With oil and gas futures prices hitting new highs, it's hard not to be enthusiastic about investments in energy-related industries. As I previously wrote, my dentist feels a whole lot better about the high cost of gasoline these days because he invested in a large oil company.

For small- and micro-cap speculators, all kinds of interesting investment opportunities remain in the junior oil and gas producers, drilling and services companies, and in the alternative or new energy marketplace. New energy investments (like hydrogen fuel cells for cars) remain one of my favorite investment themes for the next decade.

Two intriguing companies in this sector include Distributed Energy Systems Corp. (NASDAQ/DESC) and Evergreen Solar Inc. (NASDAQ/ESLR). I've mentioned these two before.

Another fascinating company that operates in the pollution control business is Fuel Tech N.V. (NASDAQ/FTEK). This micro-cap company operates in the U.S., Canada, and Europe, selling air pollution control products mainly for the reduction of nitrogen oxide from boilers, incinerators, furnaces, and other stationary combustion sources. The company's product line uses chemical processes to reduce pollution, which are distributed through a direct sales force to industrial and utility power- generation companies.

Even though this company is small, it is generating exceptional growth at this time. Revenues for its second quarter increased 59% to $11.8 million, with net income increasing to $3.2 million from a net loss in the comparable quarter. For the first half of this year, the company's revenues increased 76% to $23.8 million, with net income of $3.9 million from a net loss.

The pollution control business isn't a fancy industry to be operating in, but this little company must be doing something right. With demand for electricity ever-increasing, demand for pollution control at power generation plants will be robust over the next 10 years.