Project Manager Doug Moyles says the reason the system produces 80 percent of the power used by the facility rather than 100 percent comes down to efficiency and economics.
“Because the plant doesn’t use as much energy in off hours, such as weekends and holidays, constantly supplying more power would not be economically feasible,” he says. “So, by aggregating the power at 80 percent of the annual demand, the majority of the plant’s needs are being met. It’s like filling up a car’s gas tank by 50 percent every day during the work week – when you might be driving the most – and again on the weekend. You’re accruing fuel for your needs during the weekend that can be put to use during the week.”
The system is designed so that it produces more electrical energy than the facility requires, especially on weekends and holidays. Then, it automatically sends the excess electricity back to the Sacramento Municipal Utility District’s (SMUD) grid system. This power then is used to power area homes and businesses. The excess electricity is “net metered,” and Siemens accrues credits for what the solar system exports to the grid.
“We’re not only generating clean electricity for use at our plant; we’re also helping to the power the community with green energy,” Moyles says.