Researchers develop model to project energy storage needs for renewable energy

Researchers have developed a model that can be used to predict what a country’s energy storage needs would be if it were to shift entirely to renewable energy sources, moving away from fossil fuels to electricity production. The model provides policy makers with essential information to use when making short-term decisions and planning the energy system for the long term.

The article titled “Modeling energy storage in long-term capacity expansion energy planning: an analysis of the Italian system” is published in the Journal of Energy Storage.

“We focused this study on the Italian energy system because it has suffered significantly in recent years, due to difficulties in obtaining affordable natural gas due to Russia’s invasion of Ukraine,” says Anderson de Queiroz, co-author of a paper on the work and associate. professor of civil, construction and environmental engineering at North Carolina State University.

“This raised questions about how Italy can make its energy system more robust. Our goal here was to develop a model that would allow us to determine what Italy’s energy storage needs would be if it completely moved away from fossil fuels and met its electricity demands with renewable resources.

Energy storage is a critical piece of this puzzle because renewable energy sources, such as solar or wind, don’t always produce energy at the same rate. For example, you need to be able to store energy generated by solar power so that you can use it at night, when the sun is not shining.

To better understand the energy storage needs of an energy system, the researchers modified an existing optimization model called Temoa.

Specifically, the researchers modified the model to account for changes in renewable energy production at different times of the day and at different times of the year. For example, solar energy production would be greater in summer when days are longer, but solar energy would still decrease during the night.

The researchers also took into account changes in energy consumption at different times of day and during different seasons. For example, energy consumption may increase during hot summer afternoons if people use air conditioners.

Capturing these daily and seasonal fluctuations in renewable energy production and energy consumption allowed researchers to create a more detailed model of the energy system, allowing them to better answer questions about the needs of energy storage of the system. How much renewable energy could be redirected to storage? How much energy would be needed to meet demand?

“Our modified model clearly shows that increasing energy storage capacity is essential to decarbonize the Italian electricity sector, but it also offers detailed insights,” says de Queiroz. “For example, the model suggests that Italy should be able to store around 10% of its electricity production in short-term energy storage devices.”

The term “short-term energy storage” is somewhat confusing. This does not refer to how long a storage device can store energy. Rather, it is how long the device can maintain its maximum power. For example, a 2-kilowatt device lasting one hour could release two kilowatts of energy for one hour, while a 2-kilowatt device lasting three hours could release two kilowatts of energy for three hours. Energy storage systems capable of releasing maximum power for four hours or less are generally considered short-term energy storage devices.

“Our projection for near-term energy storage devices is driven by both the energy storage needs of the energy system and the fact that these devices are the most cost-effective way to meet those needs, over the basis of recent projections and cost estimates,” de Queiroz said. said.

But even though this article focuses on Italy, the modified model developed by the researchers for this work can be used to project the energy storage needs of any energy system.

“As the world moves toward renewable energy sources, we need to find ways to account for their variability,” says de Queiroz.

“Energy storage devices give us the flexibility to adapt to fluctuations in energy production while still providing us with the reliability we need to meet energy demand. And models like the one we demonstrated here provide essential information to policymakers regarding their long-term energy storage needs.”