Okay, just did some calculations.
Lets say we take a 500 acre area, a zone which would contain 500 structures, no shops, and no institutions, and no food production in a typical sprawl pattern.
By applying proper low-energy-urbanism the 500 acre zone now supports 660 structures, with attendant shops, parks, farms, and institutions. A town.
The population has been doubled from 1,500 to 3,000
There are now 425 acres for growing to 75 acres of town.
Outside the inner 425 acre food ring (capable of sustaining 3400 people if biointensive practices are used) there are 3 rings of 208’ in width each
The first ring supports 84 acres of trees
The second ring supports 86 acres of trees
The third ring supports 92 acres of trees.
These rings acts as wood-lot energy producers for the town with a five year harvest cycle.
From the paulownia supply info. site the trees can be planted with a density of 132 per acre. Each tree produces 122 board feet of wood in a five year maturation period. 26 acres are harvested per year yielding:
132x122x42 bf per annum or 837,408 bf per year.
A cord of wood contains on average 500 bf so the production in cords per year is 1,675.
The 660 buildings each receive 2.5 cords of wood per year
Electrical generation by water jacket steam turbine generation have managed to achieve up to 70% efficiency.
“One cord of well-seasoned hardwood (weighing approximately two tons) burned in an airtight, draft-controlled wood stove with a 55-65% efficiency is equivalent to approximately 175 gallons of #2 fuel oil or 225 therms of natural gas consumed in normal furnaces having 65-75% efficiencies.”
So the equivalent in heating oil used for the demonstrated 1675 cords per year represents approximately 293,125 gallons per year or 444 gallons per structure per year
Reasonable amount if your climate isn’t too severe. Would work fine in New England.
You would have to plant more rings in more harsh areas. I would also say a factor of safety would have to be considered anyway, as these numbers are all taken off the internet and may not reflect what really happens.
But still, supporting the energy and food needs of a small town in the space taken up by a large subdivision isn’t that bad!
Sources:
http://www.zilkha.com/category/tree-facts/http://www.iowadnr.gov/forestry/definitions.htmlhttp://www.paulowniasupply.com/why_grow ... cially.htm