The Way To 95% New Energy By 2035
Plummeting Solar, Wind, And Battery Costs Can Accelerate Our Clean Electricity Future
June 2020 (Goldman School of Public Policy, University of California Berkeley)
Global carbon emissions must be halved by 2030 to limit warming to 1.5°C and avoid catastrophic climate impacts. Most existing studies, however, examine 2050 as the year that deep decarbonization of electric power systems can be achieved—a timeline that would also hinder decarbonization of the buildings, industrial, and transportation sectors.
In light of recent trends, these studies present overly conservative estimates of decarbonization potential. Plummeting costs for wind and solar energy have dramatically changed the prospects for rapid, cost-effective expansion of renewable energy. At the same time, battery energy storage has become a viable option for costeffectively integrating high levels of wind and solar generation into electricity grids.
This report uses the latest renewable energy and battery cost data to demonstrate the technical and economic feasibility of achieving 90% clean (carbon-free) electricity in the United States by 2035. Two central cases are simulated using state-of-the-art capacityexpansion and production-cost models: The No New Policy case assumes continuation of current state and federal policies; and the 90% Clean case requires that a 90% clean electricity share is reached by 2035.
STRONG POLICIES ARE REQUIRED TO CREATE A 90% CLEAN GRID BY 2035
The 90% Clean case assumes strong policies drive 90% clean electricity by 2035. The No New Policy case achieves only 55% clean electricity in 2035 (Figure ES-1). A companion report from Energy Innovation identifies institutional, market, and regulatory changes needed to facilitate the rapid transformation to a 90% clean power sector in the United States.
THE 90% CLEAN GRID IS DEPENDABLE WITHOUT COAL PLANTS OR NEW NATURAL GAS PLANTS
Retaining existing hydropower and nuclear capacity (after accounting for planned retirements), and much of the existing natural gas capacity combined with new battery storage, is sufficient to meet U.S. electricity demand dependably (i.e., every hour of the year) with a 90% clean grid in 2035. Under the 90% Clean case, all existing coal plants are retired by 2035, and no new fossil fuel plants are built. During normal periods of generation and demand, wind, solar, and batteries provide 70% of annual generation, while hydropower and nuclear provide 20%. During periods of very high demand and/or very low renewable generation, existing natural gas, hydropower, and nuclear plants combined with battery storage cost-effectively compensate for mismatches between demand and wind/solar generation. Generation from natural gas plants constitutes about 10% of total annual electricity generation, which is about 70% lower than their generation in 2019.
ELECTRICITY COSTS FROM THE 90% CLEAN GRID ARE LOWER THAN TODAY’S COSTS
Wholesale electricity costs, which include the cost of generation plus incremental transmission investments, are about 10% lower in 2035 under the 90% Clean case than they are today, mainly owing to low renewable energy and battery costs (Figure ES2). Pervasiveness of low-cost renewable energy and battery storage across the United States requires investment mainly in transmission spurs connecting renewable generation to existing high-capacity transmission lines or load centers. Hence, additional transmission-related costs and siting conflicts are modest. Relying on natural gas for only 10% of generation avoids large investments for infrequently used capacity, helping to avoid major new stranded-asset costs. Retaining natural gas generation averts the need to build excess renewable energy and long-duration storage capacity—helping achieve 90% clean electricity while keeping costs down. While still lower than today’s costs, wholesale electricity costs are 12% higher under the 90% Clean case than under the No New Policy case in 2035. However, this comparison does not account for the value of emissions reductions or job creation under the 90% Clean case.
THE 90% CLEAN GRID AVOIDS $1.2 TRILLION IN HEALTH AND ENVIRONMENTAL DAMAGES, INCLUDING 85,000 PREMATURE DEATHS, THROUGH 2050
The 90% Clean case nearly eliminates emissions from the U.S. power sector by 2035, resulting in environmental and health benefits largely driven by reduced mortality related to electricity generation (Figure ES-3). Compared with the No New Policy case, the 90% Clean case reduces carbon dioxide (CO2) emissions by 88% by 2035. It also reduces exposure to fine particulate (PM2.5) matter by reducing nitrogen oxide (NOx) and sulfur dioxide (SO2) emissions by 96% and 99%, respectively.1 As a result, the 90% Clean case avoids over $1.2 trillion in health and environmental costs, including 85,000 avoided premature deaths, through 2050. These savings equate roughly to 2 cents/kWh of wholesale electricity costs, which makes the 90% Clean case the lowest-netcost option when environmental and health costs are considered.
SCALING-UP RENEWABLES TO ACHIEVE 90% CLEAN ENERGY BY 2035 IS FEASIBLE
To achieve the 90% Clean case by 2035, 1,100 GW of new wind and solar generation must be built, averaging about 70 GW per year (Figure ES-4). Recent U.S. precedents for natural gas and wind/solar expansion suggest that a renewable energy buildout of this magnitude is challenging but feasible. New renewable resources can be built cost-effectively in all regions of the country.
THE 90% CLEAN GRID CAN SIGNIFICANTLY INCREASE ENERGY-SECTOR EMPLOYMENT
The 90% Clean case supports a total of 29 million job-years cumulatively during 2020–2035. Employment related to the energy sector increases by approximately 8.5 million net jobyears, as increased employment from expanding renewable energy and battery storage more than replaces lost employment related to declining fossil fuel generation. The No New Policy case requires one-third fewer jobs, for a total of 20 million job-years over the study period. These jobs include direct, indirect, and induced jobs related to construction, manufacturing, operations and maintenance, and the supply chain. Overall, the 90% Clean case supports over 500,000 more jobs each year compared to the No New Policy case.
Accelerating The Clean Energy Future
Establishing a target year of 2035, rather than the typical 2050 target, helps align expectations for power-sector decarbonization with climate realities while informing the policy dialogue needed to achieve such an ambitious goal. Aiming for 90% clean electricity—rather than 100%—by 2035 is also important for envisioning rapid, cost-effective decarbonization. By 2035, emerging technologies such as firm, low-carbon power should be mature enough to begin to replace the remaining natural gas generation as the nation accelerates toward 100%, crosssector decarbonization. Reaching 90% zero-carbon electricity in the United States by 2035 would contribute a 27% reduction in economy-wide carbon emissions from 2010 levels.