Solar and wind energy face the challenge of intermittency. Energy storage, like batteries, helps address this issue by storing electricity generated from solar panels or wind turbines for use later when the sun isn’t shining or wind isn’t blowing. Adding a battery system increases renewable energy utilization, reduces grid reliance, and enhances self-sufficiency.

Battery storage

There are three prevalent battery storage technologies: Lithium-ion, Flow batteries, and Lead-acid. While not the most eco-friendly options, natural alternatives like sand and pumped hydro are preferable when applicable.

The good news: Stored energy from the sun or wind can replace fossil fuel-derived power.
The less good news: Batteries can be costly and have environmental impacts during creation and disposal.

However, some companies are now repurposing abandoned Electric Vehicle (EV) batteries, refurbishing and stacking them together to create a less damaging storage solution.

Sand storage

A sand battery is a high-temperature thermal energy storage that uses sand or similar materials to store heat. It primarily serves as a powerful, high-capacity reservoir for excess wind and solar energy.

The good news: Sand batteries can be built almost anywhere, even underground to save land. Sand is durable, inexpensive, and can store significant heat in a small volume at about 500-600 degrees Celsius.
The less good news: Energy loss occurs during conversion between mediums, making a thermal battery less efficient for electricity generation compared to direct heating.

Hydro storage

Pumped storage hydropower (PSH) is a hydroelectric energy storage system involving two reservoirs at different elevations. Excess wind or solar energy is used to pump water to the higher reservoir, and when needed, water flows down to the lower reservoir through a turbine to generate electricity. This helps fill energy gaps on cloudy and still days, ensuring clean energy reliability. In fact, PSH provides 93% of U.S. energy storage.

The good news: This near-perfect circular solution has minimal downsides.
The less good news: Initial setup can be costly, and the system requires adequate space and suitable topography.