By Steve Haner

Dominion Energy Virginia is in the process of modernizing and upgrading the remaining natural gas fired generator at the controversial Possum Point power plant in Prince William County, seeking to squeeze out an additional 44 megawatts of output in addition to the existing 660 megawatts. Dominion claims it needs the power to serve the growing data center industry.

Come Monday, when the deepest Arctic blast to hit this part of the US in years sets in, another reason to continue investing in the old (1948) plant on the Potomac River will be evident. Once again, and as will be the case for decades to come, hydrocarbons will be keeping you warm and brewing your coffee. 

The new equipment at Possum Point was reported the other day by the Prince William Times, which gave many of the column inches over to various folks still upset that the power plant has not totally shut down (Piedmont Environmental Council, Potomac Riverkeepers). It stopped burning coal in 2003 and only one of the six generation units it once ran is still operating, but that one unit is humming along on gas.

Adding 44 megawatts doesn’t sound like much, but keep in mind it would take about a 300-acre solar facility to produce that much power, and it would only do so about 25 percent of the time. Dominion would have to add several monster offshore wind turbines to the first (and probably last) giant wind facility being built off Virginia Beach. That might operate 40-45 percent of the time.

The gas unit probably operates 80% to 85% of the time, double to triple the capacity factor of wind or solar. Most importantly, it can start or stop or adjust its output on demand, not dependent on weather or time of day. No additional land or ocean bottom will be disturbed, no new transmission lines needed. This is a far better use of capital than a comparable amount of wind or solar electrons. There is nothing in the Prince William Times coverage about the cost. 

When the PJM Interconnection, which includes Virginia, conducted its 2024 capacity auction, as you may recall, stunning prices for future generation capacity resulted. That was a signal to the energy marketplace, and Dominion’s move to expand output from Possum Point is the response the signal was demanding. 

The market said a megawatt-day of reliable generation was worth $444. Well, 44 additional megawatts of output times 365 days would seem to be up to 16,060 megawatt-days. That could be up to $7.1 million in capacity contracts Dominion does not have to buy, an annual payment, or up to $7.1 million in capacity payments Dominion would be able to collect. Even if not sold as a capacity contract, some of this power will be sold out of state at some point. The marginal prices on some days are quite high. Days like next Monday through Wednesday.

This is an absolute no-brainer investment on Dominion’s part, something all ratepayers should applaud in their warm homes next week.