Difference between solar thermal panels and photovoltaics: a guide for technical departments
In the industrial energy efficiency landscape, there is often a terminological overlap that can create confusion when planning investments. When talking about solar energy for businesses, it is essential to distinguish between solar thermal and photovoltaic technologies, two systems that use the same energy source but for completely different purposes and based on entirely different physical principles.
Understanding how solar thermal works compared to photovoltaics, and how these technologies operate, is therefore crucial for correctly defining the energy investments of a production site. For a production manager or anyone responsible for the technical office of a plant, this distinction is the first step toward a sound decarbonization strategy.
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Thermal energy vs driving power: the two faces of the sun
The main difference between solar thermal and photovoltaic systems for industrial buildings lies in the type of energy produced and in the efficiency of radiation conversion.
- Industrial solar thermal: this technology uses collectors designed to capture solar heat and transfer it to a heat-transfer fluid. Solar thermal collectors can generally achieve heat conversion efficiencies between 50% and 70%, depending on the technology used and operating conditions. They usually produce heat in the 60°C to 120°C range, which is typical of flat-plate solar collectors used in industrial systems for process hot water.
- B2B photovoltaic energy: photovoltaic modules use silicon cells to convert photons directly into electric current, with an average efficiency ranging from 18% to 23%. This technology powers the plant’s driving force, from production line motors to compressed air systems. In addition, the electricity generated can power industrial heat pumps, turning electricity into highly efficient heat for heating applications.
Which technology should you choose for your facility?
The choice between solar thermal and photovoltaics mainly depends on the type of energy required by production processes. Understanding when to adopt solar thermal or photovoltaics for businesses is essential to setting the right industrial energy strategy. In most manufacturing companies, photovoltaics are the most versatile solution: the electricity produced can power any plant utility, from production line motors and compressed air systems to lighting and HVAC installations.
Industrial solar thermal, on the other hand, becomes particularly effective in production sites with a high and continuous demand for low-temperature thermal energy. In these contexts, such as the food industry, textile sector, or industrial laundries, the ability of collectors to directly convert solar radiation into heat significantly reduces reliance on gas boilers.
In more advanced energy configurations, the two technologies can be integrated on the same company rooftop. Photovoltaics help reduce the plant’s electrical consumption, while solar thermal supports processes that require heat, such as industrial washing or heating circuits. A combined design therefore makes it possible to make the best use of roof surface area and maximize the company’s overall self-production of energy.
FAQ – Domande frequenti
La differenza sostanziale riguarda l’output: il fotovoltaico genera elettricità per alimentare macchinari e infrastrutture; i pannelli solari termici producono calore per riscaldare fluidi tecnici utilizzati direttamente nei cicli produttivi.
Dipende dal bilancio energetico dello stabilimento. Se i consumi maggiori derivano da celle frigorifere e motori, il fotovoltaico è prioritario. Se lo stabilimento necessita di grandi volumi di acqua calda per la sanificazione o la pastorizzazione, l’integrazione con il solare termico industriale garantisce un risparmio termico elevato.
Certamente. Una progettazione integrata permette di ripartire la superficie della copertura tra moduli fotovoltaici e collettori termici, massimizzando l’autoproduzione totale e riducendo contemporaneamente la dipendenza elettrica e quella dal gas.
Solitamente il fotovoltaico offre un risparmio trasversale più elevato agendo sulla forza motrice. Tuttavia, per industrie con processi termici pesanti, il solare termico può offrire tempi di rientro dell’investimento molto competitivi grazie all’altissima efficienza di conversione in calore.
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