Energy transition

It’s all very well talking about solar energy: the differences between photovoltaic and concentrated solar power

A study by researchers at ENEA compares the two types of technology, looking at land use, performance and other characteristics. Here are the results

by Davide Madeddu

31 July 2026

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3' min read

Translated by AI

Versione italiana

3' min read

Translated by AI

Versione italiana

Photovoltaics or concentrated solar power? This is not a contest, but a comparison of the two systems for producing green energy, which forms the focus of a study carried out by researchers at Enea which highlights the distinctive features of the two systems which, in the context of the energy transition and decarbonisation processes, ‘can be complementary’.

The study

The researchers (the results were published in Energies) analysed the solar potential of the entire country, calculating global and direct radiation – the two indicators used to assess the potential of photovoltaic and concentrated solar power, respectively.

The study reveals that the results ‘show clear differences between the North and the South: global radiation has average annual values generally ranging between 1,400 and 1,900 kWh per square metre, with lower levels in the Alpine and northern regions (below 1,300 kWh/m²) and higher in the South and on the islands (with peaks of over 1,900 kWh/m²)’. Direct radiation also shows marked regional variation, with the highest values in Sicily, Sardinia and the southern regions.

“However, compared with total radiation, direct radiation is more variable and sensitive to atmospheric conditions and the topography of the terrain,” emphasises Giampaolo Caputo, co-author of the study and a researcher in the Department of Energy Technologies and Renewable Sources at ENEA, “ this is a key factor in selecting the most suitable sites for concentrated solar power, for which a direct radiation value exceeding approximately 1,800 kWh/m² per year serves as an initial indicator of viability.”

The comparison

The study also compared a concentrated solar power plant with a 1 MW photovoltaic plant, using simulations carried out at four locations representative of Italia: Montalto in Lazio, Val Basento in Basilicata, Ferrara in Emilia-Romagna and Priolo in Sicily. ‘In the case of concentrated solar power, Priolo shows the best performance throughout the year, with a capacity factor (the ratio of energy actually produced to the maximum energy that the plant can produce) which reaches 78 per cent in the summer months and remains high even in the transitional seasons,’ the study highlights. Consequently, it is also the site with the highest monthly electricity production, with peaks of 530–570 MWh between July and August, and the highest annual production of around 4,100 MWh.”

Land use

Land use is a further factor distinguishing the two technologies. A 1 MW concentrated solar power plant, including the solar field and the thermal storage system, ‘requires a total of around 50,000 square metres – it is emphasised – whilst a photovoltaic plant of the same nominal power, comprising 1,818 modules, occupies around 10,000 square metres’. As a result, “in terms of output per unit area, photovoltaics are more efficient: they generate between 147 and 172 kWh per square metre per year, compared with 67.5–81.5 kWh/m² for concentrated solar power”. ‘This greater efficiency in land use,’ adds the researcher, ‘makes photovoltaics particularly suitable for contexts where land is in short supply, whilst concentrated solar power requires more careful spatial planning.’

From an economic perspective, ‘photovoltaics have a lower average cost of electricity generation over the entire life cycle of the plant than concentrated solar power, enabling electricity to be generated at a lower cost’. However, the research organisation argues, ‘the higher cost of concentrated solar power must be assessed in light of the added value this technology offers: more stable electricity generation, energy storage in the form of heat, greater flexibility and grid integration, with less need for curtailment, that is, the forced reduction of generation in the event of excess production’.

Furthermore, concentrated solar power can provide heat for medium- and high-temperature industrial processes, contributing to the decarbonisation of sectors that are more difficult to electrify. “The study therefore highlights that photovoltaics and concentrated solar power can be complementary in the energy transition,” concludes the researcher, “ the former is better suited to producing low-cost electricity on a large scale, whilst the latter proves more advantageous when programmability, storage, flexibility and integration with industrial processes are priorities.”