Stanford University researchers have created a model to estimate how much compressed air storage capacity might be needed to deeply decarbonize power systems, while compensating for the variability of wind and solar power systems. They applied the model to California’s energy system and found that compressed air could be very competitive on a dollar-per-kilowatt-hour basis.
“CAES can be suitable for any energy system such as renewable energy, gas/coal turbine, fuel cell and other systems in the future,” researcher Sarah Ashfaq said. pv magazine. “In general, it is considered the best for medium and large energy systems. The availability of suitable geographic features for the formation and location of underground storage caverns is still considered a limitation to the adoption of CAES as a bulk energy storage technology.
Academics said their new model estimate how much CAES capacity might be needed for decommissioning power systems from deep coalwhile it compensates to the variability of wind and solar power systems. They presented their findings “A Least Cost Analysis of Bulk Energy Storage for a Deep-Carbon-Free Power System with Increased Renewables,” published recently Research on electric power systems.
They used California as a case study of varying levels of renewable energy penetration. They used demand stakes US Energy Information Administration (EIA) Information Portal and Data on Wind and Solar Energy Production from NASA’s Modern-Era Retrospective Analysis for Research and Applications, Version 2 (THE SEA–2).
“The collected information was updatedwith the desired capacity factors and number of years,” they said. “Each technology is represented by fixed costs and variable costs.”
The research team did not consider the limitations of energy sources based on societal issues such as technological acceptance
or local preferences. They calculated the levelized cost of electricity (LCOE). each hourly time step based on production capacity availability, wind and solar resources, storage resources and demand.
The research examines four scenarios. It has a base case where California’s share of renewable energy is reached in 2021, as well as a scenario where wind has 50% more potential. It also looks at a case where solar has 50% more potential and a scenario where both technologies have 100% more potential.
“Iin the case of an increase in n poFor both wind and solar, the contraction of the main nodes is close to the increase in the solar spread curve due to the availability and transmission of abundant solar electricity,” the researchers said.
Scientists found it electricity mixing in the most favorable system would be more or less independent of the amount of excess generation of electricity. But they also noted that this mixt would greatly affect the required CAES capacity.
“For example, for 100% excess wind, the optimal renewable mix is 68.9% wind and 31.1% solar with a CAES capacity of 3.40 TWh, and with 100% excess solar, the optimal mix is 35.6% wind and 64.4%. solar energy with a CAES capacity of 2.77 TWh,” they stated. “If there is a 100% excess of wind and solar, the optimal combination is 52.5% solar and 47.5% wind with 3.10 TWh of CAES capacity.”
They also found that California’s estimated Annual demand of 277 TWh would require CAES capacity 3.83 TWh at the cost of $0.175/kWh. The fourth scenario mentioned above, where the penetration of wind and sun is the greatest resulting in a cost reduction of 14.1% at $0.123/kWh) and 7.4% CAES capacity reduction.
“CAES is very competitive and based on $/kWh,” Ashfaq noted. “Pumped water storage) and CAES are the most cost-effective energy storage technologies because they offer the lowest costs ($/kWh) for long-term storage. However, for short-term storage, Lithium Ion works best.