That's an interesting web site SSS. Does pellet wood need seasoning? The trees need planting a year apart as well I think? I'm reluctant to accept the claimed heat value of 4000Kw per ton. Seasoned and fully dried hardwood won't give that, so I think 3000Kwh is more likely the maximum. Our little place consumes nearly 10,000Kwh a year so perhaps aim for 4 tons minimum Oldwolf?