Insulation is very relevant for sizing the equipment, but has comparatively little influence on the $/BTU.
Hand-wavy, order-of-magnitude estimates here.
82% blended efficiency gas equipment is ~$15/1MBTU
Geothermal heat pump at a blended COP of 3 will take ~100kWh for that same 1MBTU. In MA, that 100kWh will cost you $20. (That's after a potentially $75K-100K installation cost for the geothermal wells and equipment vs $10K for a decent modcon boiler.)
So, pay an extra $50K-90K up-front and 33% more for your variable energy. (Of course, you get air-conditioning included above in most of the geothermal installs.)
Hand-wavy, order-of-magnitude estimates here.
82% blended efficiency gas equipment is ~$15/1MBTU
Geothermal heat pump at a blended COP of 3 will take ~100kWh for that same 1MBTU. In MA, that 100kWh will cost you $20. (That's after a potentially $75K-100K installation cost for the geothermal wells and equipment vs $10K for a decent modcon boiler.)
So, pay an extra $50K-90K up-front and 33% more for your variable energy. (Of course, you get air-conditioning included above in most of the geothermal installs.)