Supplying reliable and sustainable energy to the state’s economy requires planning and policies underpinned by the best available science. The impacts of climate change have potential to be drastic for the energy sector. For additional background information and discussion of climate impacts and vulnerabilities of the Energy Sector, visit the Background & Climate Impacts information excerpted from the Adaptation Planning Guide and explore the Topic search below.

To address resilience of the energy sector, partnership is needed between local jurisdictions and utilities. At the state level, the California Energy Commission (CEC) and the California Public Utilities Commission (CPUC) are working to address the effects of climate change on the energy sector. Examples of adaptation strategies are provided on the Adaptation Strategies page and can be found in many of the resources available by search below.

Defining the Sector

California’s energy system is a complex network designed to make sure that people across the state have access to the energy they need to provide light, operate equipment and appliances, maintain comfortable indoor temperatures, and for numerous other activities. For the purposes of the APG, energy use is divided between energy use in buildings and energy use in vehicles and mobile equipment.

Most energy used in buildings is in the form of electricity and natural gas (primarily methane), which is produced and distributed through statewide infrastructure systems operated by public and private utilities and overseen by state agencies and regulators such as the California Public Utilities Commission and the California Energy Commission. However, in some areas, especially rural communities and remote parts of the state, buildings may use other fuels, such as propane and wood for heating. Vehicle fuels in California are mostly petroleum-based gasoline and diesel fuels produced at refineries and delivered to retail fueling stations by road, rail, and ship. Other fuels, in particular electricity, are becoming more popular as vehicle fuels.

Where Does California’s Energy Come From?

California has an abundance of energy resources and can produce a large amount of the energy it uses in the state. California often generates between 65 and 70 percent of the electricity it uses, and the rest is imported.20 California is the fourth-largest petroleum producer in the United States, and in-state refineries produce most of the state’s gasoline and diesel fuels, which are subject to stringent air pollution requirements. California does have some methane production, but it imports about 90 percent of the natural gas it consumes. States in the Southwest and Rocky Mountain regions, as well as western Canada, supply most of California’s natural gas.21

What Are the Sources of California’s Electricity?

In 2018, approximately 35 percent of California’s electricity came from natural gas, 31 percent came from renewable sources (mostly solar and wind), 11 percent came from large-scale hydroelectric facilities, 9 percent came from nuclear facilities, and the remainder came from coal, oil, and unspecified sources.22 California is moving toward obtaining all its electricity from renewable and other carbon-free sources.

Most of the electricity used in California is generated at large power plants throughout the state and elsewhere. The electricity is transported along high-voltage power lines called transmission lines, which can carry the energy for long distances. Facilities called substations convert the power to lower voltages and send it to local buildings through smaller power lines, called distribution lines. Collectively, this system of power lines and substations is called the “grid” and is owned by public and private utilities. However, some buildings can reduce their dependence on the grid by generating some or all the electricity they need on-site, often through solar panels or wind turbines.

Currently, natural gas power plants generate the plurality of electricity consumed in California.23 Natural gas is extracted from the ground, processed, and pumped into large transmission pipes that carry it to different areas of the state. The gas is then pumped through smaller distribution pipes to individual buildings. Along the way, various facilities help ensure that the gas is flowing under safe conditions. Fuel derived from petroleum, such as gasoline, diesel, and natural gas, are produced at large industrial facilities and distributed to retail outlets throughout the state.

Major Vulnerabilities

California’s energy supplies and transmission/distribution networks are susceptible to climate change in several ways. Most notably, the state’s electricity grid is highly vulnerable. Almost all of the power lines in California are above ground and can be damaged or destroyed by high winds, downed trees and limbs, wildfire, floods, and landslides. Substations are often more resilient, but they too can be harmed by these hazards.

Damage to the electrical grid can cause widespread power outages, and downed power lines, contact with vegetation, and conductor slap can spark wildfires. Notably, some transmission lines and distribution networks feeding remote communities run through forested areas, heightening the risk of wildfire ignitions. Fallen power lines also create a public health hazard, posing a risk of electrocution. Natural gas systems are primarily underground and so are more insulated against natural hazards, but pipelines can still be damaged by landslides and other events. In some coastal areas, natural gas pipelines are at risk of being exposed to salt water as sea-level rises, which can increase corrosion. Above-ground natural gas facilities, as well as other energy facilities such as power plants and refineries, are also susceptible to being harmed by many climate-related hazards.

Defining Adaptation for Energy Utilities in California

The California Public Utilities Commission defines climate change adaptation for energy utilities as the “adjustment in utility systems using strategic and data-driven consideration of actual or expected climatic impacts and stimuli or their effects on utility planning, facilities maintenance and construction, and communications, to maintain safe, reliable, affordable and resilient operations”24

Even if the transmission and distribution infrastructure of the energy network is not harmed, there is still the potential for loss of service. High heat events cause power lines and other grid infrastructure to operate at reduced capacity, limiting the amount of energy that the system can transport. At the same time, electrical demand increases during high heat events as more people turn on cooling systems, and this is likely to become more frequent due to climate change. This combination of reduced capacity and increased demand places stress on the electrical grid, increasing the possibility that the system will fail and cause power outages. Natural gas is also susceptible to extreme heat events because very high temperatures can harm the electrical equipment used to maintain safe conditions in the pipelines.

Some climate-related events can reduce the ability of power plants and other facilities to generate energy even if they do not damage the facility itself. Hydroelectric power plants are perhaps the most obvious example. During long-term drought conditions, the amount of water available to run these facilities drops, decreasing the electricity generated. For example, in 2011, hydroelectric facilities supplied 15 percent of the state’s electricity, but during the peak of the 2012–2017 drought in 2015, these facilities met only about 6 percent of California’s needs. Increased levels of air pollution, such as smoke from wildfires, result in less light striking solar panels and lower levels of power output. Ash and other particles can also settle on solar panels, reducing capacity until they are cleaned off. Potential changes in wind patterns from climate change are not yet well understood; they may mean less wind resources available for power generation. As we increase our knowledge, it will be important to understand potential changes to magnitude and distribution of wind resources for power generation.

Fuels that are transported through the state’s existing freight system, such as roads and rails, are also vulnerable to disruption. This includes most gasoline and diesel fuels as well as some building fuels such as propane and kerosene. If roads or rails are damaged, destroyed, or blocked by climate-related hazards, deliveries of these fuels may not be able to get through, causing shortages. This is a particular risk for rural communities that may only have one central access road. Since these fuels are usually distributed at retail outlets such as gas stations, any climate-related hazard that damages these retail outlets can lead to fuel shortages.

Other forms of fuel transportation can also be vulnerable. Pipelines that transport liquid fuels (natural gas and petroleum) can be susceptible to landslides and scouring from flooding. Seaports are also a major shipping hub for some fuels, and coastal flooding and sea level rise can disrupt operations at these facilities, affecting energy supplies that pass through them.

This section of the guide focuses on the energy system itself, but the indirect effects from energy shortages or outages are also important when considering strategies to improve energy resilience. Energy supplies, including back-up generation, are needed for vital activities, including operating hospitals and other medical facilities, fueling emergency response activities, water and wastewater services distribution, and operating cooling equipment during extreme heat events. Loss of energy, particularly during another hazard event, can have serious effects on community health and well-being. Many types of economic activities are also difficult or impossible during energy outages, and long-term disruptions can cause economic harm.

Climate hazards Adaptation Strategy Factors to Consider Category Sector overlap Responsible Agencies Funding Examples & Sources
Energy Sector
Avalanches, coastal flooding, drought, flooding, forestry pests and diseases, landslides, sea level rise, severe weather, wildfire Strategy EN-1: Harden energy infrastructure systems against damage from climate-related effects and expand redundancy in the energy network. California’s energy infrastructure is a complex system of refineries, power plants, renewable generation facilities, utility lines, storage facilities, substations, and many other pieces of infrastructure, not to mention the roads, rails, and retail outlets used to distribute some energy resources. All these factors render the system vulnerable to several different types of climate-related effects. Damage to any component of these networks can cause a loss of energy supplies, and can also create additional hazard events, such as a downed power line that sparks a wildfire. Communities and other organizations that manage the energy network can construct or retrofit these infrastructure components so that they are less likely to be damaged by and so that they can quickly recover from a climate-related event. Additionally, communities and other organizations can ensure that there are redundant energy systems (e.g., backup generators, multiple transmission lines feeding a given area), which can help prevent a complete loss of service. Local governments may also consider moving toward a more decentralized electric supply system that relies on microgrids and distributed generation (e.g., local renewable energy generation), reducing the need for long-range transmission systems that may run through densely forested areas and cause wildfires, or may be impacted during utility public safety power shutoffs. See Strategy EN-5 for more examples of this. In most cases, local communities have very limited control over the energy networks. With the exception of communities that have their own publicly-owned utilities (not including community choice aggregator programs), private companies control much of the electricity and natural gas infrastructure. Private companies also control the refining and distribution systems that supply fuels such as gasoline, diesel, and propane. Because of this, coordination with external agencies is critical to hardening the energy network to enhance system resilience. Electricity and natural gas systems are heavily regulated by state agencies, who should also be involved in such efforts as feasible. Local governments should evaluate if local permitting procedures or development standards create barriers to hardened or redundant energy systems and identify ways to reduce these barriers in a way that maintains public health and safety and is compatible with the community character. In some instances, hardening energy systems may mean retreating from highly exposed areas and rebuilding in a less susceptible location. Capital Improvement & Infrastructure Projects Emergency Management Land Use and Community Development Public Health Water Utility providers Cities and Counties SDG&E and SCE weather network, Fire Potential Index (FPI) and Santa Ana Wildfire Threat Index (SAWTI) monitoring, and wildfire watch camera network concentrated in HFRAs, vegetation management programs CCCA4 Dale et al. report on wildfire impacts to the California electricity grid CCCA4 Bruzgul et al. report on Natural Gas assets in San Diego Coastal Commission Guidance 2018 Consolidated Edison Co. of New York Post Sandy Enhancement Plan, Preparedness at Greenwich Hospital, CCCA4 Bruzgul et al. Report on SDG&E electricity asset risk and adaptation to coastal flooding
All climate hazards Strategy EN-2: Transition to climate-smart sources of energy. Climate change is likely to influence the generation capacity of different energy sources. Hydroelectric facilities in particular are likely to be harmed by more frequent and severe drought events, reducing the amount of electricity available to California from these sources. Some industrial facilities and associated infrastructure that are key nodes in the state’s energy network, including refineries and seaports, may be harmed by climate change and are vulnerable to disruptions, particularly since alternatives may be limited. Centralized power generation facilities (both renewable and fossil fuel) rely on long-range transmission infrastructure which could be increasingly susceptible to impacts from climate effects. Additionally, policies to reduce greenhouse gas emissions may also affect sources of energy from fossil fuels. Communities can transition their sources of energy to those that are less likely to be affected by climate change, especially energy sources that are renewable and decentralized and do not rely on long-range transmission from centralized generation sources (see EN-5 for more information). If the community has control over its electricity sources (as a public electrical utility or a community choice aggregator), consider transitioning away from fossil fuels and hydroelectric sources in favor of local or regionally-based renewable sources. Explore opportunities to increase adoption of electric vehicles, which are less dependent on potentially vulnerable industrial facilities. Increasing public electric vehicle charging stations, as well as providing educational opportunities and incentives, can help with this. Communities also have the option to decarbonize by reducing natural gas use, or by encouraging or requiring a transition away from natural gas as part of any significant retrofit activities. When transition to a new source of energy, of any type, ensure that the new sources are also resilient in the long-term to climate change, avoiding the need for multiple adaptation efforts. New energy sources should be cost-competitive with the sources they are replacing. Communities should also ensure that the new sources of energy will not create new environmental justice issues or exacerbate existing ones. Capital Improvement & Infrastructure Projects Plans, Regulations, and Policy Development Water Ocean and Coasts Cities and Counties Councils/Associations of Government Utility Providers
Extreme Heat Strategy EN-3: Minimize stress on the electrical grid. During very high heat events, electrical equipment can operate less effectively and be more prone to failure. At the same time, power demand often rises during extreme heat due to the increased use of air conditioners and other cooling equipment. The combination of these factors places stress on the electrical grid and increases the risk of a power loss, even though there may be little or no physical damage. Communities can work to decrease their electricity use during extreme heat events, reducing the stress placed on the electrical grid. These actions may involve educational efforts and changes to behavior, upgrades to equipment and infrastructure, or some combination of the two. As a side benefit, these efforts also decrease electrical bills and reduce greenhouse gas emissions associated with energy use. Microgrids manage distributed energy resources through control technologies within or independent of a central grid. Islanding refers to the ability of microgrids to continue operating when the surrounding grid experiences an outage. Combined with storage, islanding via microgrids helps to reduce stress on the electrical grid and to maintain critical operations and services during outages due to climate-related hazards. There are several strategies at a community’s disposal to reduce energy use during extreme heat events. Demand response programs alert energy users at times when grid stress is likely to be high and provide financial incentives to users who sufficiently reduce their use. Weatherization programs help insulate buildings against very high or very low temperatures, decreasing the need for cooling (or space heating). Energy efficiency programs can replace inefficient air conditioners with more efficient models, allowing for the same level of cooling while using less energy. On-site renewable energy and storage systems allow buildings to power their air conditioning systems with electricity generated or stored on the property, rather than pulling from the grid. Numerous funding sources are available to help communities implement these programs, or communities can partner directly with local utilities. Communities should make sure that this effort (as with all other adaptation planning efforts) is conducted equitably, as different populations face different levels of vulnerable to extreme heat events and have varying levels of adaptive capacity to these events. Programmatic Plans, Regulations, and Policy Development Capital Improvement & Infrastructure Projects Emergency Management Land Use and Community Development Public Health Utility providers Cities and Counties
Drought, extreme heat, flooding, landslides, severe weather, wildfire Strategy EN-4: Maintain hydroelectric generating capacity as feasible. Hydroelectric power plants are an important source of electricity for California, in addition to other benefits that dams can provide (water storage, recreation, and flood control, among others). However, as drought conditions become more frequent and intense, and as warmer temperatures cause faster snowmelt and greater evaporation, the overall capacity of hydroelectric facilities is threatened. Communities have the opportunity to maintain generating capacity, or to work with agencies that manage these facilities to do so. Agencies that operate hydroelectric facilities should take improved hydrometeorological forecasting into account, and ensure that planning procedures for wet, normal, and dry years (including multiple dry years) reflect the new precipitation patterns that are expected in the watershed. Consider solutions such as covering reservoirs, particularly smaller ones, to reduce water loss from evaporation. If conditions change to the point where the hydroelectric facility is no longer able to function as a normal run-of-river installation, consider converting it to a pumped storage facility that can be used to store excess electricity on demand. Some hydroelectric operators may consider increasing dam capacity, especially to improve generating potential during very wet years, but be mindful of environmental barriers and other challenges that such projects are likely to face. Additionally, in the long term, recognize that some hydroelectric facilities may no longer be viable and could be deconstructed to allow river restoration. Capital Improvement & Infrastructure Projects Education, Outreach, Coordination Water Utility providers Cities and Counties International Hydropower Association Hydropower Sector Climate Resilience Guidance
All climate hazards Strategy EN-5: Decentralize energy supplies and energy storage capacity to improve energy independence. Some of the vulnerability in California’s energy network is because most energy supplies are produced at centralized large-scale facilities such as refineries and power plants and distributed across large distances. Disruptions at these centralized facilities or along the main paths for transporting energy resources can create shortages and service disruptions over large regions. Decentralizing energy generation and storage systems helps to reduce the potential for energy supplies to be disrupted by distant events. With present-day technologies, electricity is the energy source that is most suitable for decentralization, as natural gas and petroleum-derived fuels require industrial facilities, and so electrification of the built environment and transportation systems can help spur energy independence. Local governments can also seek to decentralize by creating municipal energy utilities and/or forming electric co-ops between rural jurisdictions for more local control over infrastructure and energy supply. In the future, emerging power-to-gas technologies and local sources of renewable natural gas may also enhance local energy resilience. Decentralizing the energy system, predominantly the electrical grid, allows community members to generate electricity and store it as needed at their properties or in their neighborhoods, reducing their dependence on the statewide electrical grid. Rooftop solar photovoltaic panels are often the most suitable form of decentralized energy generation, and battery storage systems are increasingly available for individual buildings. However, people living in rental units or those with limited financial means may need financial assistance or special programs to be able to install these technologies. Consider creating microgrids, which allows for a single building or group of buildings to share distributed energy generation and storage resources. Under state law, new small residential buildings are already required to install solar panels. Communities have the authority to require some or all additional types of buildings to install distributed energy, either when they are constructed or at times of significant renovations, but such actions require adopting a reach code that is subject to state review. Helping to transition building and transportation energy sources to electricity can make decentralizing the energy network easier. Capital Improvement & Infrastructure Projects Operational Emergency Management Land Use and Community Development Public Health Cities and Counties Enhancing Energy Efficiency in the Santee Unified School District CCCA4 Moezzi et al. report on energy efficiency research CCCA4 Burillo et al. report on LA County electricity grid risk to extreme heat CCCA4 Taha et al. report on urban heat islands

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