Energy storage provides capacity and resilience to the electricity grid at critical moments, helping reduce frequency of power outages as well as defer new transmission and distribution lines from being necessary.
Energy storage also reduces price spikes that occur during high demand and may help customers to avoid these additional costs. There are various technologies available for energy storage.
Hydrogen
Hydrogen is one of the world’s premier chemical energy storage options, providing clean energy production without emissions or combustion byproducts. Furthermore, hydrogen boasts nearly three times greater energy density per mass than gasoline does.
PNNL researchers are exploring new materials that can store hydrogen at low temperatures, and ways of efficiently discharging it when necessary.
Hydrogen is typically stored as a gas underground in salt caverns or depleted oil fields as an effective long-duration energy storage technology. Geologic storage also enables energy arbitrage; off-peak renewable power stored off can be utilized during peak demand periods when production drops during winter.
Solar
Solar energy storage offers one way of meeting some of solar’s challenges, such as its inability to supply electricity during cloudy days. At NREL’s research in this area, both battery technologies and thermal (in the form of water tanks) energy storage technologies are explored as possible solutions.
Integrating solar with energy storage can reduce costs for owners by taking advantage of time-of-use rates from utilities, as well as helping mitigate curtailment risks and provide backup power during blackouts.
Batteries can also help offset high demand charges associated with solar projects, making solar storage an invaluable solution for customers seeking to decrease their reliance on the grid and take advantage of public incentives like net metering or SGIP.
Wind
Wind energy often produces more electricity than is needed, necessitating its storage for use during times of low winds or power demand. Storage technologies include electric, thermal and power-to-x (convert electricity into hydrogen or synthetic fuels).
Energy storage systems can help offset the intermittent nature of wind generation, assuring consumers with reliable and consistent energy supply. Storage also can assist with frequency and voltage regulation and decrease transmission upgrade requirements.
Sri Lanka needs extensive investments in energy storage systems if it wants to achieve its full 92GW potential from wind power, but selecting and installing viable storage options requires intensive investment and careful consideration of supporting parameters for system selection. Liquid metal batteries are particularly advantageous as grid embedded storage options for voltage and frequency stability as modular units.
Biofuels
Biofuels use organic material derived from plants or animals waste or byproducts as energy source, making them renewable over time.
Utilizing biofuels can decrease dependence on fossil fuel imports while creating employment in rural communities. Furthermore, biofuel production helps lower greenhouse gas (GHG) emissions and vehicle fuel costs significantly.
Scientists are developing sustainable sources of feedstock for biofuels and bioproducts. They’re exploring fast-growing nonfood plants as well as genetically modifying microorganisms to break down complex materials more rapidly. Furthermore, scientists aim to capture carbon dioxide given off during combustion of biofuels and store it either in geologic formations or the ocean using carbon sequestration technology – this process being known as carbon sequestration. Finally, fourth-generation biofuels consist of synthetic diesel made of vegetable oils or animal fats otherwise discarded for fuel creation or carbon sequestration purposes.
Combined Heat and Power
As we move towards a 100% renewable energy economy, heat and electricity sectors will need to become more integrated; energy storage will play an essential part in this transition process.
Cogeneration systems (or combined heat and power (CHP) systems), also referred to as CHP, combine electricity generation with useful heating. Any waste heat produced during generation is captured and recycled into useful heat for later use – leading to efficiency levels as high as 75%.
Due to the nature of CHP system operations, there can be overgeneration of electricity or heat that requires storage solutions with thermal energy storage capabilities to significantly reduce this wasted energy and provide customers with attractive returns on their investments. Energy storage can also help optimize existing fossil-fueled generators. Battery systems offer another approach; unlike large-scale pumped hydro storage which often operates separately from CHP units.