The use of solar panels on the roof to heat water for the bathrooms is standard practice in many countries world wide today. Some other solar devices have been used for cooling purposes, but have not been found very economical. However the researchers at the Madrid Universities Carlos III and Politécnica are doing path breaking research in using solar power for heating as well as cooling.

Their suggestion is to incorporate  solar energy collectors into a gas-based co-generation system with an absorption machine. This will allow the energy expenditure and CO₂ emissions both to be reduced. This gas engine generates electricity which can be used to power air conditioning during the summers. The extra heat that is trapped can be used during winters to warm the rooms. The prototype has been built.

The hybrid tri-generation plant built by the researchers at Madrid upplies 1.7 MW of electricity, 1.3 MW of heating and 2 MW of air conditioning.  Unfortunately the size and scope of the gas engine is such that at present it would take 14 years of use for the machine to pay for itself.

While the concept was developed to help the energy needs of the buildings within the Madrid region, it may be a wile before the proposed gas engine can be used in an economical manner. Perhaps more science experiments could help make it more user friendly.