With solar feed-in-tariffs dropping and even going negative in some states (yes, that means you pay to export your solar), many homeowners are considering what they should do with their excess solar.
A logical starting point is storage. Instead of directing your excess solar to the grid and getting paid peanuts, buy a battery, fill it up when the sun shines, discharge at night and repeat the next day.
Recently, however, a smarter approach has had a huge push forward: Vehicle-to-Home (V2H).
Translation = using your electric vehicle to power your home.
Vehicle-to-Home
The idea of vehicle-to-home is simple: plug in your EV and use your car battery to power your home.
As with many things in life, easier said than done. There’s been a huge amount of work behind the scenes to agree and finalise standards to allow Australians to use their car to power their home. Standards were released in early November and now the key is for EV manufacturers to implement hardware upgrades which will allow bi-directional charging. Some EV manufacturers already have the hardware, but most don’t. Here is a great summary for those looking to read more about V2G, V2H, V2L.
There are many reasons why am I so excited about V2H compared to a home battery. The first is size. A typical home battery is around 10-13 kWh. The average household uses around 20 kWh, so a typical battery gives you about half your daily use.
A typical EV however has upwards of 60 kWh of storage. So your typical EV has 5 times the storage of a typical home battery.
But wait, there’s more.
The real lightbulb moment for me was when I heard the average Australian household has 1.8 cars. That’s more than 100 kWh or 5 days worth of storage!!
Another reason I’m so excited about V2H is practicality – if you need a new car, surely you’d be better off putting the $13,000 or so reserved for a home battery towards a new EV. You get both the battery (albeit much bigger) and the means of transport. An EV that can be used as a car and home battery surely looks more appealing than a petrol car with ever-increasing running costs.
A third reason is V2H will not only be great for customers, it will be great for the grid. The problem with solar is it all generates at the same time and not when demand is highest (5pm to 7pm, when people come home to cook and heat/cool their home). Widespread V2H will encourage potentially millions of customers to act like a sponge – soaking up excess solar during the day and discharging at night time when solar doesn’t produce.
The collective actions of the masses will hopefully make a huge impact on our energy transition. And it’s not influenced by politics or agendas, it’s influenced by simple economics and practical thinking.
Too good to be true?
At this point you might be thinking this all sounds too good to be true. Short term there are roadblocks. First, the cost is going to be high. I’ve heard upwards of $15,000 just for the bi-directional charger. You’re going to need to save a lot over the years to make that back.
Second, using your car as your home battery won’t suit everyone, most notably, those that drive a lot during the day. They will need to return home to charge their car. I like to think infrastructure will improve to help solve this problem. For the typical commuter parked in one spot during work hours, hopefully they can charge cheaply during the day due to an abundance of solar-generated electricity in the market. This of course will be more difficult for people that travel to multiple locations throughout the day, but it’s still not impossible with fast chargers.
Some might also argue that car batteries are not designed to be used to power a home. Perhaps we shouldn’t use it too much in case it degrades and wears out too quickly? To that, I introduce to you my Hugo Boss pants. I once bought the most beautiful pair of Hugo Boss pants, which I’ve only worn around 10 times because they are so stylish. If you have Hugo Boss pants, just wear them 🕺
What about Vehicle-to-Grid?
Bi-directional charging will also allow householders to send their excess stored electricity to the grid (rather than just their home). Why bother? There appears to be a pretty penny to be made at certain times during the year when demand for electricity is high but supply is low. If people plug in when wholesale electricity prices are spiking, they can be rewarded handsomely. While this sounds appealing, I can’t see it having broader appeal. I think trading wholesale energy markets is going to be too complicated for the average punter. I’m happy to be wrong on this one.
Summary
Despite the title, I am all for home batteries. If you already have a home battery, you probably love storing your solar and using it at nighttime. The economics might not work out perfectly, but you’re more self-sufficient and doing your bit for the energy transition. And even those that buy an EV with V2H might like a battery as well for when the car is being used.
But, if you’re yet to buy an EV, or yet to buy a home battery, V2H is an incredibly exciting development that you should certainly consider.
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