"Summer electricity use is growing year upon year, mainly due to air conditioning (AC) demand. Electricity grids are increasingly experiencing problems during the hottest summer days, to deal with the increasing demand of electricity from air conditioning systems.Absorption cooling can be a solution to this growing problem, as it can supply cooling from a heating source, with only a very small electricity input (negligible) in comparison with traditional AC systems. Due to the use of renewable energies such as solar thermal or other residual/waste energy as heat source, the primary energy consumption is much lower than with conventional chillers.However, solar cooling technology has a lot of barriers that delay the penetration of absorption machines in the market. The most important is the high costs of absorption chillers, as well as lack of standardization, market familiarity and compatibility with building design methodologies. The fact that all absorption machines based on LiBr technology currently in the market need a cooling tower is also a barrier for absorption chillers market acceptance.The objective of the CESAR project is to develop a small scale, low cost absorption cooling unit, with efficient ambient air heat dissipation and which can use renewable heat sources and therefore have a minimum electricity use.This goal will be achieved by:- Use of new working fluids and fabrication materials never used in commercial absorption chillers, more efficient and cost-effective than commonly used alternatives- Development of efficient, compact, cost-effective and simplified heat exchangers- Development of control systems for efficient operation of the absorption machine- Development of a friendly-use design tool for installers and planners in order to design and dimension solar cooling installations with the new absorption machine in an easy way"