There are several different types of technology that can be used to provide power for remote, off-grid applications. This section will provide a high level overview of these technologies and summarize the pro’s and con’s of each technology.
TEG technology has been around for 40+ years and has proven to be a reliable, low maintenance, long-life power generation system. These solid state devices operate on the Seebeck effect where the heat differential across a thermocouple produces a small direct current. Utilizing a series of these thermocouples (to comprise a thermopile) a TEG can produce low levels of power. As the heat from the burner (using propane or natural gas) is applied to one side of the thermopile, the other side is kept cool by heat sinks. The resulting temperature difference across the thermopile creates DC electricity. TEGs are available with outputs ranging from 21 watts to 550 watts but can be paralleled to service higher loads. TEGs are intended for continuous operation. TEGs typically take about 60 minutes to start up before producing electricity.
Internal Combustion Engines (ICE) Generators (Gensets) are a popular power generation technology. Having been around for years the ICE Genset technology is field proven in providing backup and continuous power.
ICE Gensets Advantages
ICE Gensets Disadvantages
Photovoltaic (PV) or solar panels have become more mainstream as the cost of this technology has dropped over the past 10 years. Solar has proven to be a viable source of DC power by converting the sun’s energy into electricity. A battery storage system is required to allow the system to provide power 24/7/365. The main advantage of using PV technology is the systems operate on sunlight and do not require any additional fuel. Solar is appropriate for use in remote areas providing unattended power output. If designed properly, with adequate solar resource and no shading, the PV system can be a reliable power generation system.
These are also referred to as Organic Rankine Cycle engines and have been in use for over 40 years. A burner uses various hydrocarbons to heat the fluid in the vapor generator. The fluid vaporizes and expands through a turbine wheel thereby producing shaft power to drive an alternator. The vapor then passes through a condenser where it is cooled and condensed back into a liquid state. The liquid returns to the vapor generator where the cycle begins again. The unit is hermetically sealed and as long as fuel is fed to the burner to heat the fluid the unit produces electricity. The AC power produced is rectified to DC current. Ratings range from 600 watts to 5kW.