Berkeley Lab Report Examines Growth Of Hybrid Power Plants

by Peter Maloney
APPA News
May 3, 2022

Generation projects that combine solar or wind generation with energy storage are poised to grow exponentially, but the success of those projects will require careful attention to factors such as project configuration and operational strategy, according to a new report from Lawrence Berkeley National Laboratory (LBNL).

At the end of 2021, there were more than 8,000 megawatts (MW) of wind or solar generation connected to storage in the United States, but a much larger number of hybrid projects — 280,000 MW of solar and 208,000 MW of storage – have applied for grid connections, the report, Batteries Included: Top 10 Findings from Berkeley Lab Research on the Growth of Hybrid Power Plants in the United States, said. The report noted that most of the proposals pair energy storage with solar photovoltaic projects.

Even if only a quarter of those projects are able to progress to commercial operation, “they will have big impacts on grid operations,” the authors of the report said in a statement. “While hybridization helps to ease the challenge of balancing variable supply and demand, its relative novelty means that research is needed to facilitate integration and promote innovation.”

In the new report, LBNL summarizes articles it published over the past two years in support of private- and public-sector decision-making about hybrid plants and presents its top ten findings.

Among the findings, LBNL noted that the growth in hybrid projects is being driven by a combination of factors, most notably falling prices and the incentives and synergies of co-locating energy storage with variable generation projects.

The report noted that power purchase agreement prices have fallen from $40-$95 per megawatt hour-photovoltaic (MWh-PV) in 2017 to $30-$75 per MWh-PV in 2021, and while the cost of adding storage to a solar project is around $10/MWh-PV for a battery sized to 50 percent of a project’s solar power capacity, the combination yields gains between $8/MWh-PV and $21/MWh-PV, depending on region and dispatch assumptions.

The authors also noted that hybrid projects can benefit from tax credits, construction cost savings, and more flexible generator dispatch, but suffer from siting constraints that make them “sensitive to local market conditions and configuration choices.”

For instance, LBNL found that, in some instances, the capacity contribution of hybrid plant is “less than the sum of its parts,” as the shared infrastructure of a hybrid project can reduce its capacity value.

Likewise, while hybrid plants can gain value from participation in ancillary service markets, at least in some markets, that value can be “fleeting” because those markets are thin and could become saturated by energy storage projects already in the interconnection queue. Expecting additional ancillary service revenues to offset declining energy and capacity value “may be a risky strategy for wind and solar hybrid project owners,” the report said.

Overall, “while hybridization of power plants provides opportunities to ease the challenge of balancing intermittent renewable resources, its relative novelty means that research is needed to facilitate integration and promote innovation,” the report’s authors said.

LBNL has scheduled a free webinar on May 5 for a closer look at its findings.