The reliability of electronics equipment is dramatically shortened if it operates in very hot conditions, which is why much electronic equipment incorporates fan cooling. Equipment builders designing for arid climates have always faced considerable environmental protection problems. Traditional cooling techniques require a power supply, which often poses severe difficulties. The problem is growing bigger as the topology of SCADA evolves towards more distributed and unmanned systems, and new solutions are being sought. Although solar cells and DC powered air conditioning techniques are making progress, their relative lack of efficiency, together with the problems of battery lifecycles in hot climates, continues to make environmental protection complicated and expensive.