If drought and extreme heat continue into next year, the shortfall on the California grid from high summer heat could escalate to 5.2 GW, up from this summer’s projected shortfall of 3.5 GW. That is according to preliminary results of the California Energy Commission’s expanded planning model released Aug. 11.
Over the following three years, another 1 GW may be needed, resulting in a total 6 MW shortfall because of intense heat, unavailable hydropower, drop in energy imports, and worsening wildfires, the CEC projected. Last month, the Bootleg Fire in Oregon caused a temporary loss of 3.7 GW of imports into California’s grid.
The forecast for shortfalls after this summer has grown because the CEC is using a higher planning reserve margin of 22.5%, up from 17.5%. The larger reserve is applied during projected western-wide heat waves, like last August’s that led to rolling outages, impacting hundreds of thousands of Californians.
For the first time, the new analysis includes hourly forecasts and extends out 15 years, five years beyond the usual decade modelling. It allows the agency to look more closely at the most difficult hours in the critical summer season, both at peak times and more importantly in the evening as demand stays high while solar resources disappear. The projected GW shortage is based on high demand, particularly in late summer between 7-8 PM. Earlier this year, the California Public Utilities Commission raised the 15% planning reserve margin to 17.5% after constraints and blackouts last summer. There were five Flex Alerts due to intense heat last year. That compares with 20 flex alerts over the previous nine years.
“This analysis is used to identify contingencies, such as new resource procurement use, backup generators and load reductions, to name a few,” Aleecia Gutierrez, with the CEC demand analysis division, told the commission. That includes a projected 1.5 GW loss of hydropower.
The expanded model is able to take in many more variables including weather, new resources and plant retirements, Gutierrez said. When finalized it will be used in the CPUC’s integrated resource planning and resource adequacy proceedings. It will also be incorporated into the California Independent System Operator’s transmission planning.
The model’s final analysis comes up for a full commission vote Sept. 9.