Energy storage is an indispensable technology for expanding renewable energy sources, offering grid operators increased flexibility and providing numerous advantages to both businesses and communities alike.
Electricity storage systems include pumped hydroelectric storage (like that found at Llyn Stwlan dam), batteries, flywheels and compressed air energy storage as well as other forms such as molten salt or thermal ice.
Battery Storage
Energy storage can help manage demand peaks by providing electricity when and where it’s most needed, thus avoiding expensive peak pricing charges. For instance, during hot summer afternoons when many homes use air conditioning, electricity prices often spike; energy storage could shift renewables during these peak times to help lower bills and help save on energy usage costs.
Batteries can help to even out the fluctuations in wind and solar generation by charging during periods of excess and discharging when demand spikes, helping align their variable output with electricity demand while decreasing fossil fuel plant usage.
Residential energy storage (BESS) systems enable homeowners with solar panels to store electricity produced during daylight hours for use at night or on cloudy days, further increasing renewable energy generation while decreasing grid dependence and demand charges from local utilities – as well as helping achieve Net Zero goals more quickly. This reduces energy independence as well as demand charges from utilities while contributing towards reaching Net Zero goals more easily.
Hydrogen Storage
Hydrogen holds great promise as an energy storage medium, potentially making renewable power cheaper to incorporate into the grid. One of the greatest challenges faced when dealing with solar and wind electricity production exceeds consumption is finding ways to store excess electricity production for later consumption.
PNNL researchers are exploring methods of optimizing hydrogen storage, which involves splitting water into hydrogen and oxygen via electrolysis powered by renewable electricity, with the purified hydrogen then stored as fuel in tanks or pipelines until needed to power fuel cells.
Presently, hydrogen can only be stored as gas using compression at high pressures or by cryogenic freezing at cold temperatures – both processes consuming considerable energy. Research is currently ongoing into materials-based storage solutions such as metal hydride or carbon nanotube adsorption which offer much lower volumetric storage densities yet still provide value addition to current compression/liquefaction technologies. Other storage options exist underground such as salt caverns or retired oil and gas fields where there has long been an established precedent for gas storage on an industrial scale.
Supercapacitor Storage
Supercapacitors are energy storage devices that serve as an intermediary between capacitors and rechargeable batteries, providing more power density than capacitors while taking less time to charge and discharge.
Supercapacitors use electrode plates separated by an insulator to store electrostatic charges, enabling them to provide backup power within seconds. Unlike batteries which gradually lose voltage over time, supercapacitors have an extended lifespan and can be recharged many times without losing their charge capacity.
Residential energy storage units enable consumers to avoid utility demand charges during peak electricity consumption periods and match renewable wind and solar generation with customer demand. Community-level ESS systems are being deployed as back-up electricity sources in rural communities or as microgrids or resiliency hubs; larger resilient systems for cities or large communities may combine solar panels with on-site energy storage to form larger resilience solutions.
Electromagnetic Storage
Magnetic storage uses mechanical and binary technologies to write information onto spinning disks coated with magnetic material. This non-volatile type of data storage maintains its information even after power has been turned off and can be found both desktop computers and servers.
Magnetic data storage systems such as hard disc drives (HDDs) use read/write heads to alter the magnetisation of particles on platters of hard drives or tape, representing data in binary form that computers understand as digital information.
Energy storage is essential to realising the full potential of renewables at utility scale. Storing electricity during periods of high production and low demand helps optimize grid operation more effectively, decrease blackouts and cut costs for customers while simultaneously decreasing fossil fuel peaker plant use that are typically located in marginalised communities and produce significant air pollution.