Is Tesla Powerwall Viable for Australian homes?
Tesla Motors have announced the launch of a new electricity storage device - Tesla Powerwall.
Designed for use in homes and businesses, Tesla Powerwall is a 6.4kWh lithium-ion battery that comes in a very stylish looking box that sits on the wall. So apart from being the best looking battery box on the market what's all the fuss about?
Well, it's the price. At around $US300 per kWh, it represents a significant breakthrough in the pricing of batteries designed for self-consumption of solar energy or energy price arbitrage on the grid.
Is Tesla Powerwall cheap enough to be a viable investment for the Australian homeowner?
Tesla's headline price for the 6.4kWh model is $US3,000. However, there are a few additional costs before it ends up on your wall:
- Crucially, it doesn't come with an inverter to convert the DC coming from the battery to AC that can be used in your home. (Add $1000 to $2000.)
- The $AUD is sitting around 73 cents US. (Add another $1,100 to convert to our currency.)
- Tesla's price is a wholesale price. (Add approximately $660 for a retail price.)
- The price doesn't include installation. (Add an extra $500 to $1000 for installation.)
Assuming no other costs, and the 6.4kWhs unit would probably come fully installed for just less than $8,000 ($800 per kWh).
So how does it benefit the Australian electricity consumer ?
Well it can do three things:
- If you have a solar power system installed, it will allow you to store any unused electricity instead of selling it out to the grid (at your feed-in tariff rate) and use it later to offset what you would buy from your electricity retailer (also offsetting the tariff at that time). Thus, you get the benefit of the differential between the two tariffs.
- If you don't have a solar power system installed, you can charge from the grid at off-peak times and use the battery at peak times. Again, you’re getting the benefit of the differential between those two tariffs. In Perth, for example, the Smart Power off-peak tariff is 12.74c kWh and the peak tariff is 47.4c kWh. Thus, the 6.4kWh unit will give a benefit of $2.22 per day. At that rate it would take you 3,603 days (10 years) to recover your initial investment of $8,000.
- Provide a UPS solution when the grid is unavailable. In other words, backup power in the event of network outages.
At Infinite Energy, we're very encouraged by these returns. This appears to be the first viable on-grid battery solution that presents viable returns for Australian homeowners.
Infinite Energy is proud to offer "Tesla ready" solar power systems using Fronius Hybrid inverters, which can serve as both the home's solar inverter and the inverter for the Tesla Powerwall. By utilising the solar system's inverter, (and the additional inverter costs are removed from the second example above) the payback period is cut to just 6.37 years.
Solar edge inverters are also available for single phase properties. In this scenario, your Powerwall can be installed straight away.
If you would like to discuss a "Tesla ready" solar system for your home or business, then please contact us.