Decarbonizing heat with PV-coupled heat pumps supported by electricity and heat storage: Impacts and trade-offs for prosumers and the grid. (15th July 2021)

• Record Type: Journal Article
• Authors: Pena-Bello, Alejandro; Schuetz, Philipp; Berger, Matthias; Worlitschek, Jörg; Patel, Martin K.; Parra, David
• Is Part Of: Energy conversion and management. Volume 240(2021)
• Publication Date: 2021-07-15
• Subjects: PV -- Heat pump -- Battery -- Heat storage -- Capacity-based tariff; PV Photovoltaics -- HP Heat pump -- FiT Feed-in Tariff -- COP Coefficient of performance -- ToU Time of use -- SFH Single-family house -- DHW Domestic hot water -- SH space heating -- NPV Net present value -- CF Cash flow -- LCOE Levelized cost of meeting the electricity consumption -- CAPEX Capital expenditure -- OPEX Operating expenditure -- SC Self-consumption -- SS Self-sufficiency -- PVSC PV self-consumption -- DLS Demand load-shifting -- DPS Demand peak shaving -- SOC State of charge -- DoD Depth of discharge -- ILR Inverter load ratio -- NMC Lithium nickel manganese cobalt oxide; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2021.114220
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Thermal retrofitting is advisable to avoid the upgrading of the distribution grid. Poorly insulated buildings with heat pumps can double the power peak demand. Open-source model of PV-coupled heat pumps assisted with storage is provided. Heat storage reduces the levelized cost of meeting the total electricity demand. Capacity-based tariffs reduce grid stress without compromising prosumer benefits. Abstract: Heat pumps play an important role in decarbonizing the heating supply of buildings and they allow to increase the self-consumption of PV electricity, especially when supported by electricity or heat storage. In this study, we develop an open-source model to optimize PV-coupled heat pumps, with and without electricity and heat storage, and we compare their performance for three types of single-family houses with different thermal envelope quality paired with 549 electricity profiles. We analyze trade-offs between prosumer benefits and grid impacts, namely bill minimization, and maximum grid relief, depending on the type of storage and incentives for grid peak reduction (i.e., a capacity-based tariff). We conclude that the use of heat storage reduces the levelized cost of meeting the electricity demand between 13–26% compared to the baseline case without storage, in particular when heat pumps are used for both space heating and domestic hot water (DHW). Regarding total self-consumption rates, both storage technologies, namely batteries and hot water tanks (which supply both space heating and DHW) achieve similar rates ranging between 30–39%. In contrast, batteries are found to be very effective in reducing the peak demand (14–17% compared to the baseline scenario), but only if the retail tariff has a capacity-based component. Interestingly, the quality of the envelope plays a key role and heat pumps can double the power peak demand in poorly insulated houses, with thermal storage increasing the power peak demand further up to 8%, compared to the baseline, regardless of the storage technology. Thus, we conclude that policy makers should promote thermal retrofitting of the building stock to avoid the upgrading of the distribution grid.