If you have an interest in technology or renewable energy, you may have heard about Tesla’s big announcement this week: their newest product, dubbed the Powerwall, is a large battery designed for your home and intended to realise the dream of true energy independence. Such an idea has huge ramifications, but it also presents a number of issues that need solving before it becomes widespread. So what functions do the Powerwall and its ilk actually perform? And are they the game-changer that we’ve been waiting for?
Batteries in the Basement
Tesla’s Powerwall is a pretty simple concept: it’s a big, elegantly-designed battery (130cm high, 86cm wide and 18cm thick) that mounts onto your wall and is charged by solar panels on your roof. As everyone knows, solar panels are a wonderful source of free power when the sun is shining, but they’re pretty useless on a cloudy day or at night – which ironically is when electricity use is highest. The electricity they produce during the day is almost always sold back to the grid; this nets you a decent amount of money, but it’s considerably less than the peak rates you’ll still need to pay later that evening.
The Powerwall solves this problem by storing the charge from your solar panels during the day, and then powering your house with that energy at night. This lets you use the free energy you’ve collected, and it eliminates the need to sell your electricity back to the grid. In other words, it makes it possible to eventually be truly energy independent. Even if you don’t have solar installed, the Powerwall can still save you plenty of money by charging from the mains during the day when rates are much cheaper.
Furthermore, having a big battery powering your house acts as insurance against power outages, which is especially good news for those living in remote, under-serviced areas or places prone to storms and flooding (i.e. much of Australia).
Tesla’s home battery currently comes in a 10kWh weekly cycle model and a 7kWh daily cycle model (both of which come with a 10-year warranty), and the technology is infinitely scalable – the batteries consist of multiple small cells, so the number of these can be increased indefinitely.
Why the hype?
The reason there’s been so much excitement about Tesla’s new offering is that it provides the final link between renewable energy and practicality. It’s the first consumer-marketed solution for storing the energy generated by renewables – it’s by no means limited to solar, potential uses include windmills and turbines as well, and pretty much any other renewable power generation method with transient supply.
It takes advantage of Tesla’s increasing economies of scale, including their current expertise with electric cars and their soon-to-be-built battery Gigafactory in Nevada, to bring the cost of the Powerwall down to a reasonable level – Deutche Bank states that the cost per kWh of power storage for Tesla’s battery is $500/kWh, which is less than half of typical industry power storage costs. As Renew Economy states:
“…it has huge implications for Australia, which because of its high retail electricity costs (around 30c/kWh and higher in time of use areas), excellent solar resource, and huge penetration of rooftop solar (one in four houses in some states) finds itself at the cutting edge of this revolution.”
And above all, it will provide a massive boost in demand for a renewable energy industry that’s already growing rapidly, resulting in a cleaner, more sustainable future for us all.
What are the current drawbacks?
Even after decades of development, batteries still require costly materials to make and are subsequently still expensive to buy – and the bigger the battery, the higher the cost. The smaller Powerwall model costs USD$3000 and the larger USD$3500, which is a big investment for your average household when combined with a solar panel system that truly makes a big domestic battery a worthwhile purchase. It’s also not available in Australia yet, with the company only taking ‘reservations’ at this point in time.
Despite the current cost and availability drawbacks, the Powerwall is a huge step forward for renewable energy. By utilising Tesla’s unique expertise and economies of scale, it provides a practical, affordable solution for bringing renewable energy to millions of homes – and saving significant amounts of money in the process. It also burns a trail for other companies to start producing their own batteries, which will expand the market even further. It really is a game-changer.
Many new technology products experience a lot of hype, but in this case, the hype truly is justified. Get ready for the renewable energy revolution.