“We use the water surface to support the panels without taking up any land”

What exactly is a floating solar PV plant?

The technology is the same as that used in other solar PV installations, with crystalline silicon panels like those used on rooftops or on the ground. The key difference is that here the panels are supported by a floating structure. We do not use land or rooftops, but instead make use of the water surface to support the panels, in this case on an irrigation pond—an area that would otherwise not be used to generate energy.

What are the technical characteristics of this type of installation?

Floating installations can be set up in reservoirs, natural lakes, or even at sea. The main challenge is that water is a dynamic medium: the water level rises and falls depending on the time of year, and there may be movement caused by wind or small waves. Therefore, the system must be securely fastened so that it does not move sideways, while at the same time allowing for vertical movement. Even in the worst-case scenario, if the pond is drained, the panels must be able to rest on the bottom. The cabling must also be designed with sufficient slack to accommodate these variations.

What are the advantages compared to using agricultural land or other spaces?

The first advantage is obvious: we do not take up land—especially agricultural or natural land—which is limited and valuable. But there are also direct benefits for the pond itself. The panels reduce water evaporation because the sun does not shine directly on the water, which can result in a reduction of over 80%. In a climate like the Mediterranean, this is essential. It also reduces algae growth, as the water remains cooler and more stable.

And in terms of energy efficiency, does it offer any improvements over other systems?

Yes, there are significant advantages here too. The water acts as a natural cooling system, which reduces the temperature of the panels. And in photovoltaics, temperature is one of the main causes of efficiency loss. By operating at a lower temperature, performance improves by between 10% and 15%. Moreover, as there is no dust on the ground, the panels get less dirty, which also helps to maintain higher energy output.

In a region like the Balearic Islands, how significant is this solution?

It is particularly significant because land is scarce and highly valuable. Just as priority is given to the use of rooftops, ponds are underused spaces that can be taken advantage of. This allows for increased generation capacity without competing with other land uses, such as agriculture or landscape conservation. On islands such as Mallorca, this type of solution makes a lot of sense.

What has been achieved in the Capdepera project?

As part of this project, 2,528 solar panels with a total capacity of 1,480 kilowatts peak have been installed. All are mounted on a single floating surface on the pond. The structure is assembled in a modular fashion, much like a Lego-style system: you start at the edge and work your way towards the water with every panel you add. In total, the installation took around 16 weeks.

What does this energy output amount to in terms that are easy to understand?

We are talking about an output of approximately 1,800,000 kilowatt-hours per year. If we break that down in terms of household consumption, it is roughly equivalent to the annual consumption of around 600 families, which helps to illustrate the real impact that a facility of this kind can have.

Beyond the energy itself, what is its environmental impact?

It has several positive effects. On the one hand, it improves water management by reducing evaporation and the growth of algae. On the other hand, the visual impact is much less than that of ground-mounted installations, as the panels are positioned at a lower height and blend in more with their surroundings. Compared to structures built on the ground, they are much less conspicuous.

What is the public perception of these projects?

From an administrative standpoint, they are viewed very positively because they do not take up agricultural or natural land. From a social standpoint, they are still relatively unknown, but once people understand them, the perception is positive because their benefits are clearly evident. What’s more, they often go unnoticed because they are not visible from a distance, which also reduces rejection.

Is this a solution that can be replicated in the Balearic Islands?

Yes, absolutely. There are already other installations in place, and more projects are currently under development. There is interest from both the government and the industry. It is a solution that fits in well with the region, although in some cases the ownership of the ponds—which may be public or shared—makes the processes somewhat more complex.

What challenges are involved in developing this type of project?

The challenges are not so much technical as they are administrative. Unlike private land, many ponds are managed by irrigation communities or public bodies, which requires coordination between multiple stakeholders. This may slow things down, but it is part and parcel of the complexity of this type of infrastructure.

Looking ahead, how do you see this technology developing in the Balearic Islands?

I believe it has clear growth potential. Any owner of a pond that uses energy—such as for irrigation, for example—will consider it. Furthermore, the current situation reinforces this trend: the need for energy independence, cost stability and the transition to clean energy mean that solutions of this kind are becoming increasingly relevant and significant for the islands’ energy future.