Mitsubishi Heavy Industries Technical Review
    Vol. 57 No. 1 (2020)   New Products & Technologies
    Technical Papers

    Thermal Storage System to Provide Highly-efficient Electric Power Resilience in the Era of Renewable Energy

    Kenjiro Yamamoto,
    Kazuhiro Domoto,
    Makoto Tobo,
    Tsutomu Kawamizu,
    Takahiro Yamana,
    Yuji Ota

    To enhance electric power resilience (robustness to endure a significant and sudden unbalance between supply and demand while regulating reserve capabilities) in line with the increasing use of renewable energy, thermal storage systems are incorporated into the turbine bypass system, etc., of thermal power plant systems so that waste heat during startup or the mismatched heat between boiler and turbine/generator outputs under extremely low load conditions can be stored. This stored heat can generate electricity by releasing its energy to the pre-boiler and/or boiler during high-load operation, which results in energy savings of around 2% or more. By utilizing the significant amount of latent heat of phase change materials (PCMs : applying melting/solidification processes) or by increasing the temperature difference of sensible heat storage materials such as molten salts and water, thermal energy storage equipment can be made compact, thereby making it possible to be installed on the premises of a power plant. We are currently working on the development of such a system to realize its practical application at a price per electric capacity comparable to battery storage systems.