You might only think about energy storage when your laptop or cellphone is running out of juice, but utilities can plug bigger versions into the electric grid. And thanks to rapidly declining lithium-ion battery prices, using energy storage to stretch electricity generation capacity is becoming more viable for utility companies. That’s important because research suggests that energy storage through batteries will not only make renewables a more reliable source, but it will also save consumers money. If you’ve been following the Optimist Daily for a long time, you’ve probably noticed that energy storage has been somewhat of a distant dream—a technology that has so much potential but has yet to fulfill it. But now it seems energy storage is on the horizon as several utilities are already investing in energy storage. For example, California utility Pacific Gas & Electric got permission to build a massive 567.5 megawatt energy-storage battery system near San Francisco, although the utility’s bankruptcy could complicate the project. Hawaiian Electric Company is seeking approval for projects that would establish several hundred megawatts of energy storage across the islands. And Arizona Public Service and Puerto Rico Electric Power Authority are looking into storage options as well.