Introduction: Why Microgrids Foster Grid Resiliency for EV Infrastructure
If global EV adoption rates grow as projected, this represents a major step in reducing emissions that contribute to global climate change and local air pollution concerns. The shift to cleaner mobility does not occur in a vacuum; it has broad implications for vehicles and power infrastructure, prompting demand for all-inclusive rather than siloed solutions.
While the electrification trend in transportation is encouraging, it comes with complications. These complications are tied directly to incumbent grid structures that threaten the reliability of electricity supply and costs. Regarding the former, increased frequency of extreme weather events is a growing challenge for reliability and jeopardizes the push toward electrification. Recent long-term power outages in Texas and California point to the need for greater resilience. In addition, many incumbent grid demand management rate structures are not designed for the load profiles EV charging creates and this has created increased costs and challenges for commercial EV charging site hosts. Additionally, many incumbent grid management and retail structures were not designed to access the value EVs can provide the grid via vehicle grid integration technologies, which can tap the flexibility of EV charging loads to increase grid energy and emissions efficiency.
The answer to these complications comes in the form of microgrids and other grid infrastructure upgrades. Microgrids can create islands of power once the grid goes down, maintaining essential electricity supplies for various forms of electric transit. Microgrids can use onsite renewable technologies such as solar PV, batteries, and even EVs as grid support assets. If equipped with advanced software systems, these microgrids can support the larger grid with real time optimization of diverse distributed energy resource assets that make up a microgrid.
What EVs and microgrids share in common is exponential growth. Tying the development of each together is possible due to rapid innovation in technology and new financial business models.
As state policymakers design and implement programs supporting the expansion of EV fleets at their own facilities and offer public financial support directly to consumers for adoption, they must account for the impact such well-intended programs will have on the reliability and efficiency of regional power grids.
What EVs and microgrids share in common is exponential growth. They are also typically deployed behind the meter (BTM) of the local distribution utility. Tying the development of each together is possible due to rapid innovation in technology and new financial business models. Microgrids can support EV charging and EVs can also support microgrids, resulting in the following benefits:
- Flexibility: Flexibility of the microgrid and EV charging can be optimized to support each other.
- Reliability and Resilience: If the grid goes down for short periods (reliability issue) or long periods (resilience issue), a steady source of sustainable energy for EV charging is onsite.
- Cost: The generation source to load distance is zero, which improves efficient distribution of energy. That in turn lowers overall development and operational costs compared to status quo utility distribution upgrades.
State funding for grid infrastructure upgrades may be limited given the current economic climate, especially in light of the COVID-19 pandemic. The Biden administration’s proposed federal infrastructure funding proposal could help overcome this limitation and is designed to provide a national network of EV charging stations. However, how such upgrades will be financed under this proposal is an area of political contention. As currently proposed, the infrastructure plan does not target heavy duty electric trucks, which will have some of the greatest impacts on the grid and major impacts for the environment, but instead targets light duty and public transit. The latter category will require significant distribution system upgrades. (The US Department of Transportation just launched two new electrification programs for heavy and medium duty trucks, further generating opportunities to increase resilience of electricity supply within the transportation sector.)
Perhaps one of the most promising solutions is an energy as a service business (EaaS) model where solution providers offer microgrids wrapped around EV charging stations with no upfront capital costs for the end user. Under this scenario, the risk for project performance falls on the shoulders of the solutions provider and its financial partners. This white paper includes a case study in Maryland, showing how EaaS microgrids can help support municipal EV fleets. This project represents a model that could be replicated throughout the US as states commit to net zero carbon goals. The white paper concludes with public policy considerations for state governments.