A Radioisotope Thermoelectric Generator is an alternate type of power generator used on Frontier worlds. Also known as an "RTG pack" or "Thermo pack", RTGs generate energy from the heat given off by radioactive isotopes as they decay. RTGs have been in use for many centuries, reaching back to before the colonization of the Frontier.

Physical Description[1] Edit

An RTG is manufactured in various configurations and sizes depending on intended purpose. One popular size for use in small- to medium-size dwellings and some ground vehicles is roughly cylindrical, measuring .22 m3 [2] and massing approximately 45 kg.

The generator contains a number of modules containing radioactive isotopes[3] encased in protective casings[4] that not only shield anyone nearby from the radiation emitted by the isotopes, but also prevent the isotopes from contaminating the environment in the event of an accident. As the isotopic "fuel" decays, the heat produced is converted into usable energy by an array of thermovoltaic cells.[5]

Older models of RTG used thermocouples instead of cells, and could only achieve half the efficiency of contemporary models.[6][7]

Power from the generator is routed directly into a device or structure or may be stored in one or more parabatteries, which must be purchased separately. RTGs are also capable of recharging power beltpacks and backpacks.

Energy Output Edit

Under optimal conditions modern RTGs operate at roughly 20% efficiency, yielding an energy output of 800 SEU per hour.[8]

Maintenance Edit

RTGs are designed to need little or no maintenance.[9] What work does need doing typically involves the power storage and distribution system rather than the RTG itself.

Operational Endurance Edit

As the fuel elements decay, the output power decreases. Typically an RTG's output drops less than 1% per year.[10] Most RTG applications are planned to have a design life of between 10-15 years. Beyond that, either the device is replaced entirely or a new RTG is installed.

Cost Edit

The price of an RTG varies according to it's type (see table below).

Types Edit

Generator Type SEU/hour SEU/second Cost (Cr) Mass Volume Maint (Cr/day)
AAA 50 0.0139 625 3 .01375m3 0.1
AA 100 0.0277 1250 6 .0275m3 0.15
A 200 0.0555 2500 10 .055m3 0.25
0 400 0.1111 5000 20 .11m3 0.50
1 800 0.2222 10000 40 .22m3 1
2 1600 0.4444 20000 80 .44m3 2
3 3200 0.8888 40000 160 .88m3 4
4 6400 1.1776 80000 320 1.76m3 8
5 12800 3.5550 160000 640 3.52m3 10
6 25600 7.1104 320000 1280 7.04m3 32
each additional x2 x2 x2 x2 x2 x2

Notes and References Edit

  1. I based this description on the current NASA MMRTG.
  2. 64 cm in diameter by 66 cm tall
  3. Plutonium-238, Curium-244 and Strontium-90 are popular choices for their balance of heat emission vs half-life.
  4. Federanium or other similar material
  5. Similar to photovoltaic cells, only using heat energy rather than light as a fuel source.
  6. This would place thermocouple RTGs at about the level of the original game's Type 1, but at only 40% of the mass.
  7. This is the current level of RTG development as represented by the MMRTG. Thermovoltaic cells are still in the developmental stages, but look promising.
  8. Based on performance tests done under laboratory conditions of real thermovoltaic cells.
  9. Ignore the Mainenance Requirements rules regarding power generators in general.
  10. Engineers and use 1% as a standard expectation at the design stage.
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