European track towards Zero Energy Buildings

Transcription

1 European track towards Zero Energy Buildings Stefano Paolo Corgnati TEBE Research Group, Department of Energy, Politecnico di Torino REHVA President-elect

2 Why do we talk about nzeb? 1997:Kyoto Protocol 2008: EU Climate and Energy Package Target Energy Roadmap 2050 in Europe Directive 2002/91/EC of the European Parliament and of the Council of 16 December 2002 on the energy performance of buildings - EPBD Decreto Legislativo 19 agosto 2005, n. 192: "Attuazione della direttiva 2002/91/CE relativa al rendimento energetico nell edilizia" Directive 2010/31/EU of the European Parliament and the Council of 19 May 2010 on the energy performance of buildings (recast) EPBD recast in Italy 2005 Legge 3 agosto 2013, n. 90: "Conversione in legge, con modificazioni, del decretolegge 4 giugno 2013, n. 63, recante disposizioni urgenti per il recepimento della Direttiva 2010/31/UE del Parlamento europeo e del Consiglio del 19 maggio 2010, sulla prestazione energetica nell'edilizia per la definizione delle procedure d'infrazione avviate dalla Commissione europea, nonché altre disposizioni in materia di coesione sociale" 2013 EPBD recast introduced the nzeb concept

3 EPBD EPBD recast recast nzeb Article 2.2 Article 2.2 nearly zero-energy building means a building that has a very high energy nearly performance, zero-energy [ ]. building The nearly means zero a or building very low that amount has a of very energy high required energy should performance, be covered [ ]. to The a nearly very significant zero or very extent low amount by energy of energy from renewable required should sources, be including covered to energy a very from significant renewable extent sources by energy produced from on-site renewable or nearby sources, including energy from renewable sources produced on-site or nearby Article 2.4 Article 2.4 energy performance of a building means the calculated or measured amount energy of performance energy needed of to a meet building the energy means demand the calculated associated or measured with a typical amount use of of energy the building, needed to which meet includes, the energy inter demand alia, energy associated used with for a heating, typical cooling, use of the ventilation, building, hot which water includes, and lighting inter alia, energy used for heating, cooling, ventilation, hot water and lighting Article 2.14 Article 2.14 cost-optimal level means the energy performance level which leads to the cost-optimal lowest cost level during means the estimated the energy economic performance lifecycle level [ ] which leads to the lowest cost during the estimated economic lifecycle [ ] Article 4.1 Article 4.1 Member States shall take the necessary measures to ensure that minimum Member energy States performance shall take the requirements necessary for measures buildings to or ensure building that units minimum are set energy with a view performance to achieving requirements cost-optimal for levels. buildings [ ]. or building units are set with a view to achieving cost-optimal levels. [ ]. >> 0 energy performances energy needs 100% of energy needs renewable energy

4 EPBD recast Nearly-zero energy building (nzeb) a building that has a very high energy performance whose nearly-zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby Energy performance of a building calculated or measured amount of energy needed to meet the energy demand associated with a typical use of the building, which includes, inter alia, energy used for heating, cooling, ventilation, hot water and lighting DISPOSITIONS 31 December December 2020 new buildings occupied and owned by PUBLIC authorities are nzebs ALL new buildings are nzebs

5 What does nzeb mean? nzeb nearly At a national level it is possible to fix minimum energy performance requirements of about 0 kwh/(m 2 a). The achievement of these low consumptions is technically feasible through optimal combination of energy efficiency measures and technologies for the exploitation of renewable energy sources, which may or may not be cost-optimal. The exploitation of renewable sources is fundamental for reaching the nearly or net-zero energy target. nearly Zero Energy Building nzeb NZEB Net Zero Energy Building Energy use > 0 kwh/(m 2 a) Energy use = 0 kwh/(m 2 a) autonomous and grid connected Zero Energy Buildings ZEB NZEB grid connected Zero Energy Buildings, with a balance between energy taken from and supplied back to the energy grid over a year

6 Balance between the renewable energy produced on-site and the building s energy uses (LOAD/GENERATION balance) nzeb Zero Energy Which energy? SITE Energy What does nzeb mean? Balance between the renewable energy produced/bought and the building s energy uses (IMPORT/EXPORT balance) Balance between the incomes due to renewable energy production and the building s energy costs PRIMARY Energy Energy COST Energy EMISSIONS Balance between the emissions credits gained by producing renewable (zero emissions) energy and the CO 2 emissions related the building s energy uses

7 Boundary conditions Energy uses Energy from renewable sources Energy needs for: Heating Cooling Ventilation DHW Lighting Appliances

8 What s new in High Performing Buildings? Amount of space heating has got significantly smaller in the total heating needs Energy needs of electricity is becoming predominant ( all-electric homes)

9 New requirements for HVAC systems Small heating loads Significant internal gains Large share of DHW needs Shortening of heating periods Overheating problems Nominal power of heating systems Response of building/hvac system Focus changing to DHW preparation System recovery Passive cooling /active cooling

10 Project assessment DESIGN TEAM ECONOMIC FEASIBILITY COST CONTROL Building designer Energy consultant Economic evaluator Evaluation between preliminary and final design Achieve the energy performance level which leads to the lowest cost during the estimated economic lifecycle /m 2 Cost Optimal Analysis Customer s awareness [EPBD recast 2010/31/EU] Global cost kwh/m 2 year Primary Energy Consumption

11 Cost-optimal analysis Energy performance Global cost Energy needs for: Heating Cooling Ventilation DHW Lighting Appliances Investment costs Energy costs Maintenance costs Replacement costs Final value 11

12 Minimum energy performance requirements by law Cost-optimal performance level EPBD recast: expected outcomes nearly Zero Energy performance level Global cost [ /m 2 ] energy need GAP financial GAP Global cost [ /m 2 ] energy need GAP financial GAP Global cost [ /m 2 ] Primary energy [kwh/m 2 ] Primary energy [kwh/m 2 ] Primary energy [kwh/m 2 ] EPBD EPBD recast 2021 Minimum energy requirements are set without considering cost-optimal level nor nzeb level Minimum energy requirements are costoptimal; nzeb requirements are set but are not cost-optimal Minimum energy requirements are cost-optimal and coincident with nzeb level

13 Energy Efficiency Measures (EEMs) and packages Combination of building envelope EEMs PACKAGES OF EEMs Combination of building system EEMs Which combination leads to the cost optimal level? Combination of EEMs that exploit renewable energy sources

14 Energy Efficiency Measures (EEMs) and packages Measures affecting Envelope components Renewables Measures affecting HVAC Systems Measures affecting the Lighting system

15 Cost Optimal Graph

16 CASE STUDIES

17 CorTau House in Piedmont (Italy) Design Team: M. Luciano, S.P. Corgnati Typology of intervention: refurbishment of a traditional rural building (2014) Features: concrete structure, rockwool external insulation, triple-glazed LowE windows, water-to-water heat pump, radiant panels for heating and cooling, PV panels (7 kw peak ), mechanical ventilation system with heat recovery nzeb ALL ELECTRIC house: all building energy needs are covered by energy produced on-site with PV system

18 CorTau House: first concept Preliminary design phase Basic HVAC System Energy Fluxes

19 CorTau House in Piedmont (Italy) NATIONAL LEVEL TURIN S REGULATION LEVEL PASSIVHAUS LEVEL CLIMATEHOUSE GOLD LEVEL Matrix of EEMs

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21 Global cost [ /m 2 ] CorTau House in Piedmont (Italy) Cost Optimal Curve Positive energy N-ZEB -50% -30% -20% The same global cost Different energy savings Cost optimal level Package 2C Turin s regulation thermal insulation level + Heat pump + PV 7kW p Primary energy consumption [kwh/m 2 year] 21

22 Global Cost [ /m 2 ] CorTau House in Piedmont (Italy) Sensitivity analysis: national tax deductions - 65% Eco-bonus - 50% Refurbishment -50% -30% -20% BASE scenario SENSITIVITY scenario. COST OPTIMAL RANGE Primary energy consumption [kwh/m 2 year] 22

23 CorTau House in Piedmont (Italy) Construction site phases

24 THANK YOU FOR YOUR ATTENTION