What is it about Elon Musk? People must think his name is “Steve Jobs” in some obscure Slavic language. Sure, I think the Tesla is cool, and think they might lead to something useful some day, but right now they’re a boutique toy for affluent people. (A friend who drives a Tesla in a Midwestern state has a custom bumper sticker: “How do you like my coal-powered car?”) And I like Musk’s enthusiasm for private space travel, since NASA has gone the way of all government monopoly bureaucracies. Not much hope for the “final frontier” when the agency head says, as NASA’s new chief did in 2010, that NASA’s “foremost” mission was “reaching out to the Muslim world.” I don’t even think that wimp Jean-Luc Picard would go for that.
Anyway, Musk’s latest invention that has everyone thinking he’s saved the world is a battery for your house, called the Powerwall. It is being represented as a breakthrough in “distributed energy,” as it suggests you could charge up your battery on solar panels or windmills during the day, and use it to run your house overnight, or provide backup power in the event of a regular grid power outage. Cost for a 7 kilowatt battery: a bit north of $7,000. Based on the expected lifecycle of the Powerwall, it is still more expensive to use than getting electricity from the grid, except possibly in places like Hawaii with extremely high electric utility rates. Maybe it will get better and cheaper—though there is no “Moore’s Law” for batteries, or any other energy technology for that matter, despite Al Gore’s fondest whimseys. But for now, as Bloomberg reports:
“It’s a luxury good—really cool to have—but I don’t see an economic argument,” said Brian Warshay, an energy-smart-technologies analyst with Bloomberg New Energy Finance.
In addition, even the 10-kilowatt version of the Powerwall will only power the average house for about five hours, and is not powerful enough to run your central air conditioning. Seeking Alpha reports:
To put the inadequacy of this product into perspective, here’s a great summary of the power requirements of many household items. It’s pretty clear that without “going crazy”, your house can easily draw 3kw of electricity; and yet, Tesla’s 10kWh back-up battery has continuous output of only 2kw, and thus is inadequate to run even a medium-sized house, and would be completely dead in five hours anyway, with no capacity to run central air conditioning or charge an electric car. (For a medium-sized house, a central air conditioner alone draws nearly 5kw.) Sure, to make that battery last longer than five hours, everyone could huddle into one broiling hot room and shut off everything but the refrigerator and a few light bulbs, but why would you do that when a comparably priced 16kw natural gas-fired generator can run your entire house (including the air-conditioning) for as many hours as needed, at a cost of less than $2/hour (assuming 195 cubic feet/hour consumption at full draw and a New York State gas price of less than $10 per 1000 cubic feet of gas)? (Okay, I concede that in a major earthquake, your gas service could suffer an outage, but for that situation, you can run a gas-fired generator off a propane tank.)
But the most devastating critique of the Musk hype comes from Will Boisvert of the Breakthrough Institute, the center-left think tank that takes energy seriously. In “The Grid Will Not Be Disrupted,” Boisvert writes:
But does all the messianic talk of battery-powered “disruption” and solar triumphalism stack up? Hardly. For all their ballyhooed price reductions, Tesla batteries are still way too feeble and expensive to come even within hyping distance of neither a reliable power supply, nor an off-grid revolution.
On cost, the average residential retail electricity prices in the US are $0.12 per-kWh, while electricity from Tesla’s Powerwall on paired rooftop solar would cost 30 c/kWh or more. Given that 80 percent of pre-orders for Tesla’s batteries are for the utility-scale Powerpack, not the residential Powerwall, battery storage will likely benefit big baseload power plants (the grid) more than solar homeowners. And no matter the staggering cost, battery storage cannot solve the problems of integrating unreliable wind and solar power into the electricity system. In fact, Tesla’s batteries spotlight just how deep and intractable those problems remain.
Do read the whole thing if you have time, as it’s a real tour de force. Be sure to take in this handy chart: