June 23, 2005

Metcalf Energy Center comes online in South San Jose

600-megawatt facility uses combined-cycle technology to generate electricity

By Shari Kaplan
Staff Writer

After several years of “stages”—from conception to design to actual construction—Calpine Corpora-tion’s Metcalf Energy Center (MEC) came online June 3 and has begun delivering up to 600 megawatts of electrical power to the Northern California power market.

Located in the northern tip of South San Jose’s Coyote Valley, the 20-acre MEC uses “combined-cycle” technology, consuming up to 30 percent less natural gas than older gas-fired plants. Photograph by the 11th Aerial Photography Squadron

In practical application, that’s enough juice to power approximately 600,000 households, 8 million 75-watt light bulbs or 2.85 million personal computers.

Located in the northern tip of South San Jose’s Coyote Valley, the 20-acre MEC uses “combined-cycle” technology, consuming up to 30 percent less natural gas than older gas-fired plants. This means less fuel needs to be burned and less greenhouse gasses are emitted per megawatt generated. It is also significantly cleaner than coal-fired power plants, which are older than the gas-fired ones.

In combined-cycle technology, gas-fired combustion turbines spin generators, which in turn generates electricity and heat. The electricity is harnessed and processed through the Coyote Valley Switching Center and the PG&E Metcalf and Monte Vista substations. It then joins the Western Power Grid, of which Northern California is a major user.

Meanwhile, the leftover steam is sent to MEC’s heat recovery steam generator, where it drives a steam turbine, which in turn spins another generator, producing additional electricity.

Extensive tests
MEC underwent several test-firings before its June debut. “First fire” for the plant’s combustion turbine number one took place April 15, with turbine number two starting up April 18. The firings lasted 204 and 300 hours, respectively. The plant’s steam turbine generator also underwent 162 test fire hours.

“These activities took a couple of hours per unit. They consisted of our technicians and PG&E’s technicians verifying that the generator controls and protective devices that ensure we will not cause or feed a system fault are functional,” said Robert “Bob” McCaffrey, Calpine’s general manager of South Bay projects.

The long hours of testing also allowed technicians to measure chemical emission by-products. These include carbon monoxide (CO), nitrogen oxides (NOx, a smog precursor) and tiny bits of soot and dust called “PM10,” which stands for particulate matter whose diameter is 10 microns or greater.

“NOx, carbon monoxide and oxygen levels were monitored continuously with site instrumentation during all hours that the combustion turbines were in operation,” McCaffrey said.

“Additional testing, including start-up, low-load and full-load testing for NOx, CO, oxygen, PM10 and toxic emissions were also performed during this period by a third party qualified by the California Air Resources Board and the Bay Area Air Quality Management District. The third party also performed a relative accuracy test audit to verify the accuracy of our site monitors during the testing period,” he added.

Emission monitoring
While MEC will continue to monitor its emissions on-site, it has also installed a temporary air quality monitoring station in Santa Teresa’s Los Paseos Park. According to McCaffrey, Calpine and the city of San Jose are still seeking a location to install a second monitoring station, which will be located south of MEC and closer to the Morgan Hill boundary. All data from MEC and Los Paseos is reported regularly to the Bay Area Air Quality Management District (BAAQMD).

“Calpine has long considered itself a partner with the state of California in developing innovative and environmentally responsible energy solutions,” said Peter Cartwright, Calpine’s chairman, president and CEO. “Metcalf is Calpine’s California flagship project and reflects our commitment to keeping the state’s lights on.”

While California is not experiencing the “energy crisis” alarmists in recent years predicted, its ever-growing population demands a significant amount of electricity, especially due to air conditioning in the summer.

Calpine cited a report issued this spring by the California Independent System Operator that predicts a record power demand in July and August that will eclipse last year’s demand record by more than 1,000 megawatts. The California Energy Commission has issued similar projections.

Supports environmentalism
On the environmental front, Calpine cited letters of support issued by several groups during the development of MEC, including the Loma Prieta chapter of the Sierra Club and the Santa Clara-San Benito County chapter of the American Lung Association.

The power plant has even donated 116 acres of adjacent Tulare Hill to the Santa Clara County Land Trust and has set aside 15 additional acres on Coyote Ridge for habitat preservation. It also donated $50,000 to Our City Forest, a non-profit that plants and tends pollution-filtering, oxygen-releasing shade trees throughout the greater San Jose area.

In response to residents who question how MEC will affect air quality, McCaffrey has answers.

“The exhaust heat generated by the natural gas combustion turbines is used to generate steam for the steam turbine. The residual exhaust from this process contains minimal emissions that are then routed to the stack,” he explained.

“The emissions coming out of the stack are expelled at a very high rate of speed, to a height of about 1,000 feet, where they are dispersed harmlessly into the atmosphere.”

McCaffrey said none of MEC’s chemical emissions exceeded state or federal ambient air standards and are well within the safety standards established by the BAAQMD. “In fact, the California Energy Commission stated in the last public meeting that MEC’s start-up was the cleanest they know of and will set a new standard that the commission will expect from similar plants,” he said.

Residents question pollution
Some South San Jose residents, however, say they are not convinced MEC was necessary in the first place, nor are they satisfied with the plant’s promises to be a good environmental neighbor.

“I was surprised by the media’s one-sided coverage of the opening of the Metcalf Energy Center,” Santa Teresa resident Jona Denz-Hamilton said a few days after the June 3 start-up, which also included a press conference and Calpine-led tours of the plant.

Calpine Corporation’s Metcalf Energy Center (MEC) came online June 3.

“There is still quite a lot of opposition to the plant, but those citizens are resolved to play watchdog,” added Denz-Hamilton, who belongs to the Santa Teresa Citizen Action Group (STCAG).

“In my five years of following this development, I’ve seen Calpine changing its mind on promises and going beyond its limits more than a few times. For this reason, I support the people who diligently volunteer their time to keep an eye on the operation and alert the community as needed,” said Denz-Hamilton, who believes the support letters from the Sierra Club and Lung Association to be several years old and wonders if the organizations would still stand behind MEC today.

Denz-Hamilton and fellow STCAG member Elizabeth Cord also are concerned about how the idea for MEC was conceived during the so-called “energy crisis” of years past. Since it turned out not to be as critical as originally touted, Denz-Hamilton said, they wonder why companies like Calpine continue to build more power plants.

“The power it generates will not necessarily go to any of us in San Jose—it will be stored on the giant Western Power Grid,” Denz-Hamilton added.

Needful or not, clean and efficient or not, Cord feels MEC should not be located in the Coyote Valley area at all. In an earlier interview with the Times, she likened it to “smoking in a closet.” Between the valley’s topography of hills and mountains, and the cool marine inversion layer floating over from the coast, Cord said smog can be trapped for days under worst-case conditions.

Denz-Hamilton is also disappointed that Calpine didn’t initially plan to install air quality monitoring stations, like the one at Los Paseos Park, until local pressure and the city of San Jose forced them to do so.

Additionally, she said that at the last MEC Community Meeting, she learned that although Calpine monitors its recycled cooling water for the presence of heavy metals, it does not monitor the water for cyanide, a possible byproduct.

Some residents at the meeting were concerned about what levels of cyanide might escape into the atmosphere.
The Calpine representative was unsure about that, Denz-Hamilton said, so the topic will be on the agenda of the next community meeting, which will take place in August.