Lågtemperaturfjärrvärme i nya bostadsområden P i samverkan med Växjö kommun, Växjö Energi AB och Växjö-bostäder AB

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1 EJ/yr Lågtemperaturfjärrvärme i nya bostadsområden P i samverkan med Växjö kommun, Växjö Energi AB och Växjö-bostäder AB Leif Gustavsson, Linnéuniversitetet E2B2s årskonferens 19, 7 februari 19, klockan 1-17 GT3, Grev Turegatan 3, Stockholm 1 Årlig global primärenergianvändning och trender (IEA) Uppskatttning gjord 11 År 1 14 Total (EJ) Distribution (%) Olja Kol Gas Totalt fossilt Bioenergi Kärnkraft Annat förnybart Uppskattning gjord 16 Source: International Energy Agency (IEA), 11. World Energy Outlook 11 IEA, 13. World Energy Outlook 13; IEA, 12. Key World Energy Statistics IEA, 16. World Energy Outlook

2 Emissioner av CO 2 från energisektorn - IEA 16 Paris agreement, article 2a: Holding the increase in the global average temperature to well be 2 C above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5 C above pre-industrial levels Source: IEA 16. World Energy Outlook 16 3 Hållbar utveckling inom byggd miljö Bygga mycket energisnåla nya byggnader och beakta hela byggnaders livscykel Kraftfull energihushållning i befintliga byggnader Energieffektiv energitillförsel, exempelvis Lägre fjärrvärmetemperaturer Lägre värmeförluster för distribution Ökad verkningsgrad för kraftvärme och värmepumpar Lättare utnyttja solenergi och spillvärme Förnybar energi och förnybara material Ökad integration av byggsektorn med avfall-, el-, transport- och värmesektorerna 4 2

3 Temperature ( o C) Analys av energianvändning och kostnader för lokal fjärrvärmedistribution till nytt bostadsområde i Växjö vid olika temperaturnivåer Exploateringen av nybyggnadsområdet varieras Energiprestanda för byggnaderna varieras 5 Project site (Topparängen) and situation in Växjö Växjö is a city of about 65 inhabitants With a district heating system (DHS) o ~ 185 MW peak and ~ 63 GWh heat /year o ~ 98% of production is based on biomass o Two CHP plants and several boilers Measured temperatures in 13 1 Ambient temp. Supply temp. Return temp Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec Day 6 3

4 Four land exploitation alternatives Low exploitation 91 m 2 heated floor area Medium-exploitation m 2 heated floor area High-exploitation m 2 heated floor area Dense-exploitation m 2 heated floor area 7 Number of buildings Land exploitation Villas Row houses 6-storey buildings 8-storey buildings 1-storey buildings Low Medium High Dense

5 We consider for each land exploitation alternative Two building energy efficiency levels Swedish building code (BBR 15) Swedish passive house criteria (Passive 12) Three different district heat supply/ return temperatures 8/4 o C (conventional system) 65/3 o C 5/ o C Lower temperature difference, more electricity for pumping of district heat water (65/3 o C and 5/ o C) Boosted hot water temperature due to the risk of legionella bacteria (5/ o C) 9 Space heating capacity (kw) House/building type Building standard Villas o m o 11 m o 1 m o 15 m Row houses o Type 1 (Regular) Beginning Middle row o End Type 2 (Offset of walls) Beginning Middle row End Multi-apartment buildings o 6-storey, 24 apartments o 8-storey, 32 apartments o 1-storey, 4 apartments

6 Heat demand (kw) Heat demand (MWh) Heat demand (MWh) Heat demand (kw) Space- and hot water heating Dense High Medium Low Dense High Medium Low Hour Hour Based on hour by hour energy balance calculations 11 Annual heat demand for space and hot water heating Hot water heating Space heating Hot water heating Space heating 5 5 Scenario of building exploitation Scenario of building exploitation 12 6

7 Heat supply network V32 B4 B5 B3 Q B6 A A B2 B1 B7 V28 V39 M V21 N V22 B H1.1 M V21 B8 B H1.1 L V14 V1 K J V6 V15 C V11 D V7 E H H2.1 H1.6 L V14 V1 K J V6 O V15 P C V11 D V7 E H H2.1 H1.6 V1 F I H2.1 V1 F I H2.1 H3.1 H m G H m G H3.13 Low exploitation, 1718m Medium exploitation, 1686m 13 Heat supply network B6 B7 B6 B7 B5 Q B8 B5 Q B8 B4 B2 B9 A B4 B2 B9 A B3 B1 B1 B H1.1 B3 B1 B1 B H1.1 B11 B15 S R C H H2.1 H1.6 B16 S R C H H2.1 H1.6 B14 B11 B15 B12 B13 B12 I H2.1 B14 B13 I H2.1 H3.1 H m G H m G H3.13 High exploitation, 1341m Dense exploitation, 1351m 14 7

8 Distribution loss (MWh) Distribution loss (%) 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C Distribution loss (MWh) Distribution loss (%) 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C 8/4 o C 8/4 o C 65/3 o C 65/3 o C 5/ o C 5/ o C Local district heat distribution losses Specific local district heat distribution losses

9 Energy use (MWh) Final Final energy Energy Energy use use (MWh) (MWh) 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 o C 65/3 o C 65/3 o C>8/4 o C>8/4 o C o C 65/3 o C 5/ o C 5/ 5/ o C>8/4 o C>8/4 o C 5/ o C 5/ o C>8/4 o C>8/4 o C o C 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 o C 65/3 o C 65/3 o C>8/4 o C>8/4 o C o C 65/3 o C 5/ o C 5/ 5/ o C>8/4 o C>8/4 o C 5/ o C 5/ o C>8/4 o C>8/4 o C o C 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 o C 65/3 o C 65/3 o C>8/4 o C>8/4 o C o C 65/3 o C 5/ o C 5/ 5/ o C>8/4 o C>8/4 o C 5/ o C 5/ o C>8/4 o C>8/4 o C o C 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 o C 65/3 o C 65/3 o C>8/4 o C>8/4 o C o C 65/3 o C 5/ o C 5/ 5/ o C>8/4 o C>8/4 o C 5/ o C 5/ o C>8/4 o C>8/4 o C o C Energy use (MWh) Final Final energy Energy energy Energy use use (MWh) (MWh) 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 65/3 o C 65/3 o C C>8/4 o C>8/4 o C o C 65/3 o C 5/ 5/ o C>8/4 o C>8/4 5/ o C 5/ o C C>8/4 o C>8/4 o C o C 5/ o C 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 65/3 o C 65/3 o C C>8/4 o C>8/4 o C o C 65/3 o C 5/ 5/ o C>8/4 o C>8/4 5/ o C 5/ o C C>8/4 o C>8/4 o C o C 5/ o C 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 65/3 o C 65/3 o C C>8/4 o C>8/4 o C o C 65/3 o C 5/ o C 5/ 5/ o C>8/4 o C>8/4 5/ o C 5/ o C C>8/4 o C>8/4 o C o C 8/4 o C 65/3 65/3 o C>8/4 o C>8/4 65/3 o C 65/3 o C C>8/4 o C>8/4 o C o C 65/3 o C 5/ o C 5/ 5/ o C>8/4 o C>8/4 5/ o C 5/ o C C>8/4 o C>8/4 o C o C District heat use, electricity use and local distribution losses 4 Electricity - pumping 4 Electricity - pumping 35 3 Electricity - hot water heating District heat - distribution losses District heat - hot water heating 35 3 Electricity - hot water heating District heat - distribution losses District heat - hot water heating 25 District heat - space heating 25 District heat - space heating Reduced district heat distribution losses compared to the 8/4 o C sy stem 65/3 o C sy stem: 24-25% 5/ o C sy stem: 48-5% 17 Annual changed final energy use when er supply/return temperatures are used instead of a 8/4 o C system 3 Electricity for electric heater 3 3 Pumping Electricity electricity for heater 3 Heat Pumping distribution electricity loss District Heat distribution heat use loss 117 District heat use Scenario -3 of building Scenario -3 exploitation: of building exploitation: Scenario of building -3 Scenario exploitation: of building exploitation: Electricity for electric heater Pumping Electricity electricity for electric heater Heat Pumping distribution electricity loss District Heat distribution heat use loss District heat use

10 Investment costs (M ) 8/4 o C 65/3 o C 5/ o C 8/4 o C 65/3 o C 5/ o C 8/4 o C 65/3 o C 5/ o C 8/4 o C 65/3 o C 5/ o C Investment costs (M ) 8/4 o C 65/3 o C 5/ o C 8/4 o C 65/3 o C 5/ o C 8/4 o C 65/3 o C 5/ o C 8/4 o C 65/3 o C 5/ o C Investment costs for local networks and substations.8.7 Network Substations.8.7 Network Substations Cost implication of reduced supply/return temperatures in local network with 8/4 o C as baseline The net present value of minus reduced distribution network heat losses and reduced use of district heat increased use of electricity for pumping and boosting hot water temperature and minus the increased investment cost for the district heat temperature alternatives is calculated assuming different real discount rates and lifetimes 1

11 Cost ( ) 65/3 o C 5/ o C District heat (MW) 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C Cost ( ) 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C District heat and electricity cost 15 Boiler - Oil CHP - Oil Boiler - Biomass CHP - Biomass, direct conr CHP - Biomass District heat production 13 in Växjö 5 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec Day Marginal costs of district heat production: 29.1 /MWh Costs of electricity use: 92.6 /MWh 21 Changed cost due to er district heat temperatures discount rate 6%, lifetime 3 years Negative values are cost increase

12 Primary energy use (MWh)) District heat load (MW) 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C Primary energy use (MWh)) 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C Changed primary energy use for er district heat temperatures - coal-based stand-alone electricity production At standalone power plants At district heat production units At standalone power plants At district heat production units Future scenario: Bioenergy optimized district-heat production MW Wood powder boiler 4 MW CHP-BST Costs are based on cost-optimal bio-based district heat production using 13 heat load curve in Växjö and bioelectricity production including capital costs 92 MW Wood chips boiler Day Costs of district heat production: 34.8 /MWh Costs of biomass-based electricity: 95.2 /MWh 24 12

13 Cost ( ) Primary energy use (MWh) 65/3 o C 65/3 o C 5/ o C 5/ o C 65/3 o C 65/3 o C 5/ o C 5/ o C 65/3 o C 65/3 o C 5/ o C 5/ o C 65/3 o C 65/3 o C 5/ o C 5/ o C Cost ( ) Primary energy use (MWh) 65/3 o C 65/3 o C 5/ o C 5/ o C 65/3 o C 65/3 o C 5/ o C 5/ o C 65/3 o C 65/3 o C 5/ o C 5/ o C 65/3 o C 65/3 o C 5/ o C 5/ o C Changed cost of er district heat temperatures Future scenario of bio-based production Negative values are cost increase Changed primary energy use for er district heat temperatures Future scenario of bio-based district heat and electricity production 6 5 At standalone power plants At standalone power plants At district heat production units At district heat production units

14 Primary energy use (MWh) 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C Primary energy use (MWh) 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C 65/3 o C 5/ o C Changed primary energy use for er district heat temperatures Future scenario of bio-based production + 25% wind power (no primary energy use for wind power) 6 5 At standalone power plants 6 5 At standalone power plants 4 At district heat production units At district heat production units Not considered 1. District heat production benefits of operating CHP-plants (heat pumps, waste heat, etc) at er district heating temperatures 2. Reduced distribution heat losses in the overall distribution system due to er supply/return temperatures 3. Implications on internal space heat distribution in buildings due to er supply/return temperatures 4. Plastic pipes for district heat distribution 28 14

15 Discussion and Conclusions 1. The heat density of the residential area has a minor impact on the local district heat distribution losses 2. Reduced district heat supply/return temperatures strongly reduce the local district heat distribution losses 3. A 5/ o C system increases electricity use, to boost hot water temperature to avoid the risk of legionella bacteria 4. A 65/3 o C system is more cost and primary energy efficient when a 5/ o C 5. A 65/3 o C system is more primary energy efficient when a 8/4 o C and about to be cost efficient 6. Important to analyze benefits of er temperature for district heat production 29 Thank you! 3 15