With the spectre of colossal electricity bills looming over us like some sort of fully charged Grim Reaper, there’s plenty of talk about how the cost benefits of running EVs might be about to suddenly disappear.
But quite apart from the fact that fossil fuel prices will only keep increasing, could there be more to the energy benefits of running an EV than merely the cost of a unit of energy?
The demand for domestic solar systems is ramping up to the extent that waiting lists for reputable installers are growing fast.
With a cheap (or in Scotland, government backed interest-free) loan, the cost of installing a solar system with battery storage could soon fall below that of paying household energy bills. Systems fitted by certified installers are also VAT-free.
Given that the majority of ‘refuelling’ for EVs is done at home, the value of installing a hybrid solar system for EV owners suddenly becomes even more attractive. It’s the equivalent of a conventional car owner having their own oil refi nery in the back garden, only more discreet.
Today’s domestic solar systems are smart, so energy generated is used to supply the house first, then charge the home system battery to supply demands after sundown – and then, if both of those demands are met, any extra can be sold back to the grid under the Smart Export Guarantee scheme. It’s better than nothing but the SEG rate is small compared with the tariff paid, so the most cost-effective method is to consume all the energy the system generates.
That’s where the EV comes in. A 5kWh lithium ion battery storage module for a domestic solar hybrid system costs in the region of £3250. But a typical EV sitting in the drive with a 64kWh battery will usually have plenty of valuable capacity sitting there doing nothing.
Charging in daylight hours makes sure all the home-generated energy is put to the most cost-effective use if an EV is plugged in whenever it’s at home instead of only when the battery is low. Owners of EVs with vehicle-to-load systems like Hyundai’s Ioniq 5 could also make use of power stored during the day to avoid drawing from the grid.
The whole equation would be even more effective had vehicle-to-grid (V2G) ever taken off. For example, home owners would have more choice as to how the investment in a solar hybrid system could be split and whether to spend more on panels and less on battery storage.
The Electric Nation V2G trial, run over two years by CrowdCharge, Western Power Distribution and partners, established that EV owners taking part were able to reduce their home energy bills through their EVs sharing energy with the grid.
According to Electric Nation, the barrier to V2G’s commercialisation right now is that it’s supported by only the Chademo connection protocol and, as far as new cars are concerned, that means only the Nissan Leaf. CCS, the most widely used system, is expected to become compatible by 2025.