Är passivhus lämpliga i fjärrvärmeområden?

Transkript

1 Är passivhus lämpliga i fjärrvärmeområden? Leif Gustavsson Energiting Sydost maj 2011 Linnéuniversitetet, Växjö

2 Världens primärenergianvändning 2007 ( 500 Exajoul) Olja 34% Kol 26% Gas 21% Totalt fossilt 81% Bioenergi 10% Kärnkraft 6% Övrigt 3% Exa = Källa: International Energy Agency, Key World Energy Statistics

3 Klimatsmarta hus i en hållbar byggd miljö Minimera primärenergianvändning och nettoutsläpp av koldioxid över husens hela livscykel - befintliga och nya hus behöver beaktas

4 Byggnaders livscykel Produktion av hus Användning av hus Rumsuppvärmning Tappvarmvatten Fastighetsel Verksamhetsel Rivning av hus

5 Energikedja - exempel eluppvärmning Naturresurs Bränslekedja Elproduktion Elektricitet Eldistribution Värmesystem slutanvändare Värme Värma rum 5

6 Elsystemet Elproduktion i ett Europaperspektiv har ofta kolkondens som marginalel Förändrad elanvändning leder då till kraftigt förändrade koldioxidutsläpp Omfattande planerad utbyggnad av fossil kondenskraft i EU Stort överskott av spillvärme (i Sverige är överskottet ca 2 gånger större än leveranserna av fjärrvärme)

7 Specific energy requirements of the Swedish building Code (BBR 2009) and the passivhus standard Description BBR 2009 electric heated BBR 2009 non-electric heated Passivhus Climate zone I II III I II III North South Specific final energy limit * (kwh/m 2 ) North zone * Comprises purchased energy for space and water heating, and electricity for fans and pumps but excludes electricity for household use South zone

8 Analysed building Located in Växjö, Sweden Constructed in the mid 1990s Climate zone III / South 4 stories 16 apartments 1190 m 2 usable floor area Wood framed Reference We compared versions of this building designed to the BBR 2009 or to the Passivhus standard

9 Energy characteristics of analyzed buildings Description Reference BBR 2009 electric heated BBR 2009 district heated Passivhus Ground floor U-value External walls U-value Windows U-value Doors U-value Roof U-value Airtightness at 50Pa Mechanical Ventilation Exhaust air Heat recovery Exhaust air Heat recovery Hot water taps Conventional Energy efficeint Conventional Energy efficeint Specific final energy (kwh/m 2 yr) U-values in W/m 2 K Airtightness in l/ s m 2

10 Life cycle activities and primary energy flows Production phase - Extraction, processing and transport of materials - On-site construction work - Energy recovery from biomass residues Operation phase - Space heating - Electricity for ventilation - Tap water heating - Electricity for household and facility management End-of-life phase - Demolition - Energy recovery from wood, and recycling of concrete and steel Energy supply system - Full energy chain accounting, including conversion / fuel cycle losses Energy supply system - Electric heating, or district heating with biomassbased supplies - Electricity produced in a biomass-fired condensing plant - District heat produced in a CHP-based bio plant - Full energy chain accounting, including conversion / fuel cycle losses Energy supply system - Full energy chain accounting, including conversion / fuel cycle losses

11 Final and primary energy use for building operation Household & facility electricity Water heating Ventilation electricity Space heating Final energy use (kwh/m 2 year) Reference BBR 2009 Passivhus Final energy use Reference BBR 2009 Passivhus Primary energy use (kwh/m 2 year) Reference BBR 2009 Passivhus Primary energy use Reference BBR 2009 Passivhus Electric heated building District heated building Electric heated building District heated building

12 Primary energy balance per year (building lifespan is 50 years) 600 Demolition Household & facility electricity Ventilation electricity Production Production residues Water heating Space heating Demolition residues/end-of-life benefit iiprimary energy use (kwh/m 2 year) Reference BBR 2009 Passivhus Reference BBR 2009 Electric heated building District heated building Passivhus

13 Retrofitting the 1995 house to pass house standard Primary energy use over time for materials, space heating and ventilation electricity Existing, RH Primary energy use (kwh/m 2 ) Retrofit, RH Existing, HP Existing, DH Retrofit, HP Retrofit, DH Year RH =Resistance heating HP = Heat pump DH = District heating, 50% CHP Biomass-based system (steam turbine technology)

14 Frågor?

15 Primary energy balance: production phase 800 Biomass residues On-site construction Material production Primary energy use (kwh/m 2 ) Reference BBR 2009 Passivhus Reference BBR 2009 Passivhus Electric heated building District heated building

16 Primary energy balance: end-of-life Wood recovery for energy Steel recycling Concrete recycling Demolition 100 Primary energy use (kwh/m 2 ) Reference BBR 2009 Reference Passivhus BBR 2009 Passivhus Electric heated building District heated building

17 Primary energy balance excluding tap water heating, household & facility electricity per year (building lifespan is 50 years) 250 Demolition Ventilation electricity Production Production residues Space heating Demolition residues/end-of-life benefit iiprimary energy use (kwh/m 2 year) Reference BBR 2009 Electric heated building Passivhus Passivhus BBR 2009 Reference District heated building

18 Conclusions A life cycle primary energy perspective is needed to minimize overall primary energy use A passivhus building with cogeneration of district heating and electricity gives low life cycle primary energy use

19 Årliga värmeprofiler av byggnadens uppvärmningsbehov med eller utan energihushållning Source: Gustavsson et al. 2011

20 Fjärrvärmelast och fjärrvärmeproduktion (1/5 - till 30/4 2009) Capacity (MW) Accumulator Discharged Heat-only boilers Flue gas condenser CHP plant Day Source: Gustavsson et al. 2011