Heat and electricity directly from the Sun

A recent decrease in the cost of photovoltaic (PV) panels resulted in a large number of cases in which solar energy companies could not stay afloat. In particular, companies that had developed alternative systems to standard silicon PVs found it difficult to provide competitive systems. Alternative systems include concentrated solar power (CSP) and concentrated PV (CPV) systems.

On the one side, a large increase in the CSP supply volumes is required to decrease their cost and enable them to compete with conventional PVs. On the other, the use of CPVs is limited as they can only be installed in countries that are Sun-rich.

With EU funding of the project 'Transparent Fresnel based concentrated photovoltaic thermal system' (INTENSOL), researchers developed an innovative concept of a low-cost high-concentration PV (HCPV) solar thermal system. Based on a combination of the latest developments in PV technology and solar thermal components, this integrated system is able to produce electricity and heat. Except for Sun-rich regions, its high-concentration factor and efficiency make it also suitable for central Europe.

Contrary to conventional PV systems, the INTENSOL solution uses cost-effective Fresnel lenses to focus sunlight onto multiple-junction solar cells. To further increase efficiency, the system is equipped with an integrated cooling and heat recuperation system, and a two-axis tracker orienting the system toward the Sun. Furthermore, it is lightweight and easy to maintain.

The INTENSOL system is a modular arrangement, consisting of the core HCPV system plus optional solar thermal components — so-called afterheaters. For example, the pure HCPV cooling system is unable to deliver hot water at useful temperatures. To this end, a one-axis concentrator system can be added to raise the temperature up to 150 Celsius degrees. This is particularly useful for heating and drying in industrial uses.

Except for industry, the INTENSOL system will benefit hotel resorts, campsites, sports centres, shopping malls, hospitals and offices.