Manufacturers could gain room to sell more petrol cars under a United Kingdom proposal intended to reward electric vehicles for supplying electricity to the grid.

Here's what to know

The government is reassessing its zero-emission vehicle rules, with ministers weighing whether to offer incentives for vehicle-to-grid technology, according to The Guardian.

Drivers can sell electricity back during periods of high demand after buying it more cheaply overnight through a system called bidirectional charging.

Manufacturers could use technology-related credits to avoid electric vehicle sales-quota penalties when selling additional petrol cars. Under the proposal, fitting cars with the technology would earn those credits.

Grid balancing is not limited to cars: Home batteries can provide it, too. Adding battery storage is one of the best ways to protect your home during outages and save money on energy. Storage is also one of the best ways to gain more energy independence.

U.S. homeowners can explore EnergySage for home battery storage options, including competitive installation estimates. EnergySage has teamed up with electrification brand Qmerit to help homeowners get the best price on home battery storage solutions.

More background

Using vehicle-to-grid systems to draw electricity from parked cars could reduce reliance on expensive gas power plants. That stored power could help meet demand when still, cloudy, or dark conditions limit wind and solar production.

The National Energy System Operator, which balances Britain's electricity grid, forecasts that these cars could supply 1.2 gigawatts on demand by 2030 — equivalent to a power station.

By 2050, that figure could reach 41 gigawatts, sufficient to cover over 25% of peak electricity needs.

Separately, The Guardian reported plans to ease the government's electric vehicle sales requirements. Environmental groups fear the mandate changes could lead to an additional 162 million U.S. tons (147 million tonnes) of carbon pollution by 2050.

For the proposed credits, a practical obstacle lies outside the car: Few drivers own the costly chargers required to send power to the grid, according to Ben Nelmes, chief executive of clean-transport think tank New AutoMotive.

What's being done?

Some drivers are already selling electricity back through the U.K.'s Octopus Energy, France's Renault, and Germany's BMW. According to Octopus Energy, its service could save drivers £620 ($830) a year.

Charging during periods of plentiful, cheap electricity can limit payments to renewable generators for halting output. Smart charging tariffs encourage drivers to use those periods without requiring bidirectional technology. For home backup, Pila offers another strong option: Its plug-and-play batteries cost a fraction of a whole-home backup system.

Nelmes said: "Vehicle-to-grid is exciting technology that could help balance the grid and cut bills, but carmakers should only be rewarded if it's actually used, not just for fitting it.

"Under these proposals, one or even two extra credits worth around £4,000 ($5,400) each would hand manufacturers thousands per car for kit that costs a few hundred pounds, even though few drivers own the expensive charger needed to use it," Nelmes added. "Ministers should make sure the people who benefit from V2G are drivers and billpayers, not carmakers' shareholders."

Where can I learn more?

Getting EVs to support the grid depends on drivers taking part and having equipment they can afford. These stories explore California's storage potential and household incentives.

• California's parked EVs could supply one-third of grid storage goals if 10% of owners enroll.

• A California bill would reward households for helping stabilize the grid with EVs, batteries, and thermostats.

• California could meet 30% of its storage goal using 10% of EVs, potentially lowering bills.

• California GM EV buyers can receive a free charger and earn money helping the grid.

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