Load shifting with smart home heating controls: satisfying thermal comfort preferences

Panel: 8. Buildings: technologies and systems beyond energy efficiency

This is a peer-reviewed paper.

Authors:
Clare Hanmer, University College London, United Kingdom
Michelle Shipworth, UCL, United Kingdom
David Shipworth, UCL, United Kingdom
Charlotte Johnson, UCL, United Kingdom

Abstract

This paper investigates how UK households react to changes in daily heating patterns from a hybrid heat pump and the altered diurnal temperature profiles, which result from these new heating patterns. In the UK over 80% of homes are heated by a gas boiler heating water circulating through radiators. Most emissions reduction scenarios include a major shift to electric heat pumps. This would change home heating dynamics significantly because UK households are habituated to significant temperature fluctuations over the day as gas boilers are typically only operated in the morning and evening.

Electric heat pumps run for longer at lower outputs than gas boilers and are likely to require demand management to shift times of heating operation away from electricity network peaks. Consequently the patterns of both heat delivery and the resultant room temperatures are likely to change, flattening the diurnal temperature profiles currently found in UK homes.

Results are presented from a UK trial in which conventional gas boilers were replaced by a "hybrid" combination of electric heat pump and gas boiler, operated by smart heating controllers. Setpoint and actual temperature data from heating controllers in 71 homes were analysed and compared with data from conventional heating controllers in 3,579 homes. Interviews with 11 households explored residents' reactions to the changed heat delivery patterns from the heat pump.

Interview responses indicated that residents' temperature requirements are not simply linked to patterns of occupancy but also to the timing of practices taking place in the home, such as childcare. Analysis of setpoint data showed temperature settings were adjusted manually upwards in the evening in a significant proportion of trial homes, indicating a change in temperature requirements at this point in the day. The implications for home heating control and demand management are discussed, in particular the need to satisfy varying temperature requirements at different times of day.