Electricity, gas, heat integration via residential hybrid heating technologies – An investment model assessment

Integrating gas, electricity and residential heating sectors through hybrid heating technologies equipped with smart controls could provide energy system planning and operational benefits. Hybrid heaters combine different heating appliances in one device and can switch between those appliances during operation. Different configurations are possible: B-R (gas boiler-resistance), HP-B (heat pump-gas boiler), and HP-R (heat pump-resistance) heaters. A linear programming investment model is formulated and applied to an Irish test system with 40% wind energy generation to determine the optimal capacities and dispatch for the power and residential heat systems, including thermal storage. No technology is a silver bullet, but this paper finds that the widespread deployment of hybrid HP-B systems delivers a wide range of cost and strategic benefits: This hybrid technology minimises total system cost, reduces gas consumption and CO2 emissions compared to B-only, and, compared to HP-only, reduces power generation capacity requirements and heater capital cost. Other hybrid heaters are effective in addressing a specific challenge, although with drawbacks: Hybrid B-Rs considerably reduce wind curtailment, but increase the use of carbon-intensive coal generation; HP-Rs mainly only benefit consumers by reducing heater capital cost compared to HPs and require more generation capacity additions and thermal storage tanks.