Mitt Romney plays a role in the clean energy debate that many casual observers might find unlikely: Wild card.

There is a very big parking lot at 3001 Chestnut Street in Philadelphia, and soon its owners will receive a very big bill.

Chinese regulators have launched a probe into the trade practices of European suppliers of solar raw materials while installing new measures to rescue China's struggling solar industry....

The U.S. National Research Council said algae biofuel is not sustainable and likely not ready to supply even a small fraction of U.S. fuel needs.

Solar City is the first promising IPO for the alternative energy sector in a long time and may help renew VC interest in the sector and pave the way for its competitors to go public....

Siemens is in discussions to sell its solar business, which it acquired three years ago. At the time, its CEO said the acquisitions would make Siemens a solar-thermal power leader.

Sales of plug-in electric vehicles (PEVs) in the United States will climb steadily over the remainder of this decade, with Ford and Toyota leading the market in sales. PEV sales in the United States will reach nearly 48,000 units in 2012, making the United States the country with the highest number of PEV sales. The key challenges to consumer adoption of PEVs are insufficient range, high charging times and price.

Cleantech Group’s new report on innovation in the water sector uncovers the perspectives of leading utility and engineering executives on: smart water networks, financing innovation, sustainable water management, and water use in agriculture.

Americans' increased use of renewable energy in 2011 was driven mainly by the increased availability of wind and hydroelectric sources in the transportation and residential sectors, according to a report by the Lawrence Livermore National Laboratory. Meanwhile, less coal was used.

The U.S. National Research Council said biofuels cannot yet be made from algae on a large scale because the process requires unsustainable levels of energy, water and fertilizer. According to the report's author, biofuels are likely not ready to supply even a small fraction of U.S. fuel needs.The council study also said it was unclear whether producing biofuel from algae would actually lead to reduced greenhouse gas emissions.