Generators provide “external power” . . . while their fuel holds out. Explorers, military units, and similar expeditions use them for base camps; others use them to power cabins. They can also provide backup power for everything from hospitals to shopping malls. Below, generators are divided into two types:

Portable: Usually provides enough external power (about 1-2 kW) to keep a few small devices going at once; e.g., a computer, a TV, and a few lights.

Semi-Portable: Typically supplies external power to a whole household, workshop, or equivalent (approximately 5-10 kW).

The first steam engines in wide use were the Newcomen “atmospheric engines” of the 1690s: low-powered, stationary installations used primarily to drive mine pumps. From about 1770 to 1800, James Watt’s patents controlled steam engine manufacture in England. Watt favored low-pressure setups… which were also mostly suited to stationary applications. The firm of Boulton & Watt built more than 400 engines in those years. They were used to power pumps, machine tools, and industrial machinery, and as traction engines. Real development of the steam engine for transport began after 1800.

Semi-Portable Steam Engine (TL5). A steam engine mounted on iron-shod wheels and pulled from one worksite to the next by draft horses. It was a common sight on well-to-do farms from England to Alabama starting in the 1820s, and would likely have powered Babbage’s Difference Engine, had it been built. A typical model – trimmed in polished brass and painted in bright colors – consumes 250 lbs. of wood and 50 gallons of water per hour. A leather belt links it to various steam-powered tools. $15,000, 4 tons. LC4.

Portable Steam-Powered Generator (TL6). This is one of the smallest steam engines – the plaything of a retired railroad man. It looks like a small heating stove, but has the built-in equipment necessary to generate a small amount of electricity. Some were used as bench-top power plants, powering lathes and saws in areas without electricity. A stove engine this size was pressed into action as a clandestine generator for radios during WWII by Britain’s Special Operations Executive. It burns 20 lbs. of wood (or 5 lbs. of coal) and uses 1 gallon of water per hour. $250, 50 lbs. LC4.

Semi-Portable Homemade Steam Generator (TL7). This can be cobbled together from junk scavenged from city ruins. Roll against Scrounging +4 to find the parts in all but the most devastated cities; roll against Machinist or Mechanic (Steam Engine) to assemble it. It consumes 80 lbs. of wood and uses 5 gallons of water per hour. It converts the steam directly into electricity. Loud, ugly, and prone to malfunctions, it may be the only electrical generator available in a post-apocalypse setting. $250, 600 lbs. LC4.

At the turn of the last century, Sears, Roebuck and Company sold a primitive gasoline generator by mail order. A noisy belt-driven contraption, it spurted smoke and oil, and broke down frequently. By contrast, modern versions are whisper-quiet and small enough to fit in a large backpack. Both provide external power for a dozen or so items.

Semi-Portable Gasoline Generator (TL6). An early model gasoline generator, circa 1900. The 1-gallon tank lasts for about 3 hours. $600, 125 lbs. LC4.

Portable Gasoline Generator (TL7). The 1-gallon fuel tank lasts for 10 hours. Weight is ¥2/3 at TL8. $600, 50 lbs. LC4.

Throughout history, man has been his own best engine, capable of generating over 300 watts for hours at a time. All of the generators below convert mechanical energy provided by a human into electricity. The operator expends 1 FP an hour and the device produces electricity. As a rough estimate, assume it takes 1 hour to recharge 10 lbs. of batteries.

Portable Muscle-Powered Generator (TL6). From WWI to Vietnam, military units carried hand-crank generators to recharge radio batteries. This generator provides external power to one device, or can recharge a battery. $50, 10 lbs. LC4.

Semi-Portable Muscle-Powered Generator (TL6). This is a larger, bicycle-type generator that might be found in an “off-the-grid” cabin. It works like the generator above but can provide external power to two or three devices at once (e.g., a TV, a laptop, and a small refrigerator). A successful Machinist roll can build this system in a couple of hours; it requires simple hand tools and some creative scrounging (and a bike, of course). $125, 50 lbs. LC4.

Miniature Muscle-Powered Generator (TL8). A palm-sized generator, this can power only small electronic gadgets (cellular phone, GPS, PDA, MP3 player, etc.). Two minutes of cranking provide five minutes of operating time for such a device; in normal use, it doesn’t fatigue the operator. It has a built-in flashlight (pp. 51-52) with a 5-hour internal battery, and folds flat to fit in a pocket when not in use. $100, 0.25 lb. LC4.

Fuel cells use an electrochemical process to convert chemical energy directly into electricity, making them more like an engine than a battery. One advantage of fuel cells over more conventional generators is that they can operate indoors with less noise and no harmful emissions.

Portable Methanol Fuel Cell (TL8). A suitcase-sized generator. It uses 1 gallon of methanol every 3 days. $5,000, 13 lbs. LC4.

Semi-Portable Hydrogen Fuel Cell (TL8). A large cart capable of powering a whole household on a single hydrogen cylinder for 5 hours (extra cylinders are $100, 65 lbs.). $6,000, 100 lbs. LC4.