A vehicle-to-grid (V2G device)
(Picture: James Pike www.jimpix.com)“It’s the future!” exclaimed my Uber driver as we zipped down the highway to Washington DC airport in his Tesla. This was the start of an animated conversation on the F150 Lightning - Ford’s electric pickup truck that, according to their website, “packs enough punch to make a trip to the grocery store a thrill.” But what’s really impressive is that the truck boasts a new charging feature that could change how Americans power their homes.
This technology is known as ‘vehicle-to-home’, a type of electric vehicle charging whereby energy can be stored in a car and pumped back into a home. This kind of capability could help certain states keep the lights on during extreme weather events such as heat waves, which can cause the grid to struggle with balancing the increased energy demand from air conditioning. Demand was so high in California this year that people were advised to not charge their cars at certain times to help the grid manage. In the UK, we’ve also had warnings from the National Grid about how rolling blackouts could be introduced this winter should supply levels not meet demand - although it’s worth pointing out that this is the worst-case scenario.
What’s more, the technology also allows grid systems to use more renewable power because the vehicles can store energy when the wind is blowing and sun is shining and then direct it into homes, reducing reliance on fossil fuel power stations.
So if more people are getting electric vehicles (EVs), the technology exists and it can help the planet, then why aren’t we seeing it everywhere over here?
Well, the UK has been trialling similar technology for several years. While the US is opting for using excess energy from EVs to power homes, the UK is leaning more towards customers being able to sell their spare charge to the grid (known as ‘vehicle-to grid’ or ‘V2G’). Trials have shown that customers can make £420 on average per year by charging their car when energy prices are low and selling back the unused power at a profit, when energy prices are high. Some participants even eliminated their household energy bills. All that’s needed is the right type of electric vehicle (EV), charge point and electricity tariff. So why isn’t every EV driver doing this?
But there are three big challenges.
The chargers are expensive
A normal charge point typically costs between £500 and £1,000 but the V2G versions start at around £2,000, with some models priced as high as £5,000. This is due to the charger requiring the components to convert power from alternating current (AC) at the home supply level to direct current (DC) at the grid level. These upfront costs currently mean V2G owners would only start making a profit after several years. The good news is that the equation is shifting; through ongoing development, hardware costs are falling and the volatility of energy prices actually means that more money can be made from selling back power at peak times.
V2G could boost battery life, but more research is needed
EV manufacturers are nervous about the impact on battery health and life. Exporting energy from an EV battery will invalidate many vehicle warranties because of the potential impact on the battery. However, some studies show that V2G charging could, in fact, help to improve battery health so we should see manufacturers start to change their terms.
The grid needs modernising
For a long time, the grid has been a linear system with a gas or coal plant at one end and homes at the other with lots of copper wires in between. The system wasn’t built for energy to travel back from homes into the grid. This means that in order for a V2G charge point to be installed, local grid operators need to approve it. The right kind of standards for this to happen at scale don’t exist yet so policy development is also required. In a nutshell, our outdated grid means installation is slow and complicated, and it’s stopping many energy companies from offering new services around this kind of technology.
So, we know V2G has huge promise for drivers who make the switch to electric, helping to lower the price of owning an EV and even cut down their household energy bills. But clearly there are some significant challenges that need to be tackled in order for many more homes to turn into mini green power stations.
