Ministry of Economic Development

Transcription

1 ENER (IT-EN) Ministry of Economic Development Directorate-General for the Electricity Market, Renewables and Energy Efficiency, and Nuclear Energy UPDATE OF THE APPLICATION IN ITALY OF THE METHOD FOR CALCULATING COST-OPTIMAL LEVELS FOR MINIMUM ENERGY PERFORMANCE REQUIREMENTS (DIRECTIVE 2010/31/EU ARTICLE 5) March 2018

2 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements NOTES The Ministry of Economic Development has set up a working group to update the comparative analysis method provided for in Article 5 of Directive 2010/31/EU. The group follows the appropriate guidelines in compliance with Regulation (EU) No 244/2012 of 16 January The following entities have taken part in the working group, coordinated by the Ministry of Economic Development: ENEA (Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile), the Italian Thermal Engineering Committee (Comitato Termotecnico Italiano, CTI), the Polytechnic University of Turin (Politecnico di Torino) and the Polytechnic University of the Marches (Università Politecnica delle Marche). P. Signoretti, D. Iatauro, C. Romeo, L. Terrinoni - ENEA R. Nidasio, CTI V. Corrado, Polytechnic University of Turin G. Riva, Polytechnic University of the Marches 2

3 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements CONTENTS 1. INTRODUCTION MAIN NEW FEATURES INTRODUCED AND STRUCTURE OF THE WORK ESTABLISHMENT OF REFERENCE BUILDINGS ENERGY EFFICIENCY MEASURES DESCRIPTION OF MODEL FOR CALCULATING ENERGY PERFORMANCE ASSESSMENT OF COSTS OF ENERGY EFFICIENCY MEASURES FRAMEWORK OF CALCULATION PROCEDURE REPRESENTATION OF PROCESSING AND RESULTS

4 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements 1. INTRODUCTION The Energy Performance of Buildings Directive ( EPBD, Directive 2002/91/EC), and the recast EPBD (Directive 2010/31/EU) introduced the principles for improving the energy performance of buildings. The recast EPBD required the Member States to define the minimum energy performance requirement for buildings on the basis of cost-optimal levels. To this end, the Directive introduced a method of comparative analysis for determining the reference requirements for national standards. The Delegated Regulation (EU) No 244/2012 and the subsequent Commission Guidelines of 19 April 2012 set out a methodology framework for calculating the optimal energy requirements of buildings, from both a technical and an economic point of view. The application in Italy of the method proposed by the Commission has made it possible to identify minimum energy performance requirements based on cost-optimal levels for new buildings and for existing buildings undergoing major or minor renovation of structures and installations. These requirements were introduced into Italian law by Decree of the Minister for Economic Development of 26 June The report entitled Methodology for calculating cost-optimal levels of minimum energy performance requirements (Article 5(2) of Directive 2010/13/EU) sent to the Commission in August 2013 presented the results of these calculations and compared them with the requirements in force. This document aims to present the principles and rules that are being followed to update the comparative analysis methodology, which must be reported at regular intervals of no more than five years (Article 5 of Directive 2010/31/EU). 2. MAIN NEW FEATURES INTRODUCED AND STRUCTURE OF THE WORK The update of the comparative methodology currently underway introduces some new features since the assessments made in 2013, aimed at refining the analysis in the light of experience and making it more effective in achieving the objective. The following new features are planned: 1. Introduction and assessment of the assumption of not carrying out measures on existing buildings. As a result of this assumption, in the technical/economic assessment of energy efficiency measures (EEM), for existing buildings the overall costs of measures will be taken into consideration, not the reduced costs if work were done in a window of opportunity. In that case only costs relating to simple energy efficiency measures could be considered in so far as they were carried out at the same time as unplanned maintenance work, which had to be done in any case. This additional assessment makes it possible to calculate a more realistic amount of investment and to propose optimal levels closer to common practice, and to give more accurate indications for the purpose of assessing whether or not it is financially worthwhile to take steps to improve the energy efficiency of buildings. 2. Establishment of a new intended use among the reference buildings. The assessments will be carried out for the reference buildings previously examined and also for a school building representative of the period , located in Italian climatic zones B ( degreedays) and E ( degree-days). 3. More specific and accurate assessment of thermal bridges for both new and existing buildings. 4

5 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements 4. The energy performance of the reference buildings will be assessed using the semi-stationary calculation method according to Italian standard UNI/TS The updated version of the comparative analysis method will use the latest technical specifications (for years ); similarly, the climate data will refer to the new technical standard UNI : Change in levels of energy efficiency measures (EEM). The types of action/measure considered will be the same as those used in the 2013 assessment, although in some cases the number of levels examined and/or their intensity (scale of values) will be changed. 6. Updating of overall costs. The main changes will concern the cost values of energy carriers (methane gas and electricity) and of investment in energy efficiency measures (EEM). As in the 2013 exercise, for application of the comparative method, optimisation will be based on seeking partial optimums, using a sequential process and considering individual solutions. In order to identify the optimal energy efficiency measures package incurring the lowest overall cost over the life cycle of each reference building, the procedure will assess the annual energy consumption for heating, domestic hot water production (DHW) cooling and lighting (in the case of non-residential buildings) of the building, and the use of renewable energy sources (heat pump, solar thermal for DHW production and photovoltaic) and the overall costs (maintenance, operating costs and any disposal costs). The work will be structured in the following stages: A. Characterisation of reference buildings a. Residential buildings b. Office buildings c. School buildings B. Development of the package with integrated spreadsheets a. Calculation of energy performance b. Calculation of overall cost c. Optimising instrument C. Analysis of the energy efficiency measures and the relative levels a. Measures relating to the building envelope b. Measures relating to installations D. Cost analysis a. Investment costs b. Energy costs c. Other costs E. Identification of cost-optimal levels of energy performance F. Sensitivity analysis G. Comparison with results obtained in ESTABLISHMENT OF REFERENCE BUILDINGS In the comparative analysis as applied by Italy and sent to the Commission in August 2013, the reference buildings used were virtual buildings, i.e. representative archetypes of a given category. 5

6 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements For this purpose we referred to the TABULA project database for existing residential buildings, while for new buildings and office buildings we used the types defined by ENEA. In the updated methodology, alongside the four types of building already analysed, a school building is newly introduced, situated in two climate zones (B and E, in accordance with Presidential Decree 412/93). Therefore three types of residential building will be analysed (single-family dwelling, small and large apartment block), an office building and a school building (new case study), located in Italian climate zones B ( degree-days) and E ( degree-days. Residential buildings and office buildings cover two categories of measure: existing buildings (divided in two different time periods: and ) and new construction; the school building is representative of the period. A total of 26 case studies will be analysed, including 18 residential buildings (six new and 12 existing) six office buildings (two new and four existing) and two existing school buildings. INTENDED USE TYPE OF BUILDING CONSTRUCTION PERIOD CLIMATIC ZONE B E CASE STUDIES Single-family house (RMF) (E1) 1 1 Existing (E2) 1 1 New (N0) 1 1 RESIDENTIAL Small apartment block (RPC) (E1) 1 1 Existing (E2) 1 1 New (N0) Large apartment block (RGC) (E1) 1 1 Existing (E2) 1 1 New (N0) 1 1 TERTIARY SECTOR Office buildings (UFF) (E1) 1 1 Existing (E2) 1 1 New (N0) SERVICES School buildings (SCU) Existing (E1) TOTAL 26 Table 1 - Case studies The following tables summarise the geometric/dimensional characteristics of the building models and the thermal/physical parameters that make up the building envelope by type, by construction period and by climate zone. The residential building models correspond to the following types of building: single-family house consisting of a single floor; 6

7 CLIMATIC ZONE Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements small apartment block of 3 floors, with 6 housing units; large apartment block of 8 floors, with 24 housing units. These buildings have the form of a regular box and are equipped with a loft (not heated), with insulated roof, and they stand on a non-air-conditioned space (a garage, for example). GEOMETRIC DATA CONSTRUCTION DATA ID of building A f V g A env A w A env /V g h n,interp floors units U wall U w U roof/uf U lf [m 2 ] [m 3 ] [m 2 ] [m 2 ] [m -1 ] [m] [W/m 2 K] [W/m 2 K] [W/m 2 K] [W/m 2 K] RMF_E1 RMF_E2 RMF_N B E B E B E Table 2 - Principal data of residential reference buildings - single-family house 7

8 CLIMATIC ZONE CLIMATIC ZONE Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements GEOMETRIC DATA CONSTRUCTION DATA ID of building A f V g A env A w A env /V g h n,interp floors units U wall U w U roof/uf U lf [m 2 ] [m 3 ] [m 2 ] [m 2 ] [m -1 ] [m] [W/m 2 K] [W/m 2 K] [W/m 2 K] [W/m 2 K] RPC_E1 see original for picture B E RPC_E B see original for picture E RPC_N0 see original for picture B E Table 3 - Principal data of residential reference buildings small apartment block GEOMETRIC DATA CONSTRUCTION DATA ID of building A f V g A env A w A env /V g h n,interp floors units U wall U w U roof/uf U lf [m 2 ] [m 3 ] [m 2 ] [m 2 ] [m -1 ] [m] [W/m 2 K] [W/m 2 K] [W/m 2 K] [W/m 2 K] RGC_E1 see original for picture B E RGC_E B see original for picture E RGC_N0 see original for picture B E Table 4 - Principal data of residential reference buildings large apartment block 8

9 CLIMATIC ZONE CLIMATIC ZONE Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements The models for office buildings correspond to the following two types of building, characterised by a different distribution of internal space, different measurements and different ratios between transparent and opaque surfaces. - 2-floor office building; - 5-floor office building. GEOMETRIC DATA CONSTRUCTION DATA ID of building A f V g A env A w A env /V g h n,interp floors units U wall U w U roof/uf U lf [m 2 ] [m 3 ] [m 2 ] [m 2 ] [m -1 ] [m] [W/m 2 K] [W/m 2 K] [W/m 2 K] [W/m 2 K] UFF_E1 see original for picture B E UFF_E B see original for picture E UFF_N0 see original for picture B E Table 5 - Principal data of office reference buildings The new model introduced is an existing school building, dating back to the 1940s, spread over four floors above ground with a non-heated basement. The outer perimeter walls are solid clay-brick cavity walls, the upper floor of the main building is in non-insulated clay-cement, and is directly under the unheated loft; the ground floor flooring is partly over the ground and partly over the unheated basement; there are two types of window: timber frame with single glazing, original and in disrepair, and aluminium frame with double glazing. GEOMETRIC DATA CONSTRUCTION DATA ID of building A f V g A env A w A env /V g h n,interp floors units U wall U w U roof/uf U lf 9

10 OPAQUE ENVELOPE Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements [m 2 ] [m 3 ] [m 2 ] [m 2 ] [m -1 ] [m] [W/m 2 K] [W/m 2 K] [W/m 2 K] [W/m 2 K] SCU_E1 see original for picture B E Table 6 - Principal data of school reference building 4. ENERGY EFFICIENCY MEASURES As in the 2013 exercise, we will assess the interaction between different measures (e.g. envelope insulation affecting the power and dimensions of installations), combining them in packages and/or variants in order to create synergies to achieve better results (in terms of costs and energy performance) than can be achieved with single measures. The energy retrofitting measures considered in the comparative methodology have been divided into different categories, depending on the type of building analysed: existing residential buildings, new residential buildings, existing office buildings, new office buildings, existing school building. In each category, for each measure we use a scale of values on several levels (2 to 5); the first one represents the present situation for existing buildings, which is inferior and not in line with current legal requirements for new buildings (e.g. non-insulated envelope), and the last level always considers solutions for improvement. The intermediate levels are set incrementally to reflect the increasing performance of the parameters being assessed. Seventeen (17) energy efficiency measures will be assessed. They can be grouped into three subgroups: 1. opaque and transparent building envelope; 2. heating, cooling, DHW, ventilation and lighting installations; 3. renewable energy installations. No ENERGY EFFICIENCY MEASURES PARAMETER Max No of levels Thermal insulation of: 1 vertical covering on the outside cladding see original for pictures U wall [W/m 2 K] 5 2 alternatively in cavity (if present) 3 horizontal upper covering (top floor) 4 horizontal lower covering (first floor) U roof/uf [W/m 2 K] U lf [W/m 2 K]

11 HEATING, COOLING, DHW, VENTILATION AND LIGHTING TRANSPARENT ENVELOPE Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements 5 Installation of high energy performance door and window frames U w [W/m 2 K] 5 6 Installation of external solar shading τ sol 2 Table 7 Energy efficiency measures of envelope No ENERGY EFFICIENCY MEASURES PARAMETER Max No of levels 7 Installation of air-to-air (multi-split) cooling device see original for pictures EER 3 8 Installation of thermal energy generator for heating * η H,gn /COP 3 9 Installation of thermal energy generator for DHW * η W,gn /COP 3 10 Installation of combined thermal energy generator for heating and DHW * η H+W,gn /COP 3 11 Installation of heat pump for heating, cooling and DHW (with fan coil units) COP EER 3 12 Installation of high-precision control system for heating and cooling η rg 3 13 Heat recovery on ventilation η hru 4 14 Installation of high-efficiency lighting equipment PN [W/m 2 ] 4 15 Installation of a lighting control system Occupancy dependency factor Daylight dependency factor Constant illuminance factor Table 8 Energy efficiency measures for heating, cooling, ventilation, domestic hot water and lighting installations F o F D F C 4 11

12 RENEWABLE SOURCES Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements No ENERGY EFFICIENCY MEASURES PARAMETER Max No of levels 16 Installation of solar collectors (only for DHW) see original for pictures A coll [m 2 ] 3 17 Installation of photovoltaic panels W p [kwp] 4 Table 9 - Energy efficiency measures relating to renewable energy installations 5. DESCRIPTION OF MODEL FOR CALCULATING ENERGY PERFORMANCE The objective of the calculation procedure is to determine the annual overall energy requirement in terms of primary energy, which includes the energy requirement for heating, cooling, ventilation, domestic hot water and lighting. The procedure comprises the following phases: 1) Calculation of the building s net thermal energy needs to satisfy the users requirements. For example, in winter the energy requirement is calculated as dispersion of thermal energy for transmission through the envelope and for ventilation minus internal gains (from devices, lighting systems and occupancy) and natural energy gains (passive solar heating); 2) subtraction of thermal energy generated from renewable sources and used on site (for example, from solar collectors); 3) calculation of energy needs for each end use (space heating and cooling, hot water, lighting, ventilation) and for each energy carrier (electricity, fuels), taking account of the characteristics of generation, distribution, emissions and control systems; 4) subtraction of electricity generated from renewable sources and used on site (for example, from photovoltaic panels); 5) calculation of energy delivered to the building for each energy carrier; 6) calculation of primary energy delivered, using national conversion factors (Ministerial Decree of 26 June 2015); At national level the energy needs of buildings were calculated using the semi-stationary method based on standard UNI/TS Compared to the previous application of the comparative methodology in 2013, the following analysis was conducted with the updated package now in force based on the UNI/TS series. The following parts of the series were used: 12

13 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements o UNI/TS :2014 Energy performance of buildings Part 1: Evaluation of energy need for space heating and cooling o UNI/TS :2014 Energy performance of buildings Part 2: Evaluation of primary energy need and of system efficiencies for space heating and domestic hot water production, for ventilation and lighting in non-residential buildings o UNI/TS :2010 Energy performance of buildings Part 3: Evaluation of primary energy need and of system efficiencies for space cooling o UNI/TS :2016 Energy performance of buildings Part 4: Renewable energy and other generation systems for space heating and domestic hot water production o UNI/TS :2016 Energy performance of buildings Part 5: Calculation of primary energy and the share of energy from renewable sources In addition, for calculation of the energy need for lighting in non-residential buildings, reference was made to standard UNI EN 15193:2008 Energy performance of buildings Energy requirements for lighting. Finally, it should be remembered that evaluation of the energy performance of buildings, according to UNI/TS 11300, is a calculation based on the data for the components of a building, as assembled, under certain conditions such as climate, use and operation. This choice does not present problems for assessment of the design of new buildings, while in the case of existing buildings the lack of data on components and construction methods (which in some cases it is not possible or at least too costly to check) raises difficulties in assessing and classifying the energy status of buildings. UNI/TS 11300, in consideration of these difficulties, provides reference data for existing buildings for cases where adequate information is not available. 6. ASSESSMENT OF COSTS OF ENERGY EFFICIENCY MEASURES Costs for measures to improve the envelope The costs associated with the energy retrofitting of the building envelope will be assessed by considering their main elements, such as: opaque elements (vertical walls, floors, roofs); transparent elements (windows and doors, frames); shading systems (external fixed screens, mobile screens, etc.); and establishing a parametric index representative of the overall cost associated with possible improvements or replacement of the component. The costs will be obtained from national price lists, including the type of material used, installation, compliance with building specifications, and any associated construction works closely linked to carrying out the improvement measure. Costs for measures to improve installations The overall costs associated with the various technical building solutions adopted for the heating, ventilation, and air conditioning (HVAC) of the buildings studied, and those for energy production from renewable sources (PV and SOL), are not easy to evaluate since they are influenced by multiple parameters. 13

14 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements The wide range of models and technologies on the market make the costs parameter highly variable. It is also possible that installations that are similar in terms of energy performance have significantly different costs in that they are different in other respects, such as technologies used, materials, acoustic classification, control devices, trademarks or other components. As we did for the previous report in 2013, for the purposes of the calculation method it will be necessary to organise the various installations using standard configurations in order to identify the most common types of installation in the buildings studied. For each installation, the overall cost will be established by associating an average market cost with the main subsystems: generation, type of control, emission system and main electrical/hydraulic components. The various types of generator will be identified by taking account of the heating requirements of the various buildings being studied, both new and existing. Then these will be linked to the types of terminal and control compatible with the technologies under consideration. The costs for installations run on renewables will be assessed by looking at, for photovoltaic installations, the installed capacity with reference to a percentage of the roof surface area available, and for thermal solar installations, a surface area calculated for daily water needs in line with the intended use. 7. FRAMEWORK OF CALCULATION PROCEDURE The calculation will follow the same procedure as for the previous study: starting from the energy requirement for the reference buildings, we proceed, by way of an iterative calculation, to the package of measures that will guarantee the cost-optimal level for that specific building category. For the optimisation procedure, an optimisation macro was developed which interfaces with the spread sheets for calculating the energy requirement and the overall cost. Figure 1 charts the optimisation procedure used. 14

15 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements Key: EEM LEVELS EEM COST DATABASE EEM levels cost AUXILIARY SPREADSHE ET EEM levels parameters OPTIMISATION PROCEDURE TOOL EEM levels cost OVERALL COST OVERALL COST TOOL EEM OPTIMAL LEVELS EEM LEVELS building parameters EEM LEVELS installation parameters EEM LEVELS installation parameters UNI/TS Q H,nd UNI/TS UNI/TS heat pump district heating biomass solar thermal photovoltaic E H,W,del E PV EP UNI/TS Q C,nd Appendix D E V,del UNI/TS UNI/TS UNI/TS Figure 1 - Optimisation procedure E L,del E C,del The optimisation method considers discrete energy efficiency options (for example, different levels of installed peak capacity of photovoltaic installations), applied one at a time to obtain a new partial optimised building for each calculation step. The procedure makes it possible to establish a succession of configurations (packages of measures) which constitute partial optimums. In order to move from a partial optimum to the successive one, all the parameters that characterise the levels of each energy efficiency measure are modified. Among all the configurations analysed, the successive partial optimum is that which allows for the greatest reduction of overall cost. Example: EEM Levels No EEM Parameters UM Value of parameters 1 2 Thermal insulation of EXTERNAL WALLS with cladding U w [Wm -2 K -1 ] Thermal insulation of EXTERNAL WALLS in cavity U w,c [Wm -2 K -1 ] 3 Thermal insulation of UPPER FLOOR U r [Wm -2 K -1 ] Thermal insulation of LOWER FLOOR U f [Wm -2 K -1 ] Replacement of DOORS AND WINDOWS U w [Wm -2 K -1 ]

16 Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements 6 Installation of SOLAR SHADING (τ = 0,2) - - Fixed Mobile 7 Air-to-air COOLING DEVICE EER HEAT GENERATOR for HEATING (+ emission system) η gn,h /COP HEAT GENERATOR for DHW η gn,w /COP COMBINED GENERATOR for HEATING and DHW (+ emission system) η gn /COP Reversible air-to-air heat pump (for HEATING, COOLING and DHW) COP 3 4 EER SOLAR THERMAL DEVICE A sol [m 2 ] 2 13 PHOTOVOLTAIC DEVICE P PV [kwp] 1 14 HEAT RECOVERY DEVICE (ventilation) η hru 15 CONTROL SYSTEM - - Space 16 LIGHTING SYSTEM Lighting control system PN [Wm -2 ] F O F C F D Table 10 Example of identification of an EEM package for an optimised building 8. REPRESENTATION OF PROCESSING AND RESULTS The processing and results will be shown as for the 2013 report. For each of the 26 model buildings, alongside the optimisation trajectories represented by the Pareto Front, four more graphics will be presented, described below and shown by way of example in Figures Delivered energy by energy carrier/fuel for each of the energy services assessed (see Figure 2); 2. Index of overall energy performance and for the individual energy service based on primary energy with % breakdown of renewable and non-renewable energy share (see Figure 3); 3. Energy produced from renewable sources on site, with breakdown by individual energy service (see Figure 4); 4. Discounted costs by energy, operation and maintenance, initial investment (see Figure 4). 16

17 Energy delivered [kwha] Thousands Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements By processing the results obtained by applying the method it will be possible to establish the optimal solutions for the various categories of building and for the different scenarios predicted, and it will then be possible to compare these values with existing legal requirements. 9 Thermal energy (heat pump) 8 Electricity (photovoltaic) 7 Thermal solar 6 District heating 5 Grid Electricity 4 [see original] Biomass 3 LPG 2 Gas oil 1 Natural gas 0 H C W V L Figure2 - Energy delivered (Example of representation) 17

18 Energy from renewable sources on site [kwha] Cost [ /m 2 ] Update of the application in Italy of the method for calculating cost-optimal levels for minimum energy performance requirements Figure 3 - Energy performance indices (Example of representation) Surplus L V W 500 see original 400 C H Photovoltaic Thermal solar 0 Overall cost Operation and maintenance Initial investment Energy Figure 4 - Energy from renewable sources and discounted costs (Examples of representation) 18