SAND STORAGE FOR RENEWABLES.

Its main purpose is to work as a high-power and high-capacity reservoir for excess wind and solar energy. The energy is stored as heat, which can be used to heat homes, or to provide hot steam and high temperature process heat to industries that are often fossil-fuel dependent. As the world shifts towards higher and higher renewables fraction in electricity production, the intermittent nature of these energy sources cause challenges to energy networks. The sand battery helps to ambitiously upscale renewables production by ensuring there’s always a way to benefit from clean energy, even if the surplus is massive. The first commercial sand battery in the world is in a town called Kankaanpää, Western Finland. It is connected to a district heating network and heating residential and commercial buildings such as family homes and the municipal swimming pool. The district heating network is operated by an energy utility called Vatajankoski. The storage can take place next to where the energy will be used in say a insulated metal or concrete container or better still underground with the new build above. This idea has to be incorporated in the design. The quality of the sand (or similar material) is not critical avoiding construction sand which is in demand and becoming scare (see elsewhere on the site about the mining of sand becoming a major eco problem). The battery can be charged when there is excess energy from say wind or solar and then utilised when it is either dark or windstill. This form of storage is limitless as there is no materials which can decay over time as with lithium batteries.