Background Within the framework of the Kyoto Protocol, Europe has committed itself to reducing its greenhouse gas emissions to 8% below 1990 levels by 2008-2012. Lighting and air-conditioning of buildings account for a substantial proportion of Europe’s carbon dioxide (CO2) emissions and energy consumption. Two technologies are currently considered to have a great potential for contributing to a reduction in the CO2 emissions of buildings. “Solar cooling” uses excess solar energy to cool buildings during the hottest hours of the day; while “hydrogen conversion” allows the storage of energy in form of hydrogen. Both technologies have been developed and successfully tested by the project partners on an experimental scale. Objectives The project sought to demonstrate how renewable energy obtained from solar cells and wind turbines could, through solar cooling and hydrogen accumulation, effectively and economically supply lighting and cooling for a 2 400 m² building. The project aimed to develop pre-industrial prototypes of the two technologies, before integrating them into an existing public building. Power production, storage and use would be completely free of CO2 emissions, saving 95 tonnes of CO2 per year. Results The project demonstrated the technical viability and efficiency of a complex prototype system at industrial scale (solar cooling and hydrogen production and storage, coupled with renewable energy sources), and with an overall power of 70 kW. The system is composed of two separate prototypes: (1) A hydrogen production/ storage plant: the energy obtained through photovoltaic panels and wind turbines is stored in the form of hydrogen. The electricity obtained is then used for lighting in a small annex building. The efficiency of the plant is approximately 45%. The energy produced is estimated to be 84 000 kWh per year, with a lighting output of 3 kW. The final cost of electrical energy rises to 2.44 €/ kWh, which is about 10 times the usual cost. (2) Air conditioning system (solar coolers): 18 units using methanol adsorption enable the production and storage of cold water. The system has been coupled with the main building with the aim of it being used for air conditioning in the future. The efficiency reaches 13% and the cold water produced is estimated to be equivalent to 12 395 kWh per year. The air conditioning output reached 6 kW. A small annex building was renovated to be used as an information and awareness-raising area for the public. Unfortunately, the works to restore the demonstration public building ceased before the end of the project. This meant that the overall project system could not be properly integrated and tested. According to the beneficiary, this will be done after-LIFE. The project team also encountered a number of other problems over the course of the project, mainly due to the fact that the technology was so new. Despite these setbacks, based on its preliminary data, the project estimates that by using its prototype system, 70% of the energy requirements of the building could come from renewable energy. This would mean a saving in CO2 emissions of 9.31 tons per year (assuming an average emission of 0.4 ton of CO2 for each MWh of electricity produced in the Spanish network). To summarise, the project’s technical achievements are valuable for demonstration purposes and for further development of these pioneer technologies. The production, storage and use of energy are totally free of CO2 emissions and could be achieved locally, which also makes the findings of relevance in global efforts to reduce HGC emissions. The project also generated valuable expertise and knowledge in the fields concerned, and the possibilities of transference of the project technology are numerous. One of the most feasible and direct applications could be in the provision of energy supply locally in remote areas and in the production of cold air/water for improving conservation of food and drugs. A notable outcome of the project is the creation of a spin-off company to apply the project technology. Finally, considerable development work was carried out concerning specific components, and the project team has developed a pioneering system in the EU. There is a significant potential for long term benefits, as the technology is improved and reproduced elsewhere. The main existing barriers and limiting factors are the quality, duration and maintenance of the hydrogen cell, competition from outside EU, and above all the need for production at industrial scale to lower prices. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).