Making good money in the renewable-energy business can be tough, particularly given the slow economy and the impact of public policies (or lack thereof).

Here is a roundup of the latest earnings posted by greentech companies selling ethanol, low-emission engines, electric-grid equipment and more.

  • Archer Daniels Midland, based in Decatur, Ill. reported a net income of $1.8 billion, or $2.79 per share, on $69.8 billion in sales for its fiscal year ending June 30. The company made $2.2 billion, or $3.30 per share, on $44 billion in sales in the previous fiscal year. The company also claims to be the largest producer of ethanol fuel in the country. While the average selling prices for ethanol decreased slightly, the company increased its ethanol sales volumes. Archer Daniels doesn’t break out ethanol sales, but includes them as part of its corn-processing segment. The segment reported a 13 percent drop in operating profit for the fiscal year, but a 14.4 percent increase for the fourth quarter.
  • ADA-ES, which makes equipment to control mercury emissions at coal-fired power plants, reported a second-quarter net loss of $138,000, or 2 cents per share, on $3.8 million in revenue. The company posted a net income of $55,000, or 1 cent per share, on $4.9 million in revenue in the same period a year ago. ADA-ES, based in Littleton, Colo., blamed uncertainty over the fate of the federal Clean Air Mercury Rule for the revenue decline. A federal appeals court in Washington, D.C., ruled earlier this year that the mercury rule was invalid. The Bush administration has since filed an appeal.
  • RAE Systems, based in San Jose, Calif., makes equipment for detecting toxic gases, radiation and other chemicals, narrowed its second-quarter loss by 72 percent from the year-ago quarter. The company posted a net loss $0.7 million, or 1 cent per share, on $24.7 million revenue for the second quarter. Rae reported a net loss of $2.5 million, or 4 cents per share, on $20.1 million in revenue in the second quarter of 2007. The company said the financial results are preliminary because its audit committee is investigating some accountingand reporting issues.
  • American Superconductor Corp., which makes power converters and other equipment for the electric grid, reported a net loss of $6.1 million, or 15 cents per share, on $39.8 million in revenue for its fiscal first quarter, which ended in June. The Devens, Mass., company posted a net loss of $9.7 million, or 27 cents per share, on $19.8 million in revenue in the year-ago period. American Superconductor also designs electrical systems and other components for wind turbines.
  • Westport Innovations, based in Vancouver, designs fuel injection and engine technologies that the company said emit less greenhouse gases and use diesel, natural gas or other fuels more efficiently, posted a net loss of $3.5 million, or 13 cents per share, on $25.5 million in revenue for its fiscal first quarter, which ended in June. Westport reported a net loss of $4.7 million, or 22 cents per share, on $15.7 million in revenue in the year-ago period.
  • SCI Engineered Materials, which develops chemicals and metals forsolarpanels, batteries and other products, reported a second-quarter net loss of $108,878, or 3 cents per share, on $1.5 million in revenue. The Columbus, Ohio company posted a net income of $95,379, or 2 cents per share, on $3.4 million in revenue in the second quarter of 2007. The company said the high cost of raw materials and other expenses contributed to the loss.