Rapid Response Electrolysis for Power-to-Gas Energy Storage
Sub-second demand response achieved for both turn on and turn off
ITM Power (AIM: ITM), the energy storage and clean fuel company, is pleased to announce that it has achieved sub-second response times for both its refuelling station equipment and also its Power-to-Gas equipment. The successful completion of the InnovateUK supported Power Electronics project has demonstrated a full system “turn on” response of 40 cycles (800ms) and “turn off” in 7 cycles (140ms). This qualifies ITM Power’s electrolyser systems for frequency response services more demanding than the existing primary grid balancing payment structure and has the potential to command higher availability payments. The Group currently has £11.36m of projects under contract and £7.71m of contracts in the final stages of negotiation.
As the percentage of renewable power increases and the percentage of thermal power decreases more energy storage and grid balancing is required. The loss of system inertia from the closure of large scale thermal plant requires even faster demand response loads. Today FCDM (Frequency Control by Demand Management) requires a response time of less than 2 seconds. Enhanced frequency response is sub-second and is expected to command higher availability payments, resulting in lower cost hydrogen.
The ITM Power led collaborative project with AEG has developed a power electronics module and control parameters that has significantly improved the response time of ITM Power’s electrolyser systems. Funding from Innovate UK has allowed ITM Power and partners to develop an expandable test rig capable of testing stack load and all key balance of plant components.
The new results demonstrated full system response times both in the laboratory and in the field using measurement techniques developed in the project. For example a commissioned HyFive electrolyser unit achieved a full system “turn on” response of 40 cycles (800ms) and “turn off” in 7 cycles (140ms) without any modification to the hardware. This was made possible by the stack response times of 10 cycles (200ms) for “turn on” as has previously been reported.
The ability to respond dynamically to provide both ‘high’ and ‘low’ response enables frequency control on the grid and so allows the integration of a greater level of renewables onto the electricity network. In times of excess energy (rising frequency) the electrolysers would increase their load; in times of high demand (falling frequency) the electrolysers would decrease their load. The capability to respond to changes in load in under a second provides ITM Power the opportunity to generate additional revenue by providing grid balancing services to grid operators worldwide.
Graham Cooley, CEO, ITM Power PLC, commented: “Demand response is becoming increasingly important across Europe and the USA as the percentage of renewable power increases and the percentage of thermal power decreases. Commercial tenders from power companies are demanding fast response times including sub-second enhanced frequency response. Revenues from grid balancing payments serve to reduce the cost of hydrogen production via electrolysis. Faster response times will receive larger payments and set ITM Power apart from other electrolyser technologies.”