Big Gav has an interesting post at The Oil Drum: Australia/New Zealand on solar energy, on approaches being pursued to make solar energy economically competitive with coal fired power generation.

Bill Gross, founder of the Californian company IdeaLab, offers some lessons learned:

• Use software to analyze and optimize performance of plants.
• Don’t build plants – get utilities (customers) to build them.
• Avoid environmental conflicts and transmission line costs by building smaller plants on brownfield sites near cities.
• Leverage energy storage and volume of scale in manufacturing to reduce costs.

Big Gav expands on these points in his post. It’s worth checking out.

On the other hand, John Michael Greer has a post voicing cautionary notes about the prospects for solar:

The first is that familiar nemesis of renewable energy schemes, the problem of net energy. It would take a pretty substantial amount of highly concentrated energy to build that hundred square mile array of mirrors, counting the energy needed to manufacture the mirrors, the tracking assemblies, the pipes, the steam turbines, and all the other hardware, as well as the energy needed to produce the raw materials that go into them – no small amount, that latter. It would take another very substantial amount of concentrated energy, regularly supplied, to keep it in good working order amid the dust, sandstorms, and extreme temperatures of the Nevada desert; and if the amount of energy produced by the scheme comes anywhere close to what’s theoretically possible, that would probably be the only time in history this has ever occurred with a very new, very large, and very experimental technological project. Subtract the energy cost to build and run the plant from the energy you could reasonably (as opposed to theoretically) expect to get out of it, and the results will inevitably be a good deal less impressive than they look on paper.

The second is another equally common nemesis of renewable energy schemes, the economic dimension. . . . If investing billions of dollars (and, more importantly, the equivalent amounts of energy and resources) in mirrors in the Nevada desert doesn’t produce as high an economic return as other uses of the same money, energy, and resources, the mirrors are going to draw the short end of the stick. Political decisions can override that calculus to some extent, but impose an equivalent requirement: if investing that money, energy, and resources in mirrors doesn’t produce as high a political payoff as other uses of the same things, once again, the fact that the mirrors might theoretically allow America’s middle classes to maintain some semblance of their current lifestyle is not going to matter two photons in a Nevada sandstorm.

Stuart Staniford at Early Warning takes issue with Greer, noting that photovoltaic (PV) systems can produce a positive energy return in the range of 4.8–13.9, a range pretty consistent with the findings in this 2009 report that net life-cycle EROEI for PV was in the range of 3.75:1 to 10:1.  Regarding solar thermal, the same report did not give numerical findings, but rather stated:

The energy balance of this technology is highly variable depending on location, thus few studies have been done. In the best locations (areas
with many sunny days per year), EROEI is likely to be relatively high.

Even the most optimistic estimates for thermal energy are a long way from the 100:1 return on energy investment that oil gave in the 1940s – though not quite so far from the 23:1 energy return that oil provided in the 1970s. Oil EROEI has certainly dropped even more today. For example, oil production in deep water currently achieves an EROEI of less than 5. For the production of Canadian syncrude the EROEI is less than one – that is, it takes more energy to produce a barrel of oil than the barrel of oil contains.

If – as Greer suggests – the future is unlikely to fulfill our cornucopian fantasies, the future need not be grim:

When concentrated energy is scarce, local production of relatively diffuse energy for local use is a far more viable approach for a great many uses. This will allow the highly concentrated energies that are left to be directed to those applications that actually need them, while also shielding local communities from the consequences of the failure or complete collapse of centralized systems. The resulting economy may not have much resemblance to today’s fantasies of a high-tech future, but the barbarism Frank Shuman feared is not the only alternative to that future; there’s something to be said for a society, even a relatively impoverished and resource-scarce one, that can still reliably provide its inhabitants with hot baths, warm rooms in winter, and well-done pot roasts – and, of course, good brandy.

The U.S. Department of the Interior has announced an “environmentally-sensitive” plan to provide landscape-scale planning and zoning for solar projects on BLM lands in the West, allowing a more efficient process for permitting and siting responsible solar development. The Interior Department, in collaboration with the Department of Energy, will identify appropriate Interior-managed lands that have excellent solar energy potential and limited conflicts with wildlife, other natural resources or land users.

The 24 Solar Energy Study Areas, located in Nevada, Arizona, California, Colorado, New Mexico and Utah, encompass about 670,000 acres. Only lands with excellent solar resources, suitable slope, proximity to roads and transmission lines or designated corridors, and containing at least 2,000 acres of BLM-administered public lands were considered for solar energy study areas. Sensitive lands, wilderness and other high-conservation-value lands as well as lands with conflicting uses were excluded. The BLM will temporarily “segregate” the study areas from new mining claims and other actions initiated by third parties under public land laws during the environmental reviews until any final decisions are made.

BLM has provided a map showing solar potential in the four southwestern states:

Albiasa Solar of Spain next year will begin construction on a 200 MW solar-thermal power – with thermal storage – near Kingman, Arizona. The Kingman area was selected because it is one of the few places with transmission capability on existing power lines.

The plant will use mirrors to focus sunlight on tubes containing liquid, heating the liquid and turning it to steam, which then spins turbines. Molten salt will store heat from the plant so it can keep generating power after sunset.

Joseph Romm at Climate Progress has posted a schematic of the design:

There’s a new article in Environment 360 titled “A Potential Breakthrough In Harnessing the Sun’s Energy” on solar thermal. The article notes solar thermal projects are currently being planned or built in many regions around the globe, including North Africa, Spain, Australia, and the southwestern U.S.

While utility-scale solar thermal projects have provoked opposition due to the large land area occupied by the arrays, it’s hard to see how we’re going to solve our energy and climate change problems without large-scale concentrated solar facilities.

Nate Hagens at The Oil Drum has a good introductory post about simple solar design. Hagens provides this slick diagram that shows the basic concept at work.

This basic design isn’t nearly as efficient as the Passivhaus – but it’s simple, and can be done cheaply.

This is the concept Irina and I followed when we first renovated our house, which was nothing more than a pole-barn sheepshed converted (badly) into a dwelling, back in 1994.  Fortunately the building was oriented to face the south (which is one of the reasons we purchased the property).  We closed up most of the east- and west-facing windows and enlarged and added windows on the south side, with double-glazed glass. We laid black tile over the concrete slab floor to absorb heat (too bad we couldn’t insulate under concrete, which could easily be done with new construction). Wall insulation was R-19, ceiling R-30. All this was done for a few thousand dollars – cheap (we later replaced the roof with a white steel roof, which added considerably to the cost, and summer performance).

And the house has performed well.  Without any heating or cooling other than a small wood stove, it’s warm and cozy in winter, and cool in summer except for a couple of hours in the late afternoon/early evening on the few very hottest days which a small fan makes tolerable. A couple of cords of wood gets us through the winter.

Starting from scratch would have made it possible to increase performance by better sealing, insulating the floor, and controlling thermal mass more precisely. But then consider all the energy saved by recycling an existing structure. We’re happy with the results.

California is at the vanguard of solar power in the U.S., with at least 80 large-scale projects on the drawing board. Concentrated solar power, which is cheaper than silicon panels, is the technology of choice.

Solar thermal electric energy generation concentrates the light from the sun to create heat, and that heat is used to run a heat engine, which turns a generator to make electricity. Solar thermal power costs about 18 cents a kilowatt-hour at present,  roughly 40% cheaper than electricity generated by the silicon-based panels. Improved technology and economies of scale are expected to eventually lower the cost of solar thermal to about 5 cents a kilowatt-hour – about the same as carbon-spewing coal, which generates about half the nation’s electricity.

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Joseph Romm at Climate Progress reminds us that concentrated solar thermal power or “solar baseload”, as he likes to call it - is the technology that will save humanity.”

It is highly scalable, eventually able to achieve 50 to 100 gigawatts a year growth or more. And its ultimate trump card is storage. No batteries required, just a heat sink – and the round-trip efficiency is 90%.

Forget the oxymoronic “clean coal.” Concentrated solar thermal will be delivering reliable, low-cost power while “clean coal” will forever remain nothing more than a chimera.

The first solar thermal plant in nearly two decades was launched last week in Bakersfield, California. The Carrizo Plains solar plant in Central California will generate enough power for 120,000 homes.

Unlike solar photovoltaic systems that convert sunlight into electricity, this plant will focus sunlight on tubes that contains water. The light heats the water, creating steam, thus turning turbines. Solar thermal plants have an advantage compared to photovoltaic technology because energy can be stored as heat without being converted to another form or relying on batteries.

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Ausra Inc., the developer of utility-scale solar thermal power technology, says the daily and seasonal variation in grid load in the United States matches solar availability and claims solar thermal power could supply over 90% of U.S. grid plus auto fleet.

Robert Rapier at his R-Squared Energy Blog reports on innovative transportation options in India.

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 Here’s the auto rickshaw – essentially an enclosed three-wheeled motorcycle. It supposedly gets 82 mpg.

And now it’s going solar.  The solar version can either be pedaled or run on a 36-volt battery. Yahoo! News reports:

“The fully-charged solar battery will power the rickshaw for 50 to 70 kilometres (30 to 42 miles). Used batteries can be deposited at a centralised solar-powered charging station and replaced for a nominal fee.”

Renewable energy is bumping up against the reality of a power grid that cannot handle the new demands. Achieving a goal of getting 20% of our electricity from wind would require moving large amounts of power over long distances, from the windy, lightly populated plains in the middle of the country to the coasts where many people live. Solar-power stations in the nation’s deserts  pose the same transmission problems.

Many transmission lines, and the connections among them, are simply too small for the amount of power companies would like to squeeze through them. The difficulty is most acute for long-distance transmission, but shows up at times even over distances of a few hundred miles. Today’s grid is a system conceived 100 years ago to let utilities prop each other up, reducing blackouts and sharing power across small regions. It resembles a network of streets, avenues and country roads. What we need, as FERC member Sudeen Kelley says, is “an interstate transmission superhighway system.”

But the grid is balkanized, with about 200,000 miles, or 322,000 kilometers, of power lines divided among 500 owners. States have traditionally exercised authority over the grid but have little incentive to push improvements that would benefit neighboring states. Big transmission upgrades often involve multiple companies, many state governments, and numerous permits. Construction costs are astronomical, and every addition to the grid provokes fights with property owners who do not want to look at a line of power pylons marching across their landscape.

Our rickety grid would have to be transformed if we are to ever achieve  an all-electric automobile fleet.  But that’s just one problem with the dream.

As Richard Heinman points out, cars are inherently inefficient. We can make them smaller and lighter. We can power them with renewable electrons instead of nasty old hydrocarbons. But in the final analysis, pushing a ton or three of steel down the highway just to move a two-hundred pound person to and from a shopping mall is both wasteful and plain stupid in a multitude of ways.

Heinberg consider just two: tires and asphalt.

“Tires are made largely of non-renewable petroleum, and after 40,000 miles or so they tend to wear out. Americans discard them at a rate of one tire per person per year.

“Then there’s the stuff that roads are made of. We build roads compulsively so as to give our precious cars more places to roam, but those roads also soon wear out, so we have to constantly repair them; this requires enormous amounts of asphalt (25 million tons annually in the US). But asphalt is, once again, a petroleum product, and as oil gets scarce the building and maintenance of roads becomes unmanageable.”

“Electric cars are a sparky idea if you consider only what they are designed to replace. But we really need to be thinking about how to reduce our need for motorized transport altogether by redesigning our cities and shortening our supply chains. And where something more than a scooter is necessary, we should move people and freight by rail or water rather than by highway.”

Two solar power plants are slated for construction in California that together will put out more than 12 times as much electricity as the largest existing plant.

OptiSolar, a company that has just begun making a type of solar panel with a thin film of active material, will install 550 megawatts in San Luis Obispo County. The SunPower Corporation, which uses silicon-crystal technology, will build about 250 megawatts at a different location in the same county.

The plants will cover 12.5 square miles with solar panels, and in the middle of a sunny day will generate about 800 megawatts of power, roughly equal to the size of a large coal-burning power plant or a small nuclear plant.

The power will be sold to Pacific Gas & Electric, which is under a state mandate to get 20% of its electricity from renewable sources by 2010. The utility said that it expected the new plants, which will use photovoltaic technology to turn sunlight directly into electricity, to be competitive with other renewable energy sources, including wind turbines and solar thermal plants, which use the sun’s heat to boil water.