V2G: Delivering limitless energy to feed the grid

by Eric Cohen

Much of the world, including the United States, is moving quickly to replace coal and natural gas-fired electric plants with renewable energy, like wind, solar, and hydrogen. Wind and solar are great. Once built, they essentially supply “free” electricity that feeds our grids. The shortcoming that we are all familiar with, however, is that they only produce energy when the sun is shining, and the wind is blowing.

But there is another challenge with renewable energy production. In many places, there are frequent incidents of solar and wind producing a surplus of power. The name for these two challenges is “intermittency.” And it’s a very real, growing challenge globally, especially as countries everywhere have rapidly growing needs for more electricity.

What happens to that surplus energy during times of peak energy generation? You either need to find a way to store it or get rid of it. That’s right, in many places, excess energy is dumped in one place when other areas are starving for it. It’s called curtailment: the action that reduces the amount of energy generated to maintain the balance between supply and demand. One example is in the state of Texas. It was reported that, in 2022, the Electric Reliability Council of Texas (ERCOT) curtailed 5% of its total available wind generation and 9% of total available utility-scale solar generation. By 2035, however, it is projected that wind curtailments in ERCOT could increase to 13% of total available wind generation, and solar curtailments could reach 19%.

You heard that right: In Texas, as is the case elsewhere, the utilities that manage the grids need to turn away – just waste really – essentially free energy. And as reported above, this problem is only going to get worse over the next ten years.

The good news is that, over that same time, we’ll have built millions of high-energy batteries. 90% of which run on wheels. Electric vehicles have the potential to become virtual power plants through what is called “vehicle to grid,” or V2G. You may also hear it referred to as “bidirectional charging.”

V2G allows the vehicle to store electricity during peak supply periods, and then discharge it back into the grid during peak demand periods. For instance, electric school buses are already being leveraged. Once students are delivered to school, the majority of school buses sit idle until the end of the school day, and then sit idle again overnight. That means they could charge when demand is low and return energy to the grid when demand is high. The result is a reduction in energy use during high demand times, less stress on our electric infrastructure, and a huge reduction in “curtailed” or wasted energy production from renewables.

The same model can be leveraged for passenger vehicles by introducing V2G technologies to EV charging. For the system to work, however, there needs to be a dependable supply of vehicles to tap; that means they would have to be plugged in. Humans, generally, are not necessarily dependable; typical EV drivers only plug in when they need a charge.

That’s one more place where wireless EV charging shines. Wireless EV charging technology allows not only convenient charging, but will also allow for V2G with no need to remember to plug in. Soon, whenever an electric vehicle is parked over a wireless charger, it’s ready to power the grid. WiTricity calls this the Wireless Energy Cloud™ Ecosystem. And it’s one more reason to love wireless charging.