No life without Sun
All life on Earth depends on the Sun and, more and more, the electrical energy that we need and use in our daily lives comes from a renewable source such as photovoltaic energy (with a weight of more than 10% in the generation of energy total electricity in the year 2022 in our country). This month of February we dedicate our Blog to this source of energy and its situation at a national, European and global level.
The discovery of the photovoltaic effect, understood as the production of electric current between two materials exposed to electromagnetic radiation, was first documented in 1839 by Edmond Becquerel. However, it was not until the end of the s. XIX when Heinrich Hertz first observed the photoelectric effect, on which solar cells currently depend, and which would be explained by Albert Einstein in 1905. It was not until 1954 when the first commercial silicon cells began to be manufactured at Bell Laboratories ( USA), and since then the position of silicon in the solar cell market has been hegemonic, largely thanks to advances in the microelectronics industry.
From that moment in history, there were several events that accelerated the development and improvement of solar panels: the space race, where solar energy was used to power satellites, as well as the first (1973) and second (1979) crises. of oil, which caused a major change in world energy policy, once again putting the focus on the incipient solar technologies.
kWp pilot plant was installed in San Agustín de Guadalix, remaining for almost 10 years as the only photovoltaic installation in our country. It would not be until 1993 when new installations were made, corresponding to very small residential installations. Little by little, photovoltaic installations took place, although these remained in the demonstrative field as this type of generation is not yet regulated in Spain nor is it attractive in terms of its costs.
It would be in 1998 when different regulatory changes that promoted this renewable technology began to take place, from RD 2818/1998 to RD 661/2007, the latter being the one that represented an unprecedented boost for this type of technology. After this great growth in our country, a series of events occurred that slowed down the drive for photovoltaic generation, beginning with the crisis that began at the end of 2008 as well as different regulatory changes that slowed down its development (taxes on generation, “tax on in the sun”, among others).
Currently, taking data from 2021, photovoltaic solar energy is among the most important renewable technologies worldwide, with an installed capacity of 940 GW . Its annual growth positions it as the first renewable technology (largely due to the lower complexity of installation and processing), going from 70.47 GW installed worldwide in 2011 to the aforementioned 940 GW in 2021. The last five years , the installed global photovoltaic power has grown by more than 200% from the 306.5 GW installed in 2016 to the current ones already mentioned.
If we transfer the previous figures to the European level (EU-27), the installed capacity goes from 106.7 GW in 2017 to 159.9 GW in 2021 , increasing the ratio by 48.9%. Going one level further and taking these figures to our country, we observe contained growth until 2018, with a cumulative power of 4.77 GW, which has accelerated in recent years to reach 19.11 GW in 2022, as we can see. in the graph shown below.
Graph 1. Accumulated solar photovoltaic power in Spain from 2010 to 2022 (in MW).
The power installed in the last 4 years (2019-2022) in our country (14.3 GW), meant tripling the total photovoltaic power installed up to that moment.
Spain ranks eighth worldwide in installed photovoltaic capacity and second in Europe. The country that ranks first is China, with 377.1 GW, followed by the United States, with 122.1 GW.
Graph 2. Accumulated solar photovoltaic power in 2021, by country (in GW). Source: REN21.
The marked growth that we observe in our country in the previous graph, in the last 4 years, is due to the promotion of self-consumption and the promotion of aid and subsidies from the main European, state and regional entities around the generation of renewable energy. Added to this clear impulse derived from the decarbonisation objectives set from Europe is the decrease in the cost of generation with this technology, which allows for increasingly shorter return periods.
This installation cost has evolved in the last 10 years from $4,104/kW in 2011, to the current $857/kW (2021). The decrease that we have observed in the average price per kW makes it possible to obtain greater profitability from the installations, thus encouraging their installation. The technology currently used comes mainly from China, which has dominated the world market for photovoltaic panels and inverters for several years.
Graph 3. Evolution of the average cost of photovoltaic installations worldwide from 2010 to 2021 (in US $/kW).
It is also worth mentioning that, together with the decrease in costs, there has also been a continuous increase in the efficiency of solar cells, from 6% of the first ones to widely exceeding 20% today, and in general an improvement in the technology that continues unstoppable today.
In 2020, photovoltaic production made a total contribution to GDP of €4,686 million. With a direct contribution of 4,204 million (89.7%) and an induced contribution of 483 million (10.3%).
Today, it is the technology that is growing the most in our country due to its low environmental impact when compared to other types of facilities, the lower cost of the technology itself and the high resource available (about 2,500 hours of sunshine). annual). Spain is a country that has favorable conditions for the development of this technology, which will help us to achieve the European objectives and to advance in the energy transition in which we find ourselves worldwide.
 Solar Power Europe. (2022). Cumulative installed solar PV capacity worldwide from 2000 to 2021 (in megawatts) . Statista . Statista Inc. Accessed: February, 2023. https://www.statista.com/statistics/280220/global-cumulative-installed-solar-pv-capacity/
 EurObserv’ER (2022). Cumulative solar photovoltaic capacity in the European Union (EU-27) from 2017 to 2021 (in megawatts). Statista. Accessed: February 2023 ( https://www.statista.com/statistics/497540/connected-and-cumulated-photovoltaic-capacity-in-the-european-union-eu/ )