Social development links to the exploitation of energy resources. As a consequence of this fact, buildings, both residential and services sector play an outstanding roll on the energy consumption of our current society. Therefore, buildings have a very significant demand of heating, refrigeration system, warm sanitary water access, lighting, ventilation, etc.
In this sense, the combination of different bioclimatic strategies in existing buildings establishes the way to achieve the reduction of energy consumption and the decrease of its produced CO₂ emissions. In fact, we have worked on a five floor building in the center-west of Spain, where Central Service of SES (Mérida, Badajoz) is located. The study is based in the influence of the decrease of CO₂ emissions from the air-conditioning system by means of an absorption equipment use with biomass thermal support.
The current research identifies the different variables that determine the demand of energy in the air conditioning system of the building. It drives on an optimum parameter combination that allows adjust a correct running building and a good level of comfort to the decrease of energy use and the CO₂ emissions reduction.

In this study, design of a direct type rotary coal dryer is carried out. In design, first a natural gas burner is used for producing required heat of coal drying. Because of high natural gas consumption, it has a vital importance in today’s competitive economy to find an alternative source and minimize cost of products. For this reason, a parabolic trough solar system is employed as a heat source, in order to reduce the fuel consumption and the environmental impact of the conventional drying systems. A costs/advantages analysis of the implementation is performed. By applying the parabolic solar system to the coal dryer, the results show that; annual energy saving and prevented CO₂ emissions from emitting to the atmosphere are 637,700 m³NG and 1,152 ton CO₂ per year, respectively. Moreover, annual cost saving with considering carbon credits and payback time are evaluated to be 376,500 $ per year and 6.6 years, respectively.

In this study, the variability and trends of surface radiation over the Iberian Peninsula using ERA40 reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) are examined. Monthly means of surface incident and net shortwave radiation for 40 years are computed and analyzed. Deviations from the temporal mean for each month and for each year are computed and variations discussed. The relation between the interannual variability of solar radiation over Iberian Peninsula and the cloud cover is analyzed. The trends of surface radiation for each month during the past decades are computed and discussed.