What would you do

Last year I used a large wood burner in the greenhouse but using it took a lot of wood and I felt that it was getting more difficult to provide wood for it, so I removed it, I had intended to use an electric heater, but with the temperatures we have been having over the past several weeks makes it too costly, but I also have a small pot bellied burner, which I could run to make the greenhouse a bit more comfortable to work in, but wondering what others would recommend doing