Analysis on field trial of high temperature heat pump integrated with thermal energy storage in domestic retrofit installation

Abstract

Heat pump and thermal energy storage are important technologies to decarbonise heat and electricity sector. Heat pump integrated with thermal energy storage can provide flexibility to electrical system operator to shift demand to accommodate non-synchronous generators. However, ageing housing stock and high temperature wet radiator central heating system possess some challenges for heat pump installation in the UK. To understand the challenges of retrofit technologies in the domestic sector, a field trial was carried out with a cascade heat pump integrated with a thermal storage tank. The heat pump replaced an existing gas boiler to provide flow temperature of 75°C as a retrofit measure without any modification/replacement to existing controller or radiators in the house. The heat pump was integrated with a 600l thermal store to meet heating demand and system performance was measured in different operation mode such as direct mode, storage mode and combined mode during one-year. The paper provides performance analysis of the system in different mode with operational experience, limitation and issues with the heat pump, house heat loss/insulation and sizing of thermal store in retrofit installation. Additionally, heat pump performance was compared with gas boiler to establish emission and cost saving benefits.

Techno-economic assessment of cascade air-to-water heat pump retrofitted into residential buildings using experimentally validated simulations

“…This research was carried out by gathering short-term field trial results in different sites across the UK. Another study by Shah et al [32] conducted field trials of a cascade AWHP integrated with a thermal energy storage (TES) tank to highlight its retrofit performance in the UK, but again the field trials were carried out in short periods. Shortterm field trials alone could not accurately evaluate the potential costs and carbon savings of these heat pumps because AWHPs' performance is sensitive to seasonal and boundary conditions.…”

“…For the purpose of this study aiming at assessing the performance of a stand-alone retrofit CAWHP system and its integration with TES, the field trial results of the monitoring campaigns mentioned in the previous study of Shah et al [32] were subdivided into three sessions that are described as follows:…”

The Role of Domestic Integrated Battery Energy Storage Systems for Electricity Network Performance Enhancement

“…To illustrate this, the two extremes are represented on Figure 1. The normalised electricity consumption of dwelling in Northern Ireland [6] is represented in red, and that of the entire country [7] in blue over the same three-day period (24 to 26 October 2018) (The data for the individual house comes from one of the "Test Houses", located at the University of Ulster, representing about 28% of the UK's housing stock, introduced by Shah et al [6]. The national demand data was downloaded from the Eirgrid group website [7].…”

“…Additionally, the three days of national demand present a repeating pattern over each 24-hour period, whereas such a trend is impossible to identify for the single house. [6], and the entire country (dashed blue) for a three-day period (24-26 October 2018) [7].…”

“…Figure 1. Normalised electricity consumption of an individual house (red) in Northern Ireland [6], and the entire country (dashed blue) for a three-day period (24-26 October 2018) [7].…”