Adapting to fire: How cities can enhance resilience with distributed energy
Solar-plus-storage and microgrids are among the powerful tools to help cities withstand nature disasters.
As California experienced uncharacteristically low precipitation in February, normally its peak rainy season, parts of the state are moving into drought conditions. This is likely to increase wildfire prevalence in the state in 2020, and it underscores the point that communities need to think about a range of strategies to increase their resilience to wildfires. One of these strategies is the way that communities approach their electricity systems.
Distributed energy resources (DERs) — on-site solar, battery energy storage and microgrids — can help decrease the likelihood of wildfires and protect communities from their worst effects. City governments have an important role to play to help accelerate deployment of these technologies and solutions by lowering the barriers to adoption, investing in critical facilities and community microgrids, enhancing energy efficiency and engaging in utility planning and regulatory processes.
Wildfires cause disproportionate harm to our most vulnerable communities
The fires in California recently have shown us that severe climate-related emergencies are the new normal (California’s wildfire "season" is becoming a year-round phenomenon), and the costs can be astronomical. The economic impacts of the 2018 fires alone have been estimated at $400 billion — nearly twice the biennial budget for the entire state. The costs of the mandatory blackouts, or Public Safety Power Shutoffs (PSPSs), that California utilities have been implementing to try to avoid additional wildfire damage are exorbitant as well. Consider, for example, the cost of outages on schools: the PSPS implemented by PG&E during the Kincade Fire caused about 500,000 students to miss school, at an estimated societal cost of $14 million per day (PDF).
Cities must lead in promoting resilience solutions
While companies can leave in the wake of disasters, cities cannot. Local governments are responsible to their residents and to the local businesses and institutions who remain or return. Cities need to protect their local economies and retain employers and workers. Building resilience is an essential part of that equation.
One way in which cities are acting to build resilience is by taking greater control of their energy systems. At the extreme end of the spectrum, San Jose and San Francisco are evaluating the potential to municipalize their energy systems (buying the local electricity infrastructure and running it as a city utility), which could allow them to emphasize investments such as local microgrids in their resource planning. Others are using their community choice aggregation programs to implement similar solutions (PDF).
However, cities can promote the same aims within the structure of a conventional city-utility relationship several other ways, including:
- Streamlining permitting for solar-plus-storage for individual homes and businesses.
- Enhancing community-wide resilience through investments in critical facilities and microgrids.
- Promoting building energy efficiency to address the demand side of the resilience equation.
- Helping bake resilience into electricity system planning through engagement with utilities and regulators.
Let’s look at each of these in turn.
Streamlining permitting for solar-plus-storage
Behind-the-meter solar-plus-storage can enable "continuity of operations" in our homes and businesses, allowing us to keep running our air conditioners, refrigerators, lights, computers and home medical equipment. Increased adoption of these distributed energy resources also can help reduce fire danger by lowering the strain on aging transmission equipment — the culprit in California’s Camp Fire, most destructive in the state’s history.
But these solutions are expensive — and incentives such as the $100 million for the behind-the-meter battery program implemented by the California Public Utilities Commission won’t be able to reach everyone. A 10-kilowatt solar array costs around $30,000, while the cheapest Tesla Powerwall will set you back around $10,000.
A solar industry and nonprofit consortium is working for a permitting and inspection system that is more like Australia’s or Germany’s. The system would involve a simple, free online application platform where pre-approved installers receive automatic approval as long as they draw from a certified equipment list. As part of the system, randomized spot checks would keep installers in compliance, with companies losing accreditation if or when they fail. In a system such as this, cities control permitting — and influence interconnection costs — so it significantly could accelerate DER deployment, while also promoting the local solar installation jobs that are already one of this country’s fastest growing employment categories.
Investing in critical facilities and microgrids
While back-up power can make sense at the level of the individual household or small business, these solutions are largely inaccessible to much of our population. According to U.S. census data, 34 percent of America’s homes are occupied by renters, and 57 percent of Americans live in multifamily buildings. Furthermore, having solar panels and a Powerwall won’t do anyone much good if they need to evacuate their home or place of work.
Cities therefore need to make resilience a feature of their communities by investing in essential facilities that can provide direct relief during emergencies and can serve as a foundation for more expansive local microgrids in the future. Municipal buildings such as schools, recreation centers and public housing are obvious candidates. They are often thought of as "secondary critical loads" and do not have dedicated backup power. Cities can start small, investing in enough capacity to serve the functions that usually comprise only 10 percent to 25 percent of the total energy demand of these facilities.
To maximize the resilience benefits of these solutions, it is important to base them on solar-plus-storage rather than fossil fuels. Facilities reliant on diesel generators typically only have enough fuel to last a couple of days, while batteries are replenished every time the sun comes up (and even through the wildfire haze). The Stone Edge Farm microgrid, based primarily on solar and 10 types of batteries, operated continuously through 10 days of Sonoma County fires in 2017, and again through PG&E’s PSPS in fall 2019, with its solar array operating at 50 percent of normal production despite the smoke and ash.
Emerging battery technologies, such as flow batteries or solid-state batteries, also can mitigate or eliminate the flammability concerns that come with standard lithium-ion chemistries. In addition, solar-plus-storage solutions avoid the heavy pollution emitted from burning diesel during both their emergency operation and monthly testing — which is of concern in densely populated urban areas.
The batteries used do not need to be stationary. The 60 kWh battery that comes with a mid-range Tesla Model 3 (America’s best-selling EV in 2018) stores as much electricity as the average American home consumes in two days (PDF). Electric buses could provide back-up power for schools, which often serve double duty as refuge centers in emergencies — as Holy Cross Energy is considering in Colorado’s Roaring Fork Valley.
Cities also can work more closely with private institutions providing vital public services, including healthcare, food services, telecommunications, water and waste management. While many of these facilities already have robust back-up power, they potentially could benefit from an integrated approach that increases overall system capacity and extends resilience benefits to additional facilities while lowering overall system costs. A study led by the New York State Energy Research and Development Authority (PDF) showed that the cost-effectiveness of these integrated microgrids improves if:
- the system can operate on a more frequent basis, provide more services, and access more value streams than just back-up generation;
- critical facilities are tightly clustered (within a half-mile of each other);
- system design can be optimized via access to granular consumption data (15-minute intervals); and
- the cost of installing switching equipment on existing utility wiring — a key cost driver — can be kept to a minimum.
Eventually, microgrids focused on critical facilities could be expanded further. Prioritization could go toward supporting the 16 infrastructure sectors considered by the US Department of Homeland Security to be "so vital" that their incapacitation or destruction would have a debilitating effect on national security, the national economy, public health and public safety.
Many cities also can take advantage of their "town and gown" relationships by taking microgrid lessons from their local colleges and universities. Higher education institutions long have been microgrid leaders because losing power can mean losing years of vital work. As the University of Texas, Austin’s Juan Ontiveros explains, "If a professor loses a transgenic mouse with 20 years of research built into it, that’s a nightmare." The microgrid he manages, designed to protect the university’s $500 million worth of research, is one of the biggest in the country and has delivered 99.999 percent reliability over the last 40 years. Princeton’s microgrid kept the lights on during Hurricane Sandy when much of surrounding New Jersey went dark. The University of California, San Diego’s microgrid serves 92 percent of its electricity needs.
When the technical microgrid fixes are accompanied by financing solutions, these community microgrids can be implemented without capital outlays from the city. For example, the Montgomery County microgrid in Maryland was developed and financed by Schneider Electric and Duke Energy. In California, Fremont’s fire station microgrid is projected to save the city a projected $350,000 through a power purchase agreement.
Promoting building energy efficiency
Solar-plus-storage and microgrid solutions will go a lot further if they serve buildings and equipment that operate efficiently. For example, a 10 kilowatt-hour battery can run a highly efficient (US SEER 18) 1.5 ton air conditioner for three hours, about twice as long as it can run a low-efficiency (US SEER 9) unit.
The main determinants of hours-of-safety include how well insulated a building is (to guard against temperature extremes), how much air leakage occurs between the inside and the outside (which affects indoor air quality as well as temperature) and how long critical equipment can keep functioning — a function of back-up power capacity relative to load (the energy stored in your battery relative to the power draw of your home dialysis machine).
The demand side of the resilience equation could be helped by city-led efforts to enhance building codes, establish emissions limits and minimum efficiency standards for existing buildings, require building disclosures on emissions and energy performance and enforce equipment standards.
Engaging with utilities and regulators
Even when tensions run high, as they do when power outages occur, city-utility collaboration is vital for cities to achieve their resilience and sustainability goals. The terms and goals of collaboration can vary greatly, but city-utility partnership agreements offer examples of how cities can improve communication and align resources and capacity with key planning needs. For example, as utilities such as PG&E in California move forward with the development of resilience zones and pre-installed interconnection hubs, cities could ensure that these DERs meet the cities’ goals and don’t result in investment in more fossil fuel generation capacity.
RMI analysis has shown how the cost of installing solar-plus-storage at critical facilities is the same as centralizing the assets at one utility-owned location when average annual outages hit 1 percent, and the cost is lower at any outage levels higher than 1 percent. Investments in balancing equipment and storage at or near existing substations can relieve stress on transmission lines (by mitigating the effects of solar overproduction) and enable the "islanding" of parts of the distribution network. Participation in the California energy storage market during non-emergencies can create an additional value stream and further improve the economics of these investments.
Cities in Georgia and Utah have shown how they can affect major planning decisions. After intervention by Atlanta and several other local communities in Georgia Power’s recent IRP, the utility more than doubled its use of renewables and nearly doubled its energy storage capacity numbers. According to Daniel Tait, a researcher with the Energy and Policy Institute, "Intervenors made a difference through testimony. With the information that intervenors put forward, their modeling and their testimony, it’s becoming increasingly clear how cost-competitive renewables and, increasingly, storage are in Georgia." In Utah, Rocky Mountain Power has partnered with several local governments to support passage of state legislation that authorizes a path to net-100 percent renewable electricity for communities with ambitious clean energy goals.
These types of engagement by cities will allow them to improve their energy systems to invest in their community’s resilience. In our increasingly turbulent world, all these strategies will need to move from notable to the norm.
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