I used to not buy into all the hype over heat pumps as a climate solution. Mostly because heat pumps aren’t a new technology – they’re simply air conditioners with a reversing valve – and widely used in warmer climates for both heating and cooling. And they’re part of the air conditioning industry that revolves around windows that are impossible to open like in commercial buildings or rarely opened like modern suburban houses.
Heat pumps long struck me as just woke virtue signaling that is so common and troubling on the American left. Install a heat pump, keep the heat and cooling at 72 degrees year round, with windows that don’t open. Feel good even though you’re detached from nature and are consuming gobs of electricity to keep your indoors the perfect temperature year round. No discomfort for you! No cold in the winter indoors and no hot in summer indoors. But also no bird sounds, no sense of nature outdoors. And so much electricity consumed.
Yet somethings have changed my mind about heat pumps. For one, with modern split phase inverters, lithium ion phosphate batteries and solar panels even off-grid cabins can use and often use heat pumps. It is totally possible to use a heat pump with electricity produced on site and not essentially just be importing coal or natural gas via utility lines to your home. Indeed, cooling can be a good use of excess electricity produced during bright sunny days. Heat pumps also use a lot less electricity than one might expect compared to the size of solar array needed to power them. Modern large sized panels are remarkably efficient, much more then I used to think was the case. And lithium ion phosphate batteries connected to integrated solar controllers and inverters are amazingly powerful and able to power such equipment.
Growing up in rural but cold Upstate NY with growing forests in recent decades, I always thought the primary alternative to heating with coal, oil or natural gas was wood. Never considered electric heat to be anything but a fossil fuel brought in over a wire with all the heat losses built in by conversion of fossil fuels into electricity. Don’t want to heat with fossil fuels, install a woodstove. Want more of a suburban, automatic way of heating and own a large farm wood lot you can burn up? Get an wood furnace that keeps all the chunks of wood, mud and smoke outside the house and transports the suburban style heat to the building much like electric heaters do – with similar energy losses but at least not the nuisances of the woodstove indoors.
But things are different now. Heat pumps while still not very efficient or warm on the coldest of nights are much better at colder temperatures than they once were. Their drain on your battery bank and solar is quite moderate at moderate temperatures. They can keep a building relatively warm without having to stoke and add wood to the woodstove all of the time. Still there is something to say about a woodstove in real cold weather. It’s that nice dry, warm heat radiating off and it doesn’t become weaker in warmth like heat pumps do. And you aren’t required necessarily to run a heat pump on moderate temperature days – windows can be kept open except for really cold or hot days. And having a cool bed room in the most sultry of summer days is most certainly nice.
I don’t like ever having the windows closed. I get it’s necessary in winter when I turn the heat on in my apartment but the idea of having the windows closed most of the summer to stay cool just strikes me as wrong. But you don’t have to operate heat pumps in the summer or keep things perfectly cool. And for that off-grid cabin even in the winter, you probably wouldn’t even want to keep the temperature cranked up on the heat pump all winter long, lest you put too much demand on your battery bank when sunshine is limited in the winter. But if you have excess or sufficient capacity, why burn and waste wood when the heat pump can be keeping things reasonably comfortable without the heat being excessive or decadent? I’m really okay with heat pumps even if I’m not rushing to get out an air conditioner for my apartment in the hot weather, preferring a bit of discomfort and fresh air over mechanical and fake cool.