Could we avoid installing solar panels in the countryside and use only rooftops?

1. Would it be possible to avoid installing solar farms in rural areas and rely solely on rooftops?

2. What’s the difference between solar farms and rooftop self-consumption systems?

3. Which rooftops are suitable for solar panel installation?

4. Where can photovoltaic plants be installed in Spain?

Would it be possible to avoid installing solar farms in rural areas and rely solely on rooftops?

Using rooftops to generate solar power is a key part of a more sustainable and decentralised energy transition—but it's not enough to meet the country’s entire electricity demand. 

To ensure an efficient, stable, and sustainable electricity supply, rooftop self-consumption must be combined with large-scale photovoltaic plants and other renewable sources such as wind energy and hydroelectric power.

To meet energy demand, self-consumption must be integrated with other renewable sources.

What’s the difference between solar farms and rooftop self-consumption systems?

Scale and generation capacity

Photovoltaic plants are large-scale installations, typically located in wide, sunny open areas. They are designed to produce high volumes of electricity that feed into the power grid to supply thousands or even millions of people.

Rooftop solar panels are decentralised systems with lower generation capacity, primarily intended for self-consumption in homes, businesses, or community settings. While they can inject surplus electricity into the grid, their main goal is to reduce dependence on external electricity.

Rooftop solar systems are mainly designed for self-consumption in homes, businesses, and communities.

Efficiency and costs

Solar farms are optimised to capture the maximum possible solar radiation using panels with solar tracking systems. These panels follow the sun’s path and can boost electricity generation by 25–30% compared to fixed rooftop panels.  

In addition to generating electricity, these large plants contribute to grid regulation and management, helping system operators optimise energy transmission.

Rooftop systems depend on factors like orientation, available space, and shading from nearby buildings or trees—all of which can limit electricity generation and increase the cost per kWh generated.  

They are not dispatchable and lack accurate generation forecasting capabilities.

Rooftop panels are affected by orientation, available space, and shading, which limits electricity generation.

Space availability

To generate enough electricity for a country like Spain, an enormous rooftop surface area would be required—one that simply doesn’t exist. 

Feasibility studies indicate that rooftop solar can cover part of the consumption, but not the entire demand.

Photovoltaic plants make use of available land to generate energy at scale. They also enable solutions like agrivoltaics, which combine agricultural production with solar energy generation without sacrificing usable land.

Meeting Spain’s energy needs would require a rooftop surface area that simply doesn’t exist. 

Which rooftops are suitable for solar panel installation?

According to the IDAE’s self-consumption guide, it’s essential to consider local conditions and roof orientation to maximise solar panel performance.

Solar panels work best when sunlight hits them at a perpendicular angle, making south-facing rooftops ideal—though other orientations can also be viable.

Additionally, rooftops must be able to bear the weight of the panels. In some cases, the roof structure must be reinforced.

The most important step is to conduct a detailed assessment to determine the rooftop’s suitability before installation begins.