German companies Ersol Solar Energy and Aleo Solar have reported earnings results for the first half of 2008, logging solid gains in profitability.

Ersol Solar reported $33.3 million (€ 22.4 million) in net income on $193.5 million (€ 129.9 million) in revenue for the first six months of 2008, compared with $14.3 million on $104 million in revenue for the same period in 2007.

The gains can be attributed to a variety of factors: additional suppliers, increased exports, lower pre-production costs in wafers and solar cells units, and gains from Ersol's Thin Film GmbH division.

A123 Systems, whose lithium ion batteries could determine the fate of the U.S. auto industry, Friday filed for a $175 million initial public offering.

The Watertown, Massachusetts, company has reeled in $160.9 million in venture capital from investors including North Bridge Venture Partners, which has a $13.6 percent stake, Qualcomm (8.8 percent) and Motorola (8.5 percent). Gururaj Deshpande, co-founder of Sycamore Networks, has a 12.7 percent stake.

Venture investments in “fragmented” energy storage technologies like batteries, flywheels, and fuel cells grew 74 percent to $709 million in 2007, a new study says.

The report by Lux Research described an investment theme whose technologies are shedding their teething pains and a market poised to grow by 55 percent over the next five years.

The report, “Alternative Power and Energy Storage, State of the Market Q2 2008: Making Sense of the Next Big Thing,” examined seven energy storage markets, including transportation and consumer electronics, and five technologies.

At least two solar companies have pulled plans for initial public offerings in recent weeks, further evidence of the uncertain investment climate in the sector despite a strong earnings report from bellwether First Solar on Wednesday.

Nitol Solar, a Russian company that processes silicon for the solar industry, on Thursday pulled its planned listing on the London Stock Exchange, according to Thomson Financial News. Chinese silicon ingot maker Solargiga beat the Russian company to the punch pulling its planned listing in Hong Kong in the last week of January.