In order not to impact the landscape, how much photovoltaic energy can be placed on roofs and already degraded areas?

The need to urgently increase renewable energy to curb the climate crisis is causing strong rejection in some Spanish territories due to the impact of these technologies on the environment.

In fact, many of the current projects pending evaluation are located in areas of maximum environmental sensitivity.

In the case of photovoltaics, there are alternatives, such as roof panels, which take advantage of already built or degraded areas with much less impact on the landscape and biodiversity.

The question is: how much of this solar energy can actually be placed in already man-made areas?

To meet the objectives of the National Integrated Energy and Climate Plan (PNIEC), by 2030 Spain must install an additional 30 gigawatts (GW) of photovoltaics, three times more than what already exists.

According to the Government's Self-consumption Roadmap, prepared by the Institute for Diversification and Savings (IDAE), if the solar radiation that falls on rooftops in Spain is simply considered, the data reflects an enormous potential of 500 GW.

However, the viable megawatts are much less, since other physical, technical, economic factors must be taken into account... Their estimates conclude that the real potential of self-consumption with photovoltaics on the roofs of buildings in the country (especially in commercial constructions) is 9 GW, which can reach 14 GW in a high penetration scenario.

“It is true that these calculations may fall short as self-consumption progresses, we are the first to admit it”, says Joan Groizard, director of the IDAE, who adds: “But it is not viable to think that we will achieve it only with the roofs, if not we want to give up practically a decade of renewable development at the rate we need because of the climate emergency.”

Installation of photovoltaic solar panels at the access to Caixaforum, in Seville.PACO PUENTES (EL PAIS)

Apart from the roofs of buildings, there are many other surfaces that are being considered to increase photovoltaics, in some cases with very real examples and in others with pilot tests or only theoretical designs for now: outdoor car parks, bike lanes , water infrastructures, railway facilities, roads... A few days ago, the Aliente organization, a state group that defends the development of renewables with less impact on the territory, presented a report that ensures that in Spain there are enough already transformed surfaces to install 181 GW of photovoltaic, much more than the PNIEC objective.

According to this work carried out by the Observatory of Sustainability, 57% of this potential would be on roofs, terraces, warehouses and facades;

17% in greenhouses;

16% in mining areas;

5% on the road network;

3% in channels;

1% in dumps;

1% on the railway;

and 0.2% in industrial areas.

Fernando Prieto, director of the Observatory of Sustainability, maintains that "between these surfaces there is enough space to avoid having to touch natural or agricultural areas."

“They are not just small installations on roofs, large photovoltaic plants can also be installed, but in places that are already degraded”, he maintains.

Experts consulted provide different estimates and doubt the viability of some of these alternatives, but they do agree on the need to prioritize areas with the least environmental impact and greatest benefit for local communities.

As Groizard emphasizes, “to see what we are talking about, with 0.4% of the country's territory we would reach all the photovoltaic needs we have”.

According to this engineer, who has a lot to do with the PNIEC numbers, although on paper it is easy to add square meters up to that 0.4%, actually managing to cover all those surfaces with solar panels is another story, since decisions are involved. of an infinity of different actors, between families, companies, town halls... "You have to start with the roofs of the buildings, there is no doubt there,

but I am concerned that a dynamic of moratorium or paralyzing everything will be generated until it is ordered, because anyone who has worked with a city council knows that a planning plan takes eight or 10 years, we cannot give up a decade of renewable development ”, he points out.

"A project on the ground does not mean that it is an ecological attack", emphasizes the IDAE director, who ensures that the environmental processing is precisely to exclude the most impactful: "Only one in three or four projects that are started actually end , and in the current situation it could be even less”.

we cannot give up a decade of renewable development”, he points out.

"A project on the ground does not mean that it is an ecological attack", emphasizes the IDAE director, who ensures that the environmental processing is precisely to exclude the most impactful: "Only one in three or four projects that are started actually end , and in the current situation it could be even less”.

we cannot give up a decade of renewable development”, he points out.

"A project on the ground does not mean that it is an ecological attack", emphasizes the IDAE director, who ensures that the environmental processing is precisely to exclude the most impactful: "Only one in three or four projects that are started actually end , and in the current situation it could be even less”.

For Juanfer Martín, the person in charge of climate change at Fundación Renovables, "the technical potential does exist, but to what extent can we obtain all the energy and can we fill roofs and degraded land with photovoltaics, is often not viable."

As he explains, at the top of the buildings there are already chimneys, air conditioning systems and other elements, in addition you have to take into account the shadows between the buildings, which reduce the performance of the plates.

The conclusion of the Fundación Renovables with its work on public buildings in Madrid is that a third of the space on the roofs can be used.

On the other hand, as he emphasizes, today it is not economically worthwhile for people to fill 100% of the free space on their roofs with photovoltaic panels, since excess production is paid for at low prices.

“The compensation comes from the cost of the plates, the energy that is obtained and the price of electricity;

the more expensive, the more interesting it is to go solar,” says Martín.

"Today there are many facades that are not economically viable."

Floating photovoltaic plant in the Sierra Brava reservoir (Cáceres).

Andrea Comas (THE COUNTRY)

It makes a lot of sense to take advantage of already degraded land, but if there are no electricity networks that reach there, its construction can have a high environmental impact.

"You also have to take into account the potential of non-degraded lands where the plates can coexist with agriculture, which is called agrivoltaic", highlights the representative of the Fundación Renovables, who affirms that photovoltaic installations can be built in a way that helps to agriculture.

“There are many degraded lands around the towns where you can also set up small decentralized plants for the municipality's own consumption and to generate energy communities,” he comments.

Parking lots

Recently, the French Parliament has just voted in favor of the obligation to install shade roofs with photovoltaic panels in outdoor car parks of more than 1,500 square meters.

This measure, which is still pending final approval, includes penalties ranging from 20,000 to 40,000 euros, depending on the size.

In Spain, the climate change law of the Balearic Islands requires that all publicly owned car parks of more than 1,000 square meters in the archipelago be covered with solar panels as of 2025.

channels

In Navarra, the regional government is working on a pilot project to test the feasibility of covering the Navarra canal with photovoltaic panels, a measure that could be applicable to other hydraulic infrastructures and that would also reduce water losses through evaporation.

As Yael Lorea, a technician from the public company Nasuvinsa, details, "people are beginning to express their rejection of the renewable megaprojects, by covering the canal with photovoltaics we are recovering an infrastructure that already exists, which does not have a new landscape impact, and also the energy obtained would go to the buildings of the Government of Navarra, with which all Navarrese would benefit”.

It has been calculated that covering the 77 kilometers of the canal with solar panels would provide a power of 160 megawatts (0.16 gigawatts),

with which 200 gigawatt hours a year could be generated, the equivalent of 4% of the electricity consumed in the community.

However, as Lorea specifies, as the pilot project progresses they are seeing that this amount would be less, since parts of the canal have to be left uncovered in order to carry out its maintenance.

Likewise, they have also verified that it will be difficult to avoid 30% losses due to water evaporation, as they had originally planned.

greenhouses

The report of the Observatory of Sustainability gives great weight to photovoltaics over greenhouses.

As defended by this work, the plastic roofs of areas such as Almería could become a "great power station" producing electricity using new one hundred percent transparent solar panels developed by researchers from the University of Michigan (USA).

Theoretically, the report ensures that the greenhouses could accommodate a power of 30 GW of photovoltaic, an amount similar to that which is to be installed throughout Spain by 2030. In this regard, the Andalusian Energy Agency reiterates that " One thing is the solar radiation that a certain area receives and another very different thing is that it is viable to transform it into energy, both for engineering reasons and for the economic cost”.

Photovoltaic parking in the city of Victoria, in Tamaulipas (Mexico). Quetzalli Nicte Ha

"When it is said that it is not economically viable, it depends on how you calculate it, what cost it is to charge an agricultural area or a forest area," replies the director of the Sustainability Observatory, who maintains that if more solar is achieved, this would in turn reduce conflicting wind projects.

Meanwhile, the European Parliament last week endorsed the Commission's proposal to simplify environmental procedures in the approval of renewable projects, which has put environmental groups on alert.

The text has not yet incorporated the position of the Twenty-seven, but it also affects the zoning of the territory, so that the countries identify priority places in which much more expeditious procedures are applied to install wind and photovoltaic energy.

In Spain, right now there is a non-mandatory zoning and for new projects their environmental and social impact is assessed when it comes to giving access to electrical nodes (one of the main bottlenecks for the installation of renewables).

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