Wind and solar energy can produce decarbonized electricity, but to reliably meet demand these intermittent resources require other technologies such as energy storage, supplemental generation, demand management, and transmission expansion. Many studies estimate the costs of supplying electricity with renewables for particular storage cost assumptions.
Here we study which characteristics most impact renewable electricity costs, including cost features of proposed storage technologies. Considering 20 years of resource fluctuations, we capture large, infrequent events affecting storage requirements. We estimate that cost-competitively meeting baseload demand 100% of the time requires storage energy capacity costs below $20/kWh. If other sources meet demand 5% of the time, electricity costs fall and the energy capacity cost target rises to $150/kWh. The results can inform policy and investments in technology research, development, and deployment.
- Model of renewables with storage in 4 locations over 20 years with hourly resolution
- Electricity costs respond more to costs of storage energy capacity than power capacity
- Energy storage capacity below $20/kWh could enable cost-competitive baseload power
- Meeting demand with other sources during 5% of hours can halve electricity costs”