BLOG: Tesla invention may be game-changer for solar energy

BLOG: Tesla invention may be game-changer for solar energy

Tesla… Coming to a home near you?

Tesla Motors and its founder Elon Musk have generated major buzz the last few years with the sale of the high end, all electric Tesla S. Priced at $70,000, it's a novelty for most of us. But this afternoon in California, Musk is set to make a potentially game changing announcement. Musk let it slip last week in an earnings call that Tesla is expected to unveil a new home battery storage system.

Right now, household solar is sort of like the Tesla S, an expensive luxury item. And with less than one percent of U.S. homes with solar panels, it's a bit of a novelty as well. Until now home owners could only use their solar systems when it was able to generate electricity on mainly sunny days, selling any extra energy produced back to the power company, and back in to the grid.

Now comes word of the home-scaled lithium-ion battery, which is sort of like a large reservoir or holding tank. When the sun is shining, the photovoltaic panels on your home are producing electricity. That's electricity used to heat/cool your house, to run the dishwasher, or to heat the water for your shower. But now the excess power produced by those solar panels can be stored on-site for use at night or when the sun is not providing adequate solar insolation.

As my boss pointed out, people do currently use battery storage for home use. But the batteries are big and bulky, taking up huge amounts of space, and are not very efficient. Lithium-Ion batteries, like the ones that power electric cars or your cordless tools, are vastly superior. Not perfect, but superior, producing high energy density, no battery memory and little to now power loss over time.

Just like solar panels, these batteries will come at a price. Musk hasn't said exactly how much, but some estimates have the price at more than $10,000 (we'll see later today), raising the question of what the ROI (Return On Investment) will be. Can a combination of solar panels and a Tesla storage battery be a cost effective way for consumers to power their homes? It's certainly an interesting proposition.

The average power bill in Charlotte is $130.98 in January,  and $135.32 in July according to That averages out to about $1,600 per year. Over a ten year period, that's nearly $16,000. So as solar arrays become more efficient and thus more cost effective, and energy storage potential from a system like Tesla's becomes a reality, the idea of an energy independence for the home comes closer to being a reality.

I like the saying "Give a man a fish and he'll eat for the day… teach a man to fish and he'll eat for a lifetime." It's also true, no water, no fish. And that being said, very little sun equals very little solar power.

Here's an interesting article from MIT, that lays out what it takes to produce a kWh of solar power.