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Comment by toomuchtodo | Hacker News Reader

“The results show that the total life cycle cost favors heating electrification in all cases and combining PV with heat pumps can reduce residential building GHG emissions by up to 50% immediately. This effect will grow over time, with over 90% reduction of building emissions if renewable energy targets are met. In using primary energy and emissions along with the multi-dimensional sensitivities, this study uniquely demonstrates the complex techno-economic interactions of PV and heat pumps. It is concluded that electrification is an economically viable decarbonization method for cold climates both now and in the future.”

This is expected but tremendous news, as it means no technical innovation is required, simply financial support and trades work to replace legacy HVAC systems with heat pumps to drastically reduce GHG emissions from building energy use.

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Financial support is absolutely a must-have. If the furnace/boiler goes out, most people can't "afford it", but do what they must to make do. So proactively replacing their equipment is not really viable without financial support. And to make matters worse, proactive replacement is really the only option. If the furnace/boiler goes out, you must fix/replace ASAP and that leaves no time for installing PV or a heat pump.

Prioritizing by system age (oldest to newest) for subsidies seems like the way to go, as older systems are more prone to failure and less efficient than newer systems.

I agree pro-active replacement offers the best chance to decarbonize and the best way to do that is with financial assistance. Ideally I'd like to see carbon pricing to dis-incentivize people from burning fuels and then that revenue used to fund programs to electrify low income families and rentals where the person paying for utilities isn't necessarily in control of what heat source is in use.

The Canadian federal government has started a green home grant program that offers up to $5000 back on certain energy efficiency upgrades like windows, insulation, air sealing, pv panels, and heat pumps. We do also have carbon pricing. It's not perfect, but it's a good start.

My house is roughly 100 years old and I've signed up. Getting this house close to modern insulation standards is going to be at least an order of magnitude more than 5k, but I'm using it as motivation to navigate the complex work of home renovations.

My plan is to spray foam the whole house for insulation and air sealing, install a heat recovery ventilator, and switch to a heat pump, likely a couple mini-splits throughout the house. My dream would be to switch to hydronic in-floor heat with an air-to-water heat pump so that I could store heat when electricity is cheap, but that might explode the budget too much.

Here in Ontario our grid is very low carbon (especially at off-peak times) since it's mostly hydro and nuclear with some gas plants for peak demand. I won't get much carbon reduction with personal PV, so I think I'm better off keeping the budget lower or increasing the efficiency to reduce the ongoing utility costs.

Technical innovation is the first of several inhibitors. There needs to be market availability, AND skills to install and later service a combined photovoltaic heat-pump system.

An analysis of prevalence and growth of both would be an interesting next step.

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