Are California’s energy resilience assets being put to good use? Do they provide energy security for diverse and important sub-sets of individual electricity customers? Yes, but not for all or even most important sub-sets. Has massive deployment of on-site energy resilience assets in California enabled their effective use to back up local electricity grids. Not yet. Are energy resilience assets being integrated with grid assets to maximize local energy security? Not yet. They are not even called on to feed electricity into regional grids when they are under stress.
Two opportunities are being missed. First, the opportunity to use local resilience assets to back up the state’s electricity system when California power plant output and imports don’t add up to aggregated demand. Second, the opportunity to continue to serve local areas that have been cut off from the state’s electricity system due to regional blackouts or so-called rolling blackouts.
Deployment status and trends for major energy resilience asset categories are summarized in Table 1. Local energy resilience assets deliver energy security by backing up electricity and gas transport systems. They serve selected on-site energy uses when regional or local energy transport systems are disabled. They include publicly and privately owned systems that convert fuels, waste materials or renewable energy to electricity for local use. With the exception of standby power assets using diesel fuels, almost all energy resilience assets are also decarbonization assets.
Table 1. California’s Energy Resilience Assets
Unlike the sources on which routine grid electricity service depends, local energy resilience assets typically operate independent of energy transport systems and provide backup power to only a small fraction of electricity customers. California’s currently operational on-site energy resilience asset capacities (combined heat and power and standby power) add up to 20GW, thanks to non-utility investments over decades. They are still growing at modest annual rates. For a sense of relative scale, total in-state grid electricity supply capacity, 80GW, is only four times greater. [1]
Additional available on-site energy resilience assets are being deployed at much faster rates and include on-site solar PV arrays and batteries charged by the arrays. Battery storage must be available on-site if solar PV is to enable 24/7 energy resilience. On-site solar arrays can charge vehicle batteries that both power the vehicle and feed electricity into the local distribution grid. Solar plus storage systems relying on stationary batteries or vehicle batteries can increase the current operational on-site asset total by a factor of two over the next decade. This fact should invite policy attention to the opportunity for more effective use of all resilience assets, currently operational and yet-to-be exploited.
Will the doubling of energy resilient supply assets expected in the next five to ten years materially improve energy resilience in California? Not to the extent it could. Or at minimum cost. Optimally effective asset use can only be achieved when there is more flexible local electricity grid operation that allows local decarbonization and resilience assets to be aggregated. The cost of local energy resilience can either be high or modest, depending on whether low carbon on-site energy supply and storage assets are used effectively. Resilient decarbonization is maximized when a portion of these assets rely increasingly on negative or zero carbon fuels.
Community microgrids enable aggregation and integrated operation of local resilient decarbonization assets. They are not primary targets for utility investment and rate-base building. The urgent question is whether other stakeholders - cities, counties and states - will overcome utility and regulatory resistance and lead the way on an energy resilience path that serves all energy users, not just those who have backup on-site.
Many energy users invest in energy resilience, purchasing on-site generators, including combined heat and power systems and standby generators. On-site generators provide backup that can be limited or complete, temporary or indefinite, depending on fuel supply and storage. Other local energy resilience assets include on-site solar arrays, community renewable projects, on-site fuel cell generators, vehicle based batteries and fuel cells, and microgrid controllers that enable combinations of supply assets to operate in isolation from local electricity grids.
Local energy resilience assets, other than diesel fueled backup generators, can be decarbonization assets, which suggests “resilient decarbonization” as a unifying theme of state policy. Local '‘resilient decarbonization” is maximized when a portion of these assets rely on negative or zero carbon fuels. However, energy sector decarbonization has the potential to degrade energy resilience to the extent it relies too heavily on expansion of centralized supply and transport infrastructure to achieve total electrification of energy use.
California’s investment in on-site decarbonization/energy resilience assets is comparable in dollar magnitude to California’s investment in bulk electricity generation and is expected to double in the next five years. But energy resilience benefits are currently limited to energy users owning or leasing energy resilience assets that are connected to on-site circuits. This is especially sub-optimal from energy equity[2] and community energy resilience perspectives. So, strategic and resilient decarbonization requires trade-offs that coordinate and cross-leverage existing on-site and future community decarbonization and resilience investments.
At present, on-site resilience assets typically are not coordinated to back up neighborhoods and communities. Achieving such coordination would strengthen both state and local economies. Effective coordination will require broader based, more active and purposeful stakeholder engagement animated by local government leadership and engagement.
Currently active energy resilience stakeholders include a small but growing percentage of energy users, plus backup power equipment vendors and installers. Passive stakeholders include local governments, energy product and vehicle manufacturers and retailers, energy utilities, state government, and notably, the majority of energy users that rely exclusively on energy utility service. Without engagement by all stakeholders, electricity users will continue to solve energy resilience problems on their own, typically after the fact of a major outage. The result will be continued uneven, uncoordinated and economically inefficient deployment of energy resilience assets.
Resilient decarbonization is an urgent local need requiring local initiative and leadership. It cannot be outsourced, because the best pathway is unique to each city or county. Among currently inactive stakeholders, local governments and utilities will have crucial future roles if energy resilience is to be achieved at the community level as well as the site level. Cities and counties have the most at stake economically and from a public safety perspective. They will need to fill energy management capacity gaps to engage promptly and effectively. Utilities have the technical and organizational assets to facilitate economic integration of energy resilience assets but as yet have no obligation under state law to do so. State government can facilitate local leadership and engagement. It can also reward or mandate energy utility engagement and investment.
Until currently inactive stakeholders step up, local energy resilience will depend primarily on individual energy user choices. Many energy users will continue to have no choices or ineffective ones unless local and state governments step up.
[1] Almost three-tenths of California’s electricity comes from outside the state, enhancing on both California’s vulnerabilities and buffering against disruption of in-state sources. Source: US Energy Information Administration.
[2] Energy equity refers to affordable and low income and minority communities’ access to clean and resilient energy service.