General statements regarding the economy of solar plants are very difficult to make as the reference cost of electricity varies by a factor of 5 worldwide and the efficiency of electrical cooling machines also varies. Solar radiation varies by a factor of approx. 2 between the various Locations we have measured, and additional use of the energy from the solar plant for heating and hot water purposes has to be individually assessed for each project. Grant assistance available for such projects also varies considerably.

However, it can be assumed that most of the projects will achieve a payback period of 5-15 years based on current energy prices. It is important to note that there is a minimum size for solar cooling

plants to be economic. This depends on location and certain conditions, and varies between 1000m2 — 2000m2 of area to be cooled for now.

Diagram 8: Energy Cabin for cooling and heating with solar energy.