by 2010.

One of the first towns to adopt a predominantly renewable supply, without compromising on its wealthy residents' modern lifestyle, was Three Rivers in Oregon. "We have everything - the internet, satellite TV, a washer and dryer - there is nothing I do without," says Elaine Budden, who has lived in Three Rivers for 12 years.

Ever since the mid 1980s, when the town's first permanent houses were built, Three Rivers has used solar power. The nearest power lines are several kilometres away and extending the grid would cost hundreds of thousands of dollars. So instead, Three Rivers residents decided to purchase their own photovoltaic panels and battery storage packs. The panels provide up to 2 kilowatts (kW) of power, enough for 80 to 95 per cent of each household's electricity needs. The rest is supplied by propane or diesel generators.

One community in Italy has got around the intermittent nature of solar power without the help of fossil fuels. In 2002, Varese Ligure, a village of 2400 people in northern Italy, became the first municipality in Europe to get all its electricity from renewable energy. Instead of relying entirely on one source, it uses a mix of solar, wind and small-scale hydropower. Four wind turbines on a ridge above the village provide 3.2 megawatts of electricity, 141 solar panels on the roofs of the town hall and the primary school provide 17 kW, and a small hydro station on a nearby river provides an additional 6 kW. Together, these sources now provide more than three times the community's electricity needs.

If renewable energy is going to play a significant role worldwide, however, it will need to be employed on a much larger scale. Gussing, a town of 4000 in eastern Austria, recently went 100 per cent renewable in electricity production with a highly efficient 8-megawatt biomass gasification plant fuelled by the region's oak trees. By 2010, Gussing plans to use biomass to provide electricity to the rest of the district's 27,000 inhabitants.

Meanwhile, larger communities are also beginning to make the switch. Freiburg, a city of 200,000 in south-west Germany has invested €43 million in photovoltaics in the past 20 years and has set a goal of reducing CO2 emissions to 25 per cent below 1992 levels by 2010. And if all goes well, Masdar City, a planned development in Abu Dhabi that will be home to 50,000 people, will get all its electricity from the sun, wind and composted food waste when it is completed in 2016.

New Zealand, which like Iceland also relies heavily on geothermal energy and hydropower, now gets 70 per cent of its electricity from renewables and, with the help of additional wind power, aims to increase this figure to 90 per cent by 2025.

From the smallest village to an entire nation, the evidence is already out there that powering our world with renewables can be more than a pipe dream. Now all we need is the investment to make it a reality.

Read all the articles in our special issue on renewable energy

Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.

From issue 2677 of New Scientist magazine, 08 October 2008, page 41


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