Can home batteries help save the climate and save you money?

When considering home climate solutions, solar panels might come to mind first. However, a battery the size of a suitcase stored in a closet could be a more affordable method for cutting costs and benefiting the environment.

While the use of rooftop solar panels is growing, battery storage has become the fastest-expanding power technology globally, according to the International Energy Agency. This includes home batteries capable of powering a house and selling surplus energy back to the grid. Although many are used alongside rooftop solar systems, the rise in energy prices has led to a growing number of homeowners investing in standalone batteries.

Countries are now permitting home batteries that can be plugged in without requiring professional installation. Iain Staffell from Imperial College London suggests that this development could significantly broaden access to home batteries, comparing their potential impact to that of rooftop solar panels.

In the UK, over 40,000 homes and small businesses installed battery systems last year, nearly doubling the 2024 record. This surge, fueled by disruptions in energy supplies due to the Iran war, was further bolstered when Britain’s energy regulator announced an increase in the energy price cap.

In the U.S., home battery installations increased by 75% in 2025 despite a slowdown in rooftop solar growth. The technology is also rapidly expanding in countries like China, Australia, and Germany, where one in six homeowners now have a home battery.

With a variable tariff, batteries can be charged during off-peak hours when electricity is cheaper, and then used during peak times to save on energy costs. In Britain, electricity prices can vary from as low as 5 pence per kilowatt-hour in off-peak times to as high as 50 pence during peak demand.

Currently, UK homeowners spend about £9,400 on a battery system, but Octopus Energy plans to offer a plug-in option for less than £300. Though it only stores 2 kilowatt-hours, it could be an attractive option for renters once approved for consumer use in 2027, offering a return on investment within two to three years according to Phil Steele from Octopus.

Home batteries contribute to reducing greenhouse gas emissions by lowering energy consumption during peak times, lessening the need for power companies to burn gas. On days when Britain’s grid runs almost entirely on zero-carbon sources, storing energy in home batteries can be more beneficial for the climate than generating excess energy with solar panels.

Last year, the UK paid wind farms £379 million to shut down when the grid was unable to handle the energy surplus, which could have been partly stored in home batteries. If half of Britain’s homes had a 5-kilowatt-hour battery, the country’s 2030 battery storage goal could be achieved.

As the share of solar and wind energy grows, home batteries will play an increasingly vital role in balancing the grid and aiding environmental efforts, notes Staffell.

Nonetheless, Aritra Ghosh from the University of Exeter warns that the manufacturing process might reduce the climate benefits of home batteries. Additionally, there is no current infrastructure for recycling the millions of home batteries expected to last at least 12 years. A recent study indicated that producing a lithium-ion battery emits 150 to 200 kilograms of carbon dioxide equivalent per kilowatt-hour, comparable to driving a petrol car for one kilometer. This emission could be significantly reduced if major industrial hubs, like China, were to decarbonize, but Ghosh points out that this is not the current reality.