Dec 8, 2017: Bitcoin Climate Disruption

Is Bitcoin adding to Global Warming? (Image Source:

Is Bitcoin adding to Global Warming? (Image Source:

In last week’s Newsletter I mentioned a Guardian article which claims that processing of Bitcoin transactions now requires more energy than the entire country of Ireland. My friend Kevin responded with a link to this article from Grist which makes the following predictions (emphasis mine)…

‘…at bitcoin’s current growth rate, the electricity demanded by the cryptocurrency network will start to outstrip what’s available, requiring new energy-generating plants. And with the climate conscious racing to replace fossil fuel-base plants with renewable energy sources, new stress on the grid means more facilities using dirty technologies. By July 2019, the bitcoin network will require more electricity than the entire United States currently uses. By February 2020, it will use as much electricity as the entire world does today.

This is an unsustainable trajectory. It simply can’t continue.’

Now there’s an understatement for you… to suggest that doubling the world’s energy use in the next two years is unsustainable… how dare they?

But wait, as usual it seems the issue is much more complicated than that. According to this article from Mashable

‘…things aren’t that simple. We don’t know, exactly, how power-hungry Bitcoin really is. And whatever the figure is, Bitcoin certainly doesn’t need that much energy to run. Furthermore, energy consumption issues can potentially be fixed with a future upgrade of the Bitcoin software, which is easier than, say, reducing the energy footprint of Ireland. Finally, there are other cryptocurrencies out there working on a solution to this problem.’

The article goes on the state that… ‘Bitcoin isn’t exactly doing its job the way its creator, Satoshi Nakamoto, had intended. Due to its price rise, not many owners actually use their bitcoins to purchase goods; instead, everyone is either hoarding it or speculating with it

 This means that talking about the energy cost of one Bitcoin transaction is misleading…. In fact, you could theoretically run Bitcoin’s entire network on a dozen 10-year old PCs.’

According to this article, Bitcoin will have to adapt or die as other cryptocurrencies are developed that don’t require so much energy to process transactions… ‘Ethereum, the second largest cryptocurrency right now… uses roughly three times less energy than Bitcoin; and yet there are twice as many transactions per day on Ethereum’s network.’

Another of our readers, Nick, posted the following comment… ‘Don’t confuse the mining of bitcoins with the transactions of them. Mining a bit coin is computationally expensive because it creates a new bitcoin (i.e. like making gold with a computer program) but the transactions are simple and cheap – if you think about it, no one would spend millions of dollars on a ten thousand dollar transaction’. So Nick, I guess I am confusing the two because, as I understand it, Bitcoin ‘miners’ receive Bitcoin as payment for using their vast computing power to process Bitcoin transactions, so it seems to me that the two are inseparable in terms of the energy they require. Perhaps you can explain it to me if that is incorrect.

Nevertheless, as I’m writing this I see that Bitcoin today passed US$20,000 per ‘coin’. Is it just me or does this strike anyone else as completely INSANE! Bitcoin has no use and no yield. It can’t be used to buy anything and it doesn’t pay any interest or rent or dividend. The only way to make a return on your investment is to buy it and hope that the price goes up when more people buy it. That seems like the classic definition of a Ponzi scheme to me where… ‘the operator generates returns for older investors through revenue paid by new investors, rather than from legitimate business activities’.

The fact is that, currently there isn’t much you can do with a Bitcoin. According to this article from The Telegraph‘Bitcoin has proven itself to be a completely useless currency’Bitcoin propoennts counter this by saying that the mainstream press, governments and big financial institutions are opposed to cryptocurrencies because of their power to disrupt the status quo. Personally I think these advocates are living in la-la land. They claim that the great benefit of ‘cryptos’ is that governments can’t control them and you can make your financial transactions in private without requiring a big bank to process them. If they seriously think banks and governments the world over are going to allow that situation to continue then they need their heads examined. Instead I predict that, as soon as the technology is developed to the point of being actually useful, the banks and bureaucrats will take it over and ban any transactions outside of a system that they control.

Meanwhile people the world over are investing huge sums of money and vast amounts of energy into something that is almost completely useless (a bit like our state government proposing to spend billions of taxpayer dollars on new sports stadia… click here if you would like to sign a petition opposing this). I suppose, in that sense, Bitcoin is the perfect sign of the times.

Image source: zero

Image source:

Dec 1, 2017: The Coming Disruption

When you have an hour to spare I strongly encourage you to watch the following video presented by Stanford University Futurist, Tony Seba, about the impending disruption of the transport and energy sectors. Here are just some of the information it presents:

  • Electric Vehicles (EV’s) have 100X fewer parts than Infernal Combustion Engine Vehicles (ICEV’s)
  • EV’s can last 5 to 10 times longer than ICEV’s (e.g. Tesla is saying they will put a 1 million mile warranty on their new electric truck)
  • By 2025 every new vehicle will be electric (for purely economic reasons)
  • EV’s will reach Level 5 Autonomy (i.e. requiring no human input) by 2019
  • By 2021 it will be 10X cheaper to use an autonomous ride-share EV than to own a car
  • This means that used ICEV’s will likely have negative value (i.e. you’ll have to pay someone to take it off your hands)
  • By 2030, 95% of passenger miles will be by autonomous ride-share EV’s
  • This means there will be 80% fewer cars on the road and no need for parking lots
  • The parking space that will be freed up in Los Angeles alone is enough to build 3 new San Fransisco’s
  • And by 2030 solar will account for 100% of the world’s energy generation. To back up that last point, Seba notes that Tucson Electric has recently signed a PPA (Power Purchase Agreement) for electricity from a utility-scale solar plus battery storage system for 4.5c/kWh which is cheaper than any other form of energy.

I have no idea if Tony Seba will be proven right but he makes a very compelling (and entertaining) argument that is based entirely on economics… not politics or environmentalism or climate change or anything other than economic rationalism. Whether his predictions prove accurate or not, it’s worth watching just to start thinking about how quickly things might be changing. Have a look and leave a comment to let us know what you think about the future he is predicting.

Bitcoin Energy Nightmare

Bitcoin is a MASSIVE energy consumer (source BTC Manager)

Bitcoin is a MASSIVE energy consumer (source BTC Manager)

Speaking of disruptions, I expect you’re all aware of Bitcoin by now. It has gone from under US$1000 at the start of the year to over US$10,000 a few days ago. This has created a huge amount of hype over cryptocurrencies and blockchain technology.

What you may not have read is this article from Yahoo Finance which claims that Bitcoin ‘Mining’ (the business of processing all the data required for Bitcoin transactions) uses more power than 159 countries. Or this article from The Guardian that says Bitcoin transactions consumed ‘more electricity in a year than the whole of Ireland’. In other words ‘each individual bitcoin transaction uses almost 300KWh of electricity’. That’s enough electricity to power the Greeny Flat for about two months from one, single Bitcoin transaction.

These are shocking statistics, especially because Bitcoin is still very new and can’t actually be used for anything yet. Plus it is just one of thousands of so-called ‘Cryptocurrencies’ and thousands more ‘Blockchain Technologies’ that are being developed around the world. I haven’t seen any figures on what the total energy consumption for all this number-crunching amounts to but you can rest assured (or more likely lie awake in fear) that whatever it is now will be nothing compared to what it’s going to be in the future.

I wonder if Tony Seba’s prediction of 100% solar energy by 2030 will hold true if global electricity consumption doubles simply due to processing blockchain calculations?

I also wonder (and I’ve mentioned this before) what sort of mess we’ll be in if we do go 100% solar and then suffer a massive volcanic eruption that blankets the world in ash for a year or two… ahhh! More sleepless nights!

One Promising Australian Blockchain Technology

According to this article from Energy Matters‘The Australian Government and industry partners will contribute $8.26 million to a project trialing the use of blockchain-powered renewable energy and water systems in the City of Fremantle.’

The ‘Blockchain’ part of this trial is from an Australian startup called Power Ledger which is a peer-to-peer, blockchain-based energy trading platform, where renewable energy can be sold between buyers and sellers without a middleman.

This article from Huffington Post gives a more detailed explanation of how it all works. Let’s just hope that it encourages more renewable energy development than it requires to process its own transactions.

Suncrowd Update

In last week’s Newsletter I gave a scathing review of the Suncrowd Solar Bulk Buy program along with an apology for my part in helping persuade people to join it. I requested that anyone else who had problems with either Suncrowd or Sunny Afternoons leave a comment so that all know how many others are in the same boat.

Well I did receive one comment from a customer in Berrima who had a nasty experience and one email from a friend on the coast. So it seems that, for most Suncrowd customers (at least the ones who read this Newsletter), the lengthy delays and lame excuses are not too much of a concern. If that’s true then I’m gad that most people are satisfied. If not, please go to last week’s Newsletter and leave a comment to let me and other readers know how the experience has been for you.

For anyone interested, I just received the latest update from Sunny Afternoons which claims that 71% of the approximately 320 installs have been completed which means there are still 92 systems left to be installed a full year after most people paid their initial deposit. This still looks like a very dismal performance to me but they seem happy with it. Here’s a link to the update in case you haven’t seen it.


Nov 24, 2017: Suncrowd Review – 0 Stars

Please allow me to begin this week’s Newsletter with an apology for my part in helping to organise the Suncrowd events that were held in our region a year ago and for helping to persuade people that this Community Solar Bulk Buy program was a good idea. It certainly seemed like one at the time but, I’m very sorry to say, has proved to be a bitter disappointment for many people, myself included.

The Suncrowd crew might look happy but many of their customers are not... THUMBS DOWN FOLKS.

The Suncrowd crew might look happy but many of their customers are not… THUMBS DOWN FOLKS.

A lucky few of the people who signed up to buy rooftop solar systems and/or batteries through the Suncrowd program did actually get what they wanted for a very good price and installed in a timely manner. Unfortunately they seem to be the exception rather than the rule. I’ve heard many more complaints from people who paid their deposit then waited many months without hearing a word from Suncrowd or their contracted installer, Sunny Afternoons. When rare communications were forthcoming they tended to be a list of excuses for why things were going so slowly with much of the blame being put on Tesla for being slow delivering their promised Powerwall 2 battery. Customers were advised not to expect any indication of when their installation might take place and that calling to enquire about it would only slow the process more. Eventually installations did start to trickle through but I’ve heard from a number of people that there were issues with their installation or they didn’t get what they asked for or that what they had been advised to purchase was not appropriate to their situation.

The final straw which prompted me to write this review came about a week ago when I heard from one of my very best friends (who signed up for a Suncrowd system on my recommendation) that, after a YEAR of waiting and getting no indication of when their system would be installed, they finally gave up and asked for their money back. They were told that they could get a refund of their deposit MINUS a 25% cancellation fee. I cannot believe the gall of this mob! To take someone’s money, make them wait a year with no result (or even an indication of when to expect one) then somehow feel like it’s fair to keep a quarter of the deposit…. it leaves me speechless with disgust…. especially because my friend’s system was a simple rooftop solar installation, no battery, no Reposit power, no justification for any of the excuses that were trotted out as to why people were having to wait so long.

Unfortunately my friends are not alone. I’ve heard from a number of other people, both prior to last week and since then, that they are either not happy with the service they received from Suncrowd and Sunny Afternoons or that they simply didn’t receive any service at all.

What we don’t know (because neither Suncrowd nor Sunny Afternoons have given us any useful information) is exactly how many of their customers (victims?) are dissatisfied with the program and we don’t know how many systems are still left to be installed. If you are one of those people please leave a comment at the end of this article. This is an outrage and I think something needs to be done about it. I’m not sure what that is yet but I will start by compiling information from people who feel they have been treated unfairly. I have made enquiries with the Energy Ombudsman who palmed me off onto Fair Trading who palmed me off onto the ACCC (gotta love Australian bureaucracy) so I’m getting the run-around but I will keep trying. Meanwhile please let me (and our readers) know what your experience has been with Suncrowd. I hope it has been better than my friend’s.

To be fair, I and the other people who agreed to help organise our local events, had every reason to believe that this would be a good thing for our community. Suncrowd had completed an apparently very successful community bulk buy campaign in Newcastle when they approached us wanting to do the same here. Unfortunately our campaign hasn’t turned out so successfully for a number of the participants. Once again I sincerely apologise for my part in this mess and will endeavour to do what I can to rectify it.

Brighter Notes

Tesla Tiny House Packs Them In

CIntia and I in front of the Tesla Tiny house while Matt Simms from Simmark enthrals the crowd.

Cintia and I in front of the Tesla Tiny house while Matt Simms from Simmark enthrals the crowd (except, apparently, the guy in the yellow shirt).

As mentioned in last week’s Newsletter, we had a visit from the Tesla Tiny House which is currently touring the country stirring up interest in solar, batteries and electric cars. Two events were organised for our region, one at Silos Estate Winery in Berry and one at the Bradman Oval in Bowral. These were organised and promoted by Simmark (a local solar, electrical, heating/cooling and security contractor) who kindly invited me to be there to answer people’s questions about Energy Positive Homes and Passive Solar Design. Hundreds of people came to both venues including school groups, families, home owners and retirees interested in learning more about small houses and renewable energy systems. For me it was like being a pig in mud so thanks to Simmark for asking me to be involved. It was encouraging to see so much interest in the things I’ve been banging on about for so long.

Off-Grid… No Thanks

One of those things I’ve been banging on about for years is that, rather than going off-grid, we’re all better off if we stay connected to the electricity grid so that we can all share our renewable energy. So it’s nice to see this article from ABC News that says the exactly same thing and gives detailed reasons for it.

Elon and Tesla Promise Outrageous Electric Trucks and Cars

If you’re interested in the potential of electric vehicles you’ll want to watch the video below (if you haven’t seen it already) showing Elon Musk launching Tesla’s new Semi Truck and Roadster. He’s talking about a huge truck with a better aerodynamic drag coefficient than a Bugatti sports car, 800km range and a promised 1 Million Mile Warranty PLUS a car that can go 0-100km/h in 1.9 seconds (making it the fastest production car ever made) AND with room for four people, luggage and a range of 1000 kilometres.

Neither of these EV’s is in production yet and, given Tesla’s track record for under-delivering on it’s promises, might not be available for quite some time but they seem to signal the death knell for the Infernal Combustion Engine (ICE). It’s going to be very interesting to see whether Tesla can crawl out from under the mountain of debt they have accumulated and go on to transform the world as promised or if they go broke in the attempt. Someone told me yesterday that Tesla lost $10,000 a MINUTE last year. I wish them the best of luck staying in front of the Chinese EV manufacturers and, hopefully staying in business.

By the way, if you’re interested in EV’s there’s an excellent Australian-based source of information called

I signed up for their monthly Newsletter which is full of the latest news about electric cars from around the world. Their last edition included an article which confirms that, even if charged from the dirtiest coal-powered electricity grid, EV’s produce about 25% less greenhouse gas emissions that petrol cars. But PLEASE do me a favour, if you ever hear anyone describe an EV as ‘Zero Emissions’, stop them and ask them where the power comes from to charge it. If it’s not charged with renewable energy it’s nowhere near ‘zero emissions’. And remember that, even if it is charged with 100% renewable energy (like mine usually is) there are emissions involved in the making of the car, it’s battery and the renewable energy system that is charging it. So no vehicle is ever going to be truly ‘zero emissions’ but EV’s are definitely a whole lot better than ICE vehicles.

ANU Breaks Record for Solar Cell Efficiency

According to another article from ABC News, scientists at ANU have obtained a 26% efficiency record for lower-cost solar cells that use Perovskite combined with silicon.

‘Until now efficiencies of this kind have only been achieved using high cost materials normally used on satellites,’ said Mr Duong, a PhD student. ‘We are now a step closer to a low cost alternative.’

Silicon solar cell technology is about 90 per cent of the solar market, but scientists around the world are working to find a way to make them more efficient, affordable, stable and reliable.

It seems we can expect to see the price of solar (and batteries) continue to get more and more affordable for the foreseeable future. Strange that our government seems unable to see it but I think this revolution is going to continue just fine with the COALition party’s support.

That’s all for this week. Thanks for reading. Cintia and I are off to Bong Bong Picnic Races and it’s shaping up to be a beautiful day!

Nov 17, 2017: Tesla Tiny House Here Next Week

I’ve been all over South-eastern NSW in the last couple of weeks performing Energy Audits and Assessments on homes and small businesses from Jindabyne to Maitland. Out of the twenty or so buildings I’ve investigated more than half were built in the early 80’s and have little or no insulation. Very few were correctly oriented to take advantage of Passive Solar Design and most had loads of room for improvement which makes my job very rewarding.

Every building I inspect has different issues and a unique ‘personality’ and I enjoy getting to know each one and what its strong points and needs are. I hope to have time over the coming weeks to write case studies of some of these Energy Assessments. In the meantime, if you’re interested, you can find one recent report I did for a house down the south coast by clicking here.

Tesla Tiny House Dates

The Tesla Tiny House is coming to Berry and Bowral, towed by a ModelX electric car.

The Tesla Tiny House is coming to Berry and Bowral, towed by a Model X electric car.

As we’ve mentioned previously, the Tesla Tiny House is coming to our area thanks to the efforts of local solar and energy efficiency company, Simmark.

I have been invited to attend the two events next week in order to speak to some school groups about the benefits of small, Passive Solar, energy positive and affordable homes like the Greeny Flat and to be on hand to answer people’s questions. There will also be a local builder at the events for those who want to go down that path.

Here are the locations, dates and times that the event will be open to the public.

Silos Estate, Berry. Tuesday Nov 21st, 4-7pm

Bradman Oval, Bowral. Wednesday Nov 22nd, 4-7pm

You can find more detailed information including maps to the sites on the Simmark website here.

I hope to see you there and we’re all hoping the weather cooperates.

(p.s. Just to set realistic expectations, the Tesla Tiny House is not a fully functioning dwelling. It is more of a display space for showcasing Tesla’s solar, battery and EV technology. If you want to see a fully-functioning small (but not tiny) house you can come and visit the Greeny Flat on one of our open days.)

Nov 2, 2017: Montana Off-grid Eco Tiny House

I’m happy to report that I’m now back home at the Greeny Flat with my beloved Cintia. I had a great trip and a wonderful time with my son, Sam. We managed to make a lot of improvements to his house including adding about a foot of insulation to his attic on the day before I left. There’s still plenty for him to do but for now the house is much nicer, healthier, safer, more comfortable and significantly more energy efficient than it was when we started. So I feel like the trip was worth the time, effort, expense and carbon emissions it took to get there and back.

While I was there in Missoula I had the chance to catch up with an old friend, Kevin, who has built a wonderful little energy efficient mountain cabin for himself and his wife, Tina.

Kevin outside his eco tiny house next to the yurt he and Tina lived in for a couple of years while they built the house.

Kevin outside his off-grid eco tiny house next to the yurt he and Tina lived in for a number of years while they built the house

This was a particularly great pleasure for me because I first met Kevin when he enrolled in a ‘Green Building’ class I was teaching at the University of Montana. For his main project for the semester Kevin designed a little off-grid, self-sufficient cabin that he hoped to build for himself one day in the mountains somewhere near Missoula. At the time he didn’t have land but he certainly had the dream.

A couple of years later he had bought his little piece of the forest and came to me for advice on the design and energy efficiency details of the cabin you see in the photo above. Then he and Tina bought the yurt which they erected on top of an insulated SIPS panel floor structure to serve as a place to live while they built the house.

Inside Kevin and Tina's lovely yurt

Inside Kevin and Tina’s lovely yurt

I love yurts… they are such beautiful, minimalist structures. The criss-crossed slats you see in the photo above are the entire wall framing and are attached to a wire ‘ring’ around the top of the wall which supports the roof rafters.

The entire structure of a yurt is made up of small pieces of wood cleverly attached with steel fasteners and wire

The entire structure of a yurt is made up of small pieces of wood cleverly attached with steel fasteners and wire

The rafters, in turn, support a circular skylight in the centre of the roof which bathes the whole interior in beautiful light and provides a view of the sky.

It’s a gorgeous space to be in… for a while. But Tina and Kevin lived in this through three or four Montana winters when temperatures would get down below minus 20deg. Thankfully their yurt is somewhat insulated and can be kept very warm with a wood stove. But they didn’t have running water, their kitchen was a gas stove on a trolley and their toilet was a hole in the ground. (Tina said it wasn’t as bad as when she lived in Alaska and had to take a heated cushion with her to the outhouse to prevent her bum from freezing to the seat).

These are some tough people but still, I’m sure you can imagine how happy they are to have finally moved in to their cozy little cabin.

Tina's new bathroom complete with hot and cold running water, shower, sink, gas water heater and composting toilet

Tina’s new bathroom complete with hot and cold running water, shower, sink, gas water heater and composting toilet

The cabin could be described (very fashionably) as an Off-Grid Eco Tiny House. It has a footprint of 240sf (about 24sqm… which makes our 57sqm Greeny Flat seem like a palace) with a loft/bedroom over half of the ground floor. The floor and roof are built with SIPS panels (8 inches of foam with OSB glued to both sides) while the walls are timber framed, six inches thick and with an additional four inches of rockwool insulation wrapped around the entire outside. In retrospect Kevin says he should have used SIPS panels for the walls as well. They’re expensive to buy but would have saved him a lot of trouble and time for an equivalent level of insulation. The windows are UPVC frames and I can’t remember if they were double or triple glazed.

In general this tiny house is super insulated and very well air sealed which means they have to be careful to ventilate it correctly in the winter time. The cost for materials was about $60,000 (plus a LOT of hard work) and they’re very happy with how it turned out.

It’s hard to photograph such a small space but the series of photos that follow give a pretty good idea of what it’s like inside. I’m very grateful to Kevin and Tina for inviting me up to see the finished product. It’s very much their baby and I feel like I’ve been involved since the conception in my Green Building class. But if this is Kevin and Tina’s baby which they’ve raised from the ground up, it’s now fully mature and ready to take care of its parents (as children tend to do).

The cabin is primarily heated by this tiny little wood stove in the full-height living room

The cabin is primarily heated by this tiny wood stove in the full-height living room

The kitchen isn't quite finished yet but Tina wasn't keen to spend another winter in the yurt while Kevin completes the cabinetry so they moved in anyway

The kitchen isn’t quite finished yet but Tina wasn’t keen to spend another winter in the yurt while Kevin completes the cabinetry so they moved in anyway

A loft above the kitchen and bathroom serves as the bedroom

A loft above the kitchen and bathroom serves as the bedroom

There's a nice view of the forest from the bedroom window

There’s a nice view of the forest from the bedroom window

A 1.5kW solar and battery system supplies all of their electrical needs including pumping water up to a holding tank at the top of the hill

A 1.5kW solar and battery system supplies all of their electrical needs including pumping water up to a holding tank at the top of the hill. They use propane (LPG) for heating water, cooking and keeping the house from freezing when they’re not home

In Montana water tanks have to be buried or they freeze solid and the water line (which gravity feeds from here down to the house) has to at least six feet below ground

In Montana water tanks have to be buried or they freeze solid and the water line (which gravity feeds from here down to the house) has to be at least six feet below ground

The ultimate luxury is their 'Cowboy Hot Tub' consisting of a horse trough, wrapped in insulation and heated by a tiny little wood chip heater

The ultimate luxury is their ‘Cowboy Hot Tub’ consisting of a horse trough, wrapped in insulation and heated by a tiny little wood chip heater

Congratulations Kevin and Tina for pursuing your dream and creating a little mountain paradise of your very own. Next time I visit I look forward to staying in the yurt and lying (or squatting) in the hot tub with Cintia and a glass of Pinot Noir while gazing at the stars through the trees…. I can hardly wait.

Oct 27, 2017: Glorious Rain and Good Results

Our rain gauge this morning after a long dry spell.

Our rain gauge this morning after a long dry spell.

I’m still pretty jet-lagged after arriving back in Sydney the day before yesterday but I’m very happy to report that I seem to have brought some rain with me. It’s been a long dry spell here (and in Montana too) with our weather station only recording a total of 41mm over the last four months. So we were thrilled to hear rain on the roof all night last night and to wake this morning to find over 35mm in the rain gauge. That’s on top of the 20mm we had yesterday so we’ve had over 55mm in the last two days, our tanks are full again and all our plants are breathing a big sigh of relief.

I also had time this morning to check our monitoring equipment to see how the Greeny Flat has been performing while I was away. I was particularly interested to see what difference the solar air heater (circled in blue above) made to our indoor temperature and humidity while we were gone.

Long-time readers will recall that I have written about our experiments with making a DIY solar air heater a number of times. In this Newsletter from May 2015 I described the thinking behind our Solar Air Heater prototype and in this Newsletter I showed some early results from trials of the system. Fast-forward two years and, just before we left on our trip to states, we decided to make the prototype into a permanent part of the Greeny Flat. This meant cutting holes in walls to allow us to duct the incoming heated fresh air across to the back bedroom on the south side of the house (this bedroom doesn’t get any sun and it’s been nice to have the added warmth in there in winter).

The quiet fan is mounted inside an insulated box placed on top of our bedroom closet.

The quiet fan is mounted inside an insulated box placed on top of our bedroom closet.

We also added a new, quiet fan which we mounted inside an insulated box (for sound proofing), wired it into the house power and connected it to a thermostat controller.

The thermostat controller measures the temperature inside the solar air heating box and switches on the fan when the temperature reaches the set point.

The thermostat controller measures the temperature inside the solar air heating panel on the north wall of the house and switches on the fan when the temperature reaches the set point.

As you can see from the photo above, this new and improved system was delivering 57.1degC on a day when it was only 16.3degC outside. In other words, the Solar Air Heater was adding 40.8degC to the incoming fresh air.

This photo of our weather monitor was taken at the same time. The outside air temperature is circled.

This photo of our weather monitor was taken at the same time. The outside air temperature is circled.

Needless to say I was very happy with this addition to the energy efficiency, comfort and indoor air quality of the Greeny Flat while we were here in the home. But I was also interested to see what effect it would have while we were away in winter.

One of the few drawbacks of our Passive Solar house is that it works best when we are here to operate the windows and blinds correctly… as the saying goes, ‘Passive House, Active Owner’. In winter this means opening our insulating blinds during the day to let the low winter sun stream in and warm the floor slab then closing them at night to help keep the warmth inside. It’s also up to us to run our ventilation fans as much as needed in order to keep the indoor humidity down to a reasonable level (around 50%), to reduce condensation potential and maintain good indoor air quality. But when we’re not here to open the blinds during the day or run the vent fans the temperature will go down and the humidity will go up.

This was proven true two years ago when we were away for the whole month of August. According to our weather monitoring system, the outdoor temperature for that month averaged 8.5degC and the outdoor humidity averaged 67.7%. Meanwhile the indoor temperature averaged 14.4degC and the humidity 56.7%… that was without the solar air heater operating.

As it happened, we were away again for the whole month of August on our latest trip. But this time we were able to leave the solar air heater turned on. Because it is set up on a thermostat, whenever the temperature inside the heater panel gets above 40degC the fan automatically switches on and blows warm air into the house. So, even though we weren’t there to operate the blinds or the vent fans, the house was still getting some added heat and fresh air.

The results speak for themselves. During this most recent August while we were away, the outdoor temperature averaged 8.7degC and the humidity 70.8% (almost identical to August 2015) however the indoor temperature averaged 16.2degC and the indoor humidity 47.4%. This means that the Solar Air Heater by itself raised our indoor air temperature by an average of about 2degC and reduced our indoor humidity level by about 10%.

Personally I think that’s a fantastic result.

Reader Responses to ‘Cattle, Good or Bad’

In last week’s Newsletter from the ranch in Montana I attempted to address a reader named Leon’s concerns about the harm that animal agriculture is doing to the global environment. During the last week I have received a number of responses including the following from Leon…

Hi Andy,

Thanks for taking it on-board, appreciated! My partner and I are both vegan, climate is only one part; cruelty, exploitation and our health are another part too. Here are some links:

Best wishes,


Also this from a reader named Doug

Hi Andy,
Thanks for another interesting Newsletter.
You’ve raised what can become a very heated debate by those who see domestic grazing animals as a huge cause of green house gases and those who defend the practice. A recent very thoughtful book on this issue  by an Australian farmer and academic, Charles Massy, called “The Call of the Reed Warbler” is worth reading before rushing to make too many judgements on this issue.
The experience and work of another author, Allan Savory, is also worth investigating. His work is also discussed in Charles Massy’s book.
Always look forward to reading your words and hope you get as much enjoyment setting your thoughts to paper as we readers do reading them.
All the best,

And this from Chris

All ruminants break down complex carbohydrates into fatty acids, then rebuild them into physiologically useful chemicals. It’s the rumen that does the heavy liting, digesting lignins and things that you and I cannot.
Other critters do it in different ways. Horses have a very large caecum – up to 6 feet of it and up to a foot in diameter. Much bigger than your appendix (if you still have one). But it seems less effective than the multi-stomach system of ruminants – consider how much fibre remains in horse faeces compared to bovine.
The breakdown of complex carbs is done by a myriad of bacteria, protozoa and aided by regurgitation and repeated cheweing (chewing the cud). And ruminants belch up the excessive gas, mainly methane.
I’m sure you’re aware of what happens if they can’t – they bloat.  Bloat occurs when the stomach outlet is underwater (cow lying on its side) or when the rumen content is a stable foam from which the methane cannot escape. The usual condition is a liquid in lower parts with a gas phase above. 
Most common cause is when cattle eat green clover.  Most common treatment is to inject a surfactant into the rumen to break down the foam. Or stab a hole in the left flank to let it out. Very messy.
Agvet companies, including SmithKline spent years trying to develop chemcials that would reduce methane production on the rumen. If it was retained in the biological system of the cow, it would be as energy and might be converted into fat, improving the feed conversion.  It was only modestly successful.
Clearly this is a tricky subject and I leave you to draw your own conclusions.

Oct 20, 2017: Cattle… Good or Bad?

Gathering cattle in Big Sky country.

Gathering cattle in Big Sky country.

I’ve spent the last week out at Sam’s grandfather’s ranch in Eastern Montana gathering the cattle in the Custer National Forest and bringing them down to the ranch in time to ship the calves to market tomorrow morning.

In last week’s Newsletter I mentioned that I was heading out here to do some cattle work and I received the following response from a reader named Leon.

‘Thanks for the on-going newsletters. Your mention of cattle got me thinking. Animal agriculture is responsible for about 15% of greenhouse gas emissions around the world, possibly more. Yet most “green” movements and environmental information makes no or very little mention of this. Why is it being ignored?’

This is a very good question and I can’t speak to the issue of why it is being ignored. However I do have some thoughts on the subject which I would like the share this week (interspersed with some photos from the ranch which I promised last week).

The gathering crew heading out in search of critters.

Most of our cattle work is still done on horse back, just like the old days.

I can’t vouch for Leon’s assertion that animal agriculture is responsible for 15% of global greenhouse gas emissions but it wouldn’t surprise me. What I would like to know (and don’t have time to research right now) is how are those emissions produced? How much is due to burning fossil fuels to produce the food that the animals are fed? How much is due to transportation of either the live animals or the meat, eggs, milk, etc that they produce? And how much is due to emissions from the animals themselves?

Without putting too fine a point on it, cattle produce a lot of methane (through burping and farting) but I recently read an article suggesting that feeding cattle a certain type of seaweed can dramatically reduce the amount of methane created. For those who don’t know, methane is a powerful greenhouse gas with something like nine times the potency of carbon dioxide, so reducing methane emissions is very important for reducing greenhouse gases.

A little snow started to fall as we began to gather the cattle.

A little snow started to fall as we began to gather the cattle.

I can’t prove this but my gut feeling is that the majority of greenhouse gas emissions created by animal agriculture comes from intensive, factory style ‘farming’ such as cattle feedlots, pig farms and chicken sheds. Not only do these super-intensive ‘farming’ situations create horrible conditions for the animals to live in, they also require massive inputs of processed food, chemicals, medications and energy.

By contrast, this ranch in Eastern Montana requires very little of those things. In fact, this part of the world has always had ruminant animals grazing and fertilising the grass. Before the invasion of white settlers the West was covered with huge herds of bison (which are closely related to beef cattle) and the environment has adapted to their presence. The photos above were taken on part of the Custer National Forest that the ranch leases for summer pasture. For decades the National Forest Service has conducted field studies on the effect of cattle on the health of the ecosystem and they have found that, when cattle are kept off the land, the ecosystem suffers and biodiversity declines.

Cutting out a pair of the neighbour's cattle.

Cutting out a pair of the neighbour’s cattle.

Unfortunately the bison were wiped out by the likes of Buffalo Bill Cody as part of the the government’s efforts to subdue the Native American tribes that used to belong on this land. This is a region of very low rainfall and hilly, rocky terrain. Most of this land cannot be used for growing crops or other forms of irrigated agriculture. It does however produce wonderful grass and beef cattle are a great way to harvest grass and turn it into high-grade food for humans.

So, on balance, I think raising cattle here is a good thing for the economy, the environment and for people.

The cattle safely delivered to the 3X Bar property (which, I just learned this week, was homesteaded by Buffalo Bill Cody)

The cattle safely delivered to the 3X Bar property (which, I just learned this week, was homesteaded by Buffalo Bill Cody)

Here at the ranch we eat local, grass-fed, natural beef that tastes delicious and does minimal harm to the environment. I think the problems associated with animal agriculture happen when beef cattle are taken away from grass land, crammed into feedlots and stuffed full of corn-based food and antibiotics. Unfortunately that is how the majority of beef in the US is raised and I agree with Leon, that this is a serious environmental problem. Not to mention the suffering that it causes to the animals themselves. And I think the situation is probably worse in the huge barns where pigs and chickens are fattened in the most in-humane conditions.

The last time I checked (which was a few years ago) most of Australia’s beef was raised in the country and fattened on grass which is a good thing. But cattle and sheep are not native to Australia and create other environmental concerns because the ecosystem has not evolved to cope with these types of animals. On the other hand there are plagues of every kind of imported animal right across Australia from rabbits to deer, horses, donkeys, camels, goats, pigs, water buffalo, foxes and cats. In fact the last two are probably the most serious problem. I just read an article last week that estimated that cats and foxes kill a million native birds and animals every night in Australia.

Back at the barn at the end of another long day.

Back at the (100 year-old) barn at the end of another long day.

It seems to me that the best thing we could do in Oz would be to start eating deer, horses, donkeys, camels, goats, pigs and water buffalo. All of these are eaten in other parts of the world and some are considered absolute delicacies. There are millions of these feral animals infesting the outback as well as our national parks and forests. Why not eat them and reduce both the pressure they put on our natural ecosystems and our demand for beef, pork, chicken and lamb which all carry varying degrees of carbon footprint and environmental problems?

171018 Shadow

Until those kinds of meat become available I can only suggest that the best thing you can do (if you plan to eat meat like I do) is to know where your meat (or eggs or milk) comes from. If it is locally raised and the animals are treated fairly then it is likely to be much better for you and for the planet.

Bon appetit and here are a few more photos from ranch.

Loading chute at the 3X Bar

Loading chute at the 3X Bar

Log barn at the 3X Bar

Log barn at the 3X Bar

Driving across Montana is always spectacular

Driving across Montana is always spectacular

Corrals at the 3X Bar

Corrals at the 3X Bar

Logs and Grass

Logs and Grass

Sunset at the ranch

Sunset at the ranch

Thanks for reading. By next Newsletter I’ll be back home at the Greeny Flat.


Oct 13, 2017: The Snow Shows Where the Heat Goes

A fresh dusting of snow shows where heat is escaping through the roof of this house in Missoula

A fresh dusting of snow shows where heat is escaping through the roof of this house in Missoula.

Greetings (for the last time on this trip) from Missoula, Montana where we woke up to find a fresh dusting of snow on the ground this morning. This will be just the first of many snow falls over the coming long, cold winter. There was one year while I lived here, we had the first snow in October and I didn’t see the grass in my back yard again until April. As you can imagine, good insulation and air sealing are essential for keeping a house comfortable and energy efficient through such an extreme winter. Roof insulation is especially important and a good way to gauge its effectiveness is to watch what happens to snow on the roof.

As you can see from the photo above, this house does not have a well-insulated attic. The snow has melted off most of the roof, except at the bottom and the sides where the eave extends out past the walls of the house. This is a clear indication that heat is being lost through the ceiling of the house into the attic and then from the attic to the outdoors. Apart from adding a lot of cost to the heating bills this can cause serious problems in a house like this. As the warm, moist air from inside the house escapes into the attic it can take with it a lot of water vapour that will condense when it finds the cold surface of the underside of the roof. I’ve seen some horrible mould problems in attics in Montana due to condensation problems.

Dammed Ice

Another issue that often happens with a roof like this is called ‘Ice Damming’. As the snow melts off the upper part of the roof it runs down towards the eave, hits the cold area near the bottom (where the snow hasn’t melted in the photo above) and freezes again. Over the course of a bad winter this ice can build up until it creates a dam that can cause water to run back under the roof shingles and into the attic, potentially causing serious mould, rot and water damage.

Thankfully we don’t have to deal with the worst of these issues in most parts of Australia. But, if you happen to live in a snowy area, it can tell you a lot about where heat is escaping. And, even if you don’t get snow, good insulation and air-sealing between the house and the attic, and good ventilation of the attic are very important for maintaining comfort, health, durability and energy efficiency. The following photo shows the house directly across the street from the first one. Clearly it has much better insulation, air sealing and attic ventilation as the snow hasn’t melted off the roof at all.

No snow melt on a house with good insulation and ventilation in the attic

The Halloween decorations aren’t nearly as scary as the roof of the house across the street

My son Sam’s house (the one I’ve been hard at work renovating for the last couple of months) used to have problems with snow melt and ice damming. This was hardly surprising when I saw the state of things in his attic. Unfortunately all of the ducting from his gas-powered, forced-air central heating system runs through the attic. Ducts in attics are a bad idea at the best of times, even when they are properly sealed and insulated they still lose a lot of heat to the attic. In Australia the problem is the opposite with heat gain due to air conditioning ducts running though poorly ventilated and scorching hot attics (often sitting directly under a dark tile roof that soaks up a huge amount of heat from our hot summer sun) but just as big of an issue.

Ducts in Attics are a BAD IDEA!

Ideally all duct work should be inside the ‘Thermal Boundary‘ of the building (the insulation and air-sealing layer that surrounds the ‘Conditioned Space’). But if the attic (or uninsulated crawl space) is the only possible place to run the ducts, then it is essential they are tightly sealed and well-insulated.

This duct boot has become disconnected and is leaking hot air into the attic

This duct boot has become disconnected and is leaking hot air into the attic

Unfortunately, as you can see from the photo above, this was not the case in Sam’s attic. All of the ductwork was uninsulated and poorly sealed. In fact I found three places where ducts had become completely disconnected and were letting tons of heat escape into the attic. I would guess that a quarter of Sam’s winter heating bill was being lost through duct leakage to the attic.

So I’ve spent the last week crawling around inspecting, sealing and insulating all of the duct work. In the case shown above I reconnected the duct then sprayed foam around where it connects to the ceiling of the house. Then I sealed all of the joints with a special duct sealing compound before wrapping all of the ducts with insulation.

Sealing the joints in the ducts with a special paint-on compound

Sealing the joints in the ducts with a special paint-on compound

I also added vents in the gables of the roof, built a dam around the access hatch (to stop the cellulose insulation from falling on your head when you open the hatch) and built a catwalk (above the eventual height of the insulation) from the access hatch all the way to the far ends of the attic. This is so that, in future, when anyone needs to inspect the attic or do electric or duct work, they can access the whole attic without disturbing the insulation.

Now all that’s left to do is to get our friendly insulation contractor to come and blow more cellulose into the attic. I spoke to him this morning and, with winter approaching, he’s so busy that the only day he can come is the day I fly out to return home. So I’ll be meeting him early in the morning to get him going then I’ll have to leave him to it. But I’ll leave happy in the knowledge that Sam’s house will be much more comfortable, healthy and energy efficient this winter.

Tomorrow Sam and I are heading back out to his family’s ranch to help bring all the cattle down from the forest to the meadows along the creek bottom near the homestead where they will spend the winter being fed all the hay that Sam’s uncle worked so hard to put up over the summer. It should be absolutely beautiful at the ranch at this time of year and I’ll try to post some photos next week.

Sept 6, 2017: Tesla Tiny House coming to Bowral

The Tesla Tiny House is touring Australia towed by a Tesla Model-X

The Tesla Tiny House is touring Australia towed by a Tesla Model-X

Readers in Australia may have heard of the ‘Tesla Tiny House’ which is currently doing a tour of capital cities around the country to showcase Tesla’s home energy storage systems and, of course, the Model-X SUV that is pulling it. The good news (for those who live near the Greeny Flat) is, thanks to local solar-storage company Simmark, the Tiny House is coming to Bowral’s Bradman Oval on November 22nd.

I wrote about Simmark (and their admirable philosophy of understanding their customer’s energy requirements in order to find ways to conserve energy before installing solar on their roof) in our Newsletter on May 4th, 2017. I applaud their initiative in bringing the Tiny House to our area and I’m particularly happy to know it’s coming after I return from Montana so I’ll be able to attend. I hope to see you there. Here’s a bit more information about the tour (sorry some of it is a bit out of date) from a Gizmodo article dated August 14.

Beginning in Melbourne’s Federation Square today and tomorrow (August 14 and 15), there’s a tiny Tesla house making the rounds of the country – showing off the Powerwall and educating the public on how to generate, store and use renewable energy for your home.

Oh, and the tiny home is towed by a Tesla Model X, because of course it is.

The tiny home is completely powered by renewable energy courtesy of a 2kw solar power system and a Powerwall. Inside, there’s a design studio and configurator so you can calculate your own home’s needs. There will be Tesla staff on hand to answer questions, too.

For readers not from the Southern Highlands of NSW the following are some of the other stops on the tour and you can visit the Tesla Tiny House Website for the latest locations or to request that it comes to your community. The confirmed portion of the tour includes Federation Square 14-15 August, Melbourne Home Show at Melbourne Convention and Exhibition Centre 17-20 August, Eco-Living Fair at Randwick Community Centre in NSW 3 September, Brisbane Home Show at Brisbane Convention and Exhibition Centre 8 – 10 September, Rundle Mall in South Australia 20 September – 2 October, Sustainability Lane at Lane Cove Shopping Centre in NSW 8 October and Sydney Home Show at Sydney Showground, Sydney Olympic Park on 27 – 29 October.

Simmark’s Response to Last Week’s Newsletter

In last week’s Newsletter I suggested that anyone considering installing a solar system on their home who is primarily motivated by environmental concerns should think seriously about what they do with the STC ‘rebate’ they get off the price of the system. These STC’s are sold to big polluters to allow them to ‘offset’ their GHG emissions. So, if you’re installing solar to reduce your own emissions, you might not want to sell the rights to those emissions to a big industrial polluter.

In order to get a second opinion about this I emailed Mark Horsfall, co-owner of Simmark, to see what he thought. The following is his response.

Not sure I am 100% with you on that one mate. The system is a reality. Boycotting it is unlikely to hurt the polluters or accelerate their demise. Take it to the extreme. Let’s say almost everybody refused to sell their STCs. All that would do is reduce supply and drive up the price, rewarding the few who do monetise. The polluters are just going to pass on the higher cost to the grid so they don’t really care. Furthermore, if a stigma or distaste associated with selling your STCs develops, that is likely to slow down solar adoption as the STC component is still 20-30% of a system’s gross value, making the subsidy an integral part of the investment decision for most people. I think STCs and the 15 year phase out are a rare example of good environmental public policy. I actually think the Federal government should do much more to reward home efficiency. I also think there should be a program to support/backstop the financing of solar/storage investment at the residential level for homeowners of limited means, much like HECS debt for tertiary education. Too often, solar and especially batteries are a wealthy person’s luxury and that’s wrong. 

So, as you can see, Mark approves of the STC system which, as he points out, is due to be phased out in stages over the next 15 years. I guess my point was not to boycott the system on a large scale. Most people installing solar are not motivated purely by environmental altruism but, if you are one of those few, I still suggest you give thought to the STC’s and what they mean for your hopes of reducing your own carbon emissions.

If you want to discuss any of this with me or with Mark, we’ll both be at Bradman Oval on the 22nd of November for the Tesla Tiny House event.

How Much Solar Do You Need To Charge an Electric Car?

Whether you already have a solar system or are thinking about installing one, another factor to consider is the coming revolution in electric vehicles. You may well want to make sure that you have enough solar (or at least enough roof space for it) to be able to charge one or two EV’s.

Our PHEV outside the Greeny Flat and charging from the solar system on our garage.

Our PHEV outside the Greeny Flat and charging from the solar system on our garage.

We have 3kW of solar on our garage roof which is enough to run our house and to charge our PHEV for most of my local driving. But if you want more detailed information, here is a link to a very thorough article from Solar Quotes on how much solar it takes to charge an EV. In short, depending on where you are in the country and how much you drive, you will probably need about 2kW of solar for each EV.

Sept 29, 2017: Home Solar and Double-dipping on Carbon Emissions

I’ll be in Montana for another month and we’re making some good progress on Sam’s house. This week we’ve started painting the outside with some warm colours that should help make it feel cozy through a long Montana winter.

This is how Sam's house looked yesterday

This is how Sam’s house looked yesterday

In a couple of weeks we’ll be heading back out to Sam’s family ranch in Eastern Montana to help with bringing the cattle down from the Custer National Forest and shipping the calves. I’m looking forward to lots of riding and beautiful fall weather. Montana can be truly spectacular at this time of year.

While I’m over here I’m also trying to stay in touch with what’s happening in Australia. A few days ago I read this Energy Matters article about how the recent drop in the price of STC’s (Small-scale Technology Credits) might lead to higher prices for home solar systems. STC’s are the ‘rebate’ your installer gets when they install a solar system on your roof which effectively reduces the cost of the solar system for you. According to the article, there was so much rooftop solar installed in the first half of 2017 it caused an oversupply of STC’s which, in turn, led to a 25% drop in the price of STC. This means that your installer gets less of a ‘rebate’ and will, most likely, have to pass on the extra cost to you, the homeowner. While this is probably not welcome news, there is a bigger issue with STC’s that I think we should all be aware of.

STC’s Are Sold to Polluters to ‘Offset’ Their Emissions

Under Australia’s ‘Renewable Energy Target’ there are two schemes for reducing greenhouse gas emissions. One is called the Large-scale Renewable Energy Target and the other is the Small-scale Renewable Energy Scheme.

Under the Renewable Energy Target a variety of individuals, businesses and industry groups interact with the schemes, including:

  • individuals and business who voluntarily invest in small-scale and large-scale renewable energy systems, generate renewable energy, or actively lower their consumption of main grid electricity, and
  • industry groups who are required by law to surrender large-scale generation certificates and small-scale technology certificates to offset the generation of emissions intensive energy, and meet scheme compliance obligations.

The key point to note here is the last sentence, industry groups (i.e. big polluters) are required by law to surrender both LGC’s and STC’s to offset the generation of emissions intensive energy. This means that if you as a homeowner installing a small solar system, sell the STC’s (or give them to your installer in return for a cheaper price which is usually the case) you are basically selling the emissions reductions that your system creates.

So, if you are installing solar for environmental reasons, the responsible thing to do is to pay the extra cost for your solar system, keep the STC’s and surrender them to the Clean Energy Regulator. Otherwise you cannot claim to be reducing your carbon footprint. This would be double-dipping because, if you gave away your STC’s, someone big polluter somewhere will be using them to claim a greenhouse gas emission reduction.

And let me be the first to say that I am guilty of this myself because I didn’t fully understand the system. When we installed the solar system on the Greeny Flat, we allowed the installer to keep the STC’s which he no doubt sold to some big polluter. Until recently it didn’t occur to me that I was giving away any claim to the emissions reductions.

If you’re reasons for installing solar are purely financial or you’re just wanting more independence from the electricity retailers then, by all means, use the STC’s to reduce the cost of your system. But if your motivation is primarily environmental then I suggest you give serious thought to how you deal with the STC issue.