Ignacio Mártilde la Plaza He is a professor of electronics at the Complutense University of Madrid and a member of the Royal Spanish Society of Physics. His current research led him to study advanced concepts in solar cells and silicon-based infrared photodetectors.
In addition, he is the author of “Science Communication Blog”Please a little science“And in his latest book Solar energy.From Utopia to Hope Reveals the technology, science, economics and history of this energy.
Where does solar energy take up in Spain?
Our electrical system currently has 11.547 MW The installed photovoltaic power generation accounted for 10.45% of the total. Last year, this technology accounted for 6.1% of the total electricity produced in Spain. This is a historical record, and if it meets expectations, it will exceed it in the next ten years. In the past two years, when laws and regulations allowed this unrestricted increase, the installed power increased significantly, which is contrary to the situation where there was almost no solar installation between 2011 and 2018. There is no doubt that 2020 is called the decade of photovoltaic technology.
Is the current photovoltaic development sufficient to achieve this goal?
I will say no. In Spain, we have an enviable level of solar radiation because the average level of the entire country is equivalent to 1,500 kWh/m2 pcs The annual level is approximately 1,900 kWh/m2 pcs In the southern part of the peninsula. With so much radiation, we can use photovoltaic energy to generate enough electricity to meet our national needs. Therefore, we are not at the level allowed by our superior geographical conditions.
It is a renewable energy source, but what about panel production? Is it sustainable?
In fact, manufacturing is non-renewable because it consumes a lot of energy in the purification of its raw material silicon and the subsequent battery manufacturing process. In other words, to purify 1 kilogram of silicon and then use it to make solar cells, about 150 kilowatt-hours of energy are needed in this process.If this energy is taken into account (which must be done), the photovoltaic installation will emit 25-35 gr CO during its service life (approximately 25 years)2 pcs/ kWh, ratio Emissions from fossil fuel technology. Therefore, photovoltaic power generation is not a zero-emission energy source, but it is very close to it.
In addition, the product is almost 100% manufactured in China.
Due to uncompetitive manufacturing and labor costs, this country monopolized the market. With a domestic market of 1.4 billion potential consumers, you don’t need to export any products or compete with anyone. In addition, the Chinese government has promoted unprecedented growth in the local market through its five-year plan. In the past ten years, Asian countries have installed 50 to 70 GW of photovoltaic power generation each year. This has led to a sharp drop in panel prices and has spread to the world market. Therefore, China has become almost the only supplier of photovoltaic panels.
What obstacles must be summarized for this energy?
There are two obstacles. On the one hand, politicians and regulators, for many years, have not only failed to promote the installation of solar panels, but have been punished. The notorious “solar tax” paralyzed the industry for nearly a decade. Fortunately, this situation has changed in just over a year. It is hoped that sound regulations have been installed and that the current regulations will be maintained over time.
On the other hand, like any other power generation technology, photovoltaic power generation has advantages and disadvantages. If there is no light (at night or cloudy), this energy will not work, and it cannot be stored on a large scale at a feasible cost. In the face of its faster expansion, these are its two main limitations. But it has a unique advantage: the huge potential of solar energy. The energy the earth receives from the sun each year is equivalent to 7,000 times the total energy consumption of the earth. There is no other source of “primary material” with these characteristics.
We are still highly dependent on fossil fuels. How will the energy transition in Europe proceed?
All European countries are undergoing this transition, albeit at an unbalanced pace, and there have been some obvious fiascos in the process. For example, Germany was one of the countries that began to install a large number of renewable energy sources at the beginning of this century. Due to political and social pressure, Germany quickly shut down its nuclear power plants. The result is that it must start pulling coal to meet its energy needs, thereby increasing CO emissions.2 pcs.
Our neighboring country France is a unique example, mixing Energy is mainly dominated by nuclear energy (75%), this technology does not produce emissions, but its nuclear waste must be stored. President Macron announced a plan to reduce this park to 50% in 2017, but the goal has been postponed to 2025 and it is not certain that it will be achieved. In the final analysis, every country has its own unique characteristics, and it is unrealistic to think of an even and rhythmic transition.
Is it fast enough that changes will become a reality in less than 30 years?
With Spain as the center, I think it is completely feasible to achieve the goal mixing Energetic Renewable energy accounts for about 80% 2% of the total electricity produced by 2030. To achieve this goal, by the end of this decade, photovoltaic power generation should be multiplied by 3. This is an ambitious but feasible goal.
What types of photovoltaic energy exist?
Currently, there are three commercial technologies for terrestrial applications: two variants based on silicon (single crystal silicon, c-Si and polysilicon, mc-Si) and common-name technologies based on the other two semiconductors. Thin plate technology：CdTe y CuGaInSe2 pcs. Since the beginning of this century, silicon’s hegemony has been absolute. Then there are other more advanced technologies for the space market, mainly powering artificial satellites and robotic explorers in the solar system.
What are perovskites and how do they improve the efficiency of photovoltaic panels?
Perovskite is a kind of material with more than one hundred years of history. In the photovoltaic solar world, they have recently exploded. In 2009, the results of a battery constructed with these materials were released at that time, and the efficiency of the battery was 3.8%.A new study was published a few days ago, in which the “tandem” structure used in combination with silicon cells has an efficiency of 29,52%. In other words, in less than a decade, they have walked the path that silicon took half a century to walk.
Compared with other renewable energy sources, how do you see the future of this energy in response to the climate crisis?
Photovoltaic power generation and wind power coexist and go hand in hand with other renewable energy sources (such as solar, biomass, geothermal or hydropower). The combination of wind energy and solar photovoltaic can enable our country to achieve ideal energy independence at least in terms of electricity production. In view of the huge potential of solar energy resources and their economic prices (Solar wattage is less than 20 Euro cents), coupled with the current regulations that allow the use of consumable facilities under very favorable conditions, I have no doubt that this will be a glorious future, just like the raw materials from which nutrients are obtained.