Storage technology has emerged as the next stage in the evolution of renewable energy as a viable form of power on a grid scale. Governments, utilities and residential customers are embracing a wide range of storage technology to counter the variability of wind and solar generation.


A California startup has developed a unique form of storage that could dramatically lower the cost of conventional technology. It bears a strange resemblance to a controversial form of energy extraction: hydraulic fracturing—fracking—which uses pressurized water and chemicals to extract oil from underground fractures.


Healdsburg, Calif.-based Quidnet Energy has taken some of the elements of fracking and applied them in a way that is certain to generate much less opposition. By applying pumped hydro to abandoned oil and gas wells, the company hopes to lower the cost of renewable-energy storage well below the current cost of battery technology.


Quidnet Energy’s storage technology employs no chemicals, does not trigger seismic activity and does not produce pollutants that require disposal and clean-up.


Instead, electricity generated by renewables is used to compress and pump water underground, when demand is low and power is cheap. That pressurized water is released when new generation cannot match high demand, at night when the sun isn’t shining, or when the wind isn’t blowing.


Pumped hydro is not an original concept. Injecting it into abandoned wells offers a different twist. Quidnet Energy estimates that “hundreds of thousands of wells across the country are abandoned or beyond their useful life,” and that “these same locations have significant renewable-power generation.”


Quidnet Energy asserts that its technology can reduce the cost of most advanced batteries by 90 percent.