Here comes the sun: the Spanish SME pioneering concentrated solar thermal and power systems to replace natural gas

When Marco Carrascosa talks, you notice the evident passion he has for his work; it is almost as if you can hear the Spanish sunshine in his voice. This is apt, considering he innovates in concentrated solar thermal and power. Tewer Engineering, the Spanish SME he founded and manages, is fast becoming a global leader in this domain.

Heading a Eurostars-funded consortium with partners the National Centre for Scientific Research (CNRS) in France, University West and Procada in Sweden and CIEMAT in Spain, Tewer Engineering has now succeeded in building prototypes in Plataforma Solar of Almería, Europe’s biggest testing space for large-scale industrial decarbonisation using concentrated solar thermal and power.

Located on a site that enjoys some 3,050 hours of sunlight a year, this technology has seen a resurgence in the last ten years or so as a commercially viable alternative to generating electricity by burning natural gas. Instead, thermal energy captured from sunlight can be stored and used to stabilise the electricity grid.  

A trick they do with mirrors: how concentrated solar thermal and power works

First, a series of precisely calibrated movable mirrors, known as heliostats, concentrate the energy of the sun’s rays into a central receiver. Then, using that concentrated solar energy, pressurised water or thermal oil is heated, capturing up to 60% or 70% of solar energy.

Compared to just the 15-20% of solar energy that can be captured from photovoltaic solar panels to produce electricity that have historically dominated the solar market, due in part to more investment and a dramatic drop in manufacturing costs in 2008, it is not hard to see why concentrated solar thermal and power is very much back in favour again.

The comparative efficiency gains are the result of the pioneering work of Tewer Engineering and its collaborators. Although Spain now accounts for almost one third of the total installed capacity of concentrated solar thermal and power systems globally, that still only amounts to around 2% of all solar power. With its new development, the company is hoping to boost the number of installed concentrated solar thermal and power systems.

Founded twelve years ago, Tewer Engineering has been working for years on different solar concentrator solutions, such as heliostats and parabolic trough collectors. Significant progress was made during its Eurostars collaboration with the development of a multi-material receiver with high thermal inertia that heats air, steam or other heat transfer fluids to more than 500 degrees Celsius.

This, and the advanced wider process that it is integral to, stands as convincing proof of the success of the Eurostars collaboration in bringing together complimentary skills and experiences around a common resource to create real tangible commercial value.

Carrascosa himself talks of being able to bring not only his engineering background, but also his practical hands-on project management experience in the automotive, rail and energy industries in the United States of America, China and Japan to the project. And he was happy to learn from others’ expertise in collaborative research and development, not just beyond borders and cultures but also across disciplines.

In any innovative endeavour at this level and scale, it is often difficult to achieve real and productive collaboration. Especially so in the energy business, where competing technologies, national interests and complex local market regulation apply. This makes the project’s achievements all the more impressive.

What exactly do we mean by green or renewable energy?

In any informed discussion about the energy transition, despite all the terms we use, two things at least are clear.

The first: we need to stop burning fossil fuels. And second: concentrated solar thermal and power is an effective alternative. The thermal storage and heat transfer has the capacity to decarbonise big industries struggling to turn green, like brewing and food processing.

By using thermal storage, concentrated solar thermal and power systems can generate electricity at night or when there is no wind. And these systems can even be used to produce green hydrogen in a photo-thermo catalytic process with no use of electricity like the electrolysers.

Tewer Engineering’s innovations are also creating value for Europe in skilled employment and exportable technology. In addition, concentrated solar thermal and power systems can guarantee energy security against threats from geopolitical uncertainty at low cost and with a shared global resource: the sun.

It is little wonder then, that Marco Carrascosa’s voice sounds so full of optimism.