Peninsula Clean Energy Lays Plans for 24/7 Renewables by 2025

The Community Choice Aggregator has published its aggressive strategy in a White Paper on website, peninsularcleanenergy.org,

Peninsula, located in coastal Northern California, plans to take a phased approach to meeting its 24/7 goal, and will begin by procuring 24/7 renewable energy from proven technologies based on forecasted hourly load and generation. It will rely on a centralized balancing authority to make up for load misalignment due to forecasting errors.

In the second phase Peninsula will evaluate costs and benefits of more closely matching load and generation on a real-time basis and will do so by developing more sophisticated portfolio management and dispatch tools. It will also look to adopting emerging technologies that may better match its load shape than currently available resources.

Peninsula Clean Energy started delivering 50% renewable energy to its first customers in 2016. It believes that it can demonstrate that 24/7 procurement can be achieved practically and cost-effectively and create a blueprint for the state and beyond to follow.

As of 2020 Peninsula delivered 47% of its hourly coincident load which was slightly lower than its annual renewable rate of 52%. Its contracted generators produced more renewable energy than customers consumed which it did not count toward meeting its goal. It also delivered 47% large hydro power to customers.

Based on the contracts Peninsula has signed to date, it is on track to be 64% renewable on a time-coincident basis in 2025. It is now actively working to plan and procure the remaining 36% by 2025.

The majority of Peninsula’s load is in coastal San Mateo County with mild summers. Its load seasonally peaks in the winter but starting this year (2022) it will start serving the city of Los Banos, located in the central valley which will add summer peaking load. Its daily load generally follows the pattern of system-wide load in California that peaks between 4:00 p.m. and 9:00 p.m. Thus, Peninsula must deal with the daily power slump when the sun sets.

After reviewing the characteristics of wind, solar, geothermal power, small hydropower and energy storage, Peninsula authors, primarily staff members, concluded that to meet its 24/7 renewable energy target the CCA must create a combination of supply-side and demand-side strategies that will match load requirements around the clock.

On the supply side this means procuring a diverse portfolio of resources that produces energy at different times of the day, in different geographic locations and in different seasons and which mostly matches the customer load. Energy storage can be used to shift excess generation to the times when it is needed. Operators will need to match net load but also to wholesale electricity price signals. The authors admit this will be a challenge and in some hours of seasons they will have more supply than is needed, and in others they will have less than needed.

Demand side strategies include matching load to the available supply of renewable energy by load shaping and load shifting to better manage the loads to the times when renewables are more available. Examples cited include setting high commercial rates during peak hours of the day and encouraging customers with smart thermostats to shift their heating and cooling to match the availability of renewable resources each day.

The white paper also reviews the challenges Peninsula faces. There will likely be mismatches in supply and demand usually seasonal in nature. This is where a diverse menu of renewable resources come into play. And storage technologies are still immature enough or not widely available to fill the supply gaps.

Forecasting limitations will likely create mismatches between load and supply due to errors in forecasts. Peninsula does prepare forecasts on an hourly basis for customer consumption and generation availability, but often the forecasts differ from actual demand. It also produces long-term forecasts but the authors point out that climate change is making long-term forecasting more difficult.

Another challenge Peninsula faces is uncertainty surrounding demand-side resources and how big a role they might play in the strategy laid out in the White Paper. Information on how to plan for and understand how they would perform and the costs to deploy them will determine the success of their use and modeling demand-side resources in Peninsula’s 24/7 strategy.

Peninsula intends to follow up on this paper in the next few months with a report containing the results of its modeling, including details about the costs and resource mix required to achieve its goal.