While my most pressing home renovation need is the bathroom (planning to do this the next time my sons are away on a trip), I was also thinking:
Governments should be doing a lot more on climate change, but what are the major emissions in my home, and how could I decarbonise?
The car. I recently bought a petrol car, because given how little I drive, I couldn’t justify the cost of hybrid or electric, and with brown coal power generation, electric cars arguably just move emissions from the tailpipe to elsewhere. Hopefully by the time this car is replaced, most electricity (certainly in my house) will be green and electric vehicles will be more affordable. So let’s leave the car aside just for the moment.
In the house itself, several of the appliances involved are quite old and inefficient, and may need replacing anyway in coming years. So there’s an opportunity to move away from gas (unavoidably fossil fuel) to electricity (which can be renewable).
Gas central heating — this system is more than 20 years old, and not very efficient by modern standards. Maintenance also seems to be increasing.
Current thinking seems to be that split system air-conditioners are more efficient than has central heating, particularly from electricity from renewable sources.
There’s a cost there of course — each area of the house would need a new unit fitted. I got one for the main living area a year ago for cooling, which is the other obvious benefit of installing them.
Good insulation also helps. I’ve done the roof, and we have external blinds for summer, as well as ceiling fans, but wall insulation is worth doing too.
Gas cooking — my ancient gas cooker still works around 90 years after it was installed. It’s got minor problems though with gas leakage, and both the oven and cooktop are small and lack precision. We’ve learnt to live with this, but modern facilities would be nice – for instance an oven that’s big enough to cook multiple pizzas.
Replacing these with electric could be the way to go. Electric cooktops can be induction or ceramic — I like the sound of induction, though that may require replacing some of my cookware.
Gas water heater — ten years ago I got solar hot water with a gas booster. It’s worked well, though a bloke who came recently to clean the panel mentioned that parts are likely to need replacing before too long — perhaps in the next five years.
Options might include a conventional electric hot water heater (expensive to run) or a heat pump, which can be expensive to install (up to about $3000), but are apparently quite cheap to run. Though come to think about it, I think I paid about $4000 for the solar hot water system.
Electricity — currently I pay for green power, but an obvious upgrade would be to invest in PV panels, which have dropped in price markedly, and the new subsidies make it more affordable, even if the feedback tariff isn’t very high anymore.
One benefit of removing the solar hot water would be making more space on my relatively small roof for more PV panels. Some owners of houses with a small roof have been quite creative about maximising the number of panels – see photo above.
There are also different options for PV panels, which some expensive ones generate more power — and of course one can install batteries to make use of the power generated rather than feeding it back into the grid (typically during the day) and having to buy it back at peak times (typically in the evenings). Batteries are really expensive though, well over $10,000 it seems.
Can rooftop solar generate enough power at the hottest part of the day to run air-conditioning?
I also need to keep in mind future development around me. My neighbours on the western side have rebuilt their house as two storeys, reducing sun onto the roof in the afternoon. If the same happened on the eastern side I wouldn’t be surprised — there’s been a lot of similar development in my street.
Put all these things together, and (for a cost) I could move off gas completely, and move most of my power generation to solar, cutting my household emissions to hopefully near zero.
I’m sure I’m not the only one pondering these issues. What are other people doing?