Levelized cost of excess heat method for the assessment of its utilisation in district heating systems

doctoral thesis

• Title (croatian): Metoda niveliranoga troška otpadne topline za procjenu njenog iskorištavanja u centraliziranim toplinskim sustavima
• Author: Borna Doračić; VIAF: 39160242843052431499
• Mentor: Neven Duić (mentor)
• Committee member: Tomislav Pukšec (predsjednik povjerenstva)
• Committee member: Veljko Filipan (član povjerenstva)
• Committee member: Anes Kazagić (član povjerenstva); VIAF: 305694713
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-07-05, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering
• Universal decimal classification (UDC): 628 - Public health engineering. Water. Sanitation. Illuminating engineering ; 620 - Materials testing. Power stations. Economics of energy

Abstract

To fulfil the climate neutrality goals of the European Union, as set out in the Green Deal, it is necessary to move towards sustainable energy solutions in all the subsectors of the energy sector. This is especially relevant for heating, which is responsible for 80% of the final energy consumption in the European buildings. However, 64% of the heating demand is currently covered by the fossil fuels, which shows the urgent need to act. In high density heat areas, district heating has already proven to be a sustainable solution since it enables the utilisation of renewable energy sources and the use of highly efficient production technologies. Nevertheless, most of these systems still use fossil fuels, which shows the high need for transferring to the sustainable, low temperature 4th generation district heating systems of the future.
The main heat sources for these systems would be renewables such as solar thermal, geothermal and biomass, but also excess heat sources, which represent heat produced during the certain industrial or service sector process and wasted in the environment. Excess heat sources have shown to have a high technical potential in the European Union and other countries and continents. Some sources even report that the amount of available excess heat in Europe is high enough to cover the demand of both the households and tertiary buildings. Despite it, this source remains underutilised and the research in this area is scarce.
In this thesis, the feasibility of excess heat utilisation in district heating systems was analysed by developing and implementing the levelized cost of excess heat method. The method was used to show the spatial feasibility of these sources for both high temperature and low temperature excess heat. The impact of certain parameters of the levelized cost of heat (including the capacity factor in different system configuration and the temperature level of the excess heat source) has been analysed to show their effect on the overall feasibility of this source. Furthermore, the importance of using dedicated thermal storage units for excess heat to increase their utilisation and subsequently the feasibility has been analysed and discussed. Finally, the participation of high and low temperature excess heat sources on the wholesale heat market has been studied, specifically calculating their feasibility by using levelized cost of excess heat. The results of this thesis show the high potentials of excess heat sources from the economic perspective, but also emphasize the need for shifting towards the 4th generation district heating to make the low temperature excess heat utilisation feasible.

Abstract (croatian)

Kako bi se ispunili ciljevi klimatske neutralnosti Europske unije, navedeni u Europskom Zelenom Planu, potrebna je tranzicija prema održivim energetskim rješenjima u svim sektorima energetike. To je posebno važno za sektor grijanja, koji je odgovoran za 80% finalne potrošnje energije u europskim zgradama. Međutim, 64% toplinskih potreba je trenutno pokriveno izgaranjem fosilnih goriva, što pokazuje hitnu potrebu za djelovanjem. U područjima visoke gustoće toplinskih potreba, centralizirani toplinski sustavi su se već pokazali kao održivo rješenje jer omogućuju korištenje obnovljivih izvora energije i visokoučinkovitih tehnologija. Ipak, većina ovih sustava još uvijek koristi fosilna goriva, što pokazuje veliku potrebu za prelaskom na održive, nisko temperaturne centralizirane toplinske sustave 4. generacije.
Glavni toplinski izvori za sustave 4. generacije bili bi obnovljivi izvori kao što su sunčeva energija, geotermalna energija i biomasa, ali i otpadna toplina koja predstavlja toplinu proizvedenu tijekom određenog procesa u industrijskom ili uslužnom sektoru i koja se gubi u okoliš. Pokazalo se da izvori otpadne topline imaju visok tehnički potencijal u Europskoj uniji, ali i drugim državama. Neki radovi čak navode da je količina raspoložive otpadne topline u Europi dovoljno visoka da pokrije toplinske potrebe kućanstava i zgrada uslužnog sektora. Unatoč tome, ovaj izvor ostaje nedovoljno iskorišten te je broj istraživanja u ovom području relativno malen.
U ovom doktorskom radu analizirana je isplativost iskorištavanja otpadne topline u centraliziranim toplinskim sustavima razvojem i primjenom metode niveliranog troška otpadne topline. Metoda je korištena kako bi se pokazala prostorna isplativost visoko temperaturnih i nisko temperaturnih izvora otpadne topline. Analiziran je utjecaj pojedinih parametara niveliranog troška otpadne topline (uključujući faktor kapaciteta u različitim konfiguracijama sustava i temperaturu izvora otpadne topline) kako bi se pokazao njihov utjecaj na ukupnu isplativost ovog izvora topline. Nadalje, analizirana je i diskutirana važnost korištenja toplinskih spremnika za otpadnu toplinu kako bi se povećala njihova iskorištenost. Analiza je obuhvatila i povećanje isplativosti sustava prilikom korištenja toplinskih spremnika. Konačno, istraženo je i analizirano sudjelovanje visoko i nisko temperaturnih izvora otpadne topline na tržištu toplinske energije, sa posebnim fokusom na izračun isplativosti korištenjem metode niveliranog troška otpadne topline. Rezultati ovog rada pokazuju visoke potencijale izvora otpadne topline, ali i naglašavaju potrebu za prelaskom na centralizirane toplinske sustave 4. generacije kako bi se potaknulo iskorištavanje nisko temperaturne otpadne topline.

• Keywords: district heating; excess heat; levelized cost of excess heat; energy planning; renewable energy sources; heat market
• Keywords (croatian): centralizirani toplinski sustavi; otpadna toplina; nivelirani trošak otpadne topline; energetsko planiranje; obnovljivi izvori energije; tržište toplinske energije
• Language: english
• URN:NBN: urn:nbn:hr:235:136178
• Study programme: Title: Mechanical Engineering and Naval Architecture; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti (doktor/doktorica znanosti, područje tehničkih znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-07-26 11:14:00