LEAPING OFF THE GRID

LEAPING OFF THE GRID

A new energy storage battery will make more homes sustainable than ever.

On April 30 Tesla unveiled its new Powerwall energy system: two new battery designs that can store electricity from the grid as well as from solar energy sources. Within a week, the company had taken 38,000 orders for the Powerwall systems – about $800 million in potential revenue. The surprising thing, said Tesla CEO Elon Musk, is how much demand has come from consumers relative to industrial customers. People have been waiting for a product like this, and Tesla is already sold out until 2016. At this rate, even the 5-million-square-foot Powerwall factory they are currently building in Nevada won’t be big enough. Tesla’s energy storage systems could even become bigger business than their cars.

Designed for homes as well as small businesses, Powerwall is a compact, wall-mounted, lithium-ion battery that charges via electricity generated from solar panels, load-shifting when utility rates are low. Without a storage system, excess solar energy is often sold to the power company and purchased back in the evening, adding demand on power plants and increasing carbon emissions. By creating and storing power during the day when it is in less demand, then using it to offset home consumption during the evening and/or selling back it to the supplier, the battery reduces bills while helping minimize fossil fuel dependence. It also provides backup electricity supply, safeguarding against outages.

There are two versions of Powerwall: a 7 kilowatt-hour and a 10 Kwh, with prices expected to range from $7,000 to $9,000 respectively. There’s also a larger Powerpack unit that can store 100 Kwh. Being that the average home uses between 1,000 and 1,200 kWh of electric power per month, shifting 7 Kwh of use from peak to nonpeak translates to a savings of $2 a day. That proves about 50 percent cheaper than power-storage systems now on the market. Of course, energy storage systems will have to continue getting cheaper to reach mass consumption. Meanwhile, Powerwall becomes available this summer, and many people trying to attain energy self-sufficiency will be that much closer to their goal and that much further off the grid.