How To Make A Low Energy Building Energy Efficient

Transcription

1 Klimatkonsekvenser av energival Ambrose Dodoo Malmö,

2 Sustainable Built Environment Group (SBER) at LNU

3 Picture credits belong to Joakim Lloyd Raboff Malmö

4 Source: Emily Rochon, Greenpeace

5 Source: inhabitat.com

6 Source: &

7 Sustainable future - are you an optimist or pessimist? Will future generations have at least the same quality of life as it is today? Economy Environment Society What will it take to sustain the quality of life and preserve the environment for future generations? Source:

8 Energibegrepp och energibalans

9 Content Key facts about our energy use and challenge Global European Sweden Environmental and climate impacts of energy use Why buildings matters in energy and climate change issues

10 Definition: final and primary energy use A distinction has to be made between final and primary energy: (Primary energy) (Final energy) Source: Energy in Sweden 2013

11 World energy demand is rising Source: IEA, World Energy Outlook 2010

12 Global energy

13 Sweden s primary energy use in , and projected structure in 2030

14 Relative contributions of different fuels to total primary energy suply Relative contributions of different sources to total primary energy supply of the world, EU and Sweden in % Solar, wind, geothermal & heat Biofuels and waste Oil Coal Hydro Nuclear Fossil gas 75% 50% 87% 90% Non-Renewable Fossil fuel 25% 82% 77% 65% 32% 0% World EU-28 Sweden Data for the world and Sweden are from IEA (2013a; 2013b) & that for EU-28 is from BP (2012)

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16 Global greenhouse gas emissions by gas, IPCC, 2014 Source: IPCC, 2014

17 Historical and projected trends in global CO 2 emissions under different Representative Concentration Pathways Source: Sanford, T., Frumhoff, P. C., Luers, A., and Gulledge, J The climate policy narrative for a dangerously warming world. Nature Climate Change, 4,

18 Key facts from IPCC s 2014 report Global surface temperatures have increased by ºC within the last century It is at least 95% certain that human activities have caused more than half of the temperature increase since the 1950s, through the burning of fossil fuels and land-use changes such as deforestation Most up-to-date info on climate change Source:

19 Key facts from IPCC s 2014 report Most up-to-date info on climate change Source: Source:

20 Transition to a sustainable built environment some options Source: Maria van der Hoeven, IEA Wellington

21 Transition to sustainable built environment some questions Carbon capture and storage: Technically feasible on large scale? How much fossil fuels do we have? When and how much will it cost? Nuclear: Safe? Acceptable? Next generation when? cost? Wind: how much, how fast? Solar: when can we bring the cost down? Biofuels: benefits & impacts? Smart grid: what is it? cost and barriers to achieve it? Electric cars: cost, when? Energy efficiency and conservation: cheapest, fastest, cleanest? how come we haven t achieved the potential?

22 Greenhouse gas abatement cost curve Source:

23 Global final energy use by sector and buildings energy mix, 2010 Buildings is the largest end-use energy sector! Source: OECD/IEA (2013) Transition to Sustainable Buildings

24 Energy use by end-use sectors in the EU Source:

25 How we use energy Sweden 33% 22% 33%

26 Energy use for a typical building in a holistic perspective Source: WBCSD (2008). Energy Efficiency in Buildings Facts & Trends. Full report

27 Energy use in an Swedish old building Typical miljonprogrammet building Final operation energy use (kwh/m2)

28 Energy use in a recent Swedish building Space heating Tap water heating Electricity for household and facility use Electricity for ventilation Final operation energy use (kwh/m2)

29 Energy use in a Swedish low-energy building Space heating Tap water heating Ventilation electricity Household electricity Winner of 2010 Swedish large prize for Society Constructions (Samhällsbyggarpriset) Final operation energy use (kwh/m2)

30 Operation energy Old and New typical Swedish building, and Low-energy building Household appliances Hot water Fans (ventilation) Space heating Old typical Swedish building New typical Swedish building Low energy building Source: Karlsson and Moshfegh (2007) A comprehensive investigation of a low-energy building in Sweden. Renewable Energy Volume 32, Issue

31 Key facts Why buildings matter Our society is very dependent on unsustainable energy sources 40% of the global primary energy is used in the building and construction sector Production, construction, heating, cooling, ventilation, lighting, demolition 33% of the global carbon dioxide emissions is linked to building energy use Energy-related emissions from fuel combustion Non-energy related emissions from cement process reaction Buildings offer large potential to reduce energy use and mitigate climate change There is potential for energy savings of 50 90% in existing and new buildings IPCC 2014

32 Climate- and energy-effective building 1. Very well insulated envelope 2. Airtight envelope 3. Energy-saving hot water fittings 4. Energy-saving appliances and white goods 5. Energy efficient and renewable supply s 6. Low-energy and low- carbon building materials and production of houses

33 Thank you!

34 Livscykel- och analys av byggnader

35 Standard and low-energy houses Production stage energy 10-11%* of the total energy use in standard Swedish buildings Standard house Up to 45% ** of the total energy use in a lowenergy Swedish building Low-energy house *Adalberth, K Energy Use and Environmental Impact of New Residential Buildings. Ph.D. Dissertation, Department of Building Physics, Lund University of Technology, **Thormark, C A low energy building in a life cycle: its embodied energy, energy need for operation and recycling potential. Building and Environment, 37:

36 Concrete- vs wood-frame building How do you measure or compare? Energy? CO 2 emissions? Life cycle thinking on buildings

37 System boundaries: simplified vs comprehensive Source: Wood in carbon efficient construction : Tools, methods and applications. Finland, Hämeen Kirjapaino Oy

38 Nordic electricity market Sweden ~ 150 TWh EU 27 +Norway ~ 3000 TWh The Nordic Countries ~ 380 TWh Fossil fuels Nuclear Grid connection of Nordic countries Net imports Hydro Other renewables Source: Vattenfall

39 Buildings in a life cycle perspectivemore complex than most products!! Energy supply - Full energy chain accounting, including conversion / fuel cycle losses Production / Retrofitting phases - Extraction, processing and transport of materials - Energy recovery from biomass residues - On-site construction work Operation phase - Space heating - Electricity for ventilation - Tap water heating - Electricity for household and facility management - Demolition End-of-life phase - Energy recovery from wood - Recycling of concrete and steel to replace virgin raw material Greenhouse gas (GHG) emission or displacement - Energy (fossil fuel) and non-energy related emissions

40 LCA of conventional building 4-storey building with 16 apartments and 1190 m 2 living area Built in Växjö, Sweden, during the 1994 building code regime We compared versions of this building designed to the versions of the building designed with wood-frame or concrete-frame

41 Macadam Concrete Plasterboard Lumber Mortar Plywood Insulation Particleboard Iron/steel Glass Putty/fillers Blocks Appliances Paper Plastic (PVC) Ceramic tiles Paint Porcelain Copper Zinc Material mass (kg). Material mass of buildings Wood frame Concrete frame

42 Primary energy use (kwh/m 2 ) Production primary energy balance of buildings 800 Concrete f rame Wood f rame Material production On-site construction Biomass residue recovery Total

43 Building heat demand (kw) Annual profile of final space heat demand of buildings built to different standards and located in Växjö 40 Wood f rame (Passive) Concrete f rame (Passive) Wood frame [BBR 2009] Concrete frame [BBR 2009] Wood f rame {Ref erence} Concrete f rame {Ref erence} Day

44 Primary energy use (kwh/m 2 ) Annual operation primary energy use of buildings with different heating s located in Växjö 500 Household electricity Tap water heating Ventilation electricity Space heating Concrete frame Wood frame Concrete frame Wood frame Concrete frame Wood frame Electric resistance heating Heat pump District heating Supply : Biomass-based steam turbine

45 Primary energy use (kwh/m 2 ) End-of-life primary energy balance of buildings 100 Concrete f rame Wood f rame Demolition Concrete recycling Steel recycling Wood recovery for biofuel Total

46 Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Primary energy use (kwh/m 2 ) Life cycle Wood primary recovery for bioenergy energy Steel use recyclingof district heated Concrete recycling Demolition Household electricity Tap water heating buildings in Växjö for a 50-year lifespan Ventilation electricity Space heating On-site construction Material production for bioenergy Steel recycling for Wood recovery for bioenergy Steel recycling Building Demolition demolition Concrete recycling Building Demolition demolition Household electricity Household Tap water heating Household Tap water heating electricity electricity Ventilation electricity Space heating Tap water heating On-site construction Material production Ventilation electricity Space heating On-site construction Material Wood recovery production for for bioenergy bioenergy S Demolition Concrete recycling residues/ recycling residues/ End-of-life End-of-life ben D Wood Wood recovery for for bioenergy Production Household Steel Production Steel recycling recycling residues electricity electricity T residues for Concrete recycling Ventilation Wood Demolition Ventilation Wood recovery Demolition recovery electricity for electricity for bioenergy bioenergy S Concrete recycling D Concrete recycling Household Household electricity electricity On-site Tap On-site Tap water water construction heating construction heating M Household electricity T Ventilation electricity Household electricity Ventilation electricity Ventilation Space heating Ventilation Space heating electricity On-site construction electricity On-site Material construction production S On-site On-site construction On-site Material construction production M Supply : Biomass-based steam turbine Concrete Wood frame BBR 1994 BBR Passivhus frame BBR BBR 2009 Pass BBR BBR BBR BBR BBR BBR Passivhus Passivhus BBR BBR BBR 2009 Passi Concrete Wood BBR BBR Electric heated building Concrete Concrete frame District frame Wood Woodheated building Electric Electric Electric heated heated heated 4000building building frame frame District District frame frame heated heated building Primary energy (kwh/m 2 ) Concrete frame Wood frame Difference Total used Benefits from production and end-of-life Balance Concrete

47 Net carbon emission (t C) Net carbon emissions of buildings at year of construction 150 Concrete frame Wood frame Material production Net cement reactions Biomass fossil fuel replacement Forest carbon stock change Building carbon stock change Total

48 Net carbon emission (t C) Net carbon emissions of buildings over life cycle of buildings 100 Concrete frame Wood frame Material production Net cement reactions Biomass fossil fuel replacement Forest carbon stock change Building carbon stock change Recycled concrete and steel benefits Total

49 Modern wood building s CLT Prefabricated massive wood elements Beam and column LVL and glulam columns and beams Modular Individual volumetric elements

50 Recently completed project Wood in Carbon Efficient Construction - CO2 An European project with a focus on carbon efficient wood construction 20 partners in Austria, Finland, Germany, Italy and Sweden and 7 Work Packages Financed by WoodWisdom-Net and industries Project findings documented in journal articles and a book: Dodoo, A., Gustavsson, L., Sathre, R. (2014a). Lifecycle primary energy analysis of lowenergy timber building s for multi-story residential buildings. Energy and Buildings Dodoo, A., Gustavsson, L., Sathre, R. (2014b). Lifecycle carbon implications of conventional and low-energy multi-storey timber building s. Energy and Buildings Wood in Carbon Efficient Construction - Tools, methods and applications. ISBN

51 Analysis of modern wood building s Case-study descriptions Wälludden Wood framed 4 stories 16 apartments Case-study building Case-study building used to model three building s (CLT, Beam & column, Modular ) for conventional and passive houses located in Växjö (6.5 o C*), Östersund (2.5 o C*) or Kiruna (-1.2 o C*) * Annual average temperature

52 Specific energy requirements of the Swedish building Code (BBR 2012) and passivhus criteria Description BBR 2012 electric heated BBR 2012 non-electric heated Passive house 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

53 External wall details for conventional buildings

54 External wall details for passive buildings

55 Characteristics for conventional and passive houses Description CLT Number of floors 4 Apartment area (m 2 ) 928 Common area 130 Room height 2.55 Beam and column Modular U-values (W/m 2 K): Conven. Passive Conven. Passive Conven. Passive Roof External wall Separating wall Internal floors Windows Doors Ground Floor Infiltration (l/s m 50 Pa) Mechanical ventilation Exhaust Balanced Exhaust Balanced Exhaust Balanced Heat recovery (%) Water taps Standard Efficient Standard Efficient Standard Efficient

56 Concrete Iron/steel Lumber Particle board Plywood Laminated wood floor CLT LVL Glulam Stonewool insulation Glass wool insulation Plasterboard PVC Polyurethane Expanded polystyrene (EPS) Mortar Aluminium Zinc & copper Glass Paint Putty & fillers Crushed stone Mass (tons) Material mass for building s Conventional buildings 350 CLT Beam & column Modular

57 Primary energy use for material production Conventional buildings Wooden materials Glasswool Plasterboard Stonewool Iron/steel Concrete Aluminium Polyurethane EPS Glass Zinc and copper PVC Paint Crushed stone Putty and fillers Mortar Asphalt Primary energy use for material production (kwh/m 2 [living area]) CLT Beam and column Modular Source: Dodoo et al. (2014a).

58 Primary energy for production of building elements Conventional buildings Production primary energy for elements (kwh/m 2 [living area]) External & internal walls Intermediate floor & ceiling Roof-ceiling Foundation Windows & doors Elevator & stair Services & installations Finishes CLT Beam and column Modular Source: Dodoo et al. (2014a).

59 Carbon emission for material production Plasterboard Glasswool/stonewool Iron/ steel Wooden materials Concrete Polyurethane EPS Glass Aluminium Copper Crushed stone PVC Paint Putty and fillers Mortar Asphalt Infill gas for Ceramics Greenhouse gas (fossil carbon) emission (kg CO 2 /m 2 [living area]) CLT Beam and column Modular Main bars show conventional houses Error bars show passive houses Source: Dodoo et al. (2014b).

60 Primary energy use (kwh/m 2 ) Greenhouse gas emission (kgco 2 /m 2 ) Greenhouse gas emission (kgco 2 /m 2 ) Production primary energy use and carbon emission Material production Building construction Cement reactions CLT Beam & column Conventional Modular 0 CLT CLT Beam & column Modular Beam & Modular column Passive 0 CLT Beam & column Modular CLT Beam & Conventional column Modular CLT Beam & column Passive Modular

61 Heating value (kwh/m 2 ) Heating value of production biomass residues CLT Beam & column Modular CLT Beam & column Modular Conventional Passive

62 Greenhouse gas stock (kgco 2 /m 2 ) Carbon stock in production biomass residues and materials 0 Carbon stock in biomass residues Carbon stock in building material CLT Beam & column Modular CLT Beam & column Modular Conventional Passive

63 Final energy use (kwh/m 2 ) Annual final energy for space heating Conventional and passive houses in different locations 150 Conventional Passive CLT Beam & column Modular CLT Beam & column Modular CLT Beam & column Modular Växjö climate Östersund climate Kiruna climate

64 Annual final and primary energy for space heating and ventilation Passive houses located in Växjö Supply : Biomass-based steam turbine

65 Primary energy balance (kwh/m 2 ))))) Greenhouse gas balance (kgco 2 /m 2 ))))) End-of-life primary energy and carbon balances Demolition Concrete recycling Steel recycling Heating value or carbon stock of recovered wood 200 Primary energy balance 100 Greenhouse gas balance CLT Beam & column Modular CLT CLT Beam & column Beam & column Modular Modular CLT CLT Beam & column Beam & column Modular Modular CLT Beam & column Modular Conventional Passive Conventional Passive

66 Why s perspective? Feist, W Life-cycle energy balances compared: low-energy house, passiv house, self-sufficient house Proceedings of the International Symposium of CIB W67, Vienna, Austria (1996), pp

67 Conclusions Full life cycle and energy chains should be considered to optimize primary energy use and GHG emission of buildings Passive house reduce primary energy use and greenhouse gas emission, but the significance depends on energy supply Biomass-based cogenerated district heating gives low primary energy use and carbon footprint, even with conventional house End-of-life benefits are significant for energy recovery of wood, while the benefit of recycling steel and concrete are small A wood-frame passive house supplied with cogenerated district heat from biomass gives low life cycle impacts

68 Thank you!

69 Systems upplägg till byggnads energianvändning och tillförsel

70 Contents Background Why energy renovation of existing buildings is important Demand-side measures in a s perspective Why interactions need to be considered Implications of different categories of end-use energy efficiency measures Examples of analysis of energy demand and supply for a district heated building

71 European Union s goals

72 Estimated absolute contribution to EU target by targets defined by Member States so far

73 Swedish political targets on building energy use The government has a target of reducing the final energy use per heated building area by 20% by 2020 and 50% below 2050 The reference is 1995 level Swedish Government Bill 2005/06:145

74 Sveriges totala energianvändning Källa: Energimyndigheten. Energiläget

75 Sveriges elanvändning per sektor Källa: Energimyndigheten. Energiläget

76 Percentage of buildings Swedish multi family houses building stock presented as a percentage of the final year of construction 100% 80% 60% 40% 20% 0% < >1990 Total Swedish residential building stock by period of construction

77 Bought energy for space heating, hot water and electricity according to final year of construction Source: Janson, U., Passive houses in Sweden- From design to evaluation of four demonstration projects. Lund University, Sweden.

78 How can an "optimal" solution be decided when a building s energy efficiency is improved?

79 Schematic of the Swedish energy Source:

80 Modelling building energy renovation measures

81 Intensive-energy renovation for a case-study building Wood-framed 4 stories 16 apartments 1190 m 2 usable floor area Built in Växjö Description U-value (W/m 2 K) Air leakage Ground floor External walls Windows Doors Roof at 50 Pa (l /s m 2 ) Water taps Mechanical ventilation Case-study building conventional Exhaust air

82 Analysed energy renovation measures Description Improved taps Effect of improvement Reduced hot water used by 40% a 15 cm additional mineral wool insulation added to the roof U-value from 0.13 to 0.08 W/m 2 K Windows replaced by triple-glazed units with krypton infill Doors replaced by triple-glazed units with krypton infill U-value from 1.9 to 0.90 W/m 2 K U-value from 1.19 to 0.90 W/m 2 K 25 cm additional mineral wool insulation added to external walls U-value from 0.20 to 0.10 W/m 2 K Installation of ventilation heat recovery unit with 80% efficiency Electric efficient household appliances Reduced ventilation heat loss by 57% b Reduced household electricity by 44% c a Estimated based on Swedish Energy Agency (2006). b Modeled with [VIP+ Strusoft 2008]. c Estimated based on Tommerup et al. (2007).

83 Demand-side measures in a s perspective In a perspective, several aspects has to be considered To get an optimal solution considering available resources Demand side model Case-study building Energy efficiency measures: Improved taps, windows/doors, roof, external walls, ventilation heat recovery Energy demand profiles Reference district heat production Supply side model Minimum cost district heat production Environmental taxation scenarios: No tax Swedish tax Reference power plant Social carbon cost 550 ppm Social carbon cost BAU Gustavsson, L., Dodoo, A., Truong, N.L., Danielski, I. (2011). Primary energy implications of end-use energy efficiency measures in district heated buildings. Energy and Buildings

84 Dynamic hour-by-hour simulation

85 Annual final operation energy use (kwh/m 2 ) before and after the retrofitting measures are applied Applied energy saving measures Space heating Tap water heating Ventilation electricity Household/ facility electricity Total Initial Savings + Improved taps Improved windows & doors Additional roof insulation Additional external walls insulation + Ventilation heat recovery Efficient electric appliances

86 Building s final space heating profile for January to December kwh day 1 day 41 day 81 day 121 day 161 day 201 day 241 day 281 day 321 day 361

87 Annual final heat use profiles of the building with the end-use energy efficiency measures

88 District heat demand (MW) Reduction of district heat demand (kw) Building heat demand (kw) Heat load (kw) Initial + Improved taps Heat demand of buildings depends on temperature + Improved windows & doors + Additional roof insulation and applied energy efficiency measures + Additional external wall insulation Ventilation heat recovery Initial 50 + Improved taps 40 + Improved windows & doors + Additional roof insulation 30 + Additional external wall insulation Day + Ventilation heat recovery Day 160 Boiler - Fuel oil 140 Boiler - Coal Biomass 120 CHP - BST 100 Matching the heat production unit: value of heat saving depend on the production unit Produced by Oil boiler Boiler - Fuel oil Boiler - Biomass Produced by Biomass boiler CHP - BST Produced by CHP unit Day Day

89 Primary energy saving (kw) Reduction of district heat demand (kw) Changes in district heat demand may influence the coproduction of electricity Produced by Oil boiler Day Boiler - Fuel oil Boiler - Biomass Produced by Biomass boiler CHP - BST Produced by CHP unit Cogenerated electricity Reduction in district heat production also cause a reduction in cogenerated electricity in certain periods Actual saving Day From DH s Used by standalone power plants Estimation of primary energy saving have to consider the primary energy use to compensate the electricity reduction from CHP unit.

90 Energy savings (MWh) Ratio of primary and final energy savings Ratio of primary and final energy savings Final and primary energy savings of energy efficiency measures Improved taps Improved taps + windows &doors Improved taps + windows & doors + roof Improved taps + windows & doors + roof + external walls Improved taps + windows & doors + roof + external walls + ventilation heat recovery 1,0 1,0 0,8 0,8 0,6 Improved taps Improved windows & doors Additional roof insulation ,6 0,4 Additional external wall insulation Ventilation heat recovery ,4 0, Final energy Primary energy 0,0 0,2 Primary energy savings of energy efficiency 0,0 measures depend on: the energy efficiency measures the characteristics of the district heat production

91 Conclusions In selecting energy retrofit measures for a building, it is important to consider their interaction with heat supply District heating must be combined with a much more energy efficient built environment A -wide primary energy perspective is necessary when evaluating the energy savings for VHR

92 Thank you!