Energy storage: It's everyone's favorite topic these days. Renewable power technologies like solar and wind can't be optimized without storage. Unfortunately, rigging up massive lithium-ion battery packs at wind farms would be prohibitively expensive so everyone is looking at alternatives.

And flow batteries are just one of those alternatives. Deeya Energy, one of the few companies that specializes in this area, has closed up another round of funding, according to sources. The company raised $15 million in January 2008 in a B round. The company's L-cells are supposed to cost 10 to 20 times less than lithium-ion batteries. A flow battery sounds sort of like what it does. Electrolyte flows in and out of tanks. Continually circulating the electrolyte keeps the systems charged. Some manufacturers use vanadium.

Back in 2007, Deeya talked about doing devices that could provide a few kilowatts or more of power. The company seemed to be aiming its products at industrial power users. Several sources, however, have recently said that Deeya is conducting trials on cell phone towers in India. Has Deeya figured out how to scale down its devices for cell towers? Are cell towers a bigger market? Or didn't the big ones work? We will try to find out. Some of the other flow battery companies have been moored in trial purgatory.

Meanwhile, Bloom Energy, the secretive solid fuel cell manufacturer that is trying to raise a sixth round of funding, has apparently lined up a number of customers. Bloom, of course, is going to have to deliver products to collect on those orders, but the backlog of customers partly explains some of the excitement surrounding Bloom. (Disclaimer: There is also no shortage of people who are skeptical of Bloom's chances.)

Again, I don't make these things up. I just pass them along to you.

ETV Motors, an Israeli company that has an electronic propulsion system, confirmed a $12 million dollar first round of funding today.

Although formally announced today, Quercus put money into ETV back in January along with 21Ventures, which tends to invest alongside Quercus. At last count, Quercus had invested in 47 companies, but some have hit some rough sledding. Ondyne, which makes propulsion systems for buses, called it quits in January. Entech Solar, meanwhile, announced layoffs last month. Entech makes solar thermal/PV devices, an interesting twist on solar. Others, however, are jumping into this market.

Like a lot of Quercus companies, ETV is sort of in the science experiment stage. David Gelbaum, founder of Quercus, reads scientific journals quite a bit, according to sources, and scours ideas from there. History shows that many early stage companies like this don't survive, but when they hit, they can hit big.

The long list of VC-funded solar startups is starting to shrink.  We crossed Optisolar off the list, a victim of hubris (see Inside OptiSolar's Grand Ambitions) and it looks like SV Solar is soon to be history -- a victim of a poorly hatched business plan by neophyte staff and investors who should have known better.

SV Solar received $10.2 million in funding two years ago from partners at Bessemer with scant solar experience. The company funded a low-concentration PV firm (strike one), with a staff that had very little solar experience (strike two), based on some amazing cutting edge technology that they called -- a prism (strike 3).

Tough getting IP protection on a prism, I imagine.

The company’s value proposition was based on the high price of silicon at the time by investors who didn’t fully get the concept of supply and demand -- how the price of the silicon commodity was bound to drop as capacity was added.

Even when the price of silicon was high, you could see the flop sweat come over company spokespeople when they presented.  It was clear that even they didn’t buy their own story.

I’ve emailed Justin Label of Bessemer, the VC investor in the firm, but have not heard back from him.  Steve White, the CEO, responded via email with the following:

“SV Solar is actively seeking additional funding or other strategic alternatives. NDAs preclude further comment.”

According to Linked-In:

Tim Fischer, the VP of Business Development, still listed on the SV website, is now at 3M.

Lenny Sharp, the VP of Marketing, still listed on the SV website and phone directory, is now at Hitachi.

And according to a good source, the VP of Engineering at SV is looking for a job.

The last press release they issued was in August of 2008.

All of this adds up to SV Solar being in the startup death spiral.

2009 will be a year of attrition for weak startups in solar power and greentech.  It will be a gut-wrenching experience but it will leave the industry leaner and stronger in the 20-year solar boom to come.

Abu Dhabi plans to work with Al Falah Ready Mix to develop low-carbon concrete for building what the government said will be a carbon-neutral city that would powered by renewable energy and built with cutting-edge green technologies.

Abu Dhabi, part of the United Arab Emirates, began building Masdar City last year, and expects to complete it by 2016. When completed, the 6.5-square-kilometer city could be home to 40,000 people and a host of greentech companies, Masdar officials have said. Masdar already has picked Suntech Power and First Solar to build a 10-megawatt solar farm, which will initially power construction activities. The developer plans to build about 240 megawatts worth of renewable power projects, mostly solar, for the city.

Al Falah Ready Mix, a subsidiary of Al Falah Holding in Abu Dhabi, plans to develop concrete that would use less cement, which takes a lot of water to make. The goal is to reduce the carbon dioxide emitted to make concrete by 30 percent. Al Falah would produce two million cubic meters of concrete for building the first phases of the city. Masdar didn’t disclose how much concrete would be needed to build the entire city.

A growing number of building material suppliers are developing “green” concrete that promise to embody sustainable materials or use less energy to produce. Carlstadt, N.J.-based Hycrete, Newark, Calif.-based CalStar Cement and Los Gatos, Calif.-based Calera are among the American companies developing green building materials.

Marianne Wu, a partner at Mohr Davidow Ventures said at a conference last November that American building material companies ought to aggressively pursue opportunities in countries that are experiencing building booms, such as Abu Dhabi (see Peddling Green Cement and Concrete Abroad).

The Natural Resources Defense Council has yet another map showing the connection between natural resources — sunshine, wind, crops and livestock — and the renewable energy potential attached to them.

The map on NRDC's Renewable Energy for America site color-codes the nation according to regional resources and shows the sites of existing and planned wind, biofuel and biodigester plants. Viewers can click on individual states for close-up views.

NRDC also has picked five states — Florida, Nebraska, Ohio, Pennsylvania and Tennessee — to highlight as "battlegrounds in the debate about what sort of action our country should take to stop global warming," according to a Monday blog post by Nathanael Greene, NRDC's director of renewable energy policy.

"We definitely plan to use the site as a tool for getting people excited about what they can do in their state with renewables," Greene said Monday.

The map differs from the Path to Clean Energy Google map NRDC released earlier this month in partnership with Google and the National Audubon Society.

That map overlaid renewable energy potential and areas that are environmentally protected or sensitive, in hopes of giving energy developers the tools to avoid battles with regulators and environmentalists over project siting, Greene said.

Those conflicts are already emerging. Take the recent efforts by U.S. Sen. Dianne Feinstein (D-Calif.) to designate hundreds of thousands of acres in the Mojave Desert as protected habitat off-limits to solar power development, as the Los Angeles Times reported last month.

As for its new nationwide map, NRDC plans to add data on solar power projects and geothermal power projects and potential in the coming months, Greene said. More state-by-state features are coming as well, he said — Michigan, Missouri, Indiana, Virginia and Nevada are next on the list.

Much of NRDC's data for the new map comes from the National Renewable Energy Laborator, which offers a host of solar energy maps based on data it has been collecting for decades. New research, such as that into the potential of solar thermal power sites in Arizona, continues  (see NREL Hunts for Solar-Thermal Hot Spots).

Other maps highlight energy efficiency data. The Green Grid, an industry group formed to push energy efficiency in data centers, has online tools, including a map, to show which parts of the country hold the greatest potential for using outside air to cool data centers (see Green Grid: Free Cooling for Data Centers).

The Energy Retail Association in the U.K. has its own Smart Metering Projects Map to track the latest and greatest in smart meter deployments worldwide. And the U.S. Green Building Council has included state-by-state Regional Priority Credits as part of the third version of its LEED (Leadership in Energy and Environmental Design) program released Monday.

Conergy said Monday it plans to sue MEMC Electronic Materials to end a 10-year contract for buying silicon wafers, the materials for making solar cells.

Germany-based Conergy, which makes solar cells and assembles them into panels, said efforts to renegotiate the contract and get better terms failed. As a result, it intends to file suit in New York City and ask a judge to invalidate the contract.

The negotiation to amend the contract began earlier this year. MEMC, based in St. Peters, Mo., said last week that the contract talk stalled, and that it didn’t expect to sign a modified contract. MEMC posted $214 million in sales for the first quarter, down nearly 50 percent from the same quarter in 2008, the company said last week. The company reported a first-quarter net income of $2 million, or 1 cent per share, compared with $70.3 million, or 31 cents per share, from the year-ago period.

Conergy didn’t divulge details of the contract dispute, except to say that it was able to reach some agreement on the financial terms but not on “various auxiliary conditions.” The two companies signed the contract in late 2007, before the financial market crisis severely crimped demand for solar power components and materials, leading to much lower prices than anticipated.

Conergy and MEMC amended their contract once before. In July last year, the compaies announced that they had agreed to reduce their 10-year wafer agreement from about $7 billion to $8 million to about $4 billion.

Many solar cell and panels makers all have talked about efforts to re-negotiate their silicon contracts to get better prices. Meanwhile, producers of silicon and other components used for making solar panels are scaling back production or factory expansion plans.

Two weeks ago, Pocatello, Ind.-based Hoku Materials said it had modified its silicon contract with Wealthy Rise International, a maker of ingots and wafers in China. The new agreement reduced the 10-year contract from $455 million to $136 million. Hoku also will delay delivering silicon by three months to June 30, 2010, the company said.