Tips makes a couple of good points in a comment.
…the difference in efficiency between an old tank-type water heater and a newer one is minimal at best. Tankless is a bit better but probably not worthy of a subsidy.
Tankless can be really good in some situations where hot water demand is not regular and constant such as spare bedrooms.
Heat pump water heaters offer very substantial energy savings (comparable to even solar which actually DOES require electricity) but don’t seem to be ready for the single-family home market yet.
My understanding is that there are corrosion issues that make Bermuda especially troublesome.
When it comes to the typical Bermudian household, solar water heating is the greenest and most cost-effective way to heat your water. In my opinion, it should be legally required for all new home construction as it is now in places like Israel.
There is a proposal to do just this circling at the moment (or was a few months ago). I’m not sure I agree because we’re talking a few thousand dollars extra added to the cost of each housing unit. This comes as essentially a fixed cost of more debt and more interest and lower affordability for housing… on the other hand, it is much cheaper to install the plumbing and hardware on a new build than it is to retrofit an older house. As a compromise I might argue for renovations to include mandatory hot water. That way we’re not limiting new housing supply but still able to manage the growth of electricity demand to some degree.
Convince me either way.