Life Cycle Analysis of energy systems used in residential buildings Manoudis Alexandros Supervisor: Dr. Anastaselos Dimitrios SCHOOL OF SCIENCE & TECHNOLOGY MSc in Energy Systems – October 2011

Environmental performance from “cradle to grave” Systems, materials, services and products Includes transportation of materials and fuels in all phases Introduction 2 Sustainable development Quantification of environmental impact Life cycle analysis (LCA)

Scope of the study 3 Residential buildings quite important LCA of Energy systems Most studies focus on building envelope and structural system Buildings’ environmental performance as a whole Database of environmental impact Collaboration with integrated dynamic decision support tools Assist the selection of the environmentally better system

Assessment tools CML 2 baseline 2000 assessment method Ten environmental impact categories Cumulative energy demand (CED) method Production processes from previous studies, industrial reports and the Ecoinvent database SimaPro 7 LCA software 4 Impact categoryUnit Abiotic depletionkg Sb eq Acidificationkg SO2 eq Eutrophicationkg PO4--- eq Global warmingkg CO2 eq Ozone layer depletionkg CFC-11 eq Human toxicitykg 1,4-DB eq Fresh water aquatic ecotoxicitykg 1,4-DB eq Marine aquatic ecotoxicitykg 1,4-DB eq Terrestrial ecotoxicitykg 1,4-DB eq Photochemical oxidationkg C2H4 eq

Heating systems: ◦ Oil fired boiler (boiler, storage tank, pump, expansion vessel and chimney) ◦ Natural gas fired boiler (boiler, pump, expansion vessel and chimney) ◦ Distribution system ◦ Emission system (radiators, floor heating) Cooling system: ◦ Split unit room air conditioner Hot water systems: ◦ Flat plate solar collector ◦ Evacuated tube solar collector ◦ Auxiliaries (Storage and distribution of hot water) Electricity production systems: ◦ Mono-Si PV panels on flat/sloped roof ◦ Poly-Si PV panels on flat/sloped roof ◦ Auxiliaries (inverter, electrical and mounting equipment) Energy systems assessed 5

LCA structure 6 INFLOWS Energy and raw materials to produce one functional unit of product One functional unit of product OUTFLOWS Emissions related to the production of one functional unit of product ClassificationCharacterizationEquivalent values A single score for every impact category SystemFunctional unit Air conditioner1 kW Flat plate solar collector1 m 2 Evacuated tube solar collector1 m 2 Mono-Si PV panel1 m 2 Multi-Si PV panel1 m 2 Oil fired boiler1 kW Gas fired boiler1 kW Distribution system1 m Radiators1 p Floor heating1 m 2

Assessment flowchart 7 Production and disposal of the systems per functional unit Case study Production, operation and disposal of the systems for the whole building needs Overall environmental performance Comparison of the systems

Case study Typical four storey building in Thessaloniki Operation phase for 20 years Base case scenario - Oil boiler (efficiency 80%) with radiators 5 main impact categories: ◦ Global warming ◦ Acidification ◦ Eutrophication ◦ Photochemical oxidation ◦ Primary energy Evaluation of several proposed interventions 8

Production and disposal (for the whole building needs) 9 Interventions kg MJ eq CO 2eq SO 2eq PO 4eq C 2 H 4eq Primary Energy a) Oil boiler and radiators, (efficiency 90%) b) Natural gas boiler and radiators (efficiency 90%) c) Natural gas boiler and floor heating d) Natural gas boiler, floor heating and flat plate collector e) Natural gas boiler, floor heating and evacuated tube collector f) Natural gas boiler, floor heating and mono-Si PV system g) Natural gas boiler, floor heating and poly-Si PV system

Operation (for the whole building needs) 10 Scenarios kg MJ eq CO 2eq SO 2eq PO 4eq C 2 H 4eq Primary Energy Oil boiler and radiators, (efficiency 80%) a) Oil boiler and radiators, (efficiency 90%) b) Natural gas boiler and radiators c) Natural gas boiler and floor heating d) Natural gas boiler, floor heating and flat plate collector e) Natural gas boiler, floor heating and evacuated tube collector f) Natural gas boiler, floor heating and mono-Si PV system g) Natural gas boiler, floor heating and poly-Si PV system

Overall performance (for the whole building needs) 11 Interventions kg MJ eq CO 2eq SO 2eq PO 4eq C 2 H 4eq Primary Energy a) Oil boiler and radiators, (efficiency 90%) b) Natural gas boiler and radiators c) Natural gas boiler and floor heating d) Natural gas boiler, floor heating and flat plate collector e) Natural gas boiler, floor heating and evacuated tube collector f) Natural gas boiler, floor heating and mono-Si PV system g) Natural gas boiler, floor heating and poly-Si PV system

Annual savings 12 Interventions kg MJ eq CO 2eq SO 2eq PO 4eq C 2 H 4eq Primary Energy a) Oil boiler and radiators, (efficiency 90%) b) Natural gas boiler and radiators c) Natural gas boiler and floor heating d) Natural gas boiler, floor heating and flat plate collector e) Natural gas boiler, floor heating and evacuated tube collector f) Natural gas boiler, floor heating and mono-Si PV system g) Natural gas boiler, floor heating and poly-Si PV system

Environmental impact payback period 13 Interventions Years CO 2eq SO 2eq PO 4eq C 2 H 4eq Primary Energy a) Oil boiler and radiators, (efficiency 90%) b) Natural gas boiler and radiators c) Natural gas boiler and floor heating d) Natural gas boiler, floor heating and flat plate collector e) Natural gas boiler, floor heating and evacuated tube collector f) Natural gas boiler, floor heating and mono-Si PV system g) Natural gas boiler, floor heating and poly-Si PV system

Conclusions Production and disposal Assessment of the environmental performance of energy systems per functional unit Useful and adaptive database of environmental impact Assist the selection of the environmentally better system Better environmental performance (independent systems): ◦ Natural gas boiler ◦ Poly-Si PV installation ◦ Evacuated tube solar collector 14

Conclusions 15 Case study Combination of the systems In all phases not only one possible intervention the best option in all impact categories Higher annual savings more complex system higher production impact higher payback periods The selection of the environmentally better intervention potential user the impact category that needs improvement

Thank you for your attention! 16