Techno-economic and environmental feasibility assessment of a proposed 751 kWp rooftop PV system using PVsyst: A case study of Kastamonu University, Türkiye

Öz

Rooftop solar photovoltaic (RSPV) systems are increasingly recognized as a vital component of the decentralized energy transition, enabling on-site electricity generation that minimizes transmission losses while advancing institutional sustainability goals. This paper presents a simulation-based techno-economic and environmental feasibility assessment of a proposed 751 kWp grid-connected rooftop PV system at the Faculty of Engineering and Architecture, Kastamonu University, Türkiye, evaluated using PVsyst with three-dimensional near-shading modelling and site-specific meteorological data. The technical performance was assessed through energy yield, performance ratio (PR), normalized losses, and capacity metrics. The annual electricity generation was determined to be 1,126,006 kWh, equating to a specific yield of 1,500 kWh/kWp/year, an average PR of 86.62%, and a capacity factor of 17.12%. The projected annual generation corresponds to approximately 37.4% of the recorded campus annual electricity consumption. The dominant technical loss is thermal, while shading and electrical losses remain minor owing to the optimized tilt configuration. The economic analysis yielded a levelized cost of energy (LCOE) of $0.059/kWh, a net present value (NPV) of $722,239, an internal rate of return (IRR) of 19.91%, and a discounted payback period of 10 years over a 20-year project life. A sensitivity analysis confirmed that the NPV remains positive across all moderate adverse variations in tariff, CAPEX, discount rate, and degradation rate. The environmental life cycle assessment projected a net saving of 8,694 tonnes of CO₂ using a Turkish grid emission factor of 0.489 kgCO₂/kWh and a year-by-year degradation correction, with an environmental payback period of approximately 3 years. These findings confirm the feasibility of RSPV for institutional energy self-dependency in emerging solar economies.

Anahtar Kelimeler

• Rooftop solar photovoltaic
• PVsyst
• Performance ratio
• Levelized cost of energy
• Life cycle assessment

Kaynakça

1. [1] Adelekan OA, Ilugbusi BS, Adisa O, et al. Energy transition policies: a global review of shifts towards renewable sources. Engineering Science & Technology Journal 2024; 5: 272–287.
2. [2] Emon BA, Alam MS, Shafiullah M, et al. From Roof to Grid: A Case Study on the Technical and Economic Performance of a 27 kWp Solar PV System at University Campus. Energies (Basel) 2025; 18: 6513.
3. [3] Sander L, Schindler D, Jung C. Application of satellite data for estimating rooftop solar photovoltaic potential. Remote Sens (Basel) 2024; 16: 2205.
4. [4] Yao H, Zhou Q. Research status and application of rooftop photovoltaic Generation Systems. Cleaner Energy Systems 2023; 5: 100065.
5. [5] Aktas IS, Ozenc S. A case study of techno-economic and environmental analysis of college rooftop for grid-connected PV power generation: Net zero 2050 pathway. Case Studies in Thermal Engineering 2024; 56: 104272.
6. [6] Zhu X, Lv Y, Bi J, et al. Techno-economic analysis of rooftop photovoltaic system under different scenarios in China university campuses. Energies (Basel) 2023; 16: 3123.
7. [7] Yusri NAHM, Azmi AM, Fadzli NFAM. Techno-economic appraisal of a rooftop solar Pv project for a university campus. International Journal of Academic Reserach in Economics and Management Sciences; 12.
8. [8] Unsal DB, Aksoz A, Oyucu S, et al. A comparative study of AI methods on renewable energy prediction for smart grids: case of Turkey. Sustainability 2024; 16: 2894.

9. [9] Bakanlığı TCE ve TK. Güneş Enerjisi Potansiyeli Atlası (GEPA) – Solar Calculator, https://gepa.enerji.gov.tr/MyCalculator/Default.aspx (2026).
10. [10] Acaroğlu H, Baykul MC, Kara Ö. A Life-Cycle Cost Analysis on Photovoltaic (PV) Modules for Türkiye: The Case of Eskisehir’s Solar Market Transactions. Sustainability 2025; 17: 11023.
11. [11] Ember. Türkiye surpasses 2025 solar target as capacity doubles in 2.5 years, https://ember-energy.org/latest-insights/turkiye-surpasses-2025-solar-target-as-capacity-doubles-in-2-5-years/ (2025).
12. [12] Kartal B, Alkan RM. Solar energy based model for decarbonization: a case study in Istanbul. International Journal of Engineering and Geosciences 2025; 11: 64–77.
13. [13] Ispir M, Aksoy MH, Kalyoncu M. Estimation of solar radiation and photovoltaic power potential of Türkiye using ANFIS. Journal of King Saud University–Engineering Sciences 2025; 37: 2.
14. [14] Pamuk N, Omar FA. Techno-Economic and Environmental Assessment of On-Grid and Off-Grid Renewable Energy Systems for Çanakkale, Türkiye Using HOMER Pro. ELECTRICA 2025; 25: 1–19.
15. [15] Bernadette D, Twizerimana M, Bakundukize A, et al. Analysis of shading effects in solar PV system. International Journal of Sustainable and Green Energy 2021; 10: 47–62.
16. [16] Bocullo V, Martišauskas L, Pupeikis D, et al. Uav photogrammetry application for determining the influence of shading on solar photovoltaic array energy efficiency. Energies (Basel) 2023; 16: 1292.
17. [17] Çeçen M, Yavuz C, Tırmıkçı CA, et al. Analysis and evaluation of distributed photovoltaic generation in electrical energy production and related regulations of Turkey. Clean Technol Environ Policy 2022; 24: 1321–1336.
18. [18] Keskin V. Performance evaluation of water-based and soil-based photovoltaic systems: energy, exergy, environmental, and economic perspectives. Clean Technol Environ Policy 2025; 1–22.
19. [19] Singh TSD, Shimray BA, Singh AB, et al. Performance measurement of 5 kWp rooftop grid-connected SPV system in moderate climatic region of Imphal, Manipur, India. Energy for Sustainable Development 2023; 73: 292–302.
20. [20] Mashaly A, Elmadawy M, Elgohary M, et al. Novel and cost-efficient design of stand-alone PV system with simulation using PVsyst and experimental validation. Sci Rep.
21. [21] UMOETTE AT, EKPO DD, ENOH MC, et al. Design and performance analysis of standalone solar photovoltaic power system for health facility in EKET using PVSYST simulation software. Global Journal of Engineering and Technology Advances 2025; 25: 116–135.
22. [22] Bakanlığı TCE ve TK. GEPA Solar Energy Calculator Results – Kastamonu Global Radiation and PV Energy Data, https://gepa.enerji.gov.tr/MyCalculator/pages/37.aspx.
23. [23] Saputri FR, Robert N, Akbar AM. Assessment of the viability of photovoltaic system implementation on the New Media Tower of Universitas Multimedia Nusantara using PVSyst software: A feasibility study. PLoS One 2024; 19: e0314922.
24. [24] Ajithgopi, Sudhakar K, Wai Keng N. Design and simulation of solar roof-top projects for an energy self-reliant university campus. In: IOP Conference Series: Materials Science and Engineering. IOP Publishing, 2021, p. 012013.
25. [25] Leeabai N, Sakaraphantip N, Kunbuala N, et al. Integrated Assessment of Rooftop Photovoltaic Systems and Carbon Footprint for Organization: A Case Study of an Educational Facility in Thailand. Energies (Basel) 2025; 18: 2485.
26. [26] Milosavljević DD, Kevkić TS, Jovanović SJ. Review and validation of photovoltaic solar simulation tools/software based on case study. Open Physics 2022; 20: 431–451.
27. [27] Betti T, Bevanda I, Marasović I, et al. A new approach to comparing photovoltaic simulation software. Energy Sources, Part a: Recovery, Utilization, and Environmental Effects 2023; 45: 6290–6304.
28. [28] González-Peña D, Garcia-Ruiz I, Díez-Mediavilla M, et al. Photovoltaic prediction software: evaluation with real data from northern Spain. Applied Sciences 2021; 11: 5025.
29. [29] Borah P, Micheli L, Sarmah N. Analysis of soiling loss in photovoltaic modules: a review of the impact of atmospheric parameters, soil properties, and mitigation approaches. Sustainability 2023; 15: 16669.
30. [30] CW Enerji. Self-Cleaning And Anti-Reflection Glass Coating glass for self-cleaning reduces surface dust Excellent Durability 0~+5W Positive Power Tolerance Easy Installation Outstanding Low Irradiation Glass, https://cw-enerji.com/images/down_file/108pm12-550-530wp-perc-monocrystalline-solar-panels-630-en.pdf (2023, accessed 22 June 2026).
31. [31] Huawei. Efficiency, https://solar.huawei.com/-/media/Solar/attachment/pdf/au/datasheet/SUN2000-100KTL-M1.pdf (accessed 22 June 2026).
32. [32] Jordan DC, Kurtz SR, VanSant K, et al. Compendium of photovoltaic degradation rates. Progress in Photovoltaics: Research and Applications 2016; 24: 978–989.
33. [33] Jordan DC, Kurtz SR. Photovoltaic degradation rates—an analytical review. Progress in Photovoltaics: Research and Applications 2013; 21: 12–29.
34. [34] Ates AM, Singh H. Rooftop solar Photovoltaic (PV) plant–One year measured performance and simulations. Journal of King Saud University-Science 2021; 33: 101361.
35. [35] Cura D, Yilmaz M, Koten H, et al. Evaluation of the technical and economic aspects of solar photovoltaic plants under different climate conditions and feed-in tariff. Sustain Cities Soc 2022; 80: 103804.
36. [36] Bamisile O, Acen C, Cai D, et al. The environmental factors affecting solar photovoltaic output. Renewable and Sustainable Energy Reviews 2025; 208: 115073.
37. [37] Aksoy Tırmıkçı C, Yavuz C, Özkurt C, et al. Machine learning-assisted evaluation of PVSOL software using a real-time rooftop PV system: a case study in Kocaeli, Turkey, with a focus on diffuse solar radiation. International Journal of Low-Carbon Technologies 2025; 20: ctae292.
38. [38] Behura AK, Kumar A, Rajak DK, et al. Towards better performances for a novel rooftop solar PV system. Solar Energy 2021; 216: 518–529.
39. [39] Singh TSD, Shimray BA, Meitei SN. Performance Analysis of a Rooftop Grid-Connected Photovoltaic System in North-Eastern India, Manipur. Energies (Basel) 2025; 18: 1921.
40. [40] Tagliapietra S, Zachmann G, Fredriksson G. Estimating the cost of capital for wind energy investments in Turkey. Energy Policy 2019; 131: 295–301.
41. [41] International Energy Agency. The Cost of Capital in Clean Energy Transitions. IEA, https://www.iea.org/articles/the-cost-of-capital-in-clean-energy-transitions (2021, accessed 6 May 2026).
42. [42] Türkiye İstatistik Kurumu. Tüketici Fiyat Endeksi - Aralık 2024. TÜİK Veri Portalı, https://veriportali.tuik.gov.tr/en/press/53621 (2025, accessed 5 May 2026).
43. [43] Presidency of Strategy and Budget. Medium Term Program (2026-2028), https://www.sbb.gov.tr/wp-content/uploads/2025/10/Medium-Term-Program-2026-2028.pdf (2025, accessed 6 May 2026).
44. [44] Government of Turkey - Council of Ministers. Electricity Market Law No. 6446 of 2013 (Turkish: Elektrik Piyasasi Kanunu). ESCAP Policy Documents Management (Asia Pacific Energy Portal), https://policy.asiapacificenergy.org/node/2308 (2013, accessed 22 June 2026).
45. [45] PwC. Turkey - Corporate - Other taxes. Worldwide Tax Summaries, https://taxsummaries.pwc.com/turkey/corporate/other-taxes (2026, accessed 22 June 2026).
46. [46] Enerji Piyasası Düzenleme Kurumu. Elektrik Faturalarına Esas Tarife Tabloları. EPDK, https://www.epdk.gov.tr/Detay/Icerik/3-1327/elektrik-faturalarina-esas-tarife-tablolari (2026, accessed 6 May 2026).
47. [47] GlobalPetrolPrices. Turkey Electricity Prices, https://www.globalpetrolprices.com/Turkey/electricity_prices/ (2026, accessed 6 May 2026).
48. [48] Cui Y, Zhu J, Meng F, et al. Energy assessment and economic sensitivity analysis of a grid-connected photovoltaic system. Renew Energy 2020; 150: 101–115.
49. [49] Micheli L, Sepúlveda-Vélez FA, Talavera DL. Impact of variable economic conditions on the cost of energy and the economic viability of floating photovoltaics. Heliyon; 10.
50. [50] Stolz P, Frischknecht R, Wambach K, et al. Life cycle assessment of current photovoltaic module recycling. IEA PVPS Task 12, International Energy Agency Power Systems Programme, Report IEA-PVPS T12 2017; 13: 2018.
51. [51] Yalçın L. Iğdır ve FV Güneş Elektriği. Ankara, https://www.mgm.gov.tr/FILES/genel/kitaplar/guneselektrigi.pdf (2016, accessed 8 May 2026).
52. [52] Frischknecht RSPHGRMSP de W-SM. Life Cycle Inventories and Life Cycle Assessments of Photovoltaic Systems 2020 Task 12 PV Sustainability, https://iea-pvps.org/key-topics/life-cycle-inventories-and-life-cycle-assessments-of-photovoltaic-systems/ (accessed 21 June 2026).
53. [53] Danelli ABEGPBNLJ. What is IEA PVPS TCP? What is IEA PVPS Task 12? Ø Main Content: A: Environmental Life Cycle Assessment of Passivated Emitter and Rear Contact (PERC) Photovoltaic Module Technology, https://iea-pvps.org/wp-content/uploads/2024/03/IEA-PVPS-T12-26-Report-LCA-PERC-technology-v21.pdf (accessed 21 June 2026).
54. [54] Low-Carbon Power. Turkey Electricity Generation Mix 2025. Low-Carbon Power, https://lowcarbonpower.org/region/Turkey (2025, accessed 21 June 2026).
55. [55] Gao L, Wang S, Mao M, et al. Study on the energy consumption characteristics and the self-sufficiency rate of rooftop photovoltaic of university campus buildings. Energies (Basel) 2024; 17: 3535.
56. [56] Alfalah B. Effectiveness of installing a photovoltaic system on a high-density building in a hot climate zone. Sustainability 2025; 17: 7523.
57. [57] Shah S, Boozula AR, Lampuse RG, et al. A Systematic Framework for Reconciling Solar Energy Production Models with Operational Data: A Literature Synthesis and Methodology Development. European Journal of Energy Research 2025; 5: 7–23.