The problem that most renewables face is that they don’t generate power constantly, requiring some kind of energy storage medium to provide power when its not generating. Batteries are the first thing that comes to everyone’s mind when looking for such a device however the ones used for most home power applications aren’t anymore advanced than your typical car battery. Other methods of storing power, like pumped hydro or compressed air, are woefully inefficient shedding much of the generated power away in waste heat or in the process of converting it back to electricity when its needed. Many have tried to revolutionize this industry but few have made meaningful progress, that was until Tesla announced the Powerwall.
The Powerwall is an interesting device, essentially a 7KW (or 10KW, depending on your application) battery that mounts to your wall that can provide power to your house. Unlike traditional systems which were required to be constructed outside, due to the batteries producing hydrogen gas, the Powerwall can be mounted anywhere on your house. In a grid-connected scenario the Powerwall can store power during off-peak times and then release it during peak usage thereby reducing the cost of your energy consumption. The ideal scenario for it however is to be connected to a solar array on the roof, storing that energy for use later. All of this comes at the incredibly low price point of $3,000 for the 7KW model with the larger variant a mere $500 more. Suffice to say this product has the potential for some really revolutionary applications, not least of which is reducing our reliance on fossil fuel generated power.
The solar incentives that many countries have brought in over the last few years has seen an explosion in the number of houses with domestic solar arrays. This, in turn, has brought down the cost of getting solar installed to ridiculously low levels, even less than $1/watt installed in some cases. However with the end of the feed-in tariffs these panels are usually not economical with the feed-in rates usually below that of the retail rate. Using a Tesla Powerwall however would mean that this energy, which would otherwise be sold at a comparative loss, could be used when its needed. This would reduce the load on the grid whilst also improve the ROI of the panels and the Powerwall system, a win-win in anyone’s books.
It would be one thing if Tesla was just making another product however it seems that Elon Musk has a vision that extends far beyond just ripping the battery out of its cars and selling them as grid connected devices. The keynote speech he gave a few days ago is evidence of that and is worth the watch if you have the time:
In its current incarnation the Tesla Powerwall is a great device, one that will make energy storage feasible to a much wider consumer base. However I can’t help but feel that this is just Tesla’s beachhead into a much larger vision and that future revisions of the Powerwall product will likely bring even larger capacities for similar or lower prices. Indeed this is all coming to us before Tesla has completed their Gigafactory-1 which is predicted to reduce the cost of the batteries by some 30% with further iterations driving it down even more. Suffice to say I’m excited about this as it makes a fully renewable future not only inevitable, but tantalizingly close to reality.