EDITOR’S NOTE: This is the first installment in our two-part blog series on the role of utilities in turning EVs into a grid asset. We set the stage by examining EV adoption trends, the impact of EV charging on the grid, and the risks of unmanaged EV charging.
Which statement is correct?
- The power needs of electric vehicles (EVs) will exceed grid capacity, requiring costly upgrades to both the grid infrastructure and electricity generation capability.
- EVs themselves will become grid energy storage assets, helping to avoid costly upgrades by serving as “batteries on wheels” that store energy and send power back to the grid for balancing supply and demand.
If the industry continues on the path envisioned by EV advocates, industry experts and utilities across Europe, the U.S., and elsewhere, the second statement – EVs become grid assets – describes the future. Utilities in the U.S. and Europe< are experimenting with EVs as a grid balancing resource today, and they will play a critical role in the maturation of this approach. However, realizing the vision of an emissions-free power and transportation ecosystem will depend on the convergence of many factors over the next decade.
Progress in EV adoption
Globally, EV adoption rates continue to climb, although progress is uneven across countries. Estimates call for 22 million EVs on U.S. roads in 2030, 30–40 million in Europe, and 102 million in India. Across countries, EVs are typically projected to reach 30% of overall vehicle sales by 2030.
EV adoption will accelerate when there is greater choice in affordable vehicles. The current market is dominated by high-end luxury EVs, although an increasing number of manufacturers are adding lower-priced vehicles. Some manufacturers are pledging to produce only EVs by 2030.
Much of the progress to date in EV adoption is linked to government policies favoring EVs as a means of achieving carbon emission reduction goals, including government-funded rebates for EV purchases and funding for EV charging infrastructure. More EV-mature countries are shifting government support away from underwriting EV purchases to EV charging infrastructure.
A robust and highly convenient EV charging infrastructure that lets drivers charge when and where they want to, is key to addressing range anxiety, a significant inhibitor of EV adoption. Most EV charging today is done at home. However, EV drivers who do not have onsite or private parking need chargers on urban streets, at residential buildings, and at workplaces and destinations. More high-speed chargers distributed along highways are needed to make long-distance travel in an EV feasible.
Industry estimates call for the installation of millions of new chargers globally by 2035, at costs in the billions. Even though the majority will be home chargers, the balance will be public or semi-public. This means utility companies, including distribution companies, must operate a robust and resilient grid with ample capacity for EV charging infrastructure.
Building the charging infrastructure will also require fast and affordable access to the grid forcharge point operations. For installations with numerous chargers or fast charging, including fleet depots and service station/fuel court locations, that can mean costly upgrades to local grid resources. New policies will be needed for locations where a new grid connection or permits for a new charging location can take months to years.
The impact of EV charging on the grid
Despite variations from region to region, on average the demand for electricity overall will grow by about 1–2% a year by 2030, and up to 2.5% for developing countries. EV penetration will comprise 10–11% per year of that demand growth. Other increases in demand will come from electrification of heating (heat pumps instead of oil-burning furnaces) and industrial machinery. This gives utilities ample time to scale up generation and grid capacity incrementally to meet growing demand – if they plan ahead and make the necessary investments. That’s the good news.
But what happens when thousands or even millions of EVs attempt to charge simultaneously? For conventional electrical networks, charging all EVs when drivers come home and plugin could put a major strain on the grid and disrupt the stability of the power network. The problem is exacerbated when peak load periods coincide with EV charging, like after work when people are preparing meals, turning up the heat, and using appliances, TVs and computers.
The risk of unmanaged energy demand
The problems experienced when charging is unmanaged will be felt primarily at the local grid level, when increases in demand are likely to cause voltage fluctuations, poor power quality, and power losses. Transformer load will exceed capacity and peak usage times. Let’s consider two use cases, described by EY in collaboration with the Eurelectric consortium, where unmanaged demand will have the most negative impact on the local grid in 2035.
Highway corridors. There is little ability to predict peak demand for electricity at service plazas along the main roads, where eHDVs are using superfast 350KW or 500kW chargers to power up for long-haul delivery of goods. Light-duty trucks (eLCVs) and EVs are using the fast chargers to top up their battery charge. The result: 168% transformer utilization with EVs adding 90% to peak load over 15 hours.
Urban MDU (Multi-dwelling units). Peak load for this 15-unit residential building is highly predictable. People return home from work at 6:00 p.m. and, as described above, plug in their EVs, turn on the TV and laptop, make dinner, and use appliances. Multiple that by all the residential units served by the local transformer. The added load from EV charging is 86%, pushing transformer utilization to 107% over a one hour period. The transformer trips, the power goes out, and the grid struggles.
The alternativeis managed charging that balances EV charging with other demand on the grid. Digital capabilities enable grid operators to detect loads and smartly adjust EV charging based on demand and availability of energy supplied by local storage, renewable sources, and the batteries of EVs serving as grid assets. We’ll cover this alternative in our next installment in this two-part blog series.