BIG Solar Graz: Solar district heating in the city, m² for 20% solar fraction Results of a techno-economic feasibility Solar District

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1 BIG Solar Graz: Solar district heating in the city, m² for 20% solar fraction Results of a techno-economic feasibility Solar District Heating Workshop, Belgrad

2 Graz Situation Goal Solar heat for urban district heating BIG Solar Graz Results of the feasibility study Source: Graz Tourismus Overview

3 City of Graz - Overview The second largest city of Austria Approx inhabitants Approx people supplied by district heating District heating demand: GWh/a Peak load: 530 MW ~ 15 km Quelle: geoland.at Quelle: basemap.at

4 District heating in Graz Current situation approx. 400 MW NEW are necessary Heat supply Graz 2020 / 2030 transition of the district heating system City started a broad process of contribution 13 thematic areas, 9 workshops 80 experts, 38 proposals 16 detail analysis, 7 in preperation / realisation District heating Graz: 2020?! % of Energy provided by Mellach? Electricity market <> gas price CCGT => Sustainable, reliable & no add. costs Contract for delivery till 2020 Source: E-Stmk, C. Hackl, Vortrag: Erfahrungen mit Solar-Wärmeeinspeisung in Graz, Source: Wärmeversorgung Graz 2020/2030, Workshops 400 MWth 800 MWel X End of technical life expectancy Coal-fired power station 230 MWth 226 MWel

5 PLAN for future of DH in Graz Condition today onwards from 2020 Industrial waste heat Big Solar Graz Heat pumps Source: Grazer Umweltamt & Energie Agentur, Prutsch, Götzhaber, Papousek; Vortrag bei Fernwärmetagen in Velden,

6 Experience in solar district heating Development from Contracting Open areas Field test

7 Source: Arcon Sunmark Big field solar collectors in DK Collector array: m² with long-term storage: m³

8 Feasibility study BIG Solar Graz Excursion to Denmark

9 Summer supply: widely renewable already Source: Grazer Umweltamt & Energie Agentur, Prutsch, Götzhaber, Papousek; Vortrag bei Fernwärmetagen in Velden, In the summer months, the lion s share of district heating already comes from renewables With further measures, a 100% coverage from renewables is reached in the summer months Every production in summer going beyond that, requires long-term storage

10 Graz DH system conditions VL -> 115 C RL -> 58 C Þ Current network temperatures allow a maximum of about 30% solar coverage Þ The results from the simulations show an economic optimum at ~ 20% solar coverage

11 Sensitivity - Network Temperature Relative change of solar yield Sensitivity analysis network temperatures Parameter change [K] Example: Reduction return 57 C 55 C increase in solar yield: 2.8 % MWh/year increase in profit (at 35 /MWh): /year 4th Generation, return flow 47 C increase in profit (at 35 /MWh): ~ 1 Mio /year Further increase of renewable share!

12 Solar area: roof cadastre? 5,6 Mio m² surfaces that are suitable for solar collectors Quelle:

13 System concept

14 Dimensioning

15 System concept optimum Solar coverage: approx. 20 % Total capital expenditures: approx. 200 Mio. EUR

16 Simulated monthly generation shares Heat production / load / loss / [MWh/month] 450,000 m2 collectors + 1,800,000 m3 pit heat storage MW AHP Heat load (w/o summer) 200,000 Heat blow of Heat losses from pit 150,000 HP driving heat Solar heat via HP Solar heat - direct 100,000 Ind. waste heat 50,000 0 J F M A M J J A Month in 2nd simulation year S O N D

17 Floor space required Comparison to other infrastructure areas in Graz Airport Solar Motorway junction Airport Graz Motorw. junc. Graz West Generation System Mellach ~ 300 ha ~ 40 ha ~ 110 ha Big Solar concept ~ 100 ha Required solar system area < 0,8 % of the city area Needed space for fast growing biomass for same energy ouput factor of 30 Conventional biomass floor space requirement for same energy amount factor of 55

18 Current Steps According to Utility Acquisition of land Further development of the system concept: Strategy for operation and control Safety aspects Preparation of permissions and administrative procedures Targeted date for completion of approving: 2nd Quarter 2018 Utility presented this summer to public

19 Summary Economic competitiveness (despite high network temperatures) System solution for available heat at anytime Security of supply Long-term price stability geoland.at refinancing costs are projectable, independent from the development of prices of fossil energy sources

20 Zukunft: Solarstadt Graz Unterstützt durch: For further information visit: Erneuerbare Energien , Zeitschrift für nachhaltige Energiezukunft, AEE Intec Solarwärme neu gedacht - Fernwärme für Europas Städte und Erneuerbare Energien BIG Solar Graz: m² Solarkollektoren für 20 % Solaranteil bei Grazer Fernwärme Robert Söll Mail: r.soell@solid.at S.O.L.I.D. Gesellschaft für Solarinstallation und Design mbh Puchstraße 85, 8020 Graz, Austria