BALANCED ENERGY NETWORK 1st GENERATION STEAM Pressurised steam pipes inconcrete ducts | LONDON SOUTH BANK UNIVERSITY 2nd GENERATION ONSITE CONSTRUCTION Pressurised hot water Heavy equipment Large onsite plant 3rd GENERATION OFFSITE Pre-insulated pipes Offsite plant construction Metering and monitoring 4th GENERATION MULTI-VECTOR Improved controls 5th GENERATION AMBIENT TEMPERATURE Controls integration Heating and cooling Modular expansion Demand-side management < 100C 50-60C cy cien Effi 5-20C Heat sources Steam storage Coal waste 1880 Heat sources Heat storage CHP coal CHP oil Coal waste 1930 Heat sources CHP coal CHP oil Industrial waste heat CHP waste/coal/oil Gas 1980 Heat sources CHP waste/coal/oil Gas/waste/coal/oil Biomass/CHP biomass Industrial waste heat Thermal storage Gas/waste/coal/oil Geothermal Large-scale solar thermal 2010 Heat sources Water via heat pumps Waste heat Thermal storage Electrical sources Grid Wind PV CHP 2017 Figure 2: Heat network trends to lower distribution temperatures and higher efficiency water at temperatures of up to 80C. This allows them to be retrofitted into existing buildings in place of, or alongside, gas boilers without the need to modify the existing heat-distribution systems. In addition, using the aquifer water at a constant 14C gives the heat pumps a higher starting temperature than if air source heat pumps had been used on coldwinter mornings, so they have a higher coefficient of performance (COP). Icax has developed the control systems forthe heat pumps and connected the BEN system to WHAT IS A FUEL CELL CALCINER? The calciner works by feeding natural gas into a standard fuel cell to generate electricity. This process generates heat, which is used to break down limestone into lime (CaO) and pure CO2, to be used or stored underground. The lime produced can also be used in industrial processes, during which it absorbs CO2 and is converted back into calcium carbonate the original limestone. Overall, the process is carbon negative, absorbing 800g of carbon for every kilowatt hour of electricity generated, as opposed to releasing 400g of CO2 for every kilowatt hour with conventional combustion technologies. Origen Powers Tim Kruger suggests using the lime to counter ocean acidification. You absorb about twice as much carbon dioxide when you add it to seawater as when you use it industrially, he says. Using a BEN to support the Grid opens the door to additional revenue streams thebiggest of which is from avoiding the Use of System charges through DSM the first demand-side management (DSM) network in the world. There were concerns that replacing gas boilers with electric heat pumps, would raise peak electric loads. By working with energy aggregator Upside Energy, however, the BEN systems are all controlled by a set of algorithms. These tell the different systems when to turn on and off, when the system should store electricity as heat, or when to deliver cooling by moving heat to storage at optimal times. This creates a virtual energy store, which can be combined with other systems and used to help the Grid balance supply and demand. The Grid doesnt care about something the size of our heat pumps, which each consume about 100kW of electricity and produce 300kW of heat. Tomake a difference to the Grid, you are talking about loads of the magnitude of 5MW, which is the reason were using an energy aggregator; our campus is just one piece of their portfolio, explains Gillich. Using the BEN to support the Grid in this way opens the door to additional revenue streams the biggest of which is from avoiding the electrical Grids Use of System charges through demand-side management. The Distribution Network Operators say: If you shift the timing of your electrical demand to avoid the 4pm to 7pm peak, then well pay you X-amount ofmoney, says Gillich. That is what our control system is designed around taking every single electrical component, including the heat pumps and storage tank, and making those addressable as demand-response assets. Other potential revenue streams include short-term operating reserve (STOR) and frequency response. Revenue from STOR is based on a user agreeing to reduce their demand in a matter of minutes; revenue from frequency response is based on a user being able to flex demand in a matter of seconds. As well as turning individual electrical loads on and off in response to Grid 24 May 2019 www.cibsejournal.com CIBSE May19 pp22-25 Ben Supp.indd 24 26/04/2019 15:27