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Cutting my household emissions

I’ve been on a long term course to reduce my household emissions, so this little list caught my eye:

One by one on these (in a slightly different order):

LED lighting – yes – I think all the CfLs have been replaced by LEDs. LEDs to me seem to be living up to expectations of long life.

Double pane windows aka double glazing. No definite plans for this. I can definitely see it’s of benefit, but the cost is substantial.

Good insulation – yes – I did the roof then I did the walls. Combined they make a huge difference to keeping heat out during summer, and keeping it in during winter.

For weatherboard homes, I highly recommend wall insulation.

Heat pumps for heating and cooling – yes. In late 2020 my old gas central heating stopped working. In early 2021 I effectively replaced it (although it hasn’t been removed) with reverse cycle split systems in the main rooms.

These do a good job of heating (or cooling) the house. I’d have to admit the coverage in every room is not the same as the central heating – the heat isn’t as evenly distributed into every room. Ceiling fans help a bit with this.

If you’re wondering, the new units are Mitsubishi Heavy Industries – which to my surprise is completely separate from Mitsubishi Electric. I think I like the newer MHI units slightly more than the older Fujitsu I’d previously installed in the livingroom.

Electric water heater – I got one of these in March 2020, a pre-emptive strike against the old gas boosted solar unit failing. It works well.

Induction cooking – my one remaining gas appliance is the ancient circa 1930 cooker. I’m planning a kitchen renovation that will replace it with an induction stove top and electric oven… reasons it hasn’t happened yet include the pandemic and my own inertia.

Electric vehicle – well… my trip to work (when I’m working in the office) is via electric train. And in normal times that’s the bulk of my travel kilometres.

But my car (bought new in 2018) is still petrol. This is probably my home’s biggest emitter.

Presuming that for some trips PT will still be impractical, I am thinking the next car should be electric.

Purchase price is the main barrier. Somewhere I read that the battery is a big part of the expense, and can account for around half the total cost of the car, but this is expected to drop to a third soon. It helps explain why most electric cars are at the high end, with a few around $50K, but most north of $60K.

Some people say yeah but you can buy a secondhand Nissan Leaf for under $20K. Okay, but if I’m in the secondhand market, I can spend a lot less than that on a petrol car… and it sounds risky with regard to battery range and life.

Range is a concern for me. I don’t drive as much as many other people, but several times a year, it’s trips to regional Victoria to visit relatives, including to towns such as Heathcote which currently have zero public chargers.

Petrol Hybrid Electric Vehicles are the middle ground, with a battery providing enough storage for short trips (up to around 50-60 km in most cases) and petrol for longer distances. Sounds okay in theory but they too are quite expensive and I’m assuming the maintenance isn’t cheap.

The list doesn’t mention solar panels. I now have these – installed last year as well with the water heater (well, a year later actually, due to COVID delays).

So with the panels and the removal of 2/3 gas appliances, how is my power consumption looking?

Home energy consumption 2016-2021

Electricity consumption from the grid (the red line) went up in early 2020 when I started working from home, but down again when my sons moved out in August 2020.

The PV solar was installed in April 2021. Power consumption was back up in winter 2021 when the electric heating was used for the first time instead of gas. The real benefit of the solar panels is seen in the data for late 2021, with average daily usage from the grid down to just 6.38 kWh per day.

I’m trying to make use of the solar by running the dishwasher and washing machine during daytime. I believe the hot water system also has the smarts to do this.

Gas usage (the blue bars) dropped dramatically once it was no longer used for heating. One gas bill reckoned it had dropped 98.99% in a year. It’s now barely visible on the graph.

I notice for 4 gas bills in 2021 it said I used 117 MJ… I wouldn’t be surprised if it’s not very accurate at very low volumes. Certainly most of the bill is for the connection, not the actual gas.

I still want to get my kitchen done. That will replace the gas cooking with electric, which will mean I can remove the gas connection completely. The way COVID is going, this may or may not be this year.

Hopefully many people are on a similar journey of cutting their household emissions – which helps to save money too.

Of course no matter what I do personally to reduce my emissions doesn’t count for much if world governments and corporations don’t also make an effort. That’s the real challenge now.

11 replies on “Cutting my household emissions”

In the SA REES scheme electricity retailers invest in changes to customer premises to save energy. There is a list of changes and quantified benefits at https://www.escosa.sa.gov.au/industry/reps/activities/reps-activities you could check out to see if you’ve missed anything, sealed doors etc? (although your climate zone might be different obviously). The Victoria Energy Saver https://www.victorianenergysaver.vic.gov.au is similar but can’t find all of the activities in one place (easily).

Apart from reducing heat loss (and gain in the summer) double glazing has a secondary benefit of reducing the temperature gradient across the room, making it more comfortable. My previous home in Docklands had floor to ceiling single glazing and although a thermometer showed it was ‘warm’, it certainly didn’t feel it. Back in UK where I come from double glazing has been the norm for 25+ years and it amazed me to come here and find it so little used.

If only the government (both state and federal) would mandate a minimum of double glazing and insulation, and not just on new houses. In an ideal world, every property should be fitted with double glazing and insulation before it can be sold or rented, regardless of the age of the property. I think the pink batts controversy has kept the government once bitten twice shy though so I’m not holding my breath for any housing reform.

It’s even worse for people in public housing, as the properties almost always lack any form of insulation (just air between the outer and inner walls – if they ever had insulation it was most likely loose-fill asbestos fluff and ripped out decades ago), have what may as well be sugar glass for windows (single glazing with ¼” thick panes, which is illegal in just about every other first world country on the planet), and no air conditioning unless the renter pays for it themselves (or has a life-threatening medical condition which requires the government to actually install it). Forget about ducted heating or anything else remotely resembling HVAC in public housing built last century. Do I need to mention the half inch gap under the front and back doors, which needs a door snake at all times to keep the heat/cold out? Or the fact that rain can get through the gaps under the doors, saturating the door snakes and leaving a puddle on the floor too? Or the wind-out windows which are drafty at all times unless you seal them with silicon caulk and carefully cut around the edge of the caulk so that the window can still be opened. And yes, floor-to-ceiling windows are standard issue in most of these houses, which is just perfect for that north or west sunshine to make your house nice and toasty if your windows happen to face that way.

As you can imagine, the houses are virtually unlivable during extreme heat (think of riding in an old Hitachi train on a 40°C day, if you’re lucky the bedroom might even drop below 25 overnight between the two hot days, even if the outside temperature is in the teens), while on winter nights the same houses drop to single figures ten minutes after the heater is turned off, which I’m sure the energy companies are smiling ear to ear when the $400 energy bills are sent. Melbourne might rarely ever go below zero overnight during winter, but the outer east does, albeit hovering around zero itself rather than -10 or anything close to that (I’ve witnessed -2°C in Ringwood where a thin layer of ice had formed on the bins).

The public housing stock that always gets pictured as needing replacement are the Soviet-style high-rise towers, or lately the 1950s-era conjoined flats which the government is finally starting to bulldoze, but there are thousands of detached public housing units (in blocks e.g. there might be 8 or 10 or 20 units on one block of land) built between the 50s and 70s (maybe even 80s, not sure if the government was building public housing stock in the 90s or beyond as everything looks so old) which are just as bad, yet are not on the renewal list at all unlike the towers and flats.

One issue with induction stove is, the power is regulated by IGBT (Insulated Gate Bipolar Transistor). The selection of intermediate power levels is achieved by having the power on and off with varying “on” ratio, so it’s the average voltage that it adjusts. It’s usually not a problem until you want to do some slow cooking such as meat soup. A gas stove can be regulated so that the soup is just simmering, so the fat in the meat dissipates and floats on the soup surface, which marginally increases the pressure in the soup so it achieves a slightly higher boiling point, making meat tender. An induction stove will still make the soup boil from time to time, breaking the layer of fat.

@Yao – it sounds like you’re thinking of old fashioned electric stoves that could only turn the element on and off based on a basic thermostat, giving only ‘heat’ and ‘off’ cycles. Every modern control system turns the power on and off so many times a second it’s the same kind of control you get by turning a dial on a gas strove.

@Heihachi_73: It’s not always possible to retrofit double-glazing. Most timber windows built prior to World War 2 on heritage-listed buildings have approximately 15mm rebates with 6mm single glazing and 9mm window putty trimming on the interior face. Replacing windows for this purpose are generally frowned upon as they generally require window frames and window openings to be built deeper for the similar appearance, running contrary to the general mantra of like-for-like replacement. In the heritage world, if similar results can be achieved with less disturbance to the existing building, it is considered better.

You can use low-e glass which achieves similar results with single glazing (3-6mm thick) and keep the window frame as is. Alternately, if there are hinges on the outside, they can indicate evidences of external window shutters which can be reinstated to keep out sun during summer and keep the air warm in winter. (Similar double sliding doors are used in older Japanese homes.) Finally, you can add a secondary window on the internal side of the window reveal, separate to the main window frame. See below link for examples in the UK.

https://handrwindows.co.uk/secondary-double-glazing/

When discussing electric vehicles, the best type of personal electric vehicles is often overlooked – the ebike.

We have timber windows from 2004 that are pretty bog-standard, and lack frame depth to accommodate double-glazed panels. So we will need to replace them eventually with proper double-glazed windows. We have already replaced one because it suddenly rotted through. It was replaced with a uPVC awning unit that is without doubt the best window in the house, but cost over $3500. I’m sure prices would be better if one bought several windows, and used a normal carpenter to install them instead of dealing directly with a slightly shady (pun not intended) window company as we did.

For a west-facing window, if you have good drapes for holding in heat and aren’t worried about being unable to look through the window when it’s cold, I would heartily recommend re-glazing with a 6 mm laminated glass, where one layer is low-e glass. We had this facing west and it transformed a room that was previously oven-like in summer. It should be compulsory on all west-facing windows. It won’t be super-cheap but is definitely cheaper than window replacement, and it will fit into a normal timber frame. Standard glass on older windows (i.e. 1970s with no requirement for toughened glass) is 3 mm float glass, or 4 mm if it’s a big window. This still happens on new houses because double-glazing isn’t compulsory, except safety glass is now used if the window is within 300 mm of floor level.

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