Tesla's Powerwall is a 7kWh lithium-ion battery designed to store excess energy, whether it's off the grid or from a home's solar panels. For such a simple concept, the Powerwall has quickly drawn a lot of attention, with some pundits predicting big implications for the energy industry. The Powerwall is not the first or only innovation in battery storage technology we've seen, though — and it certainly won't be the last.
Gizmodo's Energy Smart Home series powered by Hello Grid — an initiative of the Energy Networks Association, representing the networks who deliver energy to almost all Australian homes and businesses.
The announcement of the Tesla Powerwall's imminent release in Australia comes at a time when the Climate Council has released a report concluding that battery storage could quickly become one of the biggest game-changers in the Australian energy landscape.
The report predicts that half of all Australian households will eventually adopt solar systems with battery storage, and also found that battery systems can minimise a household's overall electricity costs.
"Tesla's announcement of the Powerwall was the dawn of the consumer age of battery storage," says Energy Networks Association CEO, John Bradley, and it seems that we won't have long to wait before this age begins. Tesla has confirmed that the Powerwall will be releasing in Australia before the end of this year. We have been prioritised as a launch market alongside North America and Germany, likely due to our enthusiastic adoption of home solar technology as a country.
Tesla cannot confirm what the Australian price will be on release, as they say it will be dependent on the third parties who they are working with to release the product. "We're only one component of three — which will be solar, inverter and the Powerwall — so it'll be up to our third parties to come up with that package," says Tesla Australia's Heath Walker, although he does mention that "the Powerwall is very competitive in terms of price."
"Tesla has changed the game, and made batteries a household talking point," says Powershop's general manager, Ed McManus, pointing to the Powerwall's affordability as one of the main reasons it's become such a hot-button gadget. Walker also pinpointed the three main reasons he believes our interest in battery technology is so high:
1. Energy costs in Australia are relatively high. (Gizmodo checked this, and Australia's energy purchasing power parity is ranked 9th out of 30 OECD countries.)
2. With greater adoption of solar technology comes a marked drop in feed-in tariffs (which are the rates at which the grid will buy excess solar energy back off their customers).
3. Australians are increasingly interested in taking greater control over their energy use.
Tesla wants to facilitate this independence, offering flexibility in the way that the Powerwall can be installed. "We're looking at an option that can be used in multiple ways. We look at retrofit, new fitment and even isolation fitment whereby you can utilise the Powerwall via off-peak and then maximise your energy usage in peak times." He does add, however, that due to Tesla's focus on renewable energy they will largely be encouraging the Powerwall's use with solar panels.
Although this may be the first that many Australians have heard of it, battery storage technology is not exactly new in Australia, even if Tesla's approach to it is. Most of the home battery systems currently available in Australia are very utilitarian — looking like your average hot water system, something that should be hidden away in the shed. Tesla's offering, on the other hand, could very easily be given pride of place in any modern home, even coming in a range of colours.
Tesla's approach is also surprisingly simplistic. "We're concentrating on what we do very well, which is lithium-ion batteries at a great capacity, at a great rate, with a beautifully packaged design." Instead of trying to create a whole package with solar panels and software, Tesla is focussing on their area of strength and leaving the rest to their as-yet unnamed partners in Australia.
Tesla’s Powerwall is a great concept — with the potential to reduce electricity costs, tie in with solar and create a smarter, distributed power grid. But how long will it take to actually save you money? Let's find out.
Enphase Modular Battery
While Tesla has made the biggest splash in the market so far, they are not the only ones coming up with innovative battery storage solutions. Another American company, Enphase Energy is bringing its battery storage system to trial in Australia, but the battery has one major difference to the Powerwall and other lithium-ion batteries on the market.
To understand Enphase's approach, it's important to go back to the basics of electricity. There are two types of electrical current — AC, which is used in mains power and the appliances you plug in to run at home, and DC, which is what solar panels collect, and what is stored in batteries. All solar panels and batteries require inverters so that you can use the generated or stored energy without burning your house down.
This is what Enphase specialises in — it was the first company to produce what was considered to be a successful micro-inverter for solar panels. In a classic system, all the energy from a solar array goes through a single central inverter — which leads to the common problem with solar panels where poor performance from a single panel can drag the entire system's output down by up to 50 per cent. A micro-inverter sits behind a single panel instead, allowing them to operate far more independently and maximising the output of the entire system.
Enphase has now taken this unique approach and put it into battery storage technology. "Rather than putting it under a photovoltaic module, we're pairing it with another form of DC power — the battery," says Enphase's director of global product management, Ilen Zazueta-Hall. "We've pioneered such a fundamental change because it means that you can get that same kind of modularity — rather than a single large battery — and can size your storage needs to the needs of the home."
To test this new technology, Enphase has recently partnered with SA Power Networks in Australia — like Tesla, it has taken notice of Australia's enthusiasm for solar technology and renewables. This pilot will test Enphase's whole system approach — unlike Tesla, they produce offer solar micro-inverters, the battery storage technology and the Envoy system which monitors energy usage in your entire home system. The houses participating in the South Australian pilot have been fitted with the latest in the range, the Envoy-S.
Enphase's microinverters work by sending power over the power line, but they also have the ability to send data over these same power lines. This is how Envoy monitors data from up to 600 micro-inverters in any given system, sending it through to the Enlighten software that Enphase packages with its systems. Below is a screenshot of the MyEnlighten app, showing both solar generation and energy consumption. Orange denotes power consumption, with light orange being solar energy consumed and dark orange being grid energy; while blue shows the amount of solar power generated, where light blue is the amount of solar energy that's been used and dark blue is the excess solar energy.
Ideally, Enphase would recommend installing the solar panels and the Envoy-S before integrating the battery into the system, then being able to use an average of the dark blue figures to work out exactly how much storage they need to invest in. With Enphase's modular battery system, customers can work with 1.2kWh building blocks, combining as many of these as they need to fit their storage needs.
Enphase has estimated that the average user will probably need three or four, but the beauty of the system is that it's inherently future-proofed. Energy needs can change with factors such as a new baby in the house, or the purchase of an electric vehicle, but Enphase users can easily adapt with the addition of another 1.2kWh module. It's worth noting that Tesla's Powerwall also allows stacking of multiple batteries — but at a minimum of 7kWh each, it lacks the same nuance as Enphase's approach.
The fact that Enphase has factored in an allowance for changing storage needs is one way in which they differentiate themselves from the competition — especially taking into account the increased adoption of electric vehicles. While this trend is more pronounced in Enphase's home of California over in the States, most of CSIRO and ENA's mapping of Australia's energy future has forecast a rise in electric vehicle ownership. When you look at a MyEnlighten snapshot that includes charging an EV overnight, you can see how storage needs would easily change for an EV owner.
Orison's Tower and Panel
Of course, both Enphase's battery and the Powerwall are going to set you back quite a bit for installation by a professional, but one pioneering battery company has cut out this step altogether. Orison is a company that has just announced two new home batteries — the Tower and the Panel. Like Tesla, they are designed to fit in with your home décor rather than be hidden, with the former looking like a standing floor lamp and the latter like a wall mounted light. They both effectively function as such as well, having LED lights included as part of the design. The big difference between Orison's designs and Powerwall or Enphase's battery system is that it doesn't need an electrician for installation — instead it plugs straight into a regular old power outlet.
While the other battery technologies are designed mainly to be used with solar generating homes, Orison works well either way. For houses with solar panels it operates much as you would expect, but if installed in a house running entirely on the grid, it will automatically store power during off-peak times then run off that power while peak rates are in effect. Of course, as with most battery technology, Orison's batteries are going to offer much more of a financial benefit for houses with solar panels installed.
The Tower in particular is more than just a battery — it also has multiple usb charging ports, as well as a fancy induction charger on the top. It's currently priced at $US1995 for the Tower, whereas the panel will be $US1600. At 2kWh of storage for each battery, Orison's price per kilowatt-hour is about the same as — or potentially less than — initial price estimates for Tesla's Powerwall.
With three such different technologies — each with their own unique features and capabilities — it's impossible to pick a winner. Instead, there is a different system for each type of consumer — for those with or without solar panels, for those who are thinking about getting them put in and want to get an entire package or those who want to retrofit an existing solar array. The only surety is that as 2016 approaches we are seeing more and more options open to consumers who are looking into adopting this technology — and this is just the beginning of the home battery revolution.
It may not be as pretty as the Powerwall, but it does the same job. It’s currently undergoing trials, so the full details are not yet available, but we crunched the numbers based on what we know so far.