Lately there has been an increasing amount of encouraging news relating to the global movement towards a more sustainable future. Two of the world’s largest coal companies, Peabody and Arch, have gone bankrupt in a sign that the age of fossil fuels is coming to an end. Closer to home, this week local landowner’s in the Southern Highlands won a court case to stop Korean-owned Hume Coal from drilling on their land. Back in Montana, where I used to live, a local land-owner group has just won a thirty-year battle to stop a railroad which was proposed to open up new coal mines in the Tongue River Valley.
Solar Cheap as Chips in Dubai
Meanwhile, in Dubai they are planning to build a 5 MegaWatt solar power plant. The bids have come in and the Dubai Electricity and Water Authority has just announced that it has ‘received a bid of USD 0.0299 cents per kilowatt hour – a tad under AUD 4 cents. That’s less than average wholesale electricity prices across Australia this year from all sources; including cheap-as-chips filthy brown coal fired power generation’. According to this article from energymatters.com.au this sets a new record for low-cost solar power and is particularly remarkable because it is unsubsidised.
South Australia Closes Last Coal-fired Power Plant
According to this article from SolarQuotes South Australia has made history by closing its last remaining coal-fired power plant. SA still imports some coal-fired electricity from Victoria but only on an as-needed basis when its (very significant) renewable energy developments are not generating enough to meet the demand. The fascinating thing about this is that SA no longer has any ‘baseload’ power generation (read the article for more about this) which sets a promising precedent for our large-scale conversion to renewable energy.
‘South Australia serves as a model to the rest of the country, and the world, in how to happily run a grid without baseload generators.’
More Encouraging Signs
Lots of good stuff came in from around the web this week including:
More Feedback on Underslab Insulation
In last week’s Newsletter I wrote about whether it is better to insulate under concrete floor slabs or not. I didn’t come to any definite conclusions and I’m still not sure what the answer is but the question did raise some interesting feedback from various readers.
My dear friend Daniel wrote again with the following questions and comments:
‘What is the ground temperature in winter do you think? Because if it is lower than ~17 degrees it would be worth insulating the slab (considering only winter comfort) wouldn’t it? Which would mean you made the right decision for summer but are at a disadvantage in winter due to the slab.
As I wrote in the Newsletter two weeks ago, I think the winter ground temperature under our house is around 10.6degC because that was the temperature the house stayed at when there was no one here to open the curtains and let the sun in for about six weeks last winter. So Daniel may well be right that we’d be better off with insulation under the slab in winter. But how would this affect our ability to keep the house cool in summer? … I don’t know but I am pretty sure that insulation around the edge of the slab is even more important than insulation under the slab. The trouble is, I still haven’t found a way to insulate the slab edges AND feel confident that I can keep termites out for the next 100 years. One reader, Michael (who authors a website called handmadehome.org about the experience of building his own sustainable and natural home in Victoria) commented in response to last week’s Newsletter:
‘It seems a fairly vexed area to me.
I went around in a million circles before eventually settling on no insulation.
Passive house designers tend to insist on at least waffle pods for insulation. But there are clearly times in the year when the earth connection is beneficial…. I agree with the edge insulation. Wanted to do it, but couldn’t find a way that wasn’t a problem for termite protection. With an exposed slab edge for termite protection, part of the slab remains exposed to the outside air, which is certainly not ideal, but it is a very reliable, simple and non-toxic termite protection.
I tend to agree with Michael on this point. In Montana we always insulated the edges and underneath concrete slabs but there are no termites there. My good friend Glenn, on the other hand, was confident enough in the ‘Trithor’ termite barrier system to allow him to insulate the edges of the slabs in both his house and granny flat. Regular readers will be familiar with this wonderful project that Glenn has undertaken with his wife Lee as I have mentioned it many times. Glenn has also recently started a blog of his own which you can find at bundanoonnetzerocottage.com and I highly recommend learning about the excellent work they are doing. But back to the point at hand, they didn’t insulate under the house slab but they did use waffle pods under the granny flat slab. As Glenn commented last week:
‘I have read up on waffle pods impact on ground coupling of floor slab and the only impact seems to be a lag in exchange as a reduced portion of the mass is in direct ground contact. The biggest impact is a significant reduction in the slabs embodied energy as it uses less concrete and heaps less steel than a conventional beamed raft slab. Even an efficient house uses over 30% of it’s PV generated electricity to compensate for the energy used in the construction materials so cutting down on the slabs significant embodied energy can also reduce the size of your pv system. In our climate zone the only significant thermal losses from slabs are at the edges or underneath if excessive moisture is present.’
So Glenn is of the opinion that, from the point of view of operational energy it is only necessary to insulate the slab edges (unless you are building in very wet ground) but, from the point of view of embodied energy, waffle pods are better because they reduce the amount of concrete and steel. This is an excellent point and brings me to Ray’s comments:
And Now For The Bad News
While I always try to focus on the good stuff, it is important, from time to time, to take notice of certain things that we might prefer to ignore, such as:
‘Reaching 400pm is a stark reminder that the world is still not on a track to limit CO2 emissions and therefore climate impacts. We’re still on the ‘business-as-usual’ path, and adding more and more CO2, which will impact the generations ahead of us. Passing this mark should motivate us to advocate for focused efforts to reduce emissions across the globe.’
Meanwhile five of the Solomon Islands have disappeared under water and on other islands people have been forced to relocate due to rising sea levels.
And what are our esteemed leaders doing about it?… NOTHING!
Climate change was not even mentioned as a word, or a concept, or even an issue – despite Tuesday’s budget apparently being about growth and jobs for the future. There was no new money for climate initiatives and the only mention renewable energy got was to confirm that $1.3 billion in funds would be stripped from the Australian Renewable Energy Agency.
“There was nothing in the speech, not a word,” Professor John Hewson, a former leader of Liberal Party, told the SolarExpo conference in 2016.
“The slogan is jobs and growth. I would have though that one of the most significant sectors for economic and jobs growth is renewables – I am staggered that it didn’t get a mention in the speech or in the documents.” Hewson said the decision to remove funding from ARENA was an “absolute tragedy.”
Staggering isn’t it? Well, all I can say is… there’s work to be done friends.