This is The ChangeUnderground for the 26th of September 2022.
I’m your host, Jon Moore
Decarbonise the Air, Recarbonise the Soil!
Some good news!
The western world is about net zero by 2050. The question is how? A recent podcast from the ABC: Who’s Gonna Save Us which has run the gamut from legal actions against oil producers to household level changes focused thier last episode (Link in the show notes.) on the latter.
Heating, cooling and transport are the big areas at the household level. Heating and cooling will vary in its application across the globe as it does across this wide brown land from the tropics to the cool temperate regions but the point is these can be fixed. It just takes time and a little sensible policy setting from the state.
The big problem, as I’ve mentioned previously, is the vested interests and their ability to influence that policy.
As the current situation in Europe has demonstrated, gas is perhaps, not the ideal solution. Don’t have your own, then you can frack. That’s a good way to cause earth tremors, ignitable water supplies and not much help towards net zero.
The generation of electricity is now fully capable of being both renewable and decentralised and it’s this last bit that terrifies large corporations. Here is Australia with its population of a mere 25 millions we have enough gas supply piping to stretch around the globe twice at the equator. Changing to localised, decentralised electricity production and supply will leave these pipelines as interesting artefacts for future archaeologists and a fair bit of pain for shareholders. Shareholders who could and perhaps should have seen the time coming when these sorts of infrastructure would be obsolete.
As a species we do tend to hold onto the past. We still have water troughs for horses scattered about our towns and cities to remind us of that former technology.
Heating and cooling from renewables generally means heat pumps. Take heat our of the ambient air temperature, concentrate it and deliver it to the inside of a building. The reverse holds true for cooling. This is known as an active system. A passive version I discovered in The Complete Book of Self Sufficiency way back in 1977 is a thing called a Trombe Wall.
Quote for the Wikipedia page: Trombe Wall:
A Trombe wall is a massive equator-facing wall that is painted a dark color in order to absorb thermal energy from incident sunlight and covered with a glass on the outside with an insulating air-gap between the wall and the glaze. A Trombe wall is a passive solar building design strategy that adopts the concept of indirect-gain, where sunlight first strikes a solar energy collection surface which covers thermal mass located between the Sun and the space. The sunlight absorbed by the mass is converted to thermal energy (heat) and then transferred into the living space.
So it points north in the southern hemisphere and vice versa in the Northern. By having vents in the wall, cold air is drawn in at the bottom, heated from the thermal mass of the wall and sent back into the building at the top where it circulates, gives up its heat and is drawn back into the wall cavity. By having another vent at the top pointing to the outside world and the one pointing inside closed in summer, air is drawn through the building and vented to the outside. If the intake in summer is something like a fernery or shade house with misting micro irrigation nozzles, the temperature of the dwelling can be kept reasonably liveable.
I can attest to the cooling effects of these micro misters. A friend had them setup around their verandah and on a particularly warm evening decided to test the system. Once turned on the temperature dropped by about 7 degrees C (about 12 degrees F). A way to capture as much of the water as possible and recycle it through the system would be a further improvement.
The point is, there are ways to heat and cool that don’t involve fossil fuels, even though there’s a huge infrastructure in place to deliver gas.
Water heating can also be done with heat pumps using far less energy. The heat pump doesn’t heat the air nor the water but moves latent heat into a more concentrated form for about 25% of the cost of direct heating.
Back to the point about net zero. We are going to have to replace boilers, water heaters and cooking stoves that run on gas with electric versions before 2050 to have a hope in hell of meeting targets. The podcast provided a back of the envelope type calculation of around 100 million appliances in Australian households. Which seemed a terrifying number to deal with in 28 years.
From an article based on the podcast: Quote:
To replace all these machines within 25 years, Australia will need to swap them out at a rate of about one every 10 seconds, or six a minute.
So, like any home renovation, it would have to be done in a hurry.
Fortunately, all the machines that need to be replaced are going to have to be replaced anyway – most of them won’t last another decade.
The average age of cars in Australia is about 10 years, while gas water heaters and gas heaters tend to be replaced every 10-15 years.
The trick, Professor Blacker said, will be replacing them with the right machines.
That means buying an EV when you get your next car, or an electric heat pump (ie. reverse-cycle air conditioners) when the gas heater dies.
“It’s easy. We just have to stop like-for-like replacement,” he said.
Dr Griffith agreed.
“Next time your gas hot water heater kicks the bucket, we need the replacement to be electric. And that’s just the reality.”
So there’s a need to ban the production and sale of polluting appliances. They are generally the least expensive to purchase and the least efficient to run. This means poorer households can often only afford the most polluting appliances and are then hit with much higher running costs over the life of what seemed the “cheapest” machine. A lot of retooling is going to be needed. And things will be different.
We recently installed a heat pump space heater. Not cheap but not excessively expensive in a household with little debt and two adults working full time. This device heated us this past winter instead of our wood burning space heater. The heat is different. If we had radiators installed, the heat would have felt warmer (?). Radiant heat always feels warmer to me than hot air. The difference became obvious during a brown out after a storm a few months back. The woodstove was great but required constant feeding and clean up of ash and so on. The heat pump requires a button pushed and, of course, a supply of electricity.
Which is another problem we can solve locally, ish.
What about emissions from power generation?
Substituting electricity for fossil fuels raises other issues, such as beefing up renewable power generation, plus storage.
About one-third of annual electricity generation for the National Electricity Market (NEM) comes from renewable sources.
The federal government is targeting 82 per cent renewables in the NEM by 2030.
As part of this shift to renewables, Dr Griffith is advocating for a massive uptake of rooftop solar and batteries.
About 3 million households currently have rooftop solar, leaving 7 million without.
If each of these 7 million households had a standard 5kW system, the combined output would be an additional 35GW – which is a lot.
In other locations around the globe, wind, tidal, wave and geothermal are all possibilities but are, apart from wind, difficult to achieve at the household level. Even wind is problematic at this level. It’s much louder than a solar cell. But ways can be devised, I’m sure.
I am aware all this is predicated upon an urban or suburban setting and, perhaps, not as relevant to a rural setting. The difference out of town is the availability of space. Even if that’s just building roof space rather than giving up productive land to generate electricity. Still a battery to cover the essentials of a farm situation when the price of diesel is prohibitively high to run a generator might be a prudent thing to have on hand.
The bigger point is net zero is more than achievable. Price signals, a little proactive policy setting and getting on with the job as the more extreme nutjobs scream into AM radio talkback shows will render us a more liveable local area, a quieter one too, and a chance to reduce the effects of CO2 accumulation. We are stuck with the effects for some time, centuries perhaps, but we can do this, indeed we must.
I discovered a series of system failures in the setup for the gardening course which, fingers crossed, are now fixed. So the ChangeUnderground Academy no-dig gardening course link is in the show notes. Still currently selling for $17 dollars. Please tell your friends!
Decarbonise the air, recarbonise the soil!
Thank you all for listening and I’ll be back next week.
No Dig Quick Start Course
Facebook Group: https://www.facebook.com/groups/1546564598887681
Certified ‘genius’ Saul Griffith has a plan to decarbonise Australia — and it will only take 101 million machines
Who’s Gonna Save Us