Medium scale storage linked to on-site energy generation is being assessed at the Centre for Renewable Energy at Dundalk Institute of Technology. The campus has an 850 kW wind turbine which generates approximately 30% of the Institute’s electrical requirement each year; however, at times of low onsite demand and high winds, electricity is exported to the grid. The most economical method of using such electricity would be to offset the purchase of electricity at the retail rate, so the Institute has installed flow battery energy storage technology for electrical storage, and has a large 40 ton ice bank system which effects thermal energy storage.
The flow battery was installed in 2008 and thanks to the SPIRE project a new 50 kWh module is being installed, having been donated by its manufacturer ZBB Energy in Wisconsin, USA. This new module is the latest version of zinc-bromine flow battery technology and although smaller than its 500 kWh sister unit, which has been on site for 6 years now, the 50 kWh module is suited to research of the impact of storage on domestic or small business loads. The ice bank is also a unique facility in Ireland and is used to supply chilling capacity to the ventilation system of the Carrolls building, a large 11,500 square metre building refurbished from previous industrial use and opened by the Institute in 2010. The SPIRE project will enable monitoring of the operation of the ice bank, as well as the wind turbine and many other energy loads on campus to provide a picture of the energy flows on campus and the potential supply of renewable energy to those loads.