Protecting Grid Resilience as Electric Vehicles Surge
How will the power grid handle the rapid increase in electric vehicles? A North American Electric Reliability Corporation report outlines the need for industry standards and reliable models to predict grid impact.
As the world strides toward clean energy at an unprecedented rate, the power grid's fate and functionality hang in the balance. Many sectors of green energy are booming, but the increase in the number of electric vehicles (EVs) hitting the road will dramatically change the bulk power system (BPS) and how the grid handles this growth. Engineers often design models that can greatly improve performance and spur innovation. For example, models for lithium-ion battery performance have helped engineers continue to tweak and improve this central component of EV performance.
However, there has been a significant lack of EV charging model development. In fact, only one generic model is available to represent EV charging and how it might impact grid performance.
Electric vehicles charging. Image used courtesy of Adobe Stock
Engineers need to develop and update models while creating universal standards for charging infrastructure to predict electricity loads better. The North American Electric Reliability Corporation (NERC) has just released a white paper urgently outlining possible contributions and encouraging cross-sector collaboration between EV manufacturers, industry stakeholders, and policymakers to ensure the power grid can withstand the load massive fleets of EVs will bring in the coming years.
Challenges Faced by Local Grid Infrastructure
The projections for EV market growth show a future where the combustion engine falls into obsolescence. Government mandates for carbon emissions reduction will only continue to speed up this shift. The electricity demand hitting the grid will balloon.
EV sales projections in the United States. Image used courtesy of the U.S. EIA
Since about half of all vehicle purchases will be EVs by 2035, certain risks will inevitably arise as the grid is taxed. The total increase in domestic electricity demand by 2035 will be about 38%, which will undoubtedly complicate grid functionality.
Such big-picture data provides little information about how uneven market growth can create dramatically different loads and local strains on the grid. Engineers need grid monitoring and EV communication tools to help prevent grid failures caused by sudden demands.
In many places, local feeders will be unable to handle the growth. A recent study examining how California’s local grid infrastructure would manage increased loads found a substantial need for upgrades. In PG&E’s territory, 443 circuits will require upgrades, but only 88 are currently scheduled for improvements.
In California, the feeder circuits most likely to be overtaxed by EV growth are not evenly dispersed. Experts are concerned this unpredictable and uneven stress on the grid will disproportionately impact areas already prone to blackouts and outages.
Modeling, FIDVR, and V2G Programs
NERC’s white paper assesses and forecasts the work needed. It makes broad recommendations for increased collaboration among manufacturers, policymakers, and utility grid personnel to ensure all parties work together to protect grid resilience.
One specific recommendation is that EV charging equipment should ideally continue operating during bulk grid faults. However, transmission providers must identify areas where fault-induced delayed voltage recovery (FIDVR) conditions may alter recommended ride-through characteristics. This is a specific example of the current lack of information. Such knowledge gaps will prove problematic unless systematically filled and disseminated to all relevant parties.
The white paper also found if EV chargers must stop charging, they should do so without introducing a time delay, returning to pre-disturbance charging levels within one second of voltage recovery.
Another major recommendation is the development and facilitation of vehicle-to-grid technology (V2G), which enables EVs to become power sources for exporting excess battery capacity back to the grid, which can stabilize grid functionality. EV owners could generate revenue from such V2G tech, thus incentivizing many consumers to participate in grid stabilization efforts.
EV market growth is already here, but the reality is charging infrastructure, regulations, and protocols to protect grid resilience are lagging behind. NERC’s recent recommendations are an important step toward formalizing the path forward to support EV development while protecting the utility grid.
