Live Birth. After mating, females are pregnant for about seven months -- usually between 205 and 217 days. Instead of having a litter of several small babies like many mammals do, porcupines have one large baby. A baby weighs about a pound, typically ranging from 14 to 18 ounces. Their quills are soft when they're born, but the quills harden within an hour.
Fuel Cost. The cost of wood pellet fuel is usually given in dollars per ton; the average price of the fuel is typically around $250 per ton. The cost of a cord of wood, the fuel burned by a conventional wood stove, is around $200. The average home uses about 7.3 tons of pellet fuel or 6.5 cords of wood per season.
With the average household requiring approximately 11 tonnes of wood pellets per year, a domestic-use biomass boiler will typically cost an estimated Â£15,000 during its first year.ased on these figures, it could be around six or seven years before the systems start to pay for themselves. Biomass Boilers are a hot topic in the UK, as the Government's 2020 target of generating 15% of all power from sustainable fuels comes closer.