Few random thoughts from an energy economist; might be of some interest to you Steven and the odd reader:
Your COP assumptions seem very reasonable indeed I think.
I’m an energy engineer & economist studying practical energy and power systems. I see bias towards heat pumps all over the world, even in places where marginal implied GHG emissions with heat pumps seem higher than when directly heating with gas.
Do many heat-pump people you talk about have PV panels on the roof? Given tariff asymmetries between feeding-in and drawing power locally to/from the grid, there tends to exist a strong self-consumption incentive; it can be highly lucrative to consume your PV power rather than to sell it to the grid.
The largest share of your home electricity tariff is often not at all the “energy” component but based on transmission costs and other fees/taxes (so what @Gerald Monroe writes is not necessarily a reason not to expect high electricity price differences)
Given tariff asymmetries between feeding-in and drawing power locally to/from the grid, there tends to exist a strong self-consumption incentive
MA has net metering, so unless you are producing more electricity than your house consumes averaged over the year, this isn’t a consideration in favor of adding additional self-consumption.
In MA, it’s a bad idea (from a selfish monetary perspective) to produce more solar electricity than the amount of electricity you consume. So if you already have solar panels, then it’s plausible that you originally sized the panels to match your then-current electricity consumption. In that case, if you install mini-splits later on, then you’re consuming more electricity than you’re producing, and buying grid electricity.
However, another possibility is that you installed solar panels after already having mini-splits, or that you installed extra solar panels in the expectation that you were imminently going to also install mini-splits. In that case, I think FlorianH’s point is correct: we should be comparing to rooftop solar electricity costs not grid electricity price. (And this is a point in favor of mini-splits.)
I was getting bids from solar installers recently, and they absolutely have been saying “hey, are you planning to install mini-splits? or buy an electric car? if so, we should definitely quote you for more panels than one would think from your recent electricity bills.”
Few random thoughts from an energy economist; might be of some interest to you Steven and the odd reader:
Your COP assumptions seem very reasonable indeed I think.
I’m an energy engineer & economist studying practical energy and power systems. I see bias towards heat pumps all over the world, even in places where marginal implied GHG emissions with heat pumps seem higher than when directly heating with gas.
Do many heat-pump people you talk about have PV panels on the roof? Given tariff asymmetries between feeding-in and drawing power locally to/from the grid, there tends to exist a strong self-consumption incentive; it can be highly lucrative to consume your PV power rather than to sell it to the grid.
The largest share of your home electricity tariff is often not at all the “energy” component but based on transmission costs and other fees/taxes (so what @Gerald Monroe writes is not necessarily a reason not to expect high electricity price differences)
MA has net metering, so unless you are producing more electricity than your house consumes averaged over the year, this isn’t a consideration in favor of adding additional self-consumption.
In MA, it’s a bad idea (from a selfish monetary perspective) to produce more solar electricity than the amount of electricity you consume. So if you already have solar panels, then it’s plausible that you originally sized the panels to match your then-current electricity consumption. In that case, if you install mini-splits later on, then you’re consuming more electricity than you’re producing, and buying grid electricity.
However, another possibility is that you installed solar panels after already having mini-splits, or that you installed extra solar panels in the expectation that you were imminently going to also install mini-splits. In that case, I think FlorianH’s point is correct: we should be comparing to rooftop solar electricity costs not grid electricity price. (And this is a point in favor of mini-splits.)
I was getting bids from solar installers recently, and they absolutely have been saying “hey, are you planning to install mini-splits? or buy an electric car? if so, we should definitely quote you for more panels than one would think from your recent electricity bills.”