Category: Articles

Solar’s rapid evolution makes energy planners rethink the grid

The initiative, called RETI, is an attempt to build a statewide green grid in an environmentally sensitive way that will avoid the years-long legal battles that have short-circuited past transmission projects.

But the rapidly evolving solar photovoltaic market may moot the need for some of those expensive and contentious transmission lines, requiring transmission planners to rethink their long-term plans, according to Black & Veatch, the giant consulting and engineering firm that does economic analysis for RETI.

In short, solar panel prices have plummeted so much as to make viable the prospect of generating gigawatts of electricity from rooftops and photovoltaic farms built near cities.

“This has pretty significant implications in terms of transmission planning,” Ryan Pletka, Black & Veatch’s renewable energy project manager, told me last week. “What we thought would happen in a five-year time frame has happened in one year.”

That’s prompted Pletka to radically revise the potential for so-called distributed generation—solar systems that can plug into the existing grid without the construction of new transmission lines—to contribute to California’s need for 60,000 gigawatt hours of renewable electricity by 2020.

When Black & Veatch did its initial analysis last year, it predicted that photovoltaic solar could contribute 2,000 gigawatt hours, given the high cost of conventional solar modules and the fact that a next-generation technology, thin-film solar, had yet to make a big commercial breakthrough.

Pletka’s new number is a bit of a shocker: Distributed generation could potentially provide up to 40,000 gigawatt hours of electricity, or two-thirds of projected demand.

“Certainly some of the new transmission lines will be needed but not as many as before,” he says.

That analysis also calls into question the need for as many large-scale solar power plants. Currently there are about 35 Big Solar projects planned for California that would generate more than 12,000 megawatts of electricity.

A game-changer has been the rapid rise of thin-film solar. Thin-film solar modules are essentially printed on glass or other materials. Although such solar panels are less efficient at converting sunlight into electricity than traditional crystalline modules—which are made from silicon wafers—they can be produced more cheaply.

In the past year, utilities like Southern California Edison have signed deals with First Solar, the thin-film powerhouse, to buy electricity from four massive megawatt thin-film solar farms. And in September, China inked an agreement with the Tempe, Ariz., company to build a 2,000-megawatt power plant, the world’s largest.

The next day, Nanosolar, a Silicon Valley startup, announced it had secured $4.1 billion in orders for its thin-film modules, which it claims will be even more efficient and cost less to produce than those made by First Solar.

Meanwhile, California’s two biggest utilities, PG&E and Southern California Edison, this year each unveiled initiatives to collectively install 1,000 megawatts of distributed solar generation. SoCal Edison will put solar arrays on warehouse roofs throughout the Southland—First Solar snagged the first big contracts—while PG&E is focusing on ground-mounted solar systems near its existing substations.

So what’s behind this rooftop revolution in solar?

Partly it’s due to a glut in the solar panel market. The global economy collapsed last year just as solar module makers ramped up production. But it’s also a result of technological innovation and economies of scale that have made thin-film solar, for instance, competitive. Strides have also been made in cutting installation costs, which typically account for half the price of photovoltaic systems.

The solar market, of course, is heavily dependent on government incentives—in the United States and overseas—and thus vulnerable to disruption. But the trajectory remains one of falling prices and thus Black & Veatch’s projections pose a conundrum for transmission planners.

Given that transmission projects can take a decade to complete, power bureaucrats make their plans based on 10-year projections of energy costs according to Pletka. That wasn’t much of a problem when planning transmission for, say, a grid supplied by natural gas-fired power plants as the technology or the market was not likely to change radically.

Not so for solar, where technological advances and fast-changing market conditions are shaking long-held views that photovoltaic power, or PV, is not ready for prime time.

“I’ve worked in renewables since the ‘90s and I myself had written off solar PV for years and years and years,” Pletka says. “That’s a firmly rooted mindset among everyone who works from a traditional utility planning perspective.”

“We present this new information on photovoltaics to people and it’s still not sinking in,” he adds. “It would cause a major shift in how we plan.”

While fewer massive transmission projects would be needed if California generates gigawatts of electricity from rooftops, the distribution network will need to be upgraded and a smart grid created to manage tens of thousands of pint-sized solar power plants.

Cities, Pletka notes, could become generators of electricity rather than consumers of power.

“It brings up questions people haven’t had to talk about before,” says Pletka.

24 November, 2009

SolarReserve’s 24/7 solar plant

The company was in the news last week when it filed an application with California regulators to build a 150-megawatt solar power plant in the Sonoran Desert east of Palm Springs. The Rice Solar Energy Project will be able to store seven hours of the sun’s heat so it can be released when it’s cloudy or at night to create steam that drives an electricity-generating turbine. Future versions of the solar farm will be able to store up to 16 hours of solar energy. Other solar power companies are using energy storage but SolarReserve’s technology is a potential game-changer (more on that in a bit).

SolarReserve has kept a low-profile. Not surprising for a company founded by executives who previously needed government security clearances to get into their offices. (I only found out about the Rice project when I noticed SolarReserve had filed an application with the California Energy Commission.)

The company first caught my attention when a day after Lehman Brothers collapsed last September—setting off the global economic meltdown—the startup issued one of its rare press releases, announcing it had raised $140 million from a blue-chip roster of big players, including Citigroup and Credit Suisse.

A few weeks later I flew to Los Angeles to meet SolarReserve president Terry Murphy and his team, headquartered somewhat incongruously around the corner from Geffen Records, Lionsgate, and other outposts of the entertainment-industrial complex.

The SolarReserve execs were affable and eager to discuss their technology but close-mouthed about the dozens of deals they said were in the works for Big Solar power plants to be built in the desert Southwest and overseas. (One tantalizing hint they dropped was the interest of an unnamed utility in a massive complex of 10 SolarReserve power towers that would generate 1,000 megawatts.)

I’ve kept in touch with Murphy and even as the credit crunched worsened and the solar industry began to consolidate as startups ran out of money, he remained confident that SolarReserve would remain on track.

“We’re capable of riding this out,” Murphy told me a few months ago.

That’s because as investors run away from financing billion-dollar solar power plants using untried technology, SolarReserve’s ace in the hole is Rocketdyne and United Technologies.

The company that guaranteed Neil Armstrong made it to the moon will guarantee the performance of SolarReserve’s solar power plants. In these tough times, that’s what it takes to raise money on Wall Street or from well-capitalized utilities.

“SolarReserve has a very credit-worthy backer—United Technologies—which has said it will stand behind that technology and which gives them an edge,” said Tom Glascock, a global finance partner at the San Francisco law firm Orrick, at a recent seminar for green tech movers and shakers.

Rocketdyne’s molten salt technology was proven a decade ago at the 10-megawatt Solar Two demonstration project in the desert outside Barstow, Calif.

Solar Reserve’s planned Rice solar power plant will dwarf Solar Two. More than 17,000 heliostats—each mirror is 24 feet by 28 feet—will form a circle around a 538-foot-tall concrete tower. Atop the tower will sit a 100-foot receiver filled with 4.4 million gallons of liquefied salt.

When the sun rises each morning, the heliostats will focus their rays on the receiver, heating the salt to 1,050 degrees Fahrenheit. The hot salt will flow into a steam generation system that will drive a conventional turbine housed in a power block. After the sun sets, the salt will retain heat which can be used to generate electricity when demand spikes.

“The California utilities have peak demand from 1 p.m. until 8 p.m. so we are designed to run at 100 percent capacity during the full peak period into the evening,” Kevin Smith, SolarReserve’s chief executive, wrote in an e-mail message. “In addition, because of the storage capabilities, the facility is flexible enough to accommodate other requests from the utility after the sun goes down provided we understand the requests in advance.”

By being able to tap solar electricity on demand, utilities—at least those in the Southwest—could forgo spending billions of dollars on fossil fuel power plants that are fired up only a few times a year to prevent blackouts when everyone turns on their air conditioners on a hot day.

The Rice project is to be built on private land that is the site of a World War II-era Army airfield near the desert ghost town of Rice.

I happened to visit the site in late 2007 with an executive from Silicon Valley solar startup Ausra, which was shopping for land for solar power plants. Old artillery shell casings litter the desert scrub and you can still see the outlines of old runways. A massive concrete tarmac now serves as a parking spot for snowbirds’ RVs.

Ausra, an early player in the solar power plant business, has since dropped out, electing to focus on supplying solar thermal technology to developers rather than building its own projects.

With the Rice Solar Energy Project, SolarReserve is on the launch pad. Now it just needs to prove its salt.

17 November, 2009

The one thing depleting faster than oil is the credibility of those measuring it

If the whistleblowers are right, we should be stockpiling ammunition. If we are taken by surprise, if we have failed to replace oil before the supply peaks then crashes, the global economy is stuffed. But nothing the whistle-blowers said has scared me as much as the conversation I had last week with a Pembrokeshire farmer.

Wyn Evans, who runs a mixed farm of 170 acres, has been trying to reduce his dependency on fossil fuels since 1977. He has installed an anaerobic digester, a wind turbine, solar panels and a ground-sourced heat pump. He has sought wherever possible to replace diesel with his own electricity. Instead of using his tractor to spread slurry, he pumps it from the digester on to nearby fields. He’s replaced his tractor-driven irrigation system with an electric one, and set up a new system for drying hay indoors, which means he has to turn it in the field only once. Whatever else he does is likely to produce smaller savings. But these innovations have reduced his use of diesel by only around 25%.

According to farm scientists at Cornell University, cultivating one hectare of maize in the United States requires 40 litres of petrol and 75 litres of diesel. The amazing productivity of modern farm labour has been purchased at the cost of a dependency on oil. Unless farmers can change the way it’s grown, a permanent oil shock would price food out of the mouths of many of the world’s people. Any responsible government would be asking urgent questions about how long we have got.

Instead, most of them delegate this job to the International Energy Agency. I’ve been bellyaching about the British government’s refusal to make contingency plans for the possibility that oil might peak by 2020 for the past two years, and I’m beginning to feel like a madman with a sandwich board. Perhaps I am, but how lucky do you feel? The new World Energy Outlook published by the IEA last week expects the global demand for oil to rise from 85m barrels a day in 2008 to 105m in 2030. Oil production will rise to 103m barrels, it says, and biofuels will make up the shortfall. If we want the oil, it will materialise.

The agency does caution that conventional oil is likely to “approach a plateau” towards the end of this period, but there’s no hint of the graver warning that the IEA’s chief economist issued when I interviewed him last year: “We still expect that it will come around 2020 to a plateau … I think time is not on our side here.” Almost every year the agency has been forced to downgrade its forecast for the daily supply of oil in 2030: from 123m barrels in 2004, to 120m in 2005, 116m in 2007, 106m in 2008 and 103m this year. But according to one of the whistleblowers, “even today’s number is much higher than can be justified, and the International Energy Agency knows this”.

The Uppsala report, published in the journal Energy Policy, anticipates that maximum global production of all kinds of oil in 2030 will be 76m barrels per day. Analysing the IEA’s figures, it finds that to meet its forecasts for supply, the world’s new and undiscovered oilfields would have to be developed at a rate “never before seen in history”. As many of them are in politically or physically difficult places, and as capital is short, this looks impossible. Assessing existing fields, the likely rate of discovery and the use of new techniques for extraction, the researchers find that “the peak of world oil production is probably occurring now”.

Are they right? Who knows? Last month the UK Energy Research Centre published a massive review of all the available evidence on global oil supplies. It found that the date of peak oil will be determined not by the total size of the global resource but by the rate at which it can be exploited. New discoveries would have to be implausibly large to make a significant difference: even if a field the size of all the oil reserves ever struck in the US were miraculously discovered, it would delay the date of peaking by only four years. As global discoveries peaked in the 1960s, a find like this doesn’t seem very likely.

Regional oil supplies have peaked when about one third of the total resource has been extracted: this is because the rate of production falls as the remaining oil becomes harder to shift when the fields are depleted. So the assumption in the IEA’s new report, that oil production will hold steady when the global resource has fallen “to around one half by 2030” looks unsafe. The UK Energy Research Centre’s review finds that, just to keep oil supply at present levels, “more than two thirds of current crude oil production capacity may need to be replaced by 2030 … At best, this is likely to prove extremely challenging.” There is, it says “a significant risk of a peak in conventional oil production before 2020”. Unconventional oil won’t save us: even a crash programme to develop the Canadian tar sands could deliver only 5m barrels a day by 2030.

As a report commissioned by the US Department of Energy shows, an emergency programme to replace current energy supplies or equipment to anticipate peak oil would need about 20 years to take effect. It seems unlikely that we have it. The world economy is probably knackered, whatever we might do now. But at least we could save farming. There are two possible options: either the mass replacement of farm machinery or the development of new farming systems that don’t need much labour or energy.

There are no obvious barriers to the mass production of electric tractors and combine harvesters: the weight of the batteries and an electric vehicle’s low-end torque are both advantages for tractors. A switch to forest gardening and other forms of permaculture is trickier, especially for producing grain; but such is the scale of the creeping emergency that we can’t afford to rule anything out.

The challenge of feeding seven or eight billion people while oil supplies are falling is stupefying. It’ll be even greater if governments keep pretending that it isn’t going to happen.

Surf’s up for Cornwall’s wave hub

The Wave Hub, which will be based 10 miles off the north coast of Cornwall, will feature a large grid-connected “socket” on the seabed that will allow up to four different marine energy devices to connect to it at any one time. As a result, marine energy companies will be able to field-test devices for a number of years without the need to gain additional planning consent.

The Hub will be connected by an undersea cable to a new electricity sub-station on the site of a former power station.

Work on the sub-station will start in January and is expected to take six months to complete. The Wave Hub device will then be deployed and the sub-sea cable laid next summer, when the device is expected to become operational.

The announcement comes as the Wave Hub project announced that it has appointed Guy Lavender – formely a director for the 2012 Olympic and Paralympic Games – as general manager for the project.

Stephen Peacock, executive director of enterprise and innovation at the South West Regional Development Agency, said he hopes the device will put the area at the forefront of marine energy development in the UK. “Our aim is to create an entirely new low carbon industry in the South West and hundreds of quality jobs, ” he said.

The Wave Hub is being funded with £12.5m from the South West RDA, £20m from the European Regional Development Fund Convergence Programme and £9.5m from the UK government.

The South West development authority expect investment in local marine energy programmes to reach £100m over the next two years.

The Wave Hub project has been widely praised by the marine energy industry and three developers have already secured access to the berths – Fred Olsen Limited, Ocean Power Technologies and Orecon – with a number of developers reported to be in talks about using the fourth berth.

However, the latest stage of the project comes as industry group the BWEA last week warned that the government is failing to adequately support the sector and recommended greater funding is needed to help developers get from the concept stage to full commercial scale generators.

• This article was shared by our content partner BusinessGreen.com, part of the Guardian Environment Network

Populate and Perish

Costello liked to say it was an incentive. His theory gained traction last week with the release of Australian Bureau of Statistics figures pointing to a population boom. A record 293,600 babies were born last year, up 4per cent or 11,400 babies on the previous record. The fertility rate is now at its highest since the ’70s and close to the figure needed to maintain population by birth alone.

Demographers believe two factors are at play – women have heard the message about not waiting to have children; and economic security, which includes payments like the baby bonus.

There is also talk of a trend back towards larger families.

These figures come as the Treasury forecasts rapid population expansion – a 60per cent rise to more than 35million over the next 40years. Prime Minister Kevin Rudd thinks a “big Australia” is a great thing, so long as the population is planned for.

The head of the Treasury, Ken Henry, is more circumspect. He sees a continent stretched to its natural limits and wonders if a near doubling of the population can be managed. There are already signs the country is not coping – the Murray-Darling river system is struggling and drinking and water supplies are becoming a huge planning problem.

The big cities are already struggling to cope with moving people around. Public transport is not good enough to get people out of their cars and off the roads. Too little thought is given to where people live and work.

Overdevelopment is the last vestige of nimbyism; people may support immigration and bigger families but they don’t want those extra medium- or high-density developments in their neighbourhood.

All of these topics of conversation need to be funnelled into a larger debate about population and the consequences for lifestyle and the environment.

This wide-ranging debate is largely missing from the national political stage. Neither Rudd nor Malcolm Turnbull blanched when the Treasury’s population forecasts came out. But they were of great concern to one person.

Labor backbencher Kelvin Thomson has been increasingly vocal about the ramifications of a larger population. He is a thoughtful man and his interest stems from his time as environment spokesman during Labor’s long period in opposition, when climate change and emissions trading were not mainstream issues.

He believes the environment simply cannot sustain more and more people. Now that Labor is in government Thomson has proved to be a bit of an oddity – a backbencher prepared to speak his mind.

He has already called for greater immigration checks, scrapping the fringe benefits tax on company cars and criticised the pension increase for not being generous enough.

Last week Thomson went further, saying the population should be stabilised at 26million by 2050 – 9million people less than the current forecasts. He proposed stopping uncapped migration from New Zealand and cutting total immigration (although increasing the number of refugees).

The baby bonus and family payments are also in his sights.

Thomson thinks the bonus should be done away with and family payments made only to those families with one or two children. The money saved could be spent on education and foreign aid.

These are not the sort of the ideas that would appeal to the last treasurer.

But they are the kind of ideas that need to be discussed.

(Partly) Renewable Ethanol

Judging from a range of recent studies, corn ethanol is about one quarter renewable. Even by the most optimistic estimate — the one the Renewable Fuels Association repeatedly cites — corn ethanol is only 40% renewable.* The US may have displaced 4% of its gasoline use with energy from ethanol in 2008, but less than 2% of that energy came from sunlight captured on those 21 million acres of corn. Most of it came from the natural gas and coal used to make fertilizer and run ethanol plants.

Ethanol energy output:fossil energy input

A cursory comparison of study results emphasizes the differences between them. Delving into the data a little further shows that there is actually a remarkable degree of consistency between the studies, despite the different figures they come up with in the end. All agree that ethanol processing is by far the most energy-intensive component of the lifecycle, consuming nearly two-thirds as much energy as we get from burning the fuel. Growing the corn requires the next biggest energy investment: Most conclude that farming requires about a third as much energy as is available from the ethanol (Pimentel and Patzek’s estimate is higher; Kim and Dale’s is lower). All agree that transporting the corn and distributing the ethanol are pretty minor components of the energy investment.

Ethanol energy output:fossil energy input

So if ethanol processing takes almost two-thirds as much energy as ethanol delivers, and farming takes almost a third, how can there be any net energy benefit to making corn ethanol?

The answer lies with the co-product. For every three truckloads of corn that go into an ethanol plant, about one truck comes out full of dried distiller’s grain, a protein-rich animal feed. Since the byproduct is useful, each of the studies assigns a “co-product” credit to the process. A certain proportion of the energy that went in to the process is subtracted because the distiller’s grain co-product is assumed to have saved energy needed to grow animal feed.

Without the co-product credit all of the studies agree that corn ethanol would be less than 15% renewable.* Among the five studies that conclude there is an energy return to making corn ethanol, the co-product credit accounts for most of the benefit reported.

Renewable Proportion of Corn Ethanol

The size of the co-product credit is what really distinguishes the six studies. Those that assign a larger proportion of the energy investment to the co-product conclude that there is a greater energy return to ethanol production.

Relationship between co-product credit and energy ouput ratio

Obviously, how the co-product credit is calculated is important. Since dried distiller’s grain is a high protein feed that can substitute for soybean meal, most of the studies use an estimate of the amount of energy needed to produce the soybean meal equivalent of the distillers grain that comes out of the ethanol plant. This seems logical, but Kim and Dale point out that a sure way to improve the energy return from corn ethanol is to reduce the efficiency of soybean production (!).

The most optimistic numbers come from Shapouri et al. (2004), who calculate a credit based on the proportion of energy used to make dried distillers grain in a typical ethanol plant. They consider the amount of energy used to dry distiller’s grain an energy credit, because it is used to make the co-product, not ethanol. The net energy calculated using this method is equivalent to the net energy from a plant in which the distiller’s grain drying phase is omitted completely and animals are fed wet distiller’s grains.

Ethanol promoters understandably wish that any discussion of net energy associated with ethanol production would simply go away. This spring an advocacy group called Ethanol Across America issued a brief headlined with a statement fashioned to end all debate:

Study after study after study confirms that ethanol production from corn produces more energy than it takes to make it, period. End of story. So why is this still an issue? When you look at the facts, it simply isn’t.

The problem is, of course, that corn ethanol is being billed as a renewable fuel when it is currently mostly non-renewable. It’s true that most studies say corn ethanol does better than break even from a net energy perspective, but not much better. Calling ethanol 25% renewable (or 75% non-renewable) just doesn’t have the same ring as calling it renewable. Honesty and good policy require that we tell it like it is, though. For ethanol and other “renewable” fuels, I think we’d be well served to abandon the convenient renewable/non-renewable dichotomy, and start qualifying renewable claims with a percentage.

If you’ve read this far, you might have me pegged as an opponent of first generation (sugar and starch-based) ethanol. I’m not. Many such opponents (e.g. zFacts.com) argue that this is a mature technology, it’s already as good as it’s likely to get, and we should spend our time and resources on other pursuits, like learning to make ethanol out of cellulose. I disagree.

I think there’s plenty of room to improve first generation ethanol production. Here are some ideas:

Learn to grow feedstock crops without synthetic nitrogen fertilizer. By using biologically-fixed nitrogen, instead of synthetically fixed nitrogen we can cut the amount of energy that goes into grain production by 30-50%. That’s huge. Study after study after study after study confirms that corn yields will not fall by an equivalent amount. If we’re concerned about net energy, then low-input farming is the way to go.
Learn to use other feedstock crops. American farmers are very good at growing corn, but there are plenty of other crops that can produce lots of sugar and starch for conversion to ethanol. India and China have recognized that sweet sorghum and sweet potato can probably out-perform corn, particularly in low-input systems. America’s single minded focus on corn has led an increasing proportion of corn farmers to grow corn after corn, which is a poor management practice that ultimately compromises yields and demands more agricultural inputs. Diversifying feedstock demand can help restore crop rotations to American farms.
Re-integrate crop, animal, and fuel production systems. Drying distiller’s mash down into dried distiller’s grain is one of the most energy intensive operations at an ethanol plant. Distiller’s mash makes a fine animal feed, but it doesn’t ship or store well. The extra energy investment to dry it is unnecessary if the plant is linked to an animal-based farm with a local and immediate demand for feed. Organic waste products from the animals and the ethanol plant can be digested anaerobically to make methane for renewable energy, and the material left over after digestion can be recycled back onto the crop land as fertilizer. A study published earlier this year by Liska et al. concludes that a closed-loop corn ethanol plant like this reduces greenhouse gas emissions by 67% and increases the net energy ratio to 2.2, making corn ethanol that’s 55% renewable.* I suspect that closed-loop plants will work better on a small scale than a large scale: Here, in Kentucky, the move to drying distiller’s mash began when bourbon distilleries got too big for the farms that once were coupled with each distillery.
Stop using nonrenewable fuels for fermentation and distillation. All of the studies that conclude that cellulosic ethanol plants will offer a better energy return than first generation ethanol plants assume that the energy the cellulosic plants use for fermentation and distillation will come from plant matter, not from natural gas and coal. This difference accounts for almost all of the anticipated energy benefit expected of cellulosic ethanol. We don’t need to wait for advanced technology to become available to start converting first generation plants to draw their heat from renewable sources, like wood or crop residues. Brazilians have known this for years: Most of the energy that drives their ethanol production comes from sugarcane residues left over after sugar extraction.

By combining tactics I suspect it’s possible to make first generation ethanol competitive with cellulosic ethanol in terms of net energy return, and to move in this direction immediately, rather than waiting for the expensive and experimental enzyme technology that seems to be holding up development of the cellulosic ethanol segment. The only way that either will ever replace a substantial portion of our gasoline consumption, though, is if we can dramatically reduce our consumption. Over the past two years Americans have done just that, reducing oil use by 9%. That’s a much bigger bite out of the energy pie than we got by turning 21 million acres of corn into ethanol