Towards smart thermal grids: Techno-economic feasibility of commercial heat-to-power technologies for district heating
2018 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 228, p. 766-776Article in journal (Refereed) Published
Abstract [en]
Recent improvements in low-temperature heat-to-power (LTHtP) technologies have led to an increase in efficiency at lower temperatures and lower cost. LTHtP has so far not been used in district heating. The aim of the study is to establish under what conditions the use of existing LTHtP technology is technically and economically feasible using a district heating system as the heat source. The organic Rankine cycle (ORC) is identified as the most interesting LTHtP technology, due to its high relative efficiency and the commercial availability of devices operating at temperatures in the district heating operating range. The levelised cost of electricity of several ORC devices is calculated for temperatures found in district heating, assuming a zero cost of heat. A case study from Sweden is used to calculate the levelised cost of electricity, the net present value and payback period, based on income from the electricity produced, excluding taxes. Hourly spot market electricity prices from 2017 are used, as well as forecast scenarios for 2020, 2030 and 2040. A sensitivity study tests the importance of electricity price, cost of heat and capital/installation cost. Based on the case study, the best levelised cost of electricity achieved was 26.5 EUR/MWh, with a payback period greater than 30 years. Under current Swedish market conditions, the ORC does not appear to be economically feasible for use in district heating, but the net present value and payback period may be significantly more attractive under other countries’ market conditions or with reduced capital costs. For a positive net present value in the Swedish market the capital cost should be reduced to 1.7 EUR/W installed, or the average electricity price should be at least 35.2 EUR/MWh, if the cost of heat is zero. The cost of heat is an important factor in these calculations and should be developed further in future work.
Place, publisher, year, edition, pages
2018. Vol. 228, p. 766-776
Keywords [en]
Ancillary services, District heating, Heat to power, LCOE, Smart grids, Thermal grids
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-34358DOI: 10.1016/j.apenergy.2018.06.105Scopus ID: 2-s2.0-85049354404OAI: oai:DiVA.org:ri-34358DiVA, id: diva2:1237176
Note
Funding details: KK, Stiftelsen för Kunskaps- och Kompetensutveckling; Funding details: Knowledge Foundation; Funding details: DH, Department of Health;
Funding text: Many thanks to Sweco AB and the DH network operator for their data,
2018-08-072018-08-072018-08-07Bibliographically approved