Investors in energy technology need this one trait more than anything else: patience. Anyone who has held shares in Capstone Turbine (NASDAQ:CPST), Ballard Power Systems (NASDAQ:BLDP), or FuelCell Energy (NASDAQ:FCEL) probably knows this now, because just about anything can send these companies on stock surges or plummets. For long-term investors, though, there are really two important things that investors need to keep an eye on with these companies: increasing sales and expanding margins. For this reason, Capstone Turbine is in a better position today than Ballard Power or FuelCell Energy.

Capstone's most recent quarterly earnings weren't all that impressive, but the company did stay on the right track when it comes to to those two important metrics. Find out how the company did and why Capstone's path to profitability is considerably shorter than Ballard Power's or FuelCell Energy's by tuning into the video below.

Tyler Crowe has no position in any stocks mentioned. You can follow him at Fool.com under the handle TMFDirtyBird, on Google+, or on Twitter @TylerCroweFool.

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