EVs, Bidirectional Chargers as Tools for Energy Resiliency

Article by Constellation

The transition to electric vehicles (EVs) is well underway with more than 1 million EVs in the United States.¹ This number will only increase as states boost their carbon footprint reduction goals, such as the governor of California’s recent executive order designed to put 5 million zero emissions vehicles (ZEVs) on the road by 2030, as well as Massachusetts and Maryland’s plan to put 300,000 ZEVs in each respective state on the road by 2025.^2,3

Not only are the growth of EVs on roads a positive step towards cleaner air, but plug-in vehicles – vehicles that can recharged with electricity including both EVs and hybrid EVs – might have the ability to make the power grid more reliable and more resilient.

The generating capacity – or horsepower – of all the vehicles in the United States is over 25 times the generating capacity of all the powerplants in the United States, according to Tod Hynes, cofounder and CEO of XL, a company that offers smart and simple fleet electrification solutions for commercial and municipal companies. As more of these vehicles plug into the grid, they will have a larger impact and will need to be managed properly.

XL, one of the companies that Constellation Technology Ventures (CTV) has invested in, has been delving into the vehicle-to-grid phenomenon and in understanding its benefits for businesses. “Vehicle-to-grid (V2G) describes a system where electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) can connect to the electric grid and participate in markets managed by grid system operators,” according to an MIT study.⁴

Bidirectional Chargers as Portals for Vehicle-to-Grid

Bidirectional charging, rather than unidirectional which most EVs tend to have, may be the means for pushing energy from vehicles to the grid. It is said that vehicles are parked 95 percent of the time,⁵ allowing for more time to charge and the potential for increasing the amount of energy available in the grid.

Bidirectional chargers have the ability to maintain the equilibrium of charging vehicles and the charging site or facility’s electricity capacity to prevent overtaxing the site’s capacity. The energy flow from vehicle to building shows the chargers’ potential to positively impact the energy grid, by adding power back into the grid when it is not being used by the vehicle.

The energy flow from vehicle to building shows the chargers’ potential to positively impact the energy grid, by adding power back into the grid when it is not being used by the vehicle.

In this model, utilities could pull energy from a multitude of sources, such as EV batteries, that are plugged into the grid and inject extra power into the grid during periods of high demand, potentially avoiding brownouts or blackouts, according to the U.S. Department of Energy.⁶ This would contribute to greater grid reliability and resiliency. As the battery adoption grows and V2G technology advances, there may be more regulatory financial incentives available for EV owners that allow their batteries to be used this way.

Concerns and Benefits

Stakeholders raise the question as to whether the multi-use of the battery – for storage and charging purposes — can compromise the lifespan of the battery. An MIT study argues that using vehicles’ batteries for V2G energy results in approximately half the capacity loss as compared to the rapid cycling that is encountered while driving, meaning driving the EV is more likely to degrade the battery than using it to power the grid.⁴ A smart control algorithm with a goal of maximizing battery longevity can potentially mitigate battery degradation.⁶

Electric vehicles may play an important part in balancing the energy on the grid by serving as distributed sources of stored energy through V2G.⁷ As commercial and industrial companies continue to electrify larger percentages of their fleets, there will be a larger number of vehicles requiring power – but on the flip side, they could increase the amount of storage from EVs available on the grid, increasing availability and reliability when needed. They may also receive financial incentives, depending on their state’s policies, as well as meet business sustainability goals by reducing carbon emissions.

Learn more about CTV, the venture investing organization within Exelon Corporation, which invests in companies representing innovative energy technologies like electric vehicles and chargers.

References

1. http://www.eei.org/resourcesandmedia/newsroom/Pages/Press%20Releases/EEI%20Celebrates%201%20Million%20Electric%20Vehicles%20on%20U-S-%20Roads.aspx
2. https://www.wsj.com/articles/california-gov-jerry-brown-to-call-for-five-million-zero-emission-cars-by-2030-1516996404
3. https://mde.maryland.gov/programs/air/mobilesources/pages/zev.aspx
4. https://ctl.mit.edu/sites/ctl.mit.edu/files/IEEE_2012_DeLosRios_Goentzel_Nordstrom_Siegert.pdf
5. https://news.nationalgeographic.com/2017/09/electric-cars-replace-gasoline-engines-2040/
6. https://www.sciencedirect.com/science/article/pii/S0301421517307619
7. https://www.smartgrid.gov/the_smart_grid/plugin_electric_vehicles.html