Our base case for Compressed Air Energy Storage costs require a 26c/kWh storage spread to generate a 10% IRR at a $1,350/kW CAES facility, with 63% round-trip efficiency, charging and discharging 365 days per year. Our numbers are based on top-down project data and bottom up calculations, both for CAES capex (in $/kW) and CAES efficiency (in.
Today, an estimated 4.67 TWh of electricity storage exists. This number remains highly uncertain, however, given the lack of comprehensive statistics for renewable energy storage capacity in energy rather than power terms.
Will compressed air energy storage cost decline by 2030?
Compressed air energy storage (CAES), although based on a combination of mature technologies, could see a 17% cost decline by 2030. Flywheels store energy as rotational kinetic energy by accelerating and braking a rotating mass. They have a high power potential.
Electricity storage is currently an economic solution of-grid in solar home systems and mini-grids where it can also increase the fraction of renewable energy in the system to as high as 100% (IRENA, 2016c). The same applies in the case of islands or other isolated grids that are reliant on diesel-fired electricity (IRENA, 2016a; IRENA, 2016d).
More directly, electricity storage makes possible a transport sector dominated by electric vehicles (EVs), enables efective, 24-hour of-grid solar home systems and supports 100% renewable mini-grids. As variable renewables grow to substantial levels, electricity systems will require greater flexibility.
How will variable renewables affect electricity storage?
As variable renewables grow to substantial levels, electricity systems will require greater flexibility. At very high shares of VRE, electricity will need to be stored over days, weeks or months. By providing these essential services, electricity storage can drive serious electricity decarbonisation and help transform the whole energy sector.
Is battery electricity storage a viable alternative to diesel fuel?
In transport, the viability of battery electricity storage in electric vehicles is improving rapidly. Batteries in solar home systems and of-grid mini-grids, meanwhile, are decarbonising systems that were heavily reliant on diesel fuel, while also providing clear socio-economic benefits.