Through behavioral or direct control approaches, managed charging encourages customers to charge at times when grid and generation capacity is available. Likewise, it discourages charging during peak demand or low renewable generation periods. In doing so, it reduces the need to build additional grid and expensive or greenhouse gas emitting generators to meet the electric system load. Managed EV charging makes optimal use of existing infrastructure, lowers costs that would otherwise be incurred, and benefits ratepayers.
Analysts show steep forecasts of the number of light-duty EVs, in parallel with increasing space and water heating electrification, adoption of electrified industrial processes and expansion of intermittent renewable generation. It’s a perfect storm of the less-know new EV loads, the highly coordinated new heating loads, and the unpredictability of new renewable supply.
Many electric utilities are rightly concerned by the impact EV charging may have on their resource plans, both in terms of energy and capacity, but are also starting to see that managed — or “smart” — EV charging may be part of the solution to the disruption brought about by the electrification of the economy and the intermittency of renewables. So, although the grid impact of unmanaged light-duty EV charging may, by itself, be relatively modest or even beneficial, managed EV charging may become a new tool for utilities to provide grid services (such as peak shifting or even frequency regulations) or to help optimize customer charges.
Light-duty managed charging aims to shift EV charging to times when generation and grid capacity is available, considering the load that needs to be served, the demand on the electrical system and its markets. To effect managed charging, utilities may rely on multiple approaches, sometimes simultaneously:
- Residential unmetered incentives.
- Residential dynamic rates.
- Direct residential load control (V1G).
- Residential Vehicle-to-Grid (V2G).
Rates and incentives are behavioral approaches, attempting to nudge customer conduct, while load control systems and V2G take action on the electrical equipment itself, without customers intervening. Managed charging programs often rely on more than one option. For instance, a utility can use unmetered incentives to get customers to opt in to time-of-use rates.
However, utilities are not the only ones vying to influence the charging patterns of EV drivers. There are indeed many stakeholders vying for attention in the EV charging ecosystem: utilities, cities, charging operators, local businesses, real-estate developers, state/provincial governments, federal government, regulators, automakers, charger manufacturers, etc. For example, installation of chargers at commercial sites and the price charged to drivers (if any) is primarily driven by business considerations, such as attracting customers (a business owner objective), and not to benefit the grid (a utility objective) or to ensure sufficient charging coverage or capacity (which may be government objectives). Another example: utilities and their regulators may set electricity rates charged to public charging station owners but charging operators (which may not own the station) usually control end-user pricing and service conditions.
Because EV charging market signals are still relatively weak and could even be in opposition, greater collaboration and alignment among EV stakeholders, with better understanding of driver behavior, will be important for the EV charging infrastructure to develop harmoniously over at least the next few years.