Feasibility Study of Building Integrated Photovoltaic (BIPV) as a Building Envelope Material in Europe
Buildings play a vital role as regards the energy efficiency of urban areas since they are responsible for a significant portion of the energy demand of urban areas. In Europe, building energy use accounts for 41% of the total energy consumption of the cities . Urban energy transition has recently come about by intensifying the endeavour towards promoting distributed or decentralised energy generation (DG) and realign the energy production and consumption of buildings.
One of the leading solutions which can be of great assistance to contribute towards such an approach is building integrated photovoltaic (BIPV) systems. BIPV is a PV system on the building skin serving as both a building envelope material and a power generator. An alternative that is not covered here is PV systems nearly – in the landscape or garden. There is a tendency currently in the market to use BIPV systems in the part of the building skins with the highest incident solar radiation and, therefore, higher electricity production as an output. These areas in the northern hemisphere are roof and south façade. However, employing other facades and areas of building skins also results in many advantages. The possibility to achieve zero energy buildings (ZEB) or even plus energy building goals, using different facades and orientations of buildings to have a distributed electricity generation during the day, and the system's contribution in reinforcing the energy performance of the building skin are some advantages. To place PV modules so that they deliver energy when the energy need in the building is highest is also of importance as it reduces the need for storage.
Therefore, this thesis focuses on building integrated photovoltaic systems (BIPV) and their feasibility as a building envelope material in Europe. The main research question is defined as follows:
Is the BIPV system as an alternative for the more usual building envelope materials feasible for the entire skin of buildings in Europe?
The goal is to investigate the technical and economic aspects of such a solution in two steps. Finally, the project seeks to briefly discover the potential and challenges of such a solution in the energy transition of cities.
Both qualitative and quantitative methodologies are employed in this project, and most of the analyses are based on the data obtained from the Photovoltaic Geographical Information System (PVGIS) and the Surface Solar Radiation Data Set - Heliosat (SARAH) dataset.
The results are expected to help the end-users, architects and urban planners to acknowledge the BIPV system as a suitable option for the building skins in Europe and steer governments or decision-makers to promote the technology by rational subsidies and incentives (where it is needed). This can contribute towards making cities as well as more rural areas into “power stations”.
 C. Mora et al., "The projected timing of climate departure from recent variability," vol. 502, no. 7470, pp. 183-187, 2013.
 N. N. C. f. E. Information, "State of the Climate: Global Climate Report for Annual 2016," 2017. [Online]. Available: https://www.ncdc.noaa.gov/sotc/global/201613
 R. J. I. A. Falkner, "The Paris Agreement and the new logic of international climate politics," vol. 92, no. 5, pp. 1107-1125, 2016.
 IEA, "Net Zero by 2050," Paris, 2021. [Online]. Available: https://www.iea.org/reports/net-zero-by-2050
 R. Cazzaniga and M. Rosa-Clot, "The booming of floating PV," Solar Energy, vol. 219, pp. 3-10, 2021/05/01/ 2021,
 J. D. S. Barkaszi, "Discussion of strategies for mounting photovoltaic arrays on rooftops," in International solar energy conference, Washington, DC, 2001.
 H. Gholami, H. Nils Røstvik, N. Manoj Kumar, and S. S. Chopra, "Lifecycle cost analysis (LCCA) of tailor-made building integrated photovoltaics (BIPV) façade: Solsmaragden case study in Norway," Solar Energy, vol. 211, pp. 488-502, 2020/11/15/ 2020,
 H. Gholami and H. N. Røstvik, "Economic analysis of BIPV systems as a building envelope material for building skins in Europe," Energy, vol. 204, p. 117931, 2020/08/01/ 2020,
 H. Gholami, H. N. Røstvik, and D. Müller-Eie, "Holistic economic analysis of building integrated photovoltaics (BIPV) system: Case studies evaluation," Energy and Buildings, vol. 203, p. 109461, 2019/11/15/ 2019,
 H. Gholami and H. Nils Røstvik, "The Effect of Climate on the Solar Radiation Components on Building Skins and Building Integrated Photovoltaics (BIPV) Materials," Energies, vol. 14, no. 7, p. 1847, 2021. [Online]. Available: https://www.mdpi.com/1996-1073/14/7/1847.
 E. Esmailian, H. Gholami, H. N. Røstvik, and M. B. Menhaj, "A novel method for optimal performance of ships by simultaneous optimisation of hull-propulsion-BIPV systems," Energy Conversion and Management, vol. 197, p. 111879, 2019,
 U.e.AS. "Energibygget Project." https://www.unioneiendom.no/eiendommer- naering/energibygget/?ml=6 (accessed 2021).
 H. N. Røstvik, "Sustainable Architecture-What's Next?," Encyclopedia, vol. 1, no. 1, pp. 293-313, 2021. [Online]. Available: https://www.mdpi.com/2673-8392/1/1/25.
 J. Bloem and P. Baker, "Building integration issues for photovoltaics," Proceedings of BIAT-Technical Innovation in Design and Contsruction, Dublin Castle, 2000.
 H. Breitmeier, J. Kuhn, and S. Schwindenhammer, "Analyzing urban adaptation strategies to climate change: a comparison of the coastal cities of Dhaka, Lagos and Hamburg," in Contribution to the Panel, Regieren im Klimawandel Section, Regierungssystem und Regieren in der Bundesrepublik Deutschland, DVPW-Kongress, 2009, vol. 21, p. 25.
 I. Cities Climate Leadership Group. "Why Cities?" https://www.c40.org/why_cities (accessed 2020).
 U. Nations, "World population prospects: the 2017 revision, key findings and advance tables," Department of Economics and Social Affairs PD, editor. New York: United Nations, 2017.
 U. Nations, "World Urbanization Prospects: The 2018 Revision, Key Facts," Technical report, 2018.
 M. Villa-Arrieta and A. Sumper, "Economic evaluation of Nearly Zero Energy Cities," Applied Energy, vol. 237, pp. 404-416, 2019/03/01/ 2019,
 R. Check, P. Space-based, K. Percent, and E. Shingles, "The Future of Solar Energy," Mit, pp. 3-6, 2015.
 H. Gholami, H. N. Røstvik, and D. Müller-Eie, "Analysis of solar radiation components on building skins for selected cities," in Proceedings of 14th Conference on Advanced Building Skins. Bern, Switzerland: Advanced Building Skins. ABS, 2019, pp. 541-549.
 S. Kalogirou, "Thermal performance, economic and environmental life cycle analysis of thermosiphon solar water heaters," Solar energy, vol. 83, no. 1, pp. 39-48, 2009.
 A. Ibrahim, A. Fudholi, K. Sopian, M. Y. Othman, and M. H. Ruslan, "Efficiencies and improvement potential of building integrated photovoltaic thermal (BIPVT) system," Energy Conversion and Management, vol. 77, pp. 527-534, 2014.
 D. Groppi, L. de Santoli, F. Cumo, and D. A. Garcia, "A GIS- based model to assess buildings energy consumption and usable solar energy potential in urban areas," Sustainable Cities and Society, vol. 40, pp. 546-558, 2018,
 A. Buonomano, C. Forzano, S. A. Kalogirou, and A. Palombo, "Building-façade integrated solar thermal collectors: Energy- economic performance and indoor comfort simulation model of a water based prototype for heating, cooling, and DHW production," Renewable Energy, 2018.
 H. Gholami, A. Sarwat, H. Hosseinian, and A. Khalilnejad, "Evaluation of optimal dual axis concentrated photovoltaic thermal system with active ventilation using Frog Leap algorithm," Energy Conversion Management, vol. 105, pp. 782- 790, 2015,
 H. Gholami, A. Khalilnejad, and G. Gharehpetian, "Electrothermal performance and environmental effects of optimal photovoltaic-thermal system," Energy Conversion Management, vol. 95, pp. 326-333, 2015,
 P. Reddy K, M. Gupta, S. Nundy, A. Karthick, and A. Ghosh, "Status of BIPV and BAPV System for Less Energy-Hungry Building in India-A Review," Applied Sciences, vol. 10, no. 7, p. 2337, 2020.
 A. K. Shukla, K. Sudhakar, P. Baredar, and R. Mamat, "Solar PV and BIPV system: Barrier, challenges and policy recommendation in India," Renewable and Sustainable Energy Reviews, vol. 82, pp. 3314-3322, 2018/02/01/ 2018,
 "European Commission. Communication from the Commission to the European Parliament and the Council. The Road from Paris: Assessing the Implications of the Paris Agreement and Accompanying the Proposal for a Council Decision on the Signing, on Behalf of the European Union, of the Paris Agreement Adopted Under the United Nations Framework Convention on Climate Change," 2016. [Online]. Available: https://op.europa.eu/en/publication-detail/-/publication/62d7fdfb-e607-11e5-8a50- 01aa75ed71a1/language-en
 C. Cleveland and S. Peter, "Energy transitions past and future,"Encyclopedia of earth, 2008.
 S. Davidsson, "Global Energy Transitions: A comparative analysis of key countries and implications for the international energy debate," World Energy Council, Weltnerergierat: Berlin, Germany, 2014.
 H. Daly and M. Walton, "World Energy Outlook 2017," 2017: IEA Paris, France:.
 I. IRENA, "Renewable energy in cities," International Renewable Agency: Abu Dhabi, UAE, 2016.
 Y. Parag and B. K. Sovacool, "Electricity market design for the prosumer era," Nature energy, vol. 1, no. 4, pp. 1-6, 2016.
 M. Amado, F. Poggi, A. Ribeiro Amado, and S. Breu, "A cellular approach to net-zero Energy Cities," Energies, vol. 10, no. 11, p. 1826, 2017.
 B. Todorovic, "Towards zero energy buildings: New and retrofitted existing buildings," in 2011 IEEE 3rd International Symposium on Exploitation of Renewable Energy Sources (EXPRES), 2011: IEEE, pp. 7-14.
 P. Heinstein, C. Ballif, and L.-E. Perret-Aebi, "Building integrated photovoltaics (BIPV): review, potentials, barriers and myths," Green, vol. 3, no. 2, pp. 125-156, 2013.
 M. Raugei and P. Frankl, "Life cycle impacts and costs of photovoltaic systems: Current state of the art and future outlooks," Energy, vol. 34, no. 3, pp. 392-399, 2009/03/01/ 2009
 B. P. Jelle, C. Breivik, and H. D. Røkenes, "Building integrated photovoltaic products: A state-of-the-art review and future research opportunities," Solar Energy Materials and Solar Cells, vol. 100, pp. 69-96, 2012.
 E. Biyik et al., "A key review of building integrated photovoltaic (BIPV) systems," Engineering science technology, an international journal, vol. 20, no. 3, pp. 833-858, 2017.
 N. R. E. L. (NREL). "Best Research-Cell Efficiency Chart." US Department of Energy. https://www.nrel.gov/pv/cell- efficiency.html (accessed 2020).
 I. Fraunhofer Institute for Solar Energy Systems, "Photovoltaic Report," 2020. [Online]. Available: https://www.ise.fraunhofer.de/content/dam/ise/de/documents/pu blications/studies/Photovoltaics-Report.pdf
 C.T.Limited."Advanced glazing technology." http://www.clearvuepv.com/products-solutions/technology/ (accessed 2020).
 L. National Technology and Engineering Solutions of Sandia. "Spectral Response." https://pvpmc.sandia.gov/modeling- steps/2-dc-module-iv/effective-irradiance/spectral-response/ (accessed 2020).
 M. Kaltschmitt and A. Wiese, Potentiale und Kosten regenerativer Energieträger in Baden-Württemberg. Univ., 1992.
 M. Kaltschmitt and A. Wiese, Erneuerbare Energieträger in Deutschland: Potentiale und Kosten. Springer-Verlag, 2013.
 M. A. H. Mondal and M. Denich, "Assessment of renewable energy resources potential for electricity generation in Bangladesh," Renewable and Sustainable Energy Reviews, vol. 14, no. 8, pp. 2401-2413, 2010.
 V. Quaschning, Systemtechnik einer klimaverträglichen Elektrizitätsversorgung in Deutschland für das 21. Jahrhundert. VDI-Verlag, 2000.
 K. Mainzer, K. Fath, R. McKenna, J. Stengel, W. Fichtner, and F. Schultmann, "A high-resolution determination of the technical potential for residential-roof-mounted photovoltaic systems in Germany," Solar Energy, vol. 105, pp. 715-731, 2014.
 S. r. m. Solargis. "Solar resource maps of Europe." https://solargis.com (accessed 2019).
 A. K. Shukla, K. Sudhakar, and P. Baredar, "Recent advancement in BIPV product technologies: A review," Energy and Buildings, vol. 140, pp. 188-195, 2017.
 Y. Asiedu and P. Gu, "Product life cycle cost analysis: state of the art review," International journal of production research, vol. 36, no. 4, pp. 883-908, 1998.
 M. Sorgato, K. Schneider, and R. Rüther, "Technical and economic evaluation of thin-film CdTe building-integrated photovoltaics (BIPV) replacing façade and rooftop materials in office buildings in a warm and sunny climate," Renewable Energy, vol. 118, pp. 84-98, 2018.
 N. Aste, C. Del Pero, and F. Leonforte, "The first Italian BIPV project: Case study and long-term performance analysis," Solar Energy, vol. 134, pp. 340-352, 2016.
 D. C. Jordan and S. R. Kurtz, "Photovoltaic degradation rates- an analytical review," Progress in photovoltaics: Research Applications, vol. 21, no. 1, pp. 12-29, 2013.
 W. Wang et al., "Environmental assessments and economic performance of BAPV and BIPV systems in Shanghai," Energy and Buildings, vol. 130, pp. 98-106, 2016.
 U. Eicker, E. Demir, and D. Gürlich, "Strategies for cost efficient refurbishment and solar energy integration in European Case Study buildings," Energy and Buildings, vol. 102, pp. 237-249, 2015.
 P. Eiffert, "Guidelines for the economic evaluation of building- integrated photovoltaic power systems," National Renewable Energy Lab., Golden, CO.(US), 2003.
 N. W. Alnaser, "First smart 8.64 kW BIPV in a building in Awali Town at Kingdom of Bahrain," Renewable and Sustainable Energy Reviews, vol. 82, pp. 205-214, 2018.
 E. Saretta, P. Caputo, and F. Frontini, "A review study about energy renovation of building facades with BIPV in urban environment," Sustainable Cities and Society, vol. 44, pp. 343- 355, 2018
 M. Brito, S. Freitas, S. Guimarães, C. Catita, and P. Redweik, "The importance of facades for the solar PV potential of a Mediterranean city using LiDAR data," Renewable Energy, vol. 111, pp. 85-94, 2017.
 T. Zhang, M. Wang, and H. Yang, "A Review of the Energy Performance and Life-Cycle Assessment of Building-Integrated Photovoltaic (BIPV) Systems," Energies, vol. 11, no. 11, p. 3157, 2018.
 G. P. Hammond, H. A. Harajli, C. I. Jones, and A. B. Winnett, "Whole systems appraisal of a UK Building Integrated Photovoltaic (BIPV) system: Energy, environmental, and economic evaluations," Energy Policy, vol. 40, pp. 219-230, 2012.
 R. Jing Yang and P. X.W. Zou, "Building integrated photovoltaics (BIPV): costs, benefits, risks, barriers and improvement strategy," International Journal of Construction Management, vol. 16, no. 1, pp. 39-53, 2015.
 A. Sivanandan, "BIPV hotspots in the EU," Renewable energy focus, vol. 10, no. 2, pp. 54-55, 2009.
 L. Byrnes, C. Brown, J. Foster, and L. D. Wagner, "Australian renewable energy policy: Barriers and challenges," Renewable Energy, vol. 60, pp. 711-721, 2013.
 F. J. Osseweijer, L. B. Van Den Hurk, E. J. Teunissen, and W. G. van Sark, "A comparative review of building integrated photovoltaics ecosystems in selected European countries," Renewable Sustainable Energy Reviews, vol. 90, pp. 1027-1040, 2018.
 A. Scognamiglio and H. N. Røstvik, "Photovoltaics and zero energy buildings: a new opportunity and challenge for design," Progress in Photovoltaics: Research and applications, vol. 21, no. 6, pp. 1319-1336, 2013.
 T. C. Grenfell, S. G. Warren, and P. C. Mullen, "Reflection of solar radiation by the Antarctic snow surface at ultraviolet, visible, and near-infrared wavelengths," Journal of Geophysical Research: Atmospheres, vol. 99, no. D9, pp. 18669-18684, 1994
 W. Muehleisen et al., "Energy yield measurement of an elevated PV system on a white flat roof and a performance comparison of monofacial and bifacial modules," Renewable Energy, vol. 170, pp. 613-619, 2021/06/01/ 2021
 E. Molin, B. Stridh, A. Molin, and E. Wäckelgård, "Experimental yield study of bifacial PV modules in nordic conditions," IEEE Journal of Photovoltaics, vol. 8, no. 6, pp. 1457-1463, 2018.
 M. Tripathy, S. Yadav, P. Sadhu, and S. Panda, "Determination of optimum tilt angle and accurate insolation of BIPV panel influenced by adverse effect of shadow," Renewable Energy, vol. 104, pp. 211-223, 2017.
 C. Zomer, A. Nobre, T. Reindl, and R. Rüther, "Shading analysis for rooftop BIPV embedded in a high-density environment: A case study in Singapore," Energy and Buildings, vol. 121, pp. 159-164, 2016.
 N. M. Kumar, K. Sudhakar, and M. Samykano, "Performance of thin-film BIPV as double sloped pitched roof in buildings of Malaysia," Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 40, no. 20, pp. 2476-2484, 2018.
 F. Frontini, M. Manfren, and L. C. Tagliabue, "A case study of solar technologies adoption: criteria for BIPV integration in sensitive built environment," Energy Procedia, vol. 30, pp. 1006- 1015, 2012.
 N. M. Kumar, K. Sudhakar, and M. Samykano, "Performance comparison of BAPV and BIPV systems with c-Si, CIS and CdTe photovoltaic technologies under tropical weather conditions," Case Studies in Thermal Engineering, vol. 13, p. 100374, 2019.
 N. Poh KhaiNg, "Lifetime performance of semi-transparent building-integrated photovoltaic (BIPV) glazing systems in the tropics," Renewable and Sustainable Energy Reviews, vol. 31, pp. 736-745, 2014.
 P. Jayathissa, M. Luzzatto, J. Schmidli, J. Hofer, Z. Nagy, and A. Schlueter, "Optimising building net energy demand with dynamic BIPV shading," Applied Energy, vol. 202, pp. 726-735, 2017.
 W. Shen et al., "A comprehensive review of variable renewable energy levelized cost of electricity," Renewable and Sustainable Energy Reviews, vol. 133, p. 110301, 2020/11/01/ 2020
 S. Reichelstein and A. Sahoo, "Time of day pricing and the levelized cost of intermittent power generation," Energy Economics, vol. 48, pp. 97-108, 2015/03/01/ 2015
 K. Branker, M. Pathak, and J. M. Pearce, "A review of solar photovoltaic levelized cost of electricity," Renewable and sustainable energy reviews, vol. 15, no. 9, pp. 4470-4482, 2011.
 U. Nissen and N. Harfst, "Shortcomings of the traditional "levelized cost of energy" [LCOE] for the determination of grid parity," Energy, vol. 171, pp. 1009-1016, 2019/03/15/ 2019
 G. Pamparana, W. Kracht, J. Haas, G. Díaz-Ferrán, R. Palma- Behnke, and R. Román, "Integrating photovoltaic solar energy and a battery energy storage system to operate a semi-autogenous grinding mill," Journal of Cleaner Production, vol. 165, pp. 273- 280, 2017/11/01/ 2017
 J. N. Mayer, P. Simon, N. S. H. Philipps, T. Schlegl, and C. Senkpiel, "Current and future cost of photovoltaics," Long-term Scenarios for Market Development, System Prices and LCOE of Utility-Scale PV Systems (Fraunhofer ISE, Study on behalf of Agora Energiewende, Freiburg, 2015), 2015.
 A. S. Mundada, K. K. Shah, and J. M. Pearce, "Levelized cost of electricity for solar photovoltaic, battery and cogen hybrid systems," Renewable and Sustainable Energy Reviews, vol. 57, pp. 692-703, 2016/05/01/ 2016
 A. Limmanee et al., "Degradation analysis of photovoltaic modules under tropical climatic conditions and its impacts on LCOE," Renewable Energy, vol. 102, pp. 199-204, 2017/03/01/ 2017
 C. Parrado, A. Girard, F. Simon, and E. Fuentealba, "2050 LCOE (Levelized Cost of Energy) projection for a hybrid PV (photovoltaic)-CSP (concentrated solar power) plant in the Atacama Desert, Chile," Energy, vol. 94, pp. 422-430, 2016/01/01/ 2016
 A. Komilov, "Location and orientation based LCOE: Simplified visual analysis and generalization of the levelized cost of electricity from storageless photovoltaic systems," International Journal of Energy Research, 2020.
 D. L. Talavera, E. Muñoz-Cerón, J. P. Ferrer-Rodríguez, and P.J. Pérez-Higueras, "Assessment of cost-competitiveness and profitability of fixed and tracking photovoltaic systems: The case of five specific sites," Renewable Energy, vol. 134, pp. 902-913, 2019/04/01/ 2019
 M. T. Patel, R. Asadpour, M. Woodhouse, C. Deline, and M. A. Alam, "LCOE*: Re-thinking LCOE for Photovoltaic Systems," in 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC), 2019: IEEE, pp. 1711-1713.
 R. Sinaga, N. F. Tuati, M. D. Beily, and A. S. Sampeallo, "Modeling and analysis of the solar photovoltaic levelized cost of electricity (LCoE)-case study in Kupang," in Journal of Physics: Conference Series, 2019, vol. 1364, no. 1: IOP Publishing, p. 012066.
 C. S. Lai and M. D. McCulloch, "Levelized cost of electricity for solar photovoltaic and electrical energy storage," Applied energy, vol. 190, pp. 191-203, 2017.
 S. MacDonald and N. Headlam, Research Methods Handbook: Introductory guide to research methods for social research. Centre for Local Economic Strategies, 2008.
 I. Zanetti et al., "Building Integrated Photovoltaics: Product Overview for Solar Building Skins-Status Report 2017," in "Kidlington, UK," 2017.
 P. Bonomo, A. Chatzipanagi, and F. Frontini, "Overview and analysis of current BIPV products: new criteria for supporting the technological transfer in the building sector," VITRUVIO- International Journal of Architectural Technology and Sustainability, no. 1, pp. 67-85, 2015.
 K. Deb, A. Pratap, S. Agarwal, and T. Meyarivan, "A fast and elitist multiobjective genetic algorithm: NSGA-II," IEEE transactions on evolutionary computation, vol. 6, no. 2, pp. 182- 197, 2002.
 J. Aldersey-Williams and T. Rubert, "Levelised cost of energy- A theoretical justification and critical assessment," Energy Policy, vol. 124, pp. 169-179, 2019.
 L. Varro and J. Ha, "Projected costs of generating electricity- 2015 Edition," Paris, France, 2015.
 T. W. B. Group. "Electric power transmission and distribution losses (% of output)." https://data.worldbank.org/indicator/EG.ELC.LOSS.ZS?locatio ns=BR (accessed March 2019.
 A. Moro and L. Lonza, "Electricity carbon intensity in European Member States: Impacts on GHG emissions of electric vehicles," Transportation Research Part D: Transport and Environment, vol. 64, pp. 5-14, 2018/10/01/ 2018
 Eurostat. "Electricity price statistics." https://ec.europa.eu/eurostat/statistics- explained/index.php/Electricity_price_statistics#Electricity_pric es_for_household_consumers (accessed 2019).
 S. Kang, S. Yoo, J. Lee, B. Boo, and H. Ryu, "Experimental investigations for recycling of silicon and glass from waste photovoltaic modules," Renewable Energy, vol. 47, pp. 152-159, 2012.
 B. Huang, J. Zhao, J. Chai, B. Xue, F. Zhao, and X. Wang, "Environmental influence assessment of China's multi- crystalline silicon (multi-Si) photovoltaic modules considering recycling process," Solar Energy, vol. 143, pp. 132-141, 2017.
 J. R. Duflou, J. R. Peeters, D. Altamirano, E. Bracquene, and W. Dewulf, "Demanufacturing photovoltaic panels: Comparison of end-of-life treatment strategies for improved resource recovery," CIRP Annals, vol. 67, no. 1, pp. 29-32, 2018.
 P. Gangwar, N. M. Kumar, A. K. Singh, A. Jayakumar, and M. Mathew, "Solar photovoltaic tree and its end-of-life management using thermal and chemical treatments for material recovery," Case Studies in Thermal Engineering, vol. 14, p. 100474, 2019.
 N. w. r. a. e. d. (NVE). "Electricity disclosure 2018." https://www.nve.no/energy-market-and-regulation/retail- market/electricity-disclosure-2018/?ref=mainmenu (accessed 2019).
 H. Larsen, "Klimafotavstrykket av offentlige anskaffelser. Beregning av klimafotavtrykket av offentlige anskaffelser for årene 2008 til 2017," in Direktoratet for Forvaltning Og IKT (Difi), 2019.
This work is licensed under a Creative Commons Attribution 4.0 International License.