A New Thermoelectric
Generator for Rural
Elect rification
Jon M. Schroeder A new solid-state electric generator An inexpensive, alternative-energy
The Trymer Company can convert almost any available fuel electrification system is needed in the
into low-cost electricity. It has prom- United States and Canada. A stand-
ising application in undeveloped alone, electric power supply would
countries as well as in North increase productivity and save money
America. in a number of industries, including
farming, ranching, and light manu-
facturing, as well as provide electric-
Control & ,.
Assemb~of
One-Sized
ity to more isolated areas such as
recreational areas. An even larger
market for rural electrification exists
in less developed parts of the world,
where engine-driven generators are
the only alternative.
Concept Description
The Trymer Company has developed
a portable, solid-state, electric gener-
ator based on the thermocouple
principle. A specially configured
ring of metal plates produces a very
high electric-current circulation when
it is heated (see the figure). The cur-
rent store of energy can be tapped to
provide a source of ac and dc electric
power, and electrical energy can be
Load
stored overnight. This generator
Thermoelectric Generator Mechanism operates with fuels, such as heat from
various wastes, solar, wood, propane,
or petroleum. It can produce 5 kW of
Introduction power, at 120 V, 60 Hz; and its
weight of 75 Ibs allows portability.
Rural electrification currently re- There are no moving parts to cause
quires installing expensive, overhead vibration or to make noise.
electric transmission lines. These
transmission lines need right-of-way The thermocouple principle requires
clearing that devastates more vegeta- the ends of two different metal wires
tion than the area serviced. An alter- to be twisted together, one terminal
native--onsite power generation using heated and the other cooled. This
a motor-driven electric generator--is causes current flow in the wires. The
costly and often beyond the reach of magnitude of the current depends on
most buyers. These generators also the temperature difference between
have short lives. terminals, the characteristics of the
metals, and the electrical resistance for defense applications and for pros- types of products: electrical power
of the two wires. Typical power from pecting and mapping of natural supplies for the transportation indus-
a thermocouple is one-thousandth the resources. try and a 60-HzJ600-h4Wh, diurnal,
energy needed to power a light bulb. magnetic energy store for utility grid
A key advantage of this concept is leveling. The partner should have
To improve thermocouple perform- that it uses a wide form of common, product development experience and
ance, the number of junctions is in- energy-producing products. These manufacturing and distribution capa-
creased and placed closer together to products include hay, grass, coal, bilities. The markets for each of
reduce resistance. Connecting junc- animal dung, renewable fuels, and these products are projected to be
tions in a loop increases current cir- wood byproducts. greater than $100 million over the
culation to a maximum, thereby next 5 years.
realizing the highest magnetic field Key Experimental
and the highest magnetic energy The 5-kW rural generator is expected
store. A thermoelectric energy store Results to be completed in 1995, and a distri-
requires a means of drawing energy butor will be selected to market a
from the circulating current store as Laboratory tests on the generator family of thermoelectric generators
electricity. This is done using a spe- have achieved densities up to for sale to Third World countries.
cial Hall switch that converts mag- 120,000 ampshn.’, which have been This type of product is expected to
netic energy into conditioned elec- verified independently. Other testing have appeal to a government market,
trical energy as needed. shows that more than 1,000 V can be including the Federal Emergency
tapped by the Hall effect using a Management Agency and the U.S.
1-Tesla, 60-Hz field applied to a
Economics and Market junction; output frequencies from 1
Department of Defense. The portable
generator can serve as an engine
Potential Hz to 1 Ghz were achieved. Engi- starter or an auxiliary power unit.
neering studies performed at the The primary goal is to supply a unit
Applications of this technology Pulse Power Directorate at Picatinny that sells in the international market
include the transportation field’s need Arsenal, New Jersey tested energy for about $500.
for high-energy, low-polluting elec- densities for specific applications
tric power supplies for automobiles, ranging from high-speed train suspen-
busses, trains, trucks, tanks, and For further information, contact
sion, biomolecular separation, auto-
ships. This technology can be used motive electric power supplies, and
Jon M. Schroeder
as a suspension system for high- ship propulsion. Selected perform-
The Trymer Company
speed trains and for magnetic suspen- ance data developed with various-
14301 Bagdad Road
sion of machine elements such as ro- sized laboratory models are sum-
Leander, Tx 78641
tating shafts and sliding bearings. marized in the table below.
Phone: (512) 259-1 141
Fax: (512) 259-3833
Utility companies can benefit from Future Development
this technology by generating addi-
tional electricity from waste heat Needs Compiled by
Pacific Northwest Laboratory for the U.S.
sources, with the capability for bank- Department of Energy, Innovative Concepts
ing some electrical energy for later Trymer seeks development partner(s) Program 590240. This flier was printed on
use. Related applications will be in to prototype and commercialize two recycled paper.
the field of magnetic plasma confine-
ment for producing electrical energy
from fusion. The technology can Performance Data from Testing
also be used for biomolecular refin- Fuel
ing of pharmaceuticals and for more System Rating Power Consumption
sensitive, low-cost magnetic Operating
resonance imaging (MRI). Wireless, Temp. Voltage Amps kW HP MBtuhr GaVh
high-energy power transmission for 240°C 6.6 12,000 79 134 0.4 3.1
terrestrial and space-based power is 340°C 8.9 17,000 151 256 0.7 5.3
possible with this technology. Mag-
netic sensing, beyond the sensitivity 540°C 14.9 26,000 387 656 1.5 11.7
of radar and infrared, is also possible
