Generation · Biomass
A property with a woodlot, a herd, or a stove burning six months of the year is producing thermal energy continuously. Converting some of that into electric power is possible, and it is the least forgiving thing in this section.
These eight guides cover what each pathway is, what it costs in money and in daily attention, and where the risk sits. Most readers will finish having decided against the large ones, which is a useful outcome.
Before anything else
Sun and wind arrive whether or not you are paying attention. Biomass does not. Every kilowatt-hour on this page begins with material that somebody cut, hauled, dried, loaded, or scraped out of a barn, and the volume required is consistently larger than people expect before they measure it.
The Environmental Protection Agency screens farms for anaerobic digestion at roughly 500 head of cattle, or 2,000 hogs on a liquid or slurry manure system[1]. Most operating digesters in the United States sit above 1,000 cows or 5,000 hogs. That is not a homestead number. It is a commercial dairy number, and it is the single most useful fact on this page for a reader deciding where to spend a weekend.
Wood is more forgiving than manure, and heat conversion is more forgiving than either. The first guide below works out what your own property actually produces in a year, before any of the equipment questions become worth asking.
If you have a wood stove and no acreage
Then two pages here are for you and the rest are background. Thermoelectric generators and Stirling engines take heat you are already making and return a small amount of electricity for very little added work. Start there and skip the rest without loss.
Thermoelectric generatorsWhat the resource asks
Heat is abundant on a working property and electricity is not, because the step between them is where almost all of the energy is lost and almost all of the labour appears. These four explain the rest of the section.
Commercial thermoelectric modules convert somewhere around five to six percent of the heat passing through them into power, with a laboratory demonstration at eight percent described as forty percent better than the commercial state of the art. Everything else becomes heat on the cold side, which then has to go somewhere.
Producer gas carries far less energy per unit volume than gasoline, and the published derating for spark-ignition engines running on it spans roughly fifteen to fifty percent depending on compression ratio. A generator set rated for one number on petrol delivers a materially lower one on wood, permanently.
The larger systems here are not appliances. A gasifier wants feeding and ash removal on a schedule set by the machine rather than by you. A boiler wants a person present. Capital cost is the easy part of the decision and rarely the part that ends a project.
Syngas is largely carbon monoxide because that is what makes it fuel. A digester stores methane in a sealed vessel on purpose. Unintentional carbon monoxide poisoning kills roughly 430 people a year in the United States on the Centers for Disease Control's long-run average, and none of those deaths required anyone to be careless.
What this hub covers
Measure the feedstock, take the small wins first, then decide about the large systems with the numbers already in hand. The order below is the order the decisions arrive in, not a ranking of how impressive the equipment is. These guides are being written now, and each one stays unlinked here until it exists.
What a woodlot yields in a year without shrinking, what a herd produces that a digester could use, and how many hours your stove actually burns.
2Solid state, no moving parts, small output. Why a cooling module is not a generator, why the cold side decides everything, and what the wattage honestly is.
External combustion, so the fuel never touches the working parts. Kinematic against free-piston designs, sealed units, and what the market actually sells.
Why capturing the reject heat changes the arithmetic on every system here, what a hydronic loop needs, and when the heat is worth more than the electricity.
What a gasifier does, why tar is the failure mode that ends most projects, the engine derating, and why this one is covered without build instructions.
The feedstock threshold, why raw biogas destroys an engine if it is not scrubbed, the digestate that comes out, and the permitting layer nobody expects.
It burns anything and it asks for a person in the room. Pressure vessel law, why improvised boilers fail the way they do, and what qualified execution looks like.
The labour that never appears in the brochure, the projects that run one season and stop, and the four patterns behind almost every abandoned system.
How three of these are covered
Gasification, digesters and small-scale steam carry risk that sits in the design rather than in carelessness. A gasifier makes carbon monoxide because carbon monoxide is the fuel. A digester accumulates methane in a sealed vessel because that is the point of it. A boiler stores energy in a form that releases all at once when the vessel fails.
All three are covered here in full. Leaving them out would be dishonest about what property-scale generation involves, and a reader who wants to know will find a worse source in about ninety seconds.
What those three pages publish is what the system is, what it genuinely demands, why the risk is structural, what it costs in money and attention, and when it makes sense at all. What they do not publish is dimensioned plans or operating procedures. Each one names what qualified execution looks like and where to find it. The other five pages carry no such restriction and go into as much detail as the subject supports.
What the household actually consumes in a day, measured rather than guessed.
Read the guideThe four checks that size any system, from a device list. They do not change at this scale.
Run the numbersHeating a house with wood, which is where most readers should start and many should stop.
See the guideSources
Figures on this page are for deciding whether to look further. The governing answers come from your own measured feedstock, your state and county authority, your utility, and the manufacturer of any equipment you are considering. No figure here is taken from a company selling the equipment it describes.