by fireplaceguy » Thu 05 Oct 2006, 01:41:03
Big picture first - heating with any kind of fuel that must be stored in advance will ultimately be unsustainable. Two reasons: 1) Storage space. 2) Problematic resupply - as conventional fuels dwindle in availability competition for alternatives such as wood and pellets will become fierce.
I know I am calling for a paradigm shift, but the only viable long-term solution is to use passive and/or active solar as your primary source of heat and domestic hot water, reserving your stored fuels for use in a backup role only.
On top of that, I would not suggest that you plan to heat your entire house (unless it's very small) with your backup heater - you'll end up using too much fuel. Instead, plan on zone heat, warm clothes and good sleeping bags.
In an ideal world, your first order of business should be heat retention - insulate, insulate, insulate!!
Then size a solar system and any passive features you can incorporate to meet almost all your heating needs. Only then would you plan for the backup systems...
Now to the fuel choices:
LP GAS stores indefinitely. For SHTF scenarios the tank(s) should be buried. Very nice for cooking and backup hot water, and excellent for standby generators.
A small propane heater (don't get the cheap vent-free kind) can keep a room or two warm and protect the pipes, although personally, I'd make provisions to drain the pipes instead of wasting precious fuel under that scenario. Installed/filled cost of the larger underground tanks will be at least $6 per gallon...
HEATING OIL (very similar to diesel fuel) stores for a year or so before it starts to degrade. Mold can be a problem too. There are commercially available preservatives but the military, as I recall, uses BHT. This is a common food preservative. Again, underground storage is best and five to ten years is probably the maximum ideal life of stored oil.
WOOD PELLETS store indefinitely IF you keep them dry. The downside of pellet heat is that pellet stoves require significant (200-250 watts/hr) electricity to operate. If grid power is unavailable, that's a staggering load for a PV system.
Also, in order to truly count on a pellet stove over time, spare parts (and the necessary tools and knowledge) would need to be in your posession.
There is one biomass stove out there that will reliably burn pellets, corn and wheat. It is a clean slate design - not a modified pellet stove, which I wouldn't consider.
It uses DC motors and consequently draws about 1/10 the electricity of a conventional pellet heater. As a bonus, it uses about 25% less fuel than conventional pellet heaters. It comes with a small 12v battery backup system and is pre-wired to connect to larger 12v sources. A good deep cycle battery can run it for days. It's pricey and spare parts remain an issue.
BIOMASS (grains like corn and wheat) will probably be too desirable as feed or food to consider burning. The stalks, etc. should be plowed back into the ground to decompose (or composted) to help minimize soil depletion...
A WOOD STOVE is the simplest solution. If you follow my thinking about zone heat, a smaller stove will cost less, so buy new, and get a good one. The high efficiency and low emissions make the initial investment worthwhile. Besides, a 30 or 40 year old stove is pretty used up for something you are potentially staking your life on.
FIREWOOD stores indefinitely if you keep it indoors or well protected from the elements. Firewood grows back, and if you control enough treed land (and think you can maintain control of it) then you're set.
PELLET LOGS - some pellet plants produce pellet "logs" that can be burned in wood stoves, and these things are very dense in terms of stored energy. One cord of the "logs" equals about three cords of regular firewood. Like pellets, they store indefinitely and must be kept completely dry.
COAL is energy dense and stores indefinirtely but will void the warranty and significantly shorten the life of a wood stove. Get a real coal stove if you want to go this route. The bagged anthracite is wonderful stuff but pricey if you aren't on the east coast.
Our personal plan? Primary: Lots of down comforters and a drainback thermal system with hefty storage capacity and circulation pumps powered by PV modules. Backup: two buried 1000 gallon propane tanks and a 40 foot high cube steel container (capacity 20+ cords) filled with hardwood for a modest wood stove, in which a fire is burning as I write...
We like to be warm...