Toward a more sustainable world

Google search Ramblings



This is a time of change

This page was written in 2002. While I have edited it to some extent, many of my original thoughts from 2002 remain. Much has changed since then. I paid far more in 2006 to install 1kW of solar power than I did to install another 5.2kW in 2014. The cost of wind and solar power is continually dropping. The cost of storing power in a battery for a household was prohibitive in 2002, in 2020 it is worth considering.
There is a consensus among most well informed people that many aspects of the Western lifestyle are not sustainable. Our way of life is largely powered by the burning of fossil fuels, the rate of production of greenhouse gasses is much greater than the natural processes of the Earth can remove, we are consuming mineral resources at a rate which will leave our grandchildren with little, our soils are being damaged by erosion, salinisation and contamination, we are poisoning our oceans with plastics, we are over-exploiting our rivers and our groundwater, we are creating mountains of refuse that we should be reusing, we are causing the extinction of species at an almost unprecedented rate; the list goes on.

The Fukushima melt-down of March 2011 has shown that nuclear power still has safety problems and will make nuclear energy less acceptable to the world's people than it was before this event.
Yet while many of us recognise this problem, how many are modifying their lifestyle, or at least a part of their lifestyle, to have some chance of its being sustainable?

In what follows, I have tried to state facts, pose questions, and in some cases, provide answers. There is no attempt here to cover all the ground; that's too big a job. I've written on subjects that people might be interested in, or those where I felt I might be able to make a contribution. I am very ready, and very happy, to hear and consider opinions, dissenting ones included.

Created 2002/09/01, last edited 2020/10/18
Contact: David K. Clarke – ©

What can we do?

Many other suggestions of what can and should be done to reduce our greenhouse impact are given elsewhere on my site.
What can we, as individuals, do to make the world a more sustainable place? There are many things:
  1. Drive a smaller car or drive a little more slowly, minimise your driving, walk or ride a bike some of the time, use public transport if you can;
  2. At home, think about the energy you are using. Do you really need to run the second fridge or freezer all the time? Consider switching off your water heater if you are going away for a few days, perhaps empty your freezer and switch that off if you are going on holiday;
  3. Insulate your house;
  4. Can you install a solar PV system?
  5. Use heating sensibly: do you really need to heat your whole house? Perhaps you could just heat the kitchen in the day time and the lounge room in the evening? Do you need your house so warm in winter or so cool in summer? Sometimes it might be more efficient to use a little bar heater to warm yourself rather than trying to warm the whole of the room that you are in. Also see my page on greenhouse responsible heating
  6. Try to minimise the amount of rubbish you produce. Take cloth bags to the super markets rather than using plastic bags once and throwing them away. Re-use bottles and jars; perhaps brew your own beer rather than buying it in use-once-and-throw-away bottles.
I'll write at a little more length about some ways we can make changes below.

Green electricity

In most (all?) Australian states it is now possible to buy 'green' electricity. When you pay a little extra for green electricity the money goes to the distributor so that they can buy electricity from sustainable sources: wind generated power, hydro power, solar power, etc.

It doesn't cost much more than ordinary power, because a large part of our power bills is the supply charge anyway, but it must make a difference in reducing greenhouse gas production.

Solar water heating

It's not necessary for me to write much about it here. I'll just say that I've used it for about 40 years, it must have saved me a lot of money as well as the reduced greenhouse gas production.

I've written a little more on solar water heating on another page.

Wood fired heating

Homes can be heated by wood fires rather than by burning fossil fuels.

In Australia most electricity is produced by burning fossil fuels. So electrically powered heating, whether by reverse cycle air conditioners or by simple radiators, is largely heating by burning fossil fuels (unless you buy green electricity or produce your own power with solar panels). However, reverse cycle air conditioners should give you more heat per kilogram of carbon dioxide produced.

In the cooler part of the year, water too can usefully be heated by burning firewood. See wood-fired water heaters.

Chopping firewood for the stove will also give you some exercise, which most of us need. There is also an interrelationship between firewood, overpopulation, greenhouse and air pollution that you might consider.

Keep your car longer


Update, 2017

Consider replacing your fossil fuel powered car with an electric car and running the electric car on solar power.
Alternatively consider driving a smaller car; and walk, ride a bike or use public transport rather than using a car whenever you can.

People are sometimes told that if they want to be greenhouse friendly they should get rid of their old, inefficient, polluting, car and buy a new one. There is much validity in this, so long as the car you replace the old one with is significantly more fuel-efficient than the old one.

But what also must be considered is the balance between the amount of additional pollution that might be produced by running an old car compared to the huge waste of material involved in scrapping the old car and replacing it with a new one. There is not a lot of recycling of material from old cars. They might sit around in a wrecker's yard for a few years, then after a few parts have been taken to keep other peoples' old cars going, they will be crushed and melted down for the steel that's in them.

If the engine in an old car runs well it should produce little more pollution than a new car. (It does depend a bit on what sort of pollution we are talking about.)

I have a car that has done 330 000 km and was still going strong when I retired it a couple of years ago; although it was getting draughty and the heater no longer worked. A friend has a car that has done very nearly 400 000 km, and still going strong. If some cars can do it, why shouldn't all be able to? Consider how much less waste there would be, consider how much further your income would go if you only had to buy a new car every twenty or thirty years rather than every four or five years.

Car manufacturers would have to build more quality into cars if they were all to last 300 000 km+, but I suspect that the cost of doubling the potential life of a car might be an additional 10%. See 'Building for a longer life' below.

Drive a smaller car

Whatever you do, if you care anything about the environment, don't drive a car that is bigger or heavier than you need. Advantages of driving smaller cars include:
  1. They use less fuel;
  2. They are easier to drive because they are lighter and have tighter turning circles;
  3. They are easier to park because of the tighter turning circle and smaller size;
  4. If you have a flat tire then changing the wheel is much easier (a friend damaged his back changing the wheel on his 4WD – probably twice the weight of my car's wheel).

Big four wheel drives are modern status symbols, but they are also environmental disasters.

  1. They consume about twice as much irreplaceable fossil fuel per kilometre compared to a compact car;
  2. Similarly, they produce about twice as much greenhouse carbon dioxide and other atmospheric pollutants;
  3. They take much more resources to construct;
  4. When eventually scrapped (and you should always think about eventual disposal when you buy something) there is more to dispose of;
  5. If you collide with someone in a smaller car, you are much more likely to kill that person;
  6. They drive like trucks!
There is a graph and a calculator comparing vehicle types, numbers of passengers, and carbon dioxide production on my Greenhouse Impact page.

Drive more slowly

Driving at anything like 100km/hr, or greater, requires a huge amount of energy.

For years I have driven at 90km/hr, as much as possible, rather than the Australian open-road speed limit which is usually 110km/hr, because I was aware that the higher speeds waste energy, fuel, and produces unnecessarily large amounts of greenhouse gasses. I have also experimented with driving at 70km/hr on open roads with very little traffic, and found that fuel consumption per kilometre travelled is perhaps 20% less than when travelling at 90km/hr.

I was recently surprised to find that my car, a Honda Jazz, – driven at relatively low speeds because of mountain roads – would go up and down a 1000m mountain and average about the same fuel consumption as when travelling a similar distance on level roads at higher speeds! (The Honda Jazz can display fuel economy in litres per hundred kilometres as you drive; the mountain was Ben Lomond in Tasmania, the average speed climbing the mountain was around 40-50km/hr, the length of the climb about 7km, the gradient about 1 in 7.) Think how much energy is needed to lift a one-tonne car 1000m, and then consider that a similar amount of energy is used in pushing a car 15km or so along a level road at around 100km/hr. (In both situations the Jazz used about 5.8 litres per hundred kilometres.)

In a sane world which was running out of petroleum and had dire climate change problems due to excessive burning of fossil fuels highway speed limits would be greatly reduced. What has that to do with this world you might ask!

For a discussion of the consequences of driving more slowly see Speed limit links.

Fossil fuels

Burning fossil fuels is unsustainable for several reasons:
  1. Fossil fuel reserves are finite. We are burning them at a far greater rate than they are being replenished.
  2. Burning fossil fuels changes the carbon within them from a solid form beneath the ground, where it does no harm, to a gaseous form in the atmosphere where it does harm.
  3. Burning fossil fuels produces air pollution that damages the atmosphere and kills millions of people each year.

From George Monbiot's Internet site, losing the battle with entropy...
"The world's problem is as follows. We now consume six barrels of oil for every new barrel we discover. Major oil finds (of over 500 million barrels) peaked in 1964. In 2000, there were 13 such discoveries, in 2001 six, in 2002 two and in 2003 none. Three major new projects will come on-stream in 2007 and three in 2008. For the following years, none have yet been scheduled."

Burning natural gas as a fuel is only a little better than burning petroleum; it still releases carbon dioxide, and natural gas reserves will not last long. Burning coal, especially brown (low grade) coal, produces the highest level of carbon dioxide emissions relative to useful energy. (Some more detail on this point is given in efficiency of electricity generation methods.)

The big question is, what can we use to replace fossil fuels as an energy source? Some answers are given on these pages.

"Every time I see an adult on a bicycle I no longer despair for the human race."
H.G. Wells

Can alternative energy compete?

There is much more on wind power and solar power, especially in the context of Australia, elsewhere on this site.
It has been said many times that alternative (ie. sustainable) energy cannot compete on 'a level playing field' with conventional (ie. fossil fuel) energy. This is misleading.

When fossil fuels are burned they produce gasses (most significantly carbon dioxide, but others as well, including sulphur dioxide) which are released into, and pollute, the atmosphere. This is a cost which should be taken into account when defining what the 'level playing field' is, but it usually is not taken into account.

To fairly compare the cost of sustainable or alternative energy with fossil fuels one should add in the costs of capturing and disposing of the CO2, SO2, and other pollutants. As of November 2008 no-one has built a full-scale operational fossil-fuel-burning power station that captures and disposes of its waste gasses, so there is no level playing field.

In any case, the fossil fuel industries are powerful and entrenched; they have a huge political clout. Governments in countries such as Australia and the USA have allowed themselves to be influenced by the strong fossil fuel lobbies.

Edited 2019/10/18

Hydrogen powered transport

While our civilization has a number of alternatives open to it for the generation of electricity rather than our current reliance on burning fossil fuels (see electricity generation methods), powering transport is another matter. The 'engine' of the vehicles in common use in the early twenty-first century demand a low weight to power ratio and its fuel supply must be small, light, and portable.

Much of the information on hydrogen fuel cells was extracted from Scientific American, Oct. 2002.
A possible alternative to vehicles powered by burning fossil fuels is vehicles powered by hydrogen fuel cells. While the internal combustion engine is, at best, 25% efficient in converting the energy contents of the fuel into moving the vehicle, a hydrogen fuel cell system could be up to 55% efficient. Put very shortly, a hydrogen fuel cell 'engine' electrochemically converts hydrogen gas from a fuel tank (of some sort) and oxygen from the atmosphere into electricity to power the vehicle's wheels, and water. The water, as steam, is the only emission from the engine.

At present the fuel cell engine (FCE) is very expensive compared to the internal combustion engine (ICE), but good progress on this is being made as there has been a ten-fold fall in cost from earlier versions. The ICE has the advantage of very large scale mass production, and there is no doubt that the cost of the FCE will drop as its production numbers increase.

Western nations are currently highly dependent on petroleum supplies. As much petroleum is imported from the politically unstable Middle East, the attempts of nations to secure their fuel supplies has lead to some dirty politics. (See The Real USA.)

The hydrogen for the FCEs can be produced electrolytically from water. Some form of sustainable energy could be used to power this process. There could be a closed cycle with some form of solar energy used to break water up into hydrogen and oxygen and then the hydrogen and oxygen being recombined into water in the FCE. No emissions, no pollution.

There is a long way yet to go before hydrogen powered vehicles take over from ICE powered vehicles, but the change, if it comes, will be a big step toward sustainability.

I have written more on the production and uses, and advantages and disadvantages, of hydrogen as a fuel in Hydrogen and Energy and on converting electricity to hydrogen in Power to Gas in Australia; both on this site.

Energy from wood

A couple of centuries ago wood, firewood, and draft animals were humanity's main source of energy. Especially in the West wood has progressively been replaced by fossil fuels. Now, even though we are beginning to realise that we must break our addiction to fossil fuels, we are not significantly turning back to wood as an energy source.

While it is true that it is quite impossible to grow sufficient wood to replace our present rate of fossil fuel consumption (there just is not enough land available), wood could be at least a part of the solution. My impression is that there is a lot of money going into hydrogen fuel cell powered vehicle research, but very little into research on sustainable production of liquid or gas fuel from wood.

Wood is still a major source of energy in the Third World. A useful site is Regional Wood Energy Development Programme in Asia. The Food and Agriculture Organisation of the UN has a site on Promoting sustainable wood energy systems.

It hardly needs be said that use of wood as a fuel must be done sustainably. Plainly logging or wood-chipping of old growth forests must not happen; it is environmentally destructive.

Comparative cost of energy

Burning a tonne of oil releases about 42GJ of energy, burning a tonne of air-seasoned firewood yields about 16GJ. In May 2005 in South Australia the retail price of a tonne of heating oil is about $1400 ($1.20/L, the specific gravity of heating oil is about 0.85), while that of a tonne of firewood is $160. Therefore energy from heating oil is $34/GJ and from firewood $10/GJ; firewood is, in terms of dollars per unit of energy, about 30% of the price of heating oil in South Australia. This ratio would vary greatly in different parts of the world.

The typical retail cost of one kWh of electricity in SA is $0.17, or $170/MWh. As 1MWh is equal to 3.6GJ this converts to $47/GJ for electrical power. So firewood energy is about 21% the price of electrical energy.

Energy Calculator discusses these matters in more detail and allows you to calculate your per GJ energy costs from a variety of fuels.

Obviously, heating oil and electricity are much more convenient energy sources than is wood in most cases.

See also Energy conversions and definitions.

Hot dry rock as a source of energy

A quote from the Australian National University HDR Internet site...
"The (Australian) Federal Government has made a policy decision that 2 per cent of Australia's electricity will be generated from renewable resources by the year 2010 and is actively encouraging the development of alternative energy technologies. Hot Dry Rock (HDR) geothermal energy is a vast, environmentally benign, economically appealing energy source. HDR is a conceptually simple technology.

Water is injected into a borehole and circulated through a "reservoir" of hot cracked rock several kilometres below the surface. The water is heated through contact with the rock and is then returned to the surface through a second borehole where it is used to generate electricity. The water is then re-injected into the first borehole to be reheated and used again."

The link to this ANU site is hotrock. This site has many links to HDR sites around the world.

A company has been floated to set up a pilot plant to demonstrate the feasibility of this technology. Here is a link to their Web site; Geodynamics.

Geodynamics has prospects in the Cooper Basin (SA), Muswellbrook (NSW), Eromanga Basin (QLD), and the Hunter Valley (NSW). Their Web site provides useful information on the hot rock electricity generation principle.

Apparently the original source of the heat is the radioactive decay of some elements within the hot dry (granite) rock. All granite is slightly radioactive. Thus, unlike most energy used by mankind, the primary source of hot rock energy is not the Sun.

A method of storing solar energy

One of the problems with solar energy is that you have it only when the sun shines. Even if it is used to generate electricity, that electricity must either be stored in expensive batteries or be used immediately.

Scientists are developing ways around this problem. One solution being researched at the Australian National University is to use large dish solar collectors to heat ammonia gas (NH3) to a sufficient temperature for it to 'break up' into its constituent nitrogen (N2) and hydrogen (H2) gasses. These gasses can then be piped to wherever energy is required and, as needed, the nitrogen and hydrogen are recombined to form the original ammonia, with the release of the original solar energy in the form of heat. This process is shown symbolically in the graphic below.

Copied from the ANU site
The graphic above was lifted from the ANU Department of Engineering's Internet site.

In chemist's symbols, the reaction is 2 NH3+ Heat double arrow N2 + 3 H2

The Australian National University Department of Engineering's Internet page on the subject seems no longer to be available (October 2020).

Ethanol and sugar

"Some people say that petrol and alcohol don't mix. They do, but the mixture tastes awful."

Mixing a fixed fraction of ethanol with petrol would make Australia's petroleum reserves last a little longer and, because the ethanol would be made from sugar, would provide a much needed boost to the Australian sugar industry. It is also argued that adding ethanol to petrol would reduce the net amount of greenhouse gas production because growing the sugar cane to make the ethanol absorbs as much carbon dioxide as is released by burning the ethanol.

The petroleum industry is arguing that they would agree to a voluntary very small fraction (perhaps 2%) of ethanol in petrol, but oppose a mandatory larger fraction (say, 10%). They hold that if 10% was mandated then they would have to import ethanol because it is produced overseas much more cheaply than in Australia.

One wonders how, given that the Australian sugar industry seems to be as efficient as any in the world, ethanol can really be produced more cheaply elsewhere; perhaps the lower prices are due to subsidies?

One wonders too whether some contraction in the Australian sugar industry might be a good thing, given that it has been implicated in producing dirty run-off that, it is claimed, damages the Great Barrier Reef. However, it is undeniable that we must find alternatives to burning fossil fuels.

Pollution from cars

Pollution from cars can be placed into two classes:
  1. Running pollution
  2. Disposal pollution
By running pollution I mean things like exhaust gasses. Disposal pollution is all the stuff associated with a car that that must be disposed of. As well as used engine oil, worn-out tyres, etc., it includes all those parts of the car that cannot be (or are not) reused or recycled at the end of the car's useful life. Old cars are a huge disposal problem.

If the life of cars was doubled, by building them to a higher standard, then disposal pollution could be halved. See Building for a longer life below.

Building for a longer life

Many things in our society are built to last a short time when they might be built to last a long time. As mentioned above, some cars can last for 300 000 km or more, while many are scrapped after having done far fewer kilometres.

So long as consumers are willing to buy manufactured goods that have a short life, rather than demanding goods with a long life, it is to the advantage of the manufacturers to build short-life products. By doing so they save costs, and they can sell a replacement product earlier.

Consumers should, for their own good (and for the good of their nation and the environment), learn to buy for durability. Since the good of the state is involved a good government would educate people to discriminate durable from non-durable goods.

Why are durable products good for the state and environment?
A durable product can, because it lasts much longer, take the place of several non-durable products. It then follows that:

  1. Natural resources are conserved;
  2. There is less waste to be disposed of;
  3. If the citizens of the nation can, rather than buying two items at price $X, buy one item at price $X times 1.2 that lasts just as long, those citizens will be advantaged. In the long term, if something is to the advantage of the citizens of a nation, it is to the advantage of the nation.
Why do states not educate consumers to buy for durability?
As mentioned above, it is to the advantage of manufacturers to produce more cheaper goods than to produce fewer high-quality goods. Manufacturers, particularly the multi-national companies, have the ear of government. They can and do lobby government to change policy to suit themselves.

The fallacy of providing jobs
I'm sure that some would argue that by producing more low-durability items rather than producing fewer high-durability items, more jobs are created. Ultimately, the best course is to minimize the amount of work needed to produce a required outcome, not to maximize it. More jobs would be created by abolishing farm tractors and going back to having many rural workers and many draught horses. Would we be better off? I think not.

Post petroleum transport

How will we get from place to place, and how will we move freight when petroleum becomes much more expensive than it is in the very early 21st century?

Some ways we might use are:

  • Much smaller and lighter vehicles;
  • People moved by bus, tram and train rather than in cars;
  • If private cars are used at all, they will carry a higher 'payload ratio';
  • Freight by train rather than truck;


What will be the fuel of the future?

What will we use to fuel our vehicles when petroleum becomes too expensive to be a practicality? Petroleum will be made - at great expense to the environment - from things like tar sands and oil shales; we can only hope that concerns over climate change will strictly limit this and the damage it causes. Apart from that, a search of the Internet indicates a number of contenders:
  1. Various forms of natural gas;
  2. Biofuels;
  3. Electricity stored in batteries;
  4. Hydrogen;
  5. Ships could go 'back' to sail;
  6. Solar hybrids: wind generated electricity converted to liquid fuels, solar thermal energy used to produce liquid or gaseous fuels, etc.;
All of these have problems or limitations when compared to the convenience of the petroleum that we use in the early 2000s.
  1. Natural gas will not last much longer than liquid petroleum;
  2. Biofuel production requires a large area of productive land. This land will be needed to feed people, and in any case there is simply not enough land to produce enough biofuel to replace our present rate of consumption of liquid fuels. All biofuels are ultimately powered by the sun; the conversion efficiency from solar to biofuel is very low, around 0.2%.
  3. Even the best of modern batteries store far less energy per kilogram than is in liquid petroleum.
  4. Hydrogen it a very light gas that cannot be liquefied except if kept very cold. Even then it is light and a very large tank would be needed to hold an amount of fuel comparable to a tank of petrol or diesel. If contained as a gas then it must be kept under very high pressure and still little energy can be contained in a given volume compared to petrol. How hydrogen can be manufactured sustainably in large volumes remains to be proven. Even moving hydrogen by pipeline has its problems, much larger diameter pipes would be needed than to transport a comparable amount (in terms of energy value) of natural gas.
  5. Sail as a means of moving ships was almost universal up until the rise of steam. Sail went into decline in the nineteenth century and had almost disappeared as a commercial means of moving ships by the middle of the twentieth century. There have been attempts to resurrect sail, in a new, mechanised and aerodynamic form, in the last few decades. With rising petroleum prices, and the need to reduce greenhouse gas production, sail could make a come-back.
Some form of petroleum, because of the amount of energy effectively contained in a small mass of fuel (and fuel container), is very efficient as a transport fuel. Alcohol has a lower energy:mass ratio, but is also a viable liquid transport fuel. Both suffer from the disadvantage that they contain carbon, which when burned, is converted to the greenhouse gas carbon dioxide.

Vehicles of the future

In the first few years of the twenty-first century people of Western nations frequently use vehicles weighing about a tonne to carry one person, typically weighing 1/14 as much, from place to place. In the USA especially, large four-wheel-drive vehicles (SUVs) are common and they may weigh two tonnes. Typical speed is around 100km per hour.

A person can travel on an electrically powered bicycle weighing around 30kg at a speed of about 20km per hour; although at present these only have a range of around 30km.

The vehicle of the future may well come somewhere between these two extremes in weight, speed, and fuel consumption. It may be similar to a very light-weight, aerodynamic, and low powered version of the current very small car.

The car of the future may not be very far off; it is quite possible that the heavy 4WDs and big V8s that people are buying in 2005 may become unusable in a few years time because of steeply rising fuel prices.

The advantage of rail transport

As the price of petroleum increases another ratio will become very important; that is the fuel consumption per tonne-kilometre of freight carried. In 2005 the convenience of road transport, which is capable of pick-up and delivery to pretty much anywhere, often outweighs the fuel efficiency of rail. As the price of fuel rises this will change; rail transport, especially over long distances, will become more attractive.

Energy from algae

On 5th June 2008 the Melbourne Herrald Sun carried a story that, among other things described a process proposed by Professor Keith Lovegrove of the Australian National University.
"Prof Lovegrove's idea for a 'fully sustainable future' would have farmers growing salt water algae - which he says produces about 40 times more biomass than food crops per hectare. Once harvested the algae would be 'gasified' at 700 degrees Celsius in massive pressure cookers powered by energy from solar dishes. The resulting methane gas would be put under another high-pressure industrial process and emerge as methanol [a type of alcohol]."
Prof Lovegrove has the source of the solar energy in mind too. Quoting from the Melbourne Herrald Sun article again...
"A 500-square-metre parabolic dish [to be built in Whyalla, South Australia] - that's bigger than an average house block - consisting of 424 mirrored panels will be erected over coming months as a prototype for a solar farm planned for Whyalla, South Australia. Private company Wizard Power has partnered with the solar thermal boffins at the ANU, led by Keith Lovegrove, to build what they say will be the first renewable energy power station capable of producing electricity around the clock by the end of next year. Combined with an ammonia-based storage system, the solar thermal concentrator will not only create carbon emission-free base load power, its technology could also be used to one day solve the widening oil crisis and supplant high-earning coal exports, Prof Lovegrove said in Melbourne this week."
Unfortunately I have not been able to find more significant information on the proposal on the Net.