Active Power (NASDAQ:ACPW) makes power quality products that provide consistent, reliable electricity. It was the first to manufacture a flywheel energy storage system and has developed a battery-free runtime product based on proprietary thermal and compressed air storage technology.
The company made good progress in diversifying sales channels in 2009, and although it should continue that progress this year, volumes probably won't be high.
Q4 revenues beat forecasts on strong sales, but margins dropped 18%. For 2010, sales should pick up as the economy recovers. Caterpillar (NYSE:CAT) is their largest customer, accounting for about 9% of sales for the quarter.