People love a hero — it gives them someone to root for, someone to look up to, someone to count on. The funny thing about being a hero, though, is that someone's always looking to take your place. Sure, they may smile at you on the street and pat you on the back when you've done well, but chances are at least one of those well-wishers has been plotting your downfall. It's nothing personal — everyone just wants a shot at the title.
When it comes to the energy generation market, the reciprocating engine gen-set has played the part of the local hero for decades. Reliable and hard working, it has gotten comfortable at the top over the years. And as anyone who's ever been at the top will tell you, that's just when someone comes along to try to take your place. As Staff Writer Amy Florence Fischbach shows in her report on microturbines on page 46, there is a new kid on the energy generation block and the hometown hero has plenty of reasons to hate him.
Stationary energy generation microturbines evolved from automotive and truck turbochargers, auxiliary power units for airplanes, and small jet engines. Their simple design comprises six basic components: a compressor, combustor, turbine, alternator, recuperator, and generator. With fewer moving parts, microturbines boast reduced maintenance costs and improved reliability over conventional reciprocating engine gen-sets.
Much like an engine gen-set, these pint-sized power producers can operate in several modes: grid-connected, standalone, and dual-mode. They can supply base-load power or emergency power, or operate as a peak-shaving unit. They can be set up as standalone units or grouped together to support larger loads. In the grid-connected mode, an owner can even sell excess power back to the utility. And although their efficiency ratings currently hover in the 25% to 30% range, developers project that this number could hit 40% by 2006. That may be why the U.S. government plans to invest $60 million in the Department of Energy's Advanced Microturbine Program, with an equal cost share from industry, to develop new concepts and designs.
The most promising applications of this technology seem to be in the combined heat and power market. By using the excess heat produced by the microturbine for base heating or water heating, a distributed power system can reach efficiency ratings of 70% to 80%. One need only go to the various hotels and supermarkets around the country that have made use of the technology to see its benefits.
But as with most new technologies, these units aren't cheap. A capital cost of $700/kW to $1,000/kW presents a major hurdle for microturbine manufacturers to overcome. And although maintenance costs are projected to be on par with that of small reciprocating engine systems, not until production costs level off and the number of installed units reaches critical mass will this new technology truly compete for a sizable portion of the growing on-site power generation industry.
They may not be ready to steal the market away from gen-sets just yet, but microturbines have shown that the hero isn't quite as unbeatable as everyone once thought he was. And who knows? Maybe it's just a matter of time before the energy generation hierarchy has a new leader to look up to.