Details about the Tesla home battery are beginning to emerge. Is that what Elon Musk was hinting at when he Tweeted a few days ago about a major, non-automotive announcement coming on April 30? We don’t know, of course, but most Musk watchers think that’s what the hoopla is all about.

According to Benzinga, Trip Chowdhry, a stock analyst for Global Equities Research, has sent a note to his investors with some details. He claims 230 California homes currently have a Tesla home battery installation and that there are another 100 in homes in other states.

Want details? OK. Here’s what one of the homeowers who claims to be testing the Tesla battery told Chowdry:

  • The Battery has to be installed 1.5 feet above the ground, and should have an open space of 1 ft on all sides.
  • The battery does not make any noise, does not need any maintenance, and has no drippings.
  • The Battery includes the inverter.
  • The battery is about 3 ft tall and 2.5 ft wide and looks good.
  • The installer offered a choice between a 10 kWh and 15 kWh. He opted for the 10 kWh battery.

Price for the 10 kWh battery is said to be $13,000. At present, the local utility, Pacific Gas & Electric, is offering a 50% rebate. This particular homeowner opted for a payment plan that called for a down payment of $1500 and monthly payments of $15 for 10 years. But here’s the kicker. He charges the battery at night when electricity costs are lowest and sells it back to PG&E during the peak demand times every day. He says he makes $12 – $15 a month doing that, which pretty much covers his monthly payment.

Here’s more interesting tidbits Chowdry says he learned from the Tesla battery customer:

  • The battery can be controlled from an iPhone, and has a web application also.
  • The battery is set to charge from a solar system until fully charged and then send energy back into the grid.
  • Fully off Grid. The battery can be charged by a regular generator also.
  • He has not had any problems with the Battery System…and gets over the air wireless software updates frequently.

That is all very exciting news. But be warned. Not every utility is as generous with its rebates or willing to take back electricity from homeowners as PG&E. Part of that willingness is spurred by mandates from the California government that require them to get 33% of their electrical power from renewable sources by 2020. Not every state is as focused on environmental issues as California is. And many utilities are outright hostile to home solar power in general.

In other words, as we car people are fond of saying: “Your mileage may vary. See retailer for details.”

Image: Tesla Motors forum member myI55