Exploring feasibility thresholds for neutralizing lifecycle energy of a nZEB case study Vanessa GOMES, Marcella SAADE, Bruno LIMA, Maristela SILVA Department of Architecture and Construction, University of Campinas, vangomes@gmail.com

Introduction Net zero energy/emissions: only operation Embodied energy Energy input – building and components – not accounted for CO2eq Embodied energy Operational energy efficiency Embodied – product stage, EOL

Introduction - Transport to site = big grey area - Prediction of energy use - standard site operations = hampered by lack of data on construction equipment and activities, on energy savings - optimized site management operations - Service life of components - calculations of maintenance/repair/replacement/re-furbishment as part of the use stage - Limited data on energy used by demolition, reuse and recycling processes at EOL

Construction process stage Purpose and method Low-energy strategies, integrated design process, resource use optimization, onsite renewable energy technologies and storm water management, low energy refrigerating system, online resource use and indoor monitoring. Production cycles Building LC CED PV systems A 1-3 Product stage A 4-5 Construction process stage B 1-7 Use stage C 1-4 End-of-Life D Next product system Raw material supply Transport to manufacturer Manufacturing Transport to building site Installation into building Use Maintenance Repair Replacement Refurbishment Operational energy use Operational water use Deconstruction/demolition Transport to EoL Waste processing Disposal Reuse, recovery or recycling potential X LivingLab - UNICAMP

Purpose and method Building lifecycle stage Renewable energy generation targets Operation (net zero, NZ) statuses The PV system must produce enough energy to compensate Operational Eletricity (NRen) NZ(Emission) B The building annual non-renewable operational energy consumption Operational Eletricity (Total) NZ(E)B The total building annual operational energy consumption CED of Operational Eletricity (NRen) NZ(CEDNRen) Building The non-renewable portion of the cumulative energy demand of Brazilian mix, grid-supplied operational electricity CED of Operational Eletricity (Total) NZ(CED) Building The total cumulative energy demand of Brazilian mix, grid-supplied operational electricity

Purpose and method Building lifecycle stage Renewable energy generation targets Beyond Operation Plus statuses (+ CEDNRenPROD)   The PV system must produce enough energy to compensate Operational Eletricity (NRen) + CED (NRen) of Building Products NZ(Emission)EB Plus The building annual non-renewable operational energy consumption plus the non-renewable portion of the cumulative energy demand of building products Operational Eletricity (Total) + CED (NRen) of Building Products NZ(E)B Plus The total building annual operational energy consumption plus the non-renewable portion of the cumulative energy demand of building products CED of Operational Eletricity (NRen) + CED (NRen) of Building Products NZ(CEDNRen)B Plus The non-renewable portion of the cumulative energy demand of Brazilian mix, grid-supplied operational electricity plus the non-renewable portion of the cumulative energy demand of building products CED of Operational Eletricity (Total) + CED (NRen) of Building Products NZ(CED)B Plus The total cumulative energy demand of Brazilian mix, grid-supplied operational electricity plus the non-renewable portion of the cumulative energy demand of building products

Purpose and method Building lifecycle stage Renewable energy generation targets Lifecycle statuses The PV system must produce enough energy to compensate… Lifecycle CED (NRen) LCNZ(CEDNRen) The non-renewable cumulative energy demand over the whole building’s lifecycle Lifecycle CED (Total) LCNZ(CED) The total cumulative energy demand over the whole building’s lifecycle

Cumulative Energy Demand Purpose and method Cumulative Energy Demand Contributions from items/activities considered, in respective F.U. Construction equipment fuel use :high-rise building in Hong Kong Extraction/manufacturing – SimaPro 7.3 – Ecoinvent, ELCD, US LCI, Industry Data Transported mass, travel distance and type of modal and fuel used - Ecoinvent, ELCD – correct.: wastage factors Contributions from maintenance/repair/replacement and operational use of energy EOL1: 90% recovery rate (0% reuse | 76% recycling | 23% landfilling), crushing of concrete, recycling of metals and incineration of 90% of the wooden material, and landfilling the remaining CDW Contributions from demolition/dismantling equipment energy use and from CDW transport to end of life treatment facilities EOL2: 90% recovery rate (19% reuse | 60% recycling | 20% landfilling), 60% reuse of steel frame; recycling of metals, crushing of 90% of concrete, gypsum and uncoated glass; incineration of 90% of the wooden material, and landfilling the remaining CDW

Purpose and method Four crystalline silicon (single-Si, multi-Si) and thin film (amorphous-Si and CIGS) PV technology generations were simulated. Discounted generation losses (orientation and exposure varied for facade- and rooftop-mounted application) Degradation 0.5% per year - generation loss through time (25-year panel service life) - desired performance maintained over whole period of study

Product Stage (Modules A1, A3) CEDRen (MJ) CEDNRen (MJ) Total CED (MJ) Raw material supply (Module A1) and manufacturing (Module A3) 3,949,090.61 14,900,974.67 18,850,065.28 Construction Process Stage (Modules A2-A5) Transportation to manufacturing gates within supply chain (Module A2*) and to construction site gate (Module A4) 13,102.47 938,082.67 951,185.13 Construction – installation (Module A5) Material wastage during construction 99,955.38 606,206.21 706,161.59 CDW treatment (102.29 tones), transported 25 km (municipal facility) 65.35 5,036.75 5,102.10 Earth (547.2 tones), transported 25 km (municipal facility) 393.81 30,354.46 30748.27 Earth removal equipment (547.2 tones) 129.04 44,317.88 44,446.92 Construction equipment 162,626.33 337,904.41 500,530.74

Use stage (Modules B2-B6) CEDRen (MJ) CEDNRen (MJ) Total CED (MJ) Material replaced in Maintenance/Repair/Replacement/Refurbishment (334.52 tones) 1,552,653.13 11,445,458.00 12,998,111.14 Operational use of (electric) energy (Module B6) (111,157.20 MJelec/yr) 6,753,290.10 3,081,714.16 9,835,004.26 End of life (EOL) stage (Modules C1-C2) EOL Scenario 1 - 90%-efficient recovery (concrete and metals) demolition (1,763,52 tones) (76% recycled/23% landfilled) 387.11 132,953. 64 133,340.75 CDW (1,763.52 tones) transported to various destinations 944.14 72,773.35 73,717.50 LC Total for EOL Scenario 1 12,532,637.46 31,595,776.20 44,128,413.66   EOL Scenario 2 – 90%-recovery efficient selective dismantling (19%reuse/60%recycled, including PV panels/20%landfilled) 1,161.32 398,860.93 400,022.25 972.43 74,953.78 75,926.21 LC Total for EOL Scenario 2 12,533,052.86 31,730,910.27 44,263,963.13

Results 16% 43% 34% CED Product stage Total CED 52% 41% 7% <5% Façade Raw mat. supply and manufacturing (A1-A3) PV system plus BOS Construction process stage (A2-A4-A5) Partitions Use (B2 to B6) Structure End of Life (C1-C2) 7% 16% 43% <5% 34% CED Product stage Total CED 52% 41% <1%

Effective generation area (m2) Scenarios System power (kWp) Effective generation area (m2) Net Zero scenarios  1. Operational electricity (NRen) [NZ(Emission)EB] 3.5 20.59 2. CED Operational Eletricity (NRen) [NZ(CEDNRen)B] 12.61 74.14 3. Operational electricity (total) [NZ(E)B] 22.74 133.72 4. CED Operational Eletricity (total) [NZ(CED)B] 40.24 236.62 Plus scenarios   1a. Operational electricity (NRen) + CED (NRen) PROD [NZ(Emission)EB Plus] 64.47 379.10 2a. CED Operational Eletricity (NRen) + CED (NRen) PROD [NZ(CEDNRen)B Plus] 73.58 432.65 3a. Operational electricity total + CED (NRen) PROD [NZ(E)B Plus] 83.71 492.22 4a. CED Eletricity Operational total + CED (NRen) PROD [NZ(CED)B Plus] 101.21 595.13 Lifecycle scenarios   5. LC CED (NRen) [LCNZ(CEDNRen)] 129.28 760.17 5a. LC CED (total) [LCNZ(CED)] 180.56 1061.69

Conclusions Ubiquitous PV use CED: bar, but PV area demands Actual energy involved in delivering, using and dismantling buildings: better informs decision-making by building professionals, construction and transportation/logistic services and policy makers Onsite generation capacity was mostly limited by the available surface Powerful message for passersby, tuned with building’s mission Ubiquitous PV use Ground concepts, showed they are achievable, and showed major gaps to turn net- and lifecycle-zero goals into mainstream practice Cost: most restrictive aspect regarding aggressive neutralization of energy and GWP goals

THANK YOU! Vanessa GOMES, Marcella SAADE, Bruno LIMA, Maristela SILVA Department of Architecture and Construction, University of Campinas, vangomes@gmail.com