If you live like most of the developed world, your home and workplace are probably both perpetually connected to the power grid. Electricity is rather fashionable these days.
Perhaps it was somewhat predictable, then, to see the overwhelming response of interested consumers when the Tesla Powerwall line of home- and business-powering batteries was announced.
But is the Tesla Powerwall really worth the cost? That’s a question posed recently by Autoblog, and their hard look at the numbers certainly warrants some consideration. At its reveal event, the Tesla Powerwall was stated to cost just $3,500, but that doesn’t include installation, nor the necessary inverter to allow the DC battery to interface with your home’s AC power system.
Another company with which Tesla CEO Elon Musk is involved, SolarCity, offers a similar system which costs over $7,000 to purchase and install. According to Autoblog, the average US home loses power an average of just 2 hours out of the year, meaning that if the battery were only used for backup purposes, even if it served its purpose for a full 10 years, the owner would be paying about $350 for every hour of backup use.
Clearly, then, a generator is much more financially sensible. An alternative manner for the Tesla Powerwall to perhaps pay for itself is by collecting energy generated by your own private solar panels or windmill generator. But those devices are another expense, and in most cases, stratospherically expensive. Autoblog even went through the trouble of estimating the cost of a solar panel/Tesla Powerwall system which would theoretically allow one to live entirely off-the-grid: about $96,000 without incentives or subsidies, and that’s assuming a much larger-than-average rooftop solar panel system.
In the end, that $3,500 Tesla Powerwall looks like a much more expensive prospect than how it was initially advertised. Any early adopters out there of course get kudos for staying on the cutting edge, but solar panel and lithium-ion prices would both have to decline before something like the Tesla Powerwall would quite make financial sense.