Blackout protection from your EV?

Aug 24, 2021 Blog

You want to do what with my EV?

Power my house and my neighbour!

We have spoken numerous times about the value of batteries for home and business. We offer these as a solution to people who have specific needs. In general they don’t offer a commercial return or pay for themselves in a reasonable time. So there needs to be another motivation for buying a battery. You can contact us to go through the options to see if this is the right decision for you.

What we have been recommending for the past 12-18 months is the concept of buying an electric vehicle and using that as your emergency battery. Note here EMERGENCY battery. Not an everyday battery.

Vehicle to grid.  Electric vehicle.

How would this work?

Why would I use my car instead of a dedicated battery?

In the words of Spock – “it’s very logical”!

A typical home battery is 10kWh and without subsidies will cost around $12,000-$15,000 installed. $1200-1500/kWh

A typical electric car now has around 60kWh of battery and costs around $50,000. $833/kWh

But the home battery can only be a home battery and at 10kWh might just be enough to get you through an overnight blackout assuming you paid for the blackout protection option (another $1,000-2,000) and hope the solar system charges it up the next day (assuming there’s enough sun). If you switch off unnecessary appliances it will obviously last much longer.

However an electric car can take you to work, the supermarket, holidays AND in an emergency provide blackout protection for your home. And not just overnight. It has 6 times the capacity of a typical home battery, so that means 3-5 days of capacity if you manage your energy well in a blackout. Of course the solar on your roof can extend this almost indefinitely.

Electric vehicle battery backup

More importantly, if you start to run low, you could drive to a friend or a public charging station and fill up the EV, go home, plug in and you have another 3-5 days of energy reserve for an extended blackout.

If your neighbour, friend or family are also without power, you could always go visit them, provide them with some temporary power, plug their fridge in for an hour or two to keep the food from going off, warm up the hot water tank and at least make them comfortable for a few hours until the power came back on.

It also provides a mobile medical equipment battery for home or if you know someone in desperate need.

This sounds impossible? No. This is happening now and in the US during the big cold snap, this is exactly what EV owners were doing. Many EVs now offer bidirectional charging or vehicle to grid capabilities. Many have a standard AC socket that allows appliances to plug in without an inverter. Some offer a DC connection only requiring an inverter, but it’s still possible to provide power to almost all household appliances.

What about Australia?

The largest supplier and installer of EV charging stations now offers this service. https://jetcharge.com.au/services/vehicle-to-grid

Bidirectional electric vehicle charger

We mentioned earlier that this would primarily be an EMERGENCY use only option. The reason is that lithium batteries do have limited cycle capacity. That is the number of times they can be fully charged and discharged before they go below a practical usable level, typically 60%. Typically this is around 3,000-5000 cycles now. Note this is full cycles, so if you only use 50% each day then it takes 2 days to use one full cycle. So if you topped up and then used the energy everyday for home, this would increase the cycles and run down the battery warranty faster than you might like.

The final comment here is that you might get paid to make your EV and its battery available in an emergency or under a VPP (Virtual Power Plant) program and that might make the difference in sticking with your old petrol gas guzzler and swapping to a clean electric vehicle. Obviously the ability to generate your own “fuel” from your own solar system instead of paying extortionately high prices for petrol might make you jump to an EV even faster.

The only question now is, which EV will you buy?

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