Impact on energy requirements and emissions of heat pumps and micro-cogenerators participating in demand side management

Abstract

The potential impacts of participating in demand side management (DSM) on the performance of air source heat pumps (ASHP) and microcombined heat and power (mCHP) units are considered by this study. As significant consumers and generators of electricity at the distribution level, large numbers of heat pumps and micro-cogenerators would provide considerable scope for participation in DSM systems. However, it is possible that operating regimes which are optimised for grid considerations will not achieve the maximum performance that is possible from the units.Modelling has been conducted to investigate the significance of this effect, considering the case where local distribution constraints are the main driver for demand side interventions. A model of domestic electrical demand has been adapted to consider a neighbourhood of 128 dwellings in order to identify when interventions are necessary. This has been combined with dynamic models of two combustion engine micro-cogenerators, a solid oxide fuel cell micro-cogenerator and two ASHPs. A simple thermal model of each building is combined with a range of user preferences in order to determine the preferred operating profiles of the heating units.The DSM scheme analysed here is likely to have minimal impact on the emissions and energy requirements associated with each heating unit. Its effect is similar to that which occurs without DSM if the control system gain is relaxed such that equivalent thermal comfort is achieved. DSM can reduce the peak electrical demand of the neighbourhood. However, in the scenarios investigated, it is unlikely that the peaks can be reduced sufficiently such that they do not exceed the capacity of the local distribution transformer if ASHPs are used in all dwellings. By using a combination of mCHP units with ASHPs, it is possible to supply heating to all dwellings without exceeding this capacity. In this case, the use of DSM can increase the ratio of ASHPs used. In the context of a low carbon grid electricity supply, this will reduce the average carbon emissions associated with the neighbourhood.

Detailed simulation of electrical demands due to nationwide adoption of heat pumps, taking account of renewable generation and mitigation

“…Transmission and distribution constraints are a significant consideration and may be a major driver for the use of DSM in other contexts (e.g. [7], [8], [12]- [17]) but the present study focusses on peak power demands.…”

Innovative household systems based on solid oxide fuel cells for the Mediterranean climate

“…EEL is calculated by solving Equation (15) and also considering Equations (16)e (18) and the efficiencies of the SOFC and the ASHP. The integration of the boiler does not affect the EEL calculation because it uses natural gas to produce heat, considering that its auxiliary electric consumption is negligible.…”

“…[15] analyzed an integrated SOFCabsorption heating and cooling system for a large residential or commercial building, while [16] studied different microCHP systems for several building types, occupant-related loads and grid electricity mixes. Very recently, two works reported on a SOFC microCHP coupled to an ASHP but considering only the heating operation of the systems [17,18].…”

Smart Scheduling of Household Appliances to Decarbonise Domestic Energy Consumption

“…Aghaei et al explored the potential for DSR to fundamentally alter grid fuel mix by enabling intermittent renewable energy sources (RESs) such as wind and solar [2], albeit this is only at a conceptual level. Cooper et al analysed the impact of emissions of heat pumps and micro-cogenerators participating in DSR [3]. This was a small scale, technology-specific study but results showed that DSR programmes with heat-pumps could cause significant reductions in CO 2 emissions.…”