With an on-board battery pack capable of storing tens of kilowatt-hours of electricity — enough to power a household’s basic appliances for several days — electric cars have already proven themselves capable sources of emergency power when a natural disaster cuts power to the electrical grid. In the past year alone, we’ve seen cars like the Nissan LEAF and Nissan e-NV200 provide emergency backup power after earthquakes in Japan, ensuring communities can provide adequate emergency response as and when needed, even when the power is off.
Indeed, browse any electric car forum for long enough, and you’ll find examples of people using their electric car as an emergency power source. From running a jury-rigged mains inverter from the car’s 12-volt DC to DC converter to camping off-grid with a vehicle-attached tent, electric car owners are already using the stored power in their car’s battery pack for more than just getting from A to B.
But now a new project in the UK is exploring another way the energy stored in electric car battery packs can be put to good use: Vehicle to Grid (V2G)
Enter Nissan and power company Enel, which have teamed up to make it possible for UK Nissan e-NV200 and Nissan LEAF owners — both private and corporate — to feed excess electrical energy in the battery packs of their electric vehicles back to the electrical grid during periods of peak demand, earning money in the process.
It’s all part of a nationwide trial involving at least 100 Nissan EV customers across the country designed to see if electric cars can improve rather than destroy the electrical grid.
At the heart of the project is a new two-way vehicle charging station similar to the LEAF-to-Home energy product sold in Japan. Making use of the CHAdeMO DC quick charge port found on most Nissan LEAF and e-NV200 models, the charging station is permanently wired into a home’s electrical system and can both put power into a Nissan EV’s battery pack from the mains electrical grid and vice versa, feeding power back to the electrical grid during periods of peak demand as required.
Unlike the LEAF-to-Home energy product sold by Nissan in Japan however, the Enel V2G DC quick charging station keeps a remote connection to the local energy provider, basing its charging and discharging behavior on the current load being experienced by the electricity grid. What’s more, it also measures the local electricity load in the house, as well as any electricity being generated by photovoltaic solar panels or wind turbines attached to the home.
During the day, when electricity demand is low, the system lets a parked, connected electric car charge its batteries up, either using power from the electrical grid or renewable energy generation devices such as wind turbines or solar panels attached to the home. Then, when peak demand periods are reached — such as the evening rush hour — the car can feed some of the power stored in its battery pack back to the electrical grid.
At night time, when electricity grid demand is at its lowest, the car can yet again recharge its battery pack from the grid, ready for the morning commute or providing energy to supplement the morning peak energy rush.
While the idea of vehicle to grid has existed for many years and has been demonstrated in closed research projects around the world, this is the first time we’ve seen such a project involve mass-produced, factory-standard electric vehicles and the general public. On paper, V2G technology offers a tantalizing vision of the future where electric cars help rather than hinder the electrical grid, allowing energy companies to use electric cars to offset peak demand periods by charging them up in off-peak periods.
Aside from countering the age-old argument that mass electric car adoption will harm the electrical grid, causing mass brownouts and infrastructure failure, V2G is also something of a financial benefit to electric car owners. In the project being carried out in the UK, Nissan says that customers who allow energy to be fed from their car back to the electricity grid will essentially sell that electricity back to their local utility. If charged up using off-peak tariffs and fed back to the grid using peak-time tariffs, they could even make a little money.
It is, essentially, a feed-in tariff of sorts, where electric car owners will be compensated for the wear and tear that the extra charge cycle will place on their car’s battery — not to mention the possibility that their car may have less than a full charge when they step behind the wheel in the morning.
Which brings us nicely to the point of concern among some electric car owners when such schemes are discussed: “Will V2G mean that my car is empty when I come to use it?”
While Nissan hasn’t shared much detail about the project, it appears that there will be an opt-out for those who truly need a full battery for their next trip, ensuring that their cars are always ready for use. It’s worth noting too that the average electric car doesn’t actually get through a full charge of its batteries for everyday use. At the weekend or in exceptional circumstances the average owner may find they really do need the full capacity of their car’s battery pack and yes, once in a while, there will be an owner who makes use of a full charge (or perhaps more) every day just to do an unusually long work commute.
But it’s also worth noting that the impacts of V2G technology on the individual are inversely proportional to the number of V2G vehicles. The more V2G vehicles become popular, the smaller the impact on the grid when power companies need to pull power from parked, connected electric cars.
In other words, in everyday use, participants may not even notice much of a change to their car’s state of charge when they jump behind the wheel.
Sadly, Nissan hasn’t detailed how interested parties can sign up to be part of the trial, but we have reached out to Nissan’s UK press team for further clarification. Naturally, we’ll share any extra information concerning the program here when we have it.
In the meantime, we’re curious to know what you think of V2G. Would you sign up for the service if you thought it could help your local community and your pocket-book too? Or would you be too concerned over the long-term damage to your car or finding your car didn’t have enough power in it for that emergency trip?
Leave your thoughts in the Comments below.
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