The Killer Feature of Tesla's Powerwall is the Price

If you're not closely following the world of renewable energy, Tesla's big announcement Thursday might have been a bit of a letdown.
In the simplest of terms, Tesla Powerwall is a big battery. You mount it on your wall, and you have power even when power fails (which, in most Western countries, is rare). Weren't there similar products like that before? Don't most people with solar-powered homes already have an energy storage solution? And is Tesla's Powerwall really worth $3,500 for a 10 kilowatt-hour (kWh) model)?
According to Mashable, the answers are yes, yes and yes.
Is it cheap enough for you? That's another matter. The primary customers of Tesla's new batteries will be homeowners that use renewable energy sources to power their home. Anyone that doesn't have solar can consider a Powerwall as well — it can reduce your electricity bill by storing energy when it's cheaper (typically during the night) and then pushing it back into the system during the day when it's more expensive. You'll have to do the math yourself is not cheap, but the price point is definitely low enough to make it worthwhile for many, even without subsidies.