Glossary of Terms Books and Videos Acceptable Design Practices Think Energy Efficiency; Large electrical appliances such as hot water heaters, electric baseboard or portable space heaters, electric clothes dryers, electric furnaces, electric ranges and ovens, even incandescent light bulbs can force the cost of a renewable energy system beyond what it would be practical to spend on a system. If there is an energy-efficient alternative, find it and employ it in your home power system. Most heat-producing appliances such as stoves, furnaces, hot water heaters and clothes dryers can be readily purchased at most home appliance stores. Wherever Possible, Keep Loads at 120 Volts AC; 240 volt appliances typically are heat-producing and therefore better operated from LP (Liquid Propane) or Natural Gas. One exception to this rule is the use of a residential water pump where long wire runs and deep wells require the use of electric pump motors larger than ½ horsepower. Typically, home submersible pumps larger than ½ horsepower will be manufactured only in 240 volts AC. A 240 volt load will require either a 120 volt to 240 volt transformer installed in the system or stacking and interfacing two 120 volt AC inverters to meet the needs of the 240 volt load.