Going green
The main reason that BEC won the support of local and national environmental groups was that PSEG Power went the extra mile necessary to make the plant a good neighbor. Because the repowering project increased the site's rated capacity, it triggered a New Source Review (NSR) under the 1977 Clean Air Act Amendments, to be administered by the New York State Department of Environmental Conservation (DEC).
Retiring the Albany Steam Station and replacing it with a clean gas-fired combined-cycle system made complying with the air-quality improvement requirement of the NSR easy. Similarly, BEC's closed-cycle cooling system—a vast improvement over the Albany plant's wasteful once-through cooling system—made meeting water-quality improvement mandates child's play.
Satisfying the New York DEC would take far more than that, however. For example, as a condition of obtaining a permit for the plant, PSEG had to do some significant environmental remediation. The company had to create 1.5 acres of new wetlands for every acre displaced by the new infrastructure of the riverside plant. (Relatively, that wasn't much of an imposition; the nearby Athens Generating Plant that went on-line in 2004 had to remediate wetlands at a 5:1 ratio.)
Given the site's number of overhead power lines and underground gas lines, building the new wetlands was a bit of a tight squeeze. But PSEG turned the trick. It set up an estuary and planted indigenous trees, shrubs, and plants of the right species to maintain botanical diversity (Figure 3). The company even stocked ponds with "mosquito fish" (Gambusia affinis), known for their appetite for mosquito larvae.
3. Quacking the code. To obtain a permit for the repowering project, PSEG had to create one and a half acres of wetlands for every acre taken away by construction of the new plant. Courtesy: PSEG Power
Making BEC aesthetically pleasing was another condition of the permit to repower. To reduce the visual impact of the new plant on the surrounding area—including the river—PSEG sawed off the four stacks of the old plant, which stood 175 feet above the nine-story (162-foot-high) main building. Here, too, the presence of overhead power lines complicated the task. The crane needed for the demolition of the stacks had to be erected in place, rather than wheeled in.
Another aesthetics hoop that PSEG was asked to jump through involved the visible vapor plumes generated by the new plant's wet/dry cooling towers. The company found that the incidence of "blue plumes" could be reduced by 75% (compared with a wet tower) by installing louvers halfway up the towers (Figure 4). When the dew point hits a certain level, the louvers open automatically, releasing from the side of the tower a considerable volume of air that otherwise would have reached the top. At dew point plus several degrees, a certain amount of steam vented to atmosphere will travel only a short distance before disappearing. The part of the steam that is latent heat remains visible, but not the part that is water vapor.
4. Now you see it . . . Triggered by dew point, louvers halfway up the cooling tower bank open automatically to reduce Bethlehem Energy Center's emissions of "blue plumes." Courtesy: PSEG Power
So far, so good
Since being commissioned last summer, Bethlehem Energy Center has given PSEG Power just what it had in mind when it bought Albany Steam Station in 2000: a 750-MW addition to its 14,000-MW fleet that runs efficiently and cleanly and is well-positioned to make a profit. Between July 18, 2005, and June 30, 2006, the plant operated for 3,733 hours and generated 1,835,062 megawatt-hours.
Just as important, BEC can boast of a perfect safety record. As of this June 30, the plant had accumulated 2,294 days without a lost-time accident. Since commissioning, some 708,850 hours have been worked by plant employees without an OSHA-recordable incident.
Email
Comments
Print
Reuse
