Electricity generated through photovoltaic panels powered by the sun’s rays is one of the most promising energy options for the coming years. It is that, properly developed, it could help solve some of the severe environmental and energy problems that plague the immediate future of the planet. However, this option is not exempt from problems and if humanity really wants to make solar become a robust alternative to generate energy, its development needs to go through -and overcome- various fine-tuning problems.
One of those topics is geographical space, the earth, that requires installing the necessary number of panels for their contribution to be significant: there are many square kilometers, which need to be affected in areas of high rate of “sunbathing”. And the truth is that not all countries have so much space available. Faced with this problem of scarcity, and the costfrom vacant land in recent times a new option has emerged that is in full study and growth: floating photovoltaic panels, installed on courses and water mirrors or even in the open sea: is it time for the “flotavoltaic” energy?
To better understand why the surface where to install panels can be a complex problem, it is worth considering this fact: generating solar energy requires a lot of space: at least 20 times more square meters per Gigawatt of electricity than any power plant conventional ones that burn gas or oil. That is why it is necessary to leave the space of local comfort and not think that solar is an option that can only be used intensively and extensively by “large” countries in terms of surface area, such as Australia, United States or -even-, Argentina; nations that have extensive geographic spaces available at low cost.
But there are many other countries where the availability of the “ground” resource is scarce and the factor becomes crucial. For example, Japan or South Korea should dedicate up to 5% of their total territory to host this type of installation.s if they want the solar contribution to be significant for their energy matrix. And in these densely populated countries, the demand for free land collides with other important needs, be it for living spaces or for other productive uses.
Obviously, desert areas They seem to be an ideal space: they receive a high amount of sunlight and the density of inhabitants in these places is low. But – there is always a but – mathematical models indicate that “darkening” large desert areas with solar panels can also alter local temperatures and that influence global airflow patterns. So to cover with panels a part of the Sahara they could end up generating more droughts in tropical areas or increase the heat that reaches the Arctic sea: the famous butterfly effect.
Faced with this situation, in recent years specialists have begun to consider the possibility of installing floating solar panels which takes pressure off competition for land use. Of course, this attractive possibility needs to be analyzed in detail before knowing if it is feasible to grow it on a large scale, both from the economic point of view and also ecological, since it darkens and leaves without light direct to vast aquatic spaces can also bring negative consequences to the environment.
Leverage. In certain geographies this idea is doubly attractive. For example, in the aquatic spaces generated by the reservoirs of the large hydroelectric dams, there is an opportunity to take advantage of artificial lakes such as the Ramos Mexía, generated by the El Chocón dam, which could offer the possibility of complementing that aquatic space with a “voltaic fleet” and would make the whole generator set more efficient.
Of course the balance is delicate. Among the elements to consider are several data. For example, it is estimated that the efficiency of these aquatic structures is up to 8% higher than that of their solar equivalent on land firm because the water acts as a coolant for the panels and increases their efficiency and overall energy performance. But, of course, we must add that the investment of setting up a floating photovoltaic system is between 20 to 25% more expensive than doing it on land. This could, in part, be compensated because doing it in certain spaces It would also reduce the costs of essential infrastructure, such as being able to take advantage of the necessary high-voltage lines that already exist to be able to take this energy to the centers of high consumption. Precisely Argentina has a considerable number of dams with water mirrors where this type of device could be installed and -even- in territorially extended nations such as Brazil, the “flotavoltaic” business has already received specific legislation that seeks to stimulate the installation of panels in bodies of water associated with dams.
Impact. Of course, solving an energy problem causing an ecological one is not good social business. That is why many details must be previously analyzed before promoting this alternative. Among these studies, we must consider that climate change causes warming of water bodies throughout the world and that generates an impact. For example, the proliferation of underwater algae. Flotavoltaic devices, by giving “darkness” to the surface of a body of water, could counteract these effects. But how much? What? And, could it not also reduce the quality of the water used for drinking or reduce the concentration of essential oxygen that fish and the rest of the aquatic biota need? In other words, flotovoltaics could be a benefit against global warming, but create a disaster for fishing or drinking water. That is why it is key to complete specific environmental studies before lining rivers and lakes with floating solar panels.
