I will look at the option of the wood boiler for creating electricity and compare it other methods of generating power. So that we can see which is the best option available to you? You probably live in area where there is lots of wood. You are looking at this as an option for providing extra electricity to your house. Just because there is lots of wood available doesn't make it the best option.
Boilers are best utilized as a source of generating heat than electricity. If you want to use them to generate electricity it is possible but very inefficient. A large amount of the heat produced is lost and very little of it turns to usable electricity. They are very good if you want to supply heat to houses, buildings and other surroundings. However using them as a source of electricity is a "no-no".
There are other sources that you could use to create electricity other than opting for the wood boiler for creating electricity. Other methods are available that will not pollute the environment. The wood that you use for the wood boiler will eventually run out or become increasingly difficult to source. The methods I'm talking about; the supply will never run out.
Instead of considering the wood boiler as a source of electricity you could turn to solar power as an alternative. Solar is very efficient; freely available and in abundant supply. Worried about the cost of a solar panel. No need to. You can build one yourself. You just need to get yourself a god DIY guide and you shouldn't have any problems.
It's quite simple and cheap, about $200. Unlike choosing the wood boiler for creating electricity you don't have to keep getting up to go and throw logs into the fire to keep it going. Just simply wait for the sun to rise and you have electricity. It will easily power most of the appliances in your home.