The Possibility Of Clean Gas

on September 01, 2011 at 6:00 AM


With renewables ever more popular, the hottest new business may be flexible gas plants that can accommodate intermittent power generation.

An engine provider for both marine vessels and power plants, Finnish company Wärtsilä is busy expanding its flexible, fast-start gas-fired generation business in North America. On August 18, the company announced the commissioning of a new Modesta, California 49.6 MW natural gas plant, that uses six 20-cylinder 34SG Wärtsilä engines that can ramp up to full power within five minutes of being turned on and reach optimum efficiency within another five minutes.

“Our engines can turn down to half load with a loss in efficiency of only 10%,” Regional Sales Director for Wärtsilä North America Wayne Elmore told Breaking Energy

The engines can also be used with combined-cycle technology, which takes the steam, roughly 750 degrees Farenheit, from the exhaust–normally released as waste into the air–and redirects it back to a boiler where it heats up water and creates more steam to turn a small steam turbine.

Elmore said that using the combined cycle mode allows power companies to add 10% more power without burning any additional gas. This type of gas generation, he said, is particularly appealing in places like California where the state is trying to both reduce greenhouse gas emissions and reach 33% renewable energy by 2020.

GE has also been manufacturing flexible gas-fired turbines that can easily accommodate renewable power. Read more: The Power Plant Designed For A Supercycle.

Wärtsilä is not new to the North American market. In fact, Elmore said that the company has developed more than 1000 MW of gas-fired power in the United States alone in just the last 5-6 years.

Run by PG&E, the 163 MW Humboldt Bay Power Plant (HBPP), located just south of Eureka near Humboldt County, California uses 10 Wärtsilä reciprocating engines (model 18V50DF). And in Lovington, New Mexico, the company powers the 46.7 MW Lea County Electric Cooperative, Inc. (LCEC) Generation Plant also with flexible gas engines.

In Colorado, the 111 MW Wärtsilä Plains End plant built right next to a wind farm is dispatched multiple times a day and is used specifically for wind-firming, according to Elmore. That plant can ramp up from a warm standby mode to full capacity in under 10 minutes, according to a company report.

Already in the natural gas business for 15 years, Elmore said he is not worried about rising prices in the market.

“It appears we are going to have relatively stable fuel prices for quite a while here in the United States,” he said.