The prototype of the innovative gravity electricity storage system for the British company Gravitricity, in which the Czech plant of Huisman participated, takes shape. These days, engineers from Huisman Manufacturing are preparing to commission the system and its subsequent testing at Prince Albert Dock in Leith, Scotland.
Despite the very difficult travel conditions due to the global coronavirus pandemic, a team of Czech engineers of Huisman travelled to Scotland to complete the installation of the equipment at the client and perform its subsequent testing. In the next few days, they will perform stress tests and fine-tuning the system directly at the installation site.
The aim of the project, developed jointly by the British company Gravitricity and the Dutch company Huisman, is to use underground shafts and massive weights to store large amounts of energy. The system is designed to stabilize the grid by lifting and lowering weights in a vertical shaft. Excess energy in the distribution network is used to lift cylindrical weights using electrically driven winches. When there is a lack of energy, the weight in the shaft slowly lowers and thus generates the necessary electricity.
250kW demonstrator comprises a 15-metre high lattice tower, two 25-tonnes weights suspended by steel cables, plus two fully grid-connected generator units. Huisman supplied for this prototype a control system, a drive unit and two winches for the system demonstrator, which will carry weights.
“Our full scale projects will operate underground – but for this scale demonstrator we’ve build an above-ground structure. The tower and the upper frame were installed in perfect weather conditions last weeks This week our focus is installing the electrical connection to the winch container, with the goal of being fully commissioned by April,” explains Frances Tierney, Engineering Project Manager.
"We calculate we can go from zero to full power in less than a second – which can be extremely valuable in the frequency response and back-up power markets. This two-month test programme will confirm our modelling and give us valuable data for our first full-scale 4-8 MW project which will commence later this year," Frances concludes.
The demonstrator’s lattice tower has been fabricated by ESL engineers in Hull. Other key components including the base frame and weight baskets have been made by AJS Fabrication in Fife. The system’s custom-built winches and control modules have been made by Huisman, who are Gravitricity’s long-term partners.