We made the choice approx 4 years ago to use a wood pellet system. I like it as the unit I have sits in my sun room so is a feature as well. I use it to heat a 350l thermal store which from it the water for my UFH system is drawn. As its a thermal store and I have good water pressure coming to the house I have 2 really powerful showers.
I also have a wood burner stove in the living room. I cleared approx 35-40 trees from the boundary of my site so have plenty of wood to burn for a good few years. It's not connected to the heating system. To get all the grants from the rhi scheme the pellet system has to be my only method of heating water.
I also divert excess PV to heat the water for near enough 5-6 months of the year.
When you say you divert PV ..what do you mean? Does this happen automatically for the immersion to heat water for the thermal store? - seems large volume to tend to? Is this effective or is there an intermediate storage for this hot water? Etc ...apologies I have limited plumbing knowledge so talk simple ! Lol