RENEWABLE ENERGY TECHNOLOGIES  

The following are brief descriptions of the main GEST primary technologies.

• Solar photovoltaic (PV) electric power - Photovoltaic power systems harness the sun's energy by converting solar radiation into direct current electricity and may be used as a DC power source or with an inverter as an AC power source. PV power systems are used in a wide range of applications as enumerated below.
• Solar hot water heating - In a solar hot water heating system, solar radiation is absorbed by the evacuated tubes and converted into heat. In an active water solar thermal system, the circulating water from a hot water storage tank is heated via the header which is heated by conduction from the heat pipes within the solar tube.
• Wind turbine electric power - A wind turbine uses wind to make electricity. The wind turns the blades, which spin a shaft that is connected to a generator to make electricity. Wind turbines systems have capacities ranging from less than 1KW for small systems to several MWs for wind farms. 
• Fuel cell charger and auxiliary electric power source - In a fuel cell process, electrical power is continuously generated by converting the chemical energy of a fuel (methanol, hydogen, natural gas, gasoline) into electrical energy via electrochemical reaction. Fuel cell operation is similar to that of the battery but unlike in the battery process, the fuel cell does not run down or require recharging. Fuel cell technology commercial applications are now available including electric vehicles applications.

Uses

• Electric power generation for military and public applications - Wind turbines, solar generators (Tactical Electric Solar Generators (TESG)) and fuel cell auxiliary power units are used for charging and powering computers, electrical equipment, telecommunication equipment and water purification pumps.
• Residential, industrial, schools and hospital applications - Solar PV and wind, now are alternative economical electric power supply systems for  lighting, charging of electric vehicles and several other applications. Solar hot water heating and space heating is also now commercially viable. 
• Agricultural applications - Both solar PV and wind turbine systems are used worldwide to pump water for livestock, plants or human utilization. Incidentally, the demand for water is usually greatest on hot sunny days  and that is the period electric power from PV systems is greatest. This is therefore a perfect fit for water pumping applications. 

Benefits

• Flexible and modular: Each system can be expanded at any time to meet power demand load.
• Increase autonomy: Each can be independent from the grid or can operate as a backup during outage.
• Highly reliable and requires virtually no maintenance.
• Operates cost-effectvely in remote areas and for many residential and commercial applications.
• Reduces air pollution: Each system does not give off greenhouse gases - reducing global warming.
• Lowers dependence on fossil fuels and improves sustainability.
• Quite: PV and fuel cell systems have no moving parts.