I wonder if you might consider wood burning alternatives - given your two mentioned alternatives I suspect you may live outside urban areas or at least in a thinly developed location. There are basically two categories within wood burning, logs and pellets where "logs" is in effect any wood, importantly including scrap (but not painted/coated wood or processed board such as wood chip, MDF, etc).
We have been using the log type for 9 years and in that time have never paid a penny for wood as we either collect it from those who have waste (including for example pallets) but for some years now they have been delivering to us to avoid disposal charges or having to arrange to burn it themselves. We have to cut the wood ourselves to acceptable lengths. It must be fairly dry before it is burned in the boiler.
Our boiler is a Vigas 25, fairly typical of the genre except it is almost certainly the best for price, and is astonishingly good for output. But be warned that nobody seems to adequately teach how to run these things trouble free and it took me about 4 months to master it and since then I could teach anyone in the space of a three hour running of the boiler, even (I reckon) remotely by telephone (including troubleshooting). Pellet systems are very easy to use but you need to pay for the pellets commercially so running costs are something to be considered. The initial installation cost must be swallowed but if there is no further cost in running the system then that is quickly recovered - but you must be committed in the first place (you need to manually feed the boiler), no ifs or buts. Our wood burning system is augmented by a solar tube system (2.5m²) which sees to all space and water heating for as much as 6 months a year (in a good year, certainly 5 months on average). For us all heating is free and when at home we maintain 21 degrees (awake, 18 asleep) throughout the year. When we are away, the solar sees to the house being permanently above 10 degrees at worst, even in winter. Everything depends on the house, not least insulation - ours is 140 years old with insulation installed, including in walls.
Setting up the system requires suitable space and location (best not properly within living accommodation) and needs a large heat storage tank for best results (continuous heat between burns and storage of excess heat when only occasional burns are needed). Additionally one needs somewhere covered to store enough fuel so as not to run out.