Graetzel cells against silicon: ways of development
In the framework of the Global Energy Prize Laureate’s tour 2017, Michael Graetzel spoke at the International STAR Conference at the Shanghai Technological University, where he told why many venture investors continue to finance the development of silicon batteries despite the obvious advantages of new technologies.
The Global Energy Prize laureate 2017 took part in a meeting of the scientific advisory council within the framework of the conference of one of the universities of Shanghai. Discussing the latest developments in the field of solar energetics, Michael Graetzel analysed preferences of silicon and Graetzel cells.
Silicon technology has gone a long way. The first batteries were created for satellites in Russia and the United States at the very beginning of the fifties of the last century and had only two percent efficiency. For sixty years, this figure in the best industrial panels increased by 20 percent, and the average efficiency of the stations rarely exceeds 15 percent.
Silicon has fallen in price almost 20 times over the last ten years - from $ 400 to about $ 20 per kilogram, nevertheless, today the silicon method is still the most expensive way of producing energy, and today the cost of producing it on average is two times higher in comparison with the same energy of wind and thermal power.
By contrast, solar cells based on perovskite are simple in production and are made of inexpensive materials. Now their industrial production is just beginning, but it becomes clear that they have the potential for a multiple reduction in production costs, provided that the output is expanded.
As for the consumer qualities of solar cells, their application is much wider than that of silicon batteries. They work effectively not only on sunny days, but also in diffused light. An advantageous feature is also that they can be made flexible and perform in various color solutions, which expands the possibilities of their use in the construction of civil and industrial construction projects. Batteries can be integrated into facades, windows and other structural elements of buildings for power generation. The scientist cited as an example the noise barrier built on the motorway between the Swiss cities of Berne and Zurich, which not only protects from noise, but also generates electricity.
The scientist noted that even despite the fact that silicon went to efficiency 20 percent for sixty years, and Graetzel cells for less than ten years, and despite the profitability of perovskite technologies, silicon-based batteries are currently the only working industrial mass technology. It is the most effective of the existing commercial, cost-balanced technologies for obtaining solar energy.
Thus, it can be concluded that silicon technology in itself has great potential, but the question of cost is extremely acute. Silicon technology is very costly, even at the stage of construction of new production facilities, and initially the cost of equipment for solar power plants is too high. Accordingly, here arises a question of the further possibility and expediency of subsidizing the development of costly silicon photovoltaics.
Dr. Graetzel is sure: "The expensiveness of one technology always opens up some kind of free space for others, cheaper ones, that's why in our laboratory we are engaged in the development of hybrid technologies." On this basis that the entire growth of the perovskite market is likely to occur.