Fuel cells are used to produce electricity. They are considered a promising technology to replace conventional combustion engines in vehicles. Fuel cells may also replace batteries in portable electronic equipment. The most widely used types of fuel cells for mobile devices are Proton Exchange Membrane fuel cells (PEM FC) which are often used in vehicles, and Direct Methanol fuel cells, used in portable applications. PEM fuel cells use hydrogen or certain alcohols such as methanol as fuel.

Hybrid technology systems combine two or more technologies with the aim to achieve efficient systems. Possible combinations are: wind-solar photovoltaic (PV) hybrid systems, wind-diesel hybrid systems, fuel cell-gas turbine hybrid systems, wind-fuel cell hybrid systems, etc. (see the short descriptions below). Hybrid systems combine numerous electricity production and storage units to meet the energy demands of a given facility or community (Solar Energy Technologies Program, 2006).

A stand-alone power system (SAPS or SPS), also known as remote area power supply (RAPS), is an off-the-grid electricity system for locations that are not fitted with an electricity distribution system. Typical SAPS include one or more methods of electricity generation, energy storage, and regulation.

Electricity is typically generated by one or more of the following methods:

Aeroponics

Aeroponics is the process of growing plants in an air or mist environment without the use of soil or an aggregate medium (known as geoponics). Unlike hydroponice, which uses a liquid nutrient solution as a growin medium and essential minerals to sustain plant growth; or aquaponics which uses water and fish waste, aeroponics is conducted without a growing medium. 

In developing countries the solar lantern is a cheap alternative to a Solar Home System (SHS) providing 4-5 hours of high quality lighting service. It provides higher quality light than the use of candles or kerosene lamps. They are also used to provide street lighting in rural areas. In this case Light Emitting Diode (LED) solar lanterns are usually used. In industrial countries solar lanterns are usually used outdoors to provide lighting in the garden or driveway or for other outdoors activities such as marine or camping applications.

Many storage technologies have been considered in the context of utility-scale energy storage systems. These include:

Many storage technologies have been considered in the context of utility-scale energy storage systems. These include:

Electric vehicles are about 2.5 times more energy efficient than their counterparts which are powered solely by internal combustion engines. This high energy efficiency is the main reason why electric vehicles can contribute to lower the CO2 emission and energy consumption of traffic substantially. Electric vehicles have zero tailpipe exhaust emissions and thus contribute substantially to a better air quality. Additionally, electric vehicles are inherently silent and can help to reduce the noise levels in cities.

One approach to lowering the CO₂ emission from traffic is the hybridization of vehicles. A hybrid vehicle uses two or more distinct power sources, i.e. hybrid electric vehicles (HEVs) combine an internal combustion engine and one or more electric motors. Vehicles employed in urban areas like small passenger cars, local delivery trucks and city busses benefit from hybridization and show substantially lower CO₂ emissions, ranging from 23 to 43% depending on the traffic dynamics.

A plug in hybrid electric vehicle (PHEV) is a hybrid electric vehicle with the ability to recharge its energy storage with electricity from an off-board power source such as a grid. PHEVs have the potential to displace a significant amount of fuel in the next 10 to 20 years. It is estimated that they can reduce fuel consumption by up to 45% relative to that of a comparable combustion engine vehicle.