The Spanish Institute of Technology and Communications (CIDT) co-financed the technology throughout its development stages, and the Andalusian Technology Corporation (CTA) supported the recently completed pilot project in Puertollano.
BlueSolar has developed the first large-scale plant concept that integrates photovoltaic and solar thermal energy in a single facility using hybrid panels. These panels generate uninterrupted electricity and also function as concentrating mirrors, using a patented selective optical light filter embedded in the panel glass. The panels continue to produce electricity while reflecting heat for thermal storage or direct steam generation.
The core of the technology is a specialized glass that replaces standard glass over the photovoltaic panel and is manufactured by BlueSolar. The company said it can adapt this glass to any manufacturer’s monocrystalline silicon panels, though it achieves higher efficiency with tunnel oxide passivated contact (TOPCon) technology than with passivated emitter and rear cell (PERC) designs.
“BlueSolar has the potential to become the world's first solar technology that enables uninterrupted power supply at market prices. It efficiently harnesses 50% of the energy that a panel doesn't use, allowing for 60% more energy efficiency with a photovoltaic plant and 70% more than a solar thermal plant,” José Caparrós, CEO of Blue Solar, told pv magazine. “This is because, in the range of light that the filter allows to pass through to the photovoltaic panel, silicon is twice as efficient as a solar thermal plant, while in the percentage of reflected light, a solar thermal plant is much more efficient than a photovoltaic panel. With this interplay of light, the efficiency of a solar photovoltaic system increases by 60%.”
The plant concept integrates thermal storage using molten salts or other storage media.
“But given the system's intrinsic efficiency, it is possible to minimize all the technological barriers of solar thermal plants, with smaller towers, lower temperatures, less complex trackers, and smaller and simpler receivers, allowing for scalability, modularity, reliability, and reduced operation and maintenance costs, which are the major technical challenges of solar thermal plants,” said Caparrós. “And above all, improving the levelized cost of electricity by 50%, with the potential to reduce prices infinitely greater than that of these solar thermal plants.”
BlueSolar has designed its new plant concept to hybridize with existing and planned PV plants, aiming to optimize current grid infrastructure.
“The integration of photovoltaic plants with thermal storage plants using BlueSolar technology gives rise to a plant concept that allows base load operations for over 7,000 hours per year. The added benefit of having a steam turbine makes hybridization with gas possible, which would allow for complete grid isolation, with 80% of the supply produced using green energy and without price fluctuations,” said a BlueSolar executive. “The compatibility of the technology with green hydrogen generation, which requires an uninterrupted renewable electricity supply, is being studied, as well as for coupling to data centers or desalination plants, both thermal and reverse osmosis, which have high thermal and electrical consumption, respectively.”
BlueSolar can now market the technology for plants above 10 MW, with optimal efficiency in countries with high solar resources such as Spain, Italy, Chile, Australia, the United States, South Africa, and Morocco.
The company has already conducted financial studies for the full plant concept with major companies, citing its experience introducing new plant designs in the Spanish market, including early requests for synchronous capacity connection points with PV or wind systems and thermal storage systems paired with PV fields.
The main challenge, Caparrós said, is overcoming skepticism toward thermal storage technologies. He said the sector often sees solar thermal as obsolete because early plants were built without storage and faced high complexity as first-generation projects. But as Caparrós noted, storage is now essential – not only electrical but also thermal – since two-thirds of industrial energy demand is for heat. To decarbonize industry, he said, thermal storage is necessary, making solar thermal and BlueSolar's technology increasingly relevant for an emerging market where thermal storage is the only viable option.
The first project using this technology was inaugurated in November at the Institute of Concentrated Photovoltaic Systems (ISFOC) in Puertollano. The 300 kW system will supply power to the technology center and support development of hybrid systems requiring thermal storage, including high-temperature hydrogen production.
