Make no mistake; renewables are the future of energy generation. Fossil fuels have helped spur centuries of human innovation that would have otherwise been impossible but they are a finite resource, one that’s taking an incredible toll on our planet. Connecting renewable sources to the current energy distribution grid only solves part of the problem as many renewables simply don’t generate power at all times of the day. However thanks to some recent product innovations this problem can be wholly alleviated and, most interestingly, at a cost that I’m sure many would be able to stomach should they never have to pay a power bill again.
Thanks to the various solar incentive schemes that have run both here in Australia and other countries around the world the cost of solar photovoltaic panels has dropped considerably over the past decade. Where you used to be paying on the order of tens of dollars per kilowatt today you can easily source panels for under $1 per kilowatt with the installation cost not being much more than that. Thus what used to cost tens of thousands of dollars can now be had for a much more reasonable cost, something which I’m sure many would include in a new build without breaking a sweat.
The secret sauce to this however comes to us via Tesla.
Back in the early days of many renewable energy incentive programs (and for some lucky countries where this continues) the feed in tariffs were extremely generous, usually multiple times the price of a kilowatt consumed off a grid. This meant that most arrays would completely negate the energy usage of a house, even with only a short period of energy duration. However most of these programs have been phased out or reduced significantly and, for Australia at least, it is now preferable to use energy generated rather than to offset your grid consumption. However the majority of people with solar arrays aren’t using energy during peak times, significantly reducing their ROI. The Tesla Powerwall however shifts that dynamic drastically, allowing them to use their generated power when they most need it.
Your average Australian household uses around 16KW/h worth of electricity every day something which a 4KW photovoltaic system would be able to cover. To ensure that you had that amount of energy on tap at any given moment you’d probably want to invest in both a 10KW and 7KW Powerwall which could both be fully charged during an average day. The cost of such a system, after government rebates, would likely end up in the $10,000 region. Whilst such a system would likely still require a grid connection in order to smooth out the power requirements a little bit (and to sell off any additional energy generated during good days) the monthly power bill would all but disappear. Just going off my current usage the payback time for such a system is just on 6 years, much shorter than the lives of both the panels and the accompanying batteries.
I don’t know about you but that outlay seems like a no-brainer, especially for any newly built house. The cost of such a system is only going to go down with time as more consumers and companies increase their demand for panels and, hopefully, products like the Tesla Powerwall. Going off grid like this used to be in the realms of fantasy and conspiracy theorists but now the technology has been consumerised to the point where it will be soon available to anyone who wants it. If I was running a power company I’d be extremely worried as their industry is about to be heavily disrupted.
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.