The economic viability of a photovoltaic (PV) installation depends on regulations regarding administrative, technical and economic conditions associated with self-consumption and the sale of surplus production. Royal Decree (RD) 244/2019 is the Spanish legislation of reference for this case study, in which we analyse and compare PV installation offers by key suppliers. The proposals are not optimal in RD 244/2019 terms and appear not to fully contemplate power generation losses and seem to shift a representative percentage of consumption to the production period. In our case study of a residential dwelling, the best option corresponds to a 5 kWp installation with surplus sale to the market, with a payback period of 18 years and CO₂ emission reductions of 1026 kg/year. Demand-side management offers a potential improvement of 6%–21.8%. Based on the increase in electricity prices since 2020, the best option offers savings of up to €1507.74 and amortization in 4.24 years. Considering costs and savings, sale to the market could be considered as the only feasible regulatory mechanism for managing surpluses, accompanied by measures to facilitate administrative procedures and guarantees for end users.

Castillo-Cagigal, M., Caamaño-Martín, E., Matallanas, E., et al. (2011). PV self-consumption optimization with storage and Active DSM for the residential sector. Solar Energy, 85(9), 2338–2348. https://doi.org/10.1016/j.solener.2011.06.028

Cavicchioli, R., Ripple, W. J., Timmis, K. N., et al. (2019). Scientists’ warning to humanity: microorganisms and climate change. Nature Reviews Microbiology, 17(9), 569–586. https://doi.org/10.1038/s41579-019-0222-5

Edistribución Redes Digitales. (2022). e-distribution (Spanish). Available online: https://www.edistribucion.com/es/index.html (accessed on 9 January 2024).

esios.REE. (2022). System Operator Information System (Spanish). Available online: https://www.esios.ree.es/es?locale=es (accessed on 22 February 2022).

EPIA. (2022). Solar Photovoltaics. Competing in the energy sector. On the road to competitiveness. Available online: https://helapco.gr/pdf/tn_jsp.pdf (accessed on 11 March 2022).

Garduño, R. (2004). What is the greenhouse effect? Climate change: a view from Mexico (Spanish).

Hassan, Q. (2022). Evaluate the adequacy of self-consumption for sizing photovoltaic system. Energy Reports, 8, 239–254. https://doi.org/10.1016/j.egyr.2021.11.205

IDAE. (2020). Professional guide for self-consumption processing (Spanish). Available online: https://www.idae.es/sites/default/files/20201005_guia_autoconsumo_v.3.0.pdf (accessed on 22 February 2022).

IEA. (2015). Trends 2015 in photovoltaic applications. Survey Report of Selected IEA Countries between 1992 and 2014. Photovoltaic Power systems programme. Available online: https://iea-pvps.org/wp-content/uploads/2020/01/IEA-PVPS_-_Trends_2015_-_MedRes.pdf (accessed on 11 March 2022).

Law (Ley) 38/1992. Available online: https://www.boe.es/eli/es/l/1992/12/28/38/con (accessed on 11 March 2022).

Law (Ley) 15/2012. Available online: https://www.boe.es/eli/es/l/2012/12/27/15/con (accessed on 11 March 2022).

Luthander, R., Widén, J., Nilsson, D., et al. (2015). Photovoltaic self-consumption in buildings: A review. Applied energy, 142, 80–94. https://doi.org/10.1016/j.apenergy.2014.12.028

Mateo, C., Cossent, R., Gómez, T., et al. (2018). Impact of solar PV self-consumption policies on distribution networks and regulatory implications. Solar Energy, 176, 62–72. https://doi.org/10.1016/j.solener.2018.10.015

NASA. (2022a). NASA global climate change Vital Signs of the Planet. Available online: https://climate.nasa.gov/vital-signs/carbon-dioxide/ (accessed on 1 February 2022).

NASA. (2022b). NASA global climate change Vital Signs of the Planet. Available online: https://climate.nasa.gov/vital-signs/global-temperature/ (accessed on 1 February 2022).

Order (Order) ETU/1948/2016, 22 December, which sets certain values of the marketing costs of the reference marketers to be included in the calculation of the voluntary price for the small electricity consumer in the period 2014–2018 (Spanish). Available online: https://www.boe.es/eli/es/o/2016/12/22/etu1948/con (accessed on 1 February 2022).

Order (Order) IET/1491/2013, 1 August, revising the electricity access tolls for application as of August 2013 and revising certain tariffs and premiums for special regime facilities for the second quarter of 2013 (Spanish). Available online: https://www.boe.es/eli/es/o/2013/08/01/iet1491/con (accessed on 1 February 2022).

Order (Order) IET/107/2014, 31 January, revising the electricity access tolls for 2014 (Spanish). Available online: https://www.boe.es/eli/es/o/2014/01/31/iet107 (accessed on 1 February 2022).

Osorio Laurencio, L., & Montero Laurencio, R. (2016). Energy analysis of a photovoltaic system integrated to a horizontal flat roof (Spanish). Ingeniería Energética, 37(1), 45–54.

Prol, J. L., & Steininger, K. W. (2017). Photovoltaic self-consumption regulation in Spain: Profitability analysis and alternative regulation schemes. Energy Policy, 108, 742–754. https://doi.org/10.1016/j.enpol.2017.06.019

PVGIS, CEJR. (2022). Photovoltaic geographical information system. Available online: https://joint-research-centre.ec.europa.eu/photovoltaic-geographical-information-system-pvgis_en (accessed on 11 February 2022).

Royal Decree (Royal Decree) 661/2007, 25 May 2007, which regulates the production of electricity under the special regime (Spanish). Available online: https://www.boe.es/buscar/act.php?id=BOE-A-2007-10556 (accessed on 1 February 2022).

Royal Decree (Royal Decree) 1164/2001, October 26, establishing tariffs for access to the electricity transmission and distribution networks (Spanish). Available online: https://www.boe.es/eli/es/rd/2001/10/26/1164/con (accessed on 1 February 2022).

Royal Decree (Royal Decree) 413/2014, June 6, regulating the activity of electricity production from renewable energy sources, cogeneration and waste (Spanish). Available online: https://www.boe.es/eli/es/rd/2014/06/06/413/con (accessed on 1 February 2022).

Royal Decree (Royal Decree) 900/2015, October 9, which regulates the administrative, technical and economic conditions of the modalities of electricity supply with self-consumption and production with self-consumption (Spanish). Available online: https://www.boe.es/buscar/act.php?id=BOE-A-2015-10927 (accessed on 1 February 2022).

Royal Decree 244/2019, 5 April 2009, regulating the administrative, technical and economic conditions for the self-consumption of electric energy (Spanish). Available online: https://www.boe.es/buscar/act.php?id=BOE-A-2019-5089 (accessed on 1 February 2022).

REE. (2022). REE/REData/Generation/Installed Power (Spanish). Available online: https://www.ree.es/es/datos/generacion (accessed on 11 February 2022).

Thebault, M., & Gaillard, L. (2021). Optimization of the integration of photovoltaic systems on buildings for self-consumption—Case study in France. City and Environment Interactions, 10, 100057. https://doi.org/10.1016/j.cacint.2021.100057

UNEF. (2013). Towards new development models for solar photovoltaic energy (Spanish). Available online: https://www.unef.es/es/recursos-informes?idMultimediaCategoria=18 (accessed on 11 March 2022).

UNEF. (2018). 2017: the beginning of a new era for the photovoltaic sector (Spanish). Available online: https://www.unef.es/es/descargar-documento/291f54294f1d4f8fc093efde4367e37a (accessed on 17 February 2022).

Widén, J. (2014). Improved photovoltaic self-consumption with appliance scheduling in 200 single-family buildings. Applied Energy, 126, 199–212. https://doi.org/10.1016/j.apenergy.2014.04.008

Xu, Y., Ramanathan, V., & Victor, D. G. (2018). Global warming will happen faster than we think. Nature 564, 30–32. https://doi.org/10.1038/d41586-018-07586-5