Tuesday, September 19, 2017

What is the right way to save the world?

Myself when young did eagerly frequent
Doctor and Saint, and heard great Argument
About it and about: but evermore
Came out by the same Door as in I went.
      from The Rubaiyat of Omar Khayyam

Many people recognise that we have an ecological problem. Unfortunately for all of us, a lot of those people don’t do much to try to reduce their personal impact, instead limiting their actions to mouthing platitudes.

I have written extensively about this on this blog, and I have commented on the limitations of using economic incentives to encourage people away from engaging in carbon-emitting activities (I see this as a problem, because the most wealthy people, who have already emitted the most carbon, are those least affected by such economic costs). In other words, we need to work hard to ensure that a carbon tax is not a regressive tax. (I think the Australian Labor Party achieved this under Gillard, and that it’s a damn shame their law was repealed).

What I want to focus on here then, is the group of people who know that something needs to be done, and are prepared to make personal changes to help make it happen. I have the most respect for this group of people, because I think taking collective ownership of the problem is the only way to tackle it.

And it is a big problem. Dennis Meadows (one of the original members of the Club of Rome), in a recent interview, said that climate change is not the problem, it is the symptom, and that the problem is over-consumption (too many people, consuming too much). He said that if we can somehow “fix” climate change, but keep everything else the same, and continue growing then we’ll just encounter another symptom (eg. soil loss, ecological collapse, etc). I think this is a compelling argument.

But, as concerned citizens who want to do something active to help reduce our contribution to this problem, what should we do? Clearly over the next century or so, human life will be massively reorganised and entirely new ways of living will need to be invented. But how do we get there?

Should we stay in the city, where we remain largely reliant on industrial food/resource provisioning, where our ability to tap into natural energy flows is limited, where our ability to dispose of wastes is limited by local regulations, where houses and land are more expensive — requiring greater participation in the money economy? The benefits of doing this are that resources and knowledge can be more easily shared, and transport can be more active (less car travel). These are real and large benefits.

Alternatively, should we move to self-sufficient properties and create an independent lifestyle? In doing that we have more space and potentially more money (because land is cheaper in remote locations) so using fuel such as firewood is more feasible, and food production can be much less intensive. There is also less regulation, so more freedom to establish unconventional systems (eg. composting toilets), and opportunities to reestablish native bush. These are clear benefits, but the cost is expensive transport, and provisioning of services, both of which have environmental consequences.

Here are two big choices, but there are successively finer-grained choices all the way down.

Should we pursue a low impact, but low money lifestyle (the frugality approach), value conservation, but not invest particularly in renewable technologies?
Alternatively, should we pursue a high tech approach, investing heavily in renewables and/or batteries?
Should we invest in electric vehicles or try to minimise car use? Should we use taxis? Bicycles? Public transport on diesel buses?
Should we eat meat? Processed food? What about dairy? What about bought alcohol?
Should we buy computers? Phones? Paint? What’s worse — using petrol in an old car or electricity in a new one? Is it better to drive further to buy organic food or to buy non-organic food from the little old lady on the side of the road?

Given the greater efficiencies of collective infrastructure, is it better to focus on improving policy than personal investment (eg. is the embodied energy in rainwater tanks, batteries, cars better put towards shared infrastructure such as dams, grid-batteries or public transport?)

Clearly, when asking these questions, we need to look not only at the now, but how things might evolve as time passes. What effects will technology have? How will politics change? What about economic or demographic factors?

None of these questions have simple answers, and I believe that there is that there is no correct approach. There is no unified “green movement”, but I’m concerned that greenies are becoming divided into subgroups, each of which is firming its orthodoxy into, in some cases, dogma. This makes it harder for separate groups to work together, but it also makes it harder for individuals to explore new ideas and approaches to doing things.

We are likely to have more success, as a disparate group of people whose goal is to achieve something about ecological overshoot, if we are tolerant of different approaches and philosophies. We will work more cohesively as a group, but we will also be able to explore more ideas.

Western countries in 2117 will look very different to today. Many aspects of society will need to be reinvented to cope with ecological overshoot and resource scarcity (not to mention technological, geopolitical, economic and demographic change). We will need all the ideas we can get if we are to achieve this, and we can’t afford to dismiss any without consideration.

Monday, June 26, 2017

Council deputation

Below is a deputation I made to Unley Council on Monday, 26 June

Good evening Councillors,

I am Dr Angus Wallace, and I am here as a representative of the Unley Bicycle Users Group. I wish to speak briefly to you, regarding the Rugby/Porter bikeway, given the report in the Eastern Courier about the priority for cycle commuters being reconsidered.

Cycling has many benefits. The chief benefit is health. Cycle-commuters are 46% less likely to die of any cause than otherwise-similar people who do not cycle-commute. That is an incredible statistic, and shows the power of “incidental exercise” to make our population healthier. The other clear benefit is, or course, cost. Cycling is at least an order of magnitude cheap that car travel -- money that can be spent in the local economy. Cycling is also more convenient -- the increased density that bicycles afford means that even narrow paths can carry many people. Also, cycling is often pleasant and fun, social, communitarian and spontaneous in a way that driving in a car never can be.

Unley Council has been one of Adelaide’s far-sighted councils in encouraging cycling. Truely, you have made great strides in the last decade, and the City of Unley has reaped the rewards — quieter suburban streets, more usable spaces for children, more money being spent locally, better health of the population. And of course, the tourism that events like the Tour Down Under brings.

But we can go much further.

There is much untapped potential, and it is excellent that Unley Council recognises this. The decision to build the Rugby/Porter bikeway will be seen, in years to come, as a watershed moment, though not the only one. Right now, 500 people commute along the Rugby/Porter bikeway at each end of the day. Unley Road carries 30000, making that 500 people sound like not much. But, it is important to remember that traffic congestion is non-linear. A few extra cars make a very big difference. Who notices how much worse their driving commute is on a rainy day, when some cyclists drive instead? It is significant. But, if the Porter St bikeway was a genuine arterial cycleway, we could, in a few years, take 1000 cars OFF Unley Road, getting those motorists on their bikes instead. Imagine the effect that would have on commuting times.
For example, reflect on the proposed Adelaide Botanic High School. The school will be serviced by the Frome St bikeway, which connects to the Rugby/Porter bikeway. Empowering students to cycle to this new school frees their parents from the burden of driving them. This decreases traffic congestion and increases our productivity. I believe there is broad community support for such works.

But, for this to happen, it is imperative that an arterial cycleway has priority. It needs priority like Fisher St has over its side streets. No one would dream of giving a small cul-de-sac priority over Fisher St. This is not about safety — it is a simple, utilitarian question of the greater good. Roads with more traffic have priority over roads with less – whether the vehicles are cars or bicycles. Also, we must remember that the status quo is inherently dangerous. Commuter cyclists on Unley Rd are sharing a contested space: there are obstacles to navigate, buses and trucks. Every car passing a cyclist will be slowed by the cyclist, and every such passing is an opportunity for error. Providing a dedicated, connected, arterial cycleway is the only way to increase the safety of these cyclists, and to increase the uptake of cycling..

Unley Council’s leadership in the promotion of cycling has had great benefits already. We are on the cusp of realising yet more benefits. All that is needed is to provide the space, and the cyclists will come — decreasing demand on our over-crowded roads — increasing safety, health, our sense of community and the local economy. To allow this, dedicated arterial cycleways are needed, and they need to have appropriate priority over side streets.

Saturday, January 14, 2017

Where are you now?

Back in the mid-1990s, I was sitting in the back row of my English class, in perhaps the most un-disadvantaged non-private school in the state. A school with a catchment so that not just anyone could send their children there. Where the wealthy (but egalitarian) and upwardly-mobile bought expensive houses to send their children to an elite public school subsidised by the less-well-off.

But, being a public school, there were no fees, and anyone who lived in the catchment could send their children there. Because there were plenty of rental properties, and as-yet un-gentrified pockets of houses, the students attending the school were more diverse than the equivalent pool in one of the nearby private schools. This diversity manifested as a general reluctance, on the part of the student body, to conform to the wishes of the school administration (whether it was uniform, attendance, homework, drugs, you name it).

Next to me, in the back row of class, was a girl I thought was pretty good. Sitting there, the English class passed me by. Perhaps I had reached an age where I could consider her sexy, instead of merely attractive. I never really knew what her thoughts were – she was very intelligent: maybe the smartest kid in class – and had a bit of a detached air that I liked and was a little intimidated by. Whether it was wishful thinking, or actual encouragement, I felt like we were a something.

This went on for some time, I can’t remember now. English class was a bit of a blur for me at that point. One day, I remember her laying her head in my lap and looking up at me – her eyes alive with intelligence, humour and irony.

But all things come to an end, and we drifted apart (from whatever it was that we were when un-apart). It occurred to me at some point that if I wanted to go to university, I might actually need to do some work (that, and I really liked English as a subject), or maybe she just got tired of my juvenile attempts at wit and insight.

By and by, school came to a close. I learnt some hard lessons about overindulgence in alcohol. Others were exploring other possibilities, maybe she was one of those. Either way, I didn’t have much to do with her after our brief and platonic affair.

When school finished, I saw her once or twice by chance, but essentially never spoke to her again. I’ve often wondered about her over the years. I always knew she was smarter than me, but felt that she had somewhat squandered her final school years. I also believed that for smart people there remained options – that she could make something of her life (whatever that meant to her). I now wonder what might have happened if I’d had a bit more guts – hadn’t been so perversely shy of self-exposure. Perhaps it would have only taken a nudge, at that point, to make all the difference – like the shoe that was lost for the want of a nail.

I never did find out what she was doing or how she felt about it.

This year is the 20th anniversary of my cohort finishing school and she was one of the people I particularly wanted to see – to hear about her tussles with life, and how she’d coped with some of the bitter lessons that adulthood brings. But I now know that conversation can never take place because she killed herself a few months ago and that door is closed.

All this time, she remained (I am sure) a friend of a friend of a friend. I could have contacted her, but never did. It probably would not have helped anyway to see this long-lost-forgotten person from school settled into some comfortable stereotype of middle-class suburbia.

I can only imagine, but not know, what feelings drove her to it. A rapid shutter-fire of thought-feelings flitted through me -
An emptiness of unknown, unappreciated and unrecorded days. Of drabness and aloneness (even in the presence of others), then
That my inaction could have led to this, then
The ridiculousness of that thought, then
What it must have felt like, standing there at that final moment, then
That such thoughts are but easy stereotypes, fettering the mind from the complexity of real life, then
There must have been some kind of moral miasma, long fermenting, to lead to such a strait, then
That despite the finality of death, her life must have contained many pleasures, then
Sadness that I never attempted connection to realise any such pleasures, then
A re-kindling of an echo of a crush on the now-dead, then
That the collective mind-image we, who knew her, hold, is now all that remains -- tethering her to the world. A tether that time and our own mortality will eventually sever.

Monday, December 12, 2016

Ahh... driving

What could be more normal than getting in the car and driving somewhere?

Driving is such a normalised activity. Almost everyone I know does it -- people that don't drive are a bit strange, and their options are greatly constrained.

I love a road trip. When we moved from Brisbane back (home) to Adelaide, we took 5 weeks to drive home along the coast, which we followed from Brisbane to Melbourne. It was a fantastic trip.

It's so easy to get in the car and watch the world rush by. It's also easy to forget just how much energy is being used in that process. Here's an example:
We recently went to visit Monarto Zoo which is (the only?) open range zoo in Australia and is about 65 km from my house. It's an easy drive, about 40 minutes up the freeway. Google Maps estimates it as a 4 hour bicycle trip (I'm presuming that is without kids)
So the round trip is about 130 km. Our car uses about 8 L per 100km on the open road, so that works out to about 10.4 L of petrol, which is about 100 kWh (each liter of petrol has about 10 kWh of energy). For us, that is a month's worth of energy (as consumed by our house of four people) used in 1h:20m of travel.

Faced with these numbers, it is clear just how much of a problem driving is for our carbon emissions, and how easy we make our lives elsewhere if we can just drive less. If we want to avoid damaging climate change, we simply need to drive less, and this will make our other goals (eg. renewable electricity, reduced consumption, more sustainable agriculture, etc) that much more achievable.

Wednesday, October 12, 2016

End of winter recap

Now that winter is over, how have we done?


My last post about my solar systems' performance has made me think a bit more about their performance, so I've done some analysis.

I have taken some meter readings over winter, which gives me
  • solar PV production over winter
  • grid draw over the same period
  • grid export over the same period
This gives these data (for the period June 1st to October 6th):
average total daily consumption (PV self consumption and grid-draw): 6.26 kWh
average Daily PV production: 6.13 kWh
average daily grid draw over winter: 3.9 kWh
average daily grid export over winter:  3.7 kWh

The same calculations for the period June 1st to August 2nd look like this:
average total daily consumption (PV self consumption and grid-draw): 6.29 kWh
average Daily PV production: 4.67 kWh
average daily grid draw over winter: 3.91 kWh
average daily grid export over winter:  2.66 kWh
 We tend to cook more with the electric oven in winter, which I think largely explains the higher daily consumption. Also, we use lights more, etc. We needed to boost the solar hot water system once, for about an hour, which used about 2.4 kWh.
Overall, I am fairly happy with these numbers. I think we're losing at least 0.5 kWh/day to phantom loads, but there's only so much energy I have for turning things off at the power point. Clearly, for our PV to cover our consumption in winter, we need ~50% more panels.

Propagation area

I've been busy building a spot for seed propagation. Seeds need constant moisture, and the requirement that we keep them moist for several weeks was just too much for us (forget to water them for a day and they're dead). I built this bench using almost 100% found or scrounged materials. Even the nails and bolts were mostly reused. It's also amazing what you can build with poly pipe and clothesline! It has a watering system that waters it for 1 minute every 6 hours. Bonza!

tomatoes and beetroot and basil, oh my!

does your propagation table have turned legs? ;-)

Composting loo

Now that we've had the last rain until about March (well, we can't expect much!) I'm again feeling unhappy about putting potable water down the toilet. I've started building a box composting toilet. It's designed to hold a 20 L plastic bucket and a urine diverter. It's made from pallet wood (and pallet nails), with a few bits of nice timber I found on an old air-conditioner facade that I found on the side of the road (they made them attractive in the old days!). Not quite finished, but getting there. As I said in a previous post, I'm using this device as a urine diverter, and they have some plans online for how to make the toilet. I am vaguely following those.

It is spring, and the garden is blooming. Here are some photos from the garden:
New citrus grove (sorry for the dark photo)

Broad beans

Monday, October 10, 2016

2 years on: System performance

We've now had our solar hot water and solar PV system for 2 years. I thought it was worth commenting on them.

Solar Hot water (main)

This system is detailed here and here. Based on my meter readings, I estimate it has saved us 4500 kWh (just over 6 kWh/day), which is worth $1350 on the standard tariff (we avoid the off-peak tariff because it supports fossil fuel power, even when buying Greenpower) At this rate, the system will pay for itself in about another 18-24 months (4 years total from new).

The tank looks a little weathered, but still in very good shape. Beacuse  it is low pressured, I am confident it will last many years. I partially shade the panels (with an old cotton blind) in summer, to stop it boiling, and we lose very little water from it.

Kitchen Hot water

This system performs poorly in winter. It's nice to have instant hot water, and it was a good learning project, but I wouldn't recommend people do this if they have other solar hot water. At some point I might re-purpose this system into a backyard shower.

Solar PV

Our system has produced almost 10 MWh. Since we got the new input/output meter we've exported about 7 MWh to the grid (which means we've self-consumed 3 MWh of our solar PV). We get paid $0.24 / kWh for exported power and pay $0.32 / kWh (including the GreenPower premium) for imported power. So, the return on our solar PV has been $2600, or about 1/2 the cost of the system.
As of the end of September, we lose the $0.24 feed-in-tariff, and will be paid about $0.08 / kWh. That will reduce the return on the system cost. In another 2 years, we'll have got back an additional $1500 at these tariffs. I think we'll pay back the cost of the system in about 3 years (5 years total from new).


Our 2 kW solar PV system has produced more electricity than we use almost every day (about 50 exceptions in two years) since it was installed. I've shown the economics here, because that's of interest to some people, but it's a great feeling to look at the roof and see the power we harvest. It's strange how people carefully consider at the economics of solar PV, but not of cars.
At some point, I think we'll install a hybrid battery system. I like the idea of self-consuming more of our power. But I don't think we'll try to go fully off-grid. I think that doesn't make sense in the city (firstly, we'd need a much larger battery to provide for the small number of days when we lack solar PV and secondly it has a bit of a gated-community feel to it). I might also install a second solar PV system. That will have much worse payback than the first, but that's ok.

Wednesday, September 21, 2016

A heater battery

I've been thinking about home temperature management, and the problem as I see it is:
  • We have a huge supply of existing housing stock, with limited options and money for retrofitting improvements
  • People are unlikely to be satisfied with a 13°C house in winter and a 33°C house in summer
  • As we move to a more renewables-based energy grid, the importance of storing energy increases
  • heating/cooling is, for most people, the largest energy user
  • I believe that the burning of firewood in the city should be minimised
  • If we want to use batteries to supply electricity for heating/cooling, we will need an enormous supply, which will be very expensive (in terms of money and energy) putting it out of reach for most people.
So, we need a heating solution that is
  • Relatively cheap
  • Able to store a large amount of energy during times of plenty – I think in winter it needs to store 4 days' heat (during summer, it really only needs 1 or 2 days as solar PV is very productive)
  • Suitable for retrofitting
 I think I have come up with a possible solution.

Heater-cooler design

In Europe, it is possible to buy a storage heater. It is designed to run on off-peak electricity, which it uses to resistively heat a “bank” of iron “bricks” to about 700°C. Then, during the day when heat is wanted, it blows air over the bricks to warm the room.
My idea is a variant of this, except it uses phase change materials to store heat and “coolth” (the ability to cool air).

Phase change materials (PCMs)

You are familiar with phase change materials if you have ever put ice in a cool box. Ice keeps your food cold not (just) because it is cold, but because ice absorbs a lot of heat as it melts. To put it another way, to it takes a lot of heat to turn ice at 0°C to water at 0°C. If you add the same amount of heat again to the 0°C water, you will raise its temperature to 80°C.

My design uses this principle to store large amounts of heat and coolth.

It uses a PCM that melts at about 30°C. This is encased in small containers (eg. 1L soft-drink bottles) with a large surface area, within a tank of water surrounded by insulation.


In winter, heat is put into the tank, which melts the PCM. Because the maximum temperature of the tank only reaches about 50 – 80°C, there are more options for heating it. Instead of using a resistive heater (such as used in the European storage heater) we can use a bank of evacuated tubes or heat pump and get either free heat, or 4 kWh of heat for every 1 kWh of electricity (it might even be possible to use a roof-top solar pool heater). This melts the PCM and stores the heat. Later, when the building occupants want to warm the room, a small fan blows room air over the heated tank and warms the room air.


In summer, a heat pump can be used to pump heat out of the tank. This can freeze the PCM first (at 30°C), and then the water surrounding it (at 0°C). This stores “coolth” and in the evening when people come home from work, they can use the tank to cool the air in the room.


I have done some analysis and modelling in a spreadsheet that can be found here.
I have modelled the heater’s performance under various design considerations. At the moment, here is what I have settled on:
  • Heat/coolth storage volume: 350 L (total size: 1.2 x 0.9 x 0.5 m, allowing for 50mm of insulation all the way around)
  • Volume of hot-melt PCM: 250 L
  • Volume of water: 100 L
This design gives the following (theoretical) performance:
Heat storage (for use in winter): 31.8 kWh equivalent
Coolth storage (for use in summer): 12.5 kWh equivalent (I’ve deliberately designed it with less coolth storage, because solar PV is abundant most days in summer, but it could be adjusted. This also assumes that the heat pump can efficiently freeze the water.)


If the home occupant has solar PV and a reverse cycle system anyway, and if the marginal extra cost of my system is $1500 (my unit would replace the internal component of the split system), then even if the installation cost of an equivalent-performance battery system reduces to about $5000 (about ½ current prices) then my system is about 25% cheaper (this calculation is on the basis of heat/coolth delivered, and considers that it won’t be used in spring/autumn. It allocates batteries as having more value, but only at the same rate as heat/coolth – ie. when my heater is unused). In other words: if the price of batteries halves, my heater is still 25% cheaper.
Despite this, I doubt that this can be successfully produced as a commercial product, for the following reasons:
  • It’s a one trick pony – it can’t store energy for general use, only for heating cooling. Batteries store electricity, which is more generally useful. Batteries also have a lot of “public mindshare” and will be hard to compete against
  • The cost of the PCM is significant. To be sold for $1500, it would need to be made for 1/2 that, which I don’t think is possible. I think a bespoke heater could be made for $1500, but that would be using “scrounged” parts wherever possible, since the retail cost of PCM would be about $1500.
Despite this, I think my system has some real advantages over using batteries to power heating/cooling:
  • Its embodied-energy is very low in comparison with batteries
  • It can be expected to have a very long useful life and is repairable (the only moving part is a fan which is replaceable). I could imagine a unit lasting for decades if well-made.
  • It is (relatively) easy to integrate with evacuated tubes to collect extra heat in winter


Most Australian houses have poor thermal performance. This device allows one to store heat/coolth that can be released when it is wanted. Because there are low temperature gradients (the internal temperature range in the device might not go outside -4 to 40°C) it should be easy to insulate. It is a cheap and easy retrofit (compared with improving the building envelope) that allows people to store large amount of heat/coolth to use as they please and is inherently compatible with renewable energy systems.

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