The latest battery-powered electric cars can travel hundreds of kilometres on a single charge. That’s an impressive amount of energy. The energy demands of cars and homes are very different, but it raises an intriguing possibility. Could batteries that store renewable energy help manage electricity use and lower energy costs in our homes?
It probably depends on where you live. In the Hawaiian islands, for example, 90% of the electricity is generated by coal and oil shipped in to power plants in the scattered islands, which cannot share the same grid. Electricity prices, as a result, are often three times higher than on the mainland. And when powerful storms rage through, like Hurricane Iselle, in 2014, people lose their power for weeks.
Since the hurricane, Jeremy Setbacken, owner of Off-Grid Solar Specialists in Kurtistown, Hawaii, has been working hard to install home electricity storage systems. For now, he’s feeding electricity from solar panels into lead-based battery packs.
In northern Europe, where the sun can be scarce, the case for home batteries looks less compelling. Unless governments provide subsidies, says Peter Breithaupt, a senior researcher in innovative technologies at Shell in the Netherlands, “putting a battery into a European home is expensive.”
Breithaupt and his colleagues are working with solar power and home electrical storage in a specially adapted house in The Hague, known as EcoGenie. Solar power is hard to generate in the dim light of the Netherlands winter, when heating is a major drain on energy. Heating the EcoGenie in winter alone eats up to three times the electricity the house consumes in total in the summer.
But much of the global population lives in sunnier climes, and the question is whether home batteries can advance from niche markets like Hawaii to the global mainstream. “Batteries change the equation in the electricity business,” says Steve Levine, author of The Powerhouse, Inside the Invention of a Battery to Save the World. With effective home storage, he says, householders could not only create their own electricity, but manage it, reducing their dependence on utility companies. The key piece that’s been missing from the picture is a more affordable and efficient home battery.
Now companies around the world are ploughing billions of dollars into battery research and production. On a site outside Reno, Nevada, California-based electric carmaker Tesla Motors is building a huge factory. The company believes that production efficiencies will reduce the cost of its new home batteries, known as Powerwalls, making them more affordable.