Space, Undersea, and Terrestrial Remote Power
Teledyne Energy Systems, Inc. specializes in key technologies for highly reliable power systems, based on Thermal energy conversion and Electrochemistry. Generally our technologies provide power solutions in the harshest environments where other methods of power production cannot meet the needs. Typical markets for these technologies are space power, undersea power, and terrestrial remote power.
Thermal Energy Conversion Technologies
Thermoelectric generators operate like thermocouples, whereby electricity is generated by a temperature difference across dissimilar materials. Key advantages to the technology are it has no moving parts so it is not affected by vibration, it requires a heat source that can also be used to heat other components of an integrated system, and most importantly, it is proven and regarded as the most reliable power systems known.
Stirling generators use a heat source to expand gas in a chamber and drive a piston converting heat energy to mechanical work. The gas is then transferred in the closed system to another piston chamber, where the gas is cooled and then transferred back to the expansion chamber. When coupled with a linear alternator electrical power can be produced.
Electrochemical Energy Conversion Technologies
Fuel cells are electrochemical devices that convert hydrogen and oxygen directly to electricity, water, and heat. Fuel cells have advantages over traditional battery systems in that they can operate constantly with a continuous supply of reactants. In addition, fuel cells do not have a “memory effect” from refueling like batteries. Hydrogen and oxygen can be supplied via many different sources, making system integration for a variety of applications practical. As with thermoelectric generators, there are no moving parts in a fuel cell.
Lithium sea water batteries are an emerging technology. A Lithium anode, a liquid electrolyte, a membrane, and packaging materials form one half of a battery cell. When this half-cell is submerged in sea water, the cell is completed and produces power.
Teledyne’s radioisotope thermoelectric generators (RTG’s) have a high technology readiness level (TRL). They have been used on the Mars Curiosity Rover, Pioneer 10 and 11 spacecraft, and the Viking 1 and 2 Mars Landers. RTG’s provide highly reliable, continuous power during launch, entry, descent, and landing, and on the planetary surface. Waste heat from the radioisotope can also be used to heat onboard instrumentation, thereby making RTG’s the best power solution for deep space discovery and flagship missions.
Fuel cells are also a viable solution for launch vehicles and landers and have been used in space since the Apollo missions in the 1960s. During launch, hydrogen and oxygen can be used to supply reactants to the fuel cell. The produced water is used for drinking and the electricity is used for environmental control. On the international space station, water is split into oxygen (for breathing) and hydrogen. NASA hopes to be able to derive hydrogen from water found on other planets to limit the launch payloads to produce energy. This will enable the use of fuel cells for ground transportation. Teledyne has partnered with NASA to further this research. Closed-cycle regenerable PEM technology is the future of airless space applications.
Unmanned, underwater vehicles (UUVs) are being used by the military for purposes of clearing out mines, and commercially for monitoring, surveying, mapping, inspection and exploration. The best solution for powering these missions is largely dependent on the length of the mission. Shorter missions can benefit from Lithium Sea Water batteries, which offer tremendous advantages over traditional Lithium Ion batteries, because of the weight and volume savings associated with not having a cathode to package. There is also a trend towards longer underwater missions and completion of multiple missions. In addition, these UUVs must have the power to handle the increased onboard sensor power requirements. Fuel cells using hydrogen and oxygen provide a high energy density for this application, offering 2 to 5 times more run time than a Lithium Ion battery. In addition, fuel cells can quickly provide power again with a new supply of fuel (rather than a lengthy recharge), making the time between back to back missions shorter.
Remote Terrestrial Power
There are several applications requiring power in remote areas that are off the grid, including remote communications links, offshore drilling rigs, weather stations, navigational aids, and cathodic protection for pipelines and well casings. Thermoelectric generators (TEGs) are an excellent solution for the remote power market, due to their high reliability and long life.
TEGs have also proven to be a reliable solution for military stationary and portable power requirements. With the military being in remote locations where the use of batteries is impractical, TESI has worked with the U.S. Army in creating portable power packs to harness energy while out of reach from a power source. Not only is renewability important when operating in areas far removed from main power distribution, but it addresses the problems of rising fuel costs and security risks associated with delivering fuel.
Advanced systems using Stirling engines are also a good solution for the remote power market. Multiple heat sources can be used, in addition to operating as combined heat and power systems.
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