Batteries That Make Use of Solar Power, Even in the Dark
A new cash crop has sprung up on Nicholas Beatty’s enchanting farm near Hartwell. Rows of gray solar panels range over about 25 acres, turning sunlight into electricity, as dog-size muntjac deer hop by.
The panels, trouble-free money earners that feed into the electric grid, are no longer unusual on farms in Britain or other countries. What’s new in Beatty’s field is a hulking 40-foot-long shipping container.
Stacked inside, in what look like drawers, are about 200 lithium-ion cells that make up a battery large enough to store a substantial portion of the electricity the solar farm puts out.
The battery and its software give Beatty an advantage over other solar panel farmers. Power prices in Britain and elsewhere rise and fall, sometimes strikingly, during the day and over the year, depending on the supply and demand. By storing power in the battery, Beatty can feed it into the grid when prices are high. “The battery effectively takes power off the line when there is too much and puts it on when there is too little,” he said.
Beatty said the battery, which costs about 825,000 pounds ($1 million), could increase revenue for his solar farm by as much as 200,000 pounds a year. In addition to making more by timing his delivery to the grid, he said he planned to enter an auction to become a standby source of power to compensate for unexpected drops in the grid.
Beatty is one of many entrepreneurs and businesses trying to play the fast-shifting electric power landscape. The global effort to combat climate change is forcing what had been an old-line business to evolve. Polluting, coal-fired power stations are closing, while clean energy sources like wind and solar are growing fast.
While renewable energy sources have the huge advantage of not emitting the gases blamed for climate change, they can be tricky for a grid operator to rely on, not least because their output is dependent on wind and sunlight. In addition, the power they produce is essentially free, which puts downward pressure on prices.
“The growing use of renewables is creating an unstable energy system,” said David Hill, managing director of Open Energi, a British company that helps industrial companies save money by timing and otherwise managing their energy use. “What everyone is trading on now is that there is a value in flexibility.”
Batteries are one way of achieving that flexibility.