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How To Cut Cut Your Greenhouse Emissio The thinking person’s guide “If all Australians switched to clean, renewable energy (Green Power) today, Australia’s total greenhouse pollution would be cut by 30%.”– World Wildlife Fund Part III – by Peter Seligman, PhD E very problem is easy to solve if you know nothing about it. The statement above is on the World Wildlife Fund (Australia) website (www.wwf.org.au/act/takeaction /green-power-200603/). What was the writer thinking? Did he/she think that just by ringing our electricity suppliers a forest of wind turbines and solar panels would sprout up? Was he/she thinking that they had already been built and someone was just sitting by the phone waiting for us to ring up to throw the switch? Of course intelligent SILICON CHIP readers would not think like this. Renewable energy power sources are damn difficult to build. In Victoria, for example, a wind farm was held up for a year by the concern for the orange bellied parrot (by one assessment, it might kill one parrot every 1000 years). Progress is slow and bedeviled by obstacles technical, political and bureaucratic. But it is typical of the population at large to ignore these problems. Ideas that hydrogen or electric vehicles are the solution to CO2-induced climate change need very careful examination. Electric cars I’m not referring to hybrid-electric cars, which are a hi-tech way of improving petrol efficiency. This is about purely electric vehicles. There have been some around in the form of delivery vans for years and electric scooters are available. These vehicles are used for specific applications and with good reasons. As far as the general purpose car, as we know it is concerned, you probably realise that the pure electric car20  Silicon Chip which has the range, convenience and performance of a conventional car – is still way off in the future. Electric cars are often seen as a way of providing clean, pollution-free transport. However, that’s not what you get if the electricity comes from a fossil fuel-powered electricity grid. It just moves the pollution from one place to another. The dream is the car which derives its energy from the sun. Is this realistic – and is it a good idea? This question applies equally well to hydrogen, compressed air, flywheel and any other vehicles which store energy derived from electricity in the first place. Look at the energy . . . Let us look at the energy consumption of a typical car over a year. Let’s make an assumption of a car which does 10,000km over a year and has fuel consumption of 10 litres per 100km. Or you could assume a very efficient car using 5 litres/100km over 20,000km. Whatever assumption you make won’t affect the outcome. Let’s say it comes to 1000 litres per year. One litre of petrol contains about 10kWh of energy (that’s the energy used by a 100W light globe over 100 hours). So a 1000 litres of petrol provides 10 x 1000 = 10,000kWh of energy to the car’s engine over the year. Now let’s make another assumption. The efficiency of a car engine is about 25%. Only one quarter of the energy in the petrol gets to the engine’s output shaft. Again, you can make your own assumption, which won’t affect the outcome. For this case, the engine provides 0.25 x 10 = 2,500kWh siliconchip.com.au ons over the year. However an electric motor is not 100% efficient; nor do you get all the energy stored in a battery back out again. I’m assuming an efficiency of 90%. So we really need about 3000kWh a year. Imagine we are to provide these 3,000kWh each year from solar photovoltaic panels on our roof. How many solar panels would it take and how much would they cost? The cost of solar panels is about $10 per peak watt. A peak watt is what they output when they are directly facing the sun, with no cloud. Of course, in reality we need to take into account night time, cloud and the varying sun angle. Effectively, averaged over a year in south eastern Australia, the ratio between peak power and average power is about seven times. So the real cost of solar panels is about 7 x $10 or $70 per average watt. To calculate the cost of panels we would need to get our 3,000kWh in a year, we work out how many watts on average we will need to collect. There are 24 x 365 = 8760 hours in a year. To get the average watts, divide kWh (kilowatt hours) by hours in a year: 3000/8760 = 0.342kW (kilowatts) or 342W. What would this solar system cost? At $70 per average watt, we need about $70 x 342 = $24,000 of panels. Generally, in solar systems the cost of the panels is about half of the total cost when you include the mounting frames, labour, controllers, wiring etc. So the cost of the installation is likely to be closer to $48,000. However a good solar system will last 20 years or more. siliconchip.com.au One can image that when petrol is $2.50 a litre and solar cells are cheaper, (but at the moment they are not going down in price) that this is not beyond the realms of possibility. But is it a good idea? To answer this, we need to look at various scenarios from the carbon emissions point of view. These are: 1. Drive an ordinary petrol, diesel or LPG powered car. Let’s call it “Petrol” 2. Electric car – charged from the power grid operating predominantly on coal. Let’s call it “Elec/coal” 3. Electric car – charged from a home installed photovoltaic system (grid connected so that surplus can be put into the grid and deficiency is drawn from it. Let’s call it “Elec/PV” 4. Petrol, diesel or LPG car, with same photovoltaic solar system as above – called Petrol/PV Here is the information we need: From my electricity bill I can see that 888kWh resulted in 1.23 tonnes of CO2, that is 1.385 kg/kWh. From the Australian Greenhouse office – I can find that burning 1 litre of petrol results in 2.6 kg of CO2 being emitted. So for “Petrol” we multiply the litres per annum by 2.6 to get 2.6 x 1000 = 2,600 kg = 2.6 tonnes of CO2. For Elec/coal, we have put an extra load of 3000kWh per annum on the system resulting in 3000 x 1.385 = 4155 kg say 4.2 tonnes of CO2 For Elec/PV, there is no CO2 contribution. Finally, for Petrol/PV, the petrol car will contribute 2.6 tonnes of CO2 while the photovoltaic cells pump the same energy back into the grid saving 4.2 tonnes of CO2. The net result is that 4.2 – 2.6 = 1.6 tonnes of CO2 has been saved from entering the atmosphere. Here’s a graph: You can see that in our present situation, in which most electricity is generated from fossil fuel, electric vehicles combined with coal electricity generation are worse than the status quo. Electric vehicles combined with solar photo-voltaics are good but come with a double cost, that of setting up the solar system as well as the expensive batteries of the car. The winner, both CO2 and cost-wise, is the conventional car or hybrid-electric car, with independent renewable energy, supplied from solar, wind, geothermal or another renewable source. The good news and interesting thing is that this combiSeptember 2007  21 nation is already available, unlike the grid-charged pure electric car. Until the last greenhouse-gas-emitting power station is taken off line (don’t hold your breath!), there is no environmental advantage in taking energy out for the grid for powering cars. Niggling questions One of the questions a thinking person might ask is “what is the energy or environmental cost of energy saving measures themselves? It is not an easy question to answer. How can one calculate the environmental or energy cost of a compact fluorescent lamp? It has so many components and different materials in it. However, as far as energy is concerned, there is an easy way of thinking about it: if a CFL costs $5, at an absolute maximum it can only have used $5 worth of energy to make. Otherwise it couldn’t be sold for that price – and that’s ignoring any profit made by manufacturer, distributor or retailer. Of course you could argue that the energy was bought at a lower price. But the lamp was sold at a lower price from the factory than the retail price you paid. So let’s just compare retail with retail. A CFL has the potential to save say 80W for 5000 hours which is 400kWh. That electricity would cost about $50. So it could save up to ten times the maximum possible energy cost of its production. Even considering that it may not last as long as advertised and it might be left on longer than a tungsten lamp, that retail price is the maximum possible energy cost. So energy-wise it must be worth it. Another niggling question is the pollution aspect in the production of these lamps. I must say it concerned me too. However, here again there is a relatively simple way of thinking about it. Of course pollution is produced by manufacturing electronic goods and fluorescent tubes. But it is a little known fact that coal fired power stations put a lot of uranium into the atmosphere. And tungsten 5 lamps (ie, standard incandescent) need mining and energy to produce too. I can’t give you figures on this but you get the idea. Energy-saving devices do have their environmental costs but as a rule-of-thumb, the environmental payback period is similar to the economic payback period. It can be much better, when you are considering highlysubsidised energy, such as off-peak electricity. Carbon offset schemes per tree, that works out to 20/0.06 = 333. Please plant them! There is an organisation called Greenfleet that will plant and maintain 17 trees on your behalf for $40 to offset the CO2 for one car. Be aware, that these trees will not be mature for some years. And hope they will be cared for – and survive. See www.greenfleet.com.au/transport/technical.asp The main problem with a carbon offset scheme is that it can’t go on indefinitely. For decades we have been taking carbon out of the ground (from countless ancient forests) and putting it into the atmosphere. We can’t realistically expect to reverse this by planting trees. We aren’t going to put them back into the ground and we couldn’t if we wanted to. If you check CarbonSMART (www.carbonsmart.com. au/pdf/InformationSheet.pdf) you will see that part of the contract for people growing timber on their properties is “The carbon will remain on site for at least 100 years after the final trade of that carbon”. Another kind of carbon offset scheme is one where you pay for someone else’s energy saving or reductions of greenhouse gas emissions, where they wouldn’t have the funds to do it themselves. These are called Greentags. Examples are given in www.myclimate.org. This arrangement supports projects such as solar energy in Eritrea, electricity from Methane in South Africa and wind energy in Madagascar. Look at www.myclimate.org.index. php?lang=en&m=projects These project have a double benefit – to that community and to the environment in general. “Carbon offsetting” and “carbon neutrality” has suddenly sprung up as a growth industry (no pun intended). However as with any new industry, it is full of cowboys. There are now organizations which try to evaluate this, for example Total Environment Centre www.tec.org.au Where to from here? We have talked about how to reduce our energy use and how to offset the CO2 we do produce. However if we are ever going to make serious inroads into the looming climate change problem, we will have to do more. What we need is serious affordable alternatives to old fashioned coal. What are our best options for renewable energy? The main alternatives as we know them today are shown in the graph below. In the cases where there are greenhouse gas emissions, the cost of CO2 has been added at $60/tonne, to give a total effective cost. These are schemes that try to do good to make up for doing bad. Sounds OK – and planting trees is a great idea. If nothing else, it should at least increase the rainfall and habitat for wildlife – and that’s good. Just to spoil your warm, fuzzy feeling, let met tell you that one mature tree extracts about 60kg of CO2 from the atmosphere a year. If you have an average sort of household with an average energy use, you will be putting about 14 tonnes of CO2 into the atmosphere every year. The car accounts for another 4 tonnes and each overseas trip another 4. Let’s say 20 tonnes a year for the purpose of discussion – an order of magnitude type of calculation. What is 20 tonnes of CO2 in tree equivalents? At 60kg 22  Silicon Chip siliconchip.com.au A graph such as this is, of course, highly controversial and various camps will claim much higher or lower costs depending on their particular bent. It is interesting to note that in the media, Nuclear, Solar Wind and Geo-sequestration are frequently mentioned. How often is Geothermal mentioned in the press? Hardly ever. Why is this so? Maybe it is that both the coal and the uranium industries have powerful political lobbies associated with them. Geothermal obviously doesn’t carry much (any?) political clout. Now available: THE 5 Hot Fractured Rock Geothermal Unknown to much of the population, Australia has huge reserves of hot rock geothermal energy. This differs from “conventional” geothermal energy which is associated with volcanic activity (as used in New Zealand) In Hot Fractured Rock, (HFR) water is pumped down an injection well into heat-producing granites located three kilometres or more below the surface. Temperatures of up to 300° are obtained and the water is circulated through a heat exchanger. Australia’s recoverable HFR resources are capable of satisfying projected electricity consumption for over 450 years. 5 DC POWER FOR CRITICAL COMMERCIAL AND INDUSTRIAL APPLICATIONS           This illustration, courtesy of the International Geothermal Association (www.iga.igg.cnr.it) shows how Hot Fractured Rock Geothermal energy works. The website gives an excellent introduction to this very neglected subject. siliconchip.com.au Hospital theatre backup Portable medical instruments Portable computers & cameras Mining tools Oceanographic instrumentation Remote area power Railway signalling Rolling stock Aviation Military Systems Ph: 61 89 302 5444 or order on line <at> www.siomar.com September 2007  23 Rockby Electronics Components Est. 1987 THIS MONTH’S SPECIALS Economy SPDT Toggle Switch Type: SPDT Rating: 3A <at> 250VAC Function: ON-OFF $0.80 #35924 2700mAh "AA" Ni-MH High Cap.Batt. (Pk2) $5.90 Rech.Cycle: up to 1000 times Package: Shrink wrap Pack size” 2 #35943 Hand Held pH Meter 3 Pin Chassis Mount Socket Rating: 10A 250VAC Suits panel thickness > 1.6mm Mounting depth: 25mm Colour: White #35895 $2.50 Sounds too good to be true? RJ45 & RJ11 Modular Cable Tester Quickly & easily checks for cable continuity, miswiring, open, short, straight-through or cross pinning. #36058 $13.50 12V 150W Power Inverter Input: 11 - 15VDC Size 40(w) x 158(h) x 34(d)mm $28.50 1 - 14 pH range / 0.1 pH res. $39.00 O/p Voltage: 230 AC 50Hz Output Waveform: Mod. Sine Wave +/- 0.2 pH accuracy DC Input Voltage: 12V DC Nominal 0° - 50°C oper. temperature #35616 #36096 USB All in 1 Card Reader Compliant to USB 2.0 Hot Swappable Supports: CF/MD,SD/MMC,MS/MS PRO/MD DUO/ MS ROM & xD/SMC. Win,98Se, ME, 2000, XP $13.50 #36074 Mini 4 Port USB 2.0 Hub Mini, lightweight design Complies with USB 2.0 specs Supports high speed 480Mbps Size: 60 x 47 x 12mm Plug & Play installation Lead Included #36073 $8.50 ******** Now Open New Large Showroom ******** For a Free Monthly Mailer Up-date Please Contact us Rockby Electronics Pty Ltd Showroom & Pick-up Orders: Mail Orders To: P.O Box 1189 Huntingdale 54-56 Renver Rd. Clayton Victoria 3166 Victoria 3168 Ph: (03) 9562-8559 Fax: (03) 9562-8772 Email: salesdept<at>rockby.com.au ABN# 3991 7350 807 ACN# 006 829 821 Web Address: www.rockby.com.au The Cooper Basin in South Australia alone could provide emission-free base-load electricity for 70 years. However, a chart on the International Geothermal Association’s website (www.iga.igg.cnr.it) shows that during the years 1995-2000, Australia’s installed capacity of geothermal generating capacity didn’t change (it remained a miniscule 0.15MWe), while worldwide the increase was almost 17%. Australia has a long way to catch up. Although it is technologically difficult, it is composed of solvable problems, mostly using existing oil drilling technology. When compared with nuclear with its multiple thorny issues of safe disposal, security against terrorism and accidents, it seems a very attractive proposition. The major advantage Geothermal has over wind and solar is that it suitable for base-load supply. It can be regulated to match the load, rather than being at the whim of the elements. A major advantage of the Cooper Basin is that it is a long way from any population centres. The Swiss city of Basel has a HFR geothermal power station pilot project, which has just recently been put on hold after three earth tremors, over three on the Richter scale, were experienced. Since then an argument has developed as to whether the drilling allowed minor slippage to occur (a practice used on the San Andreas Fault), thus averting a bigger earthquake, or if it is the cause of quakes which would otherwise never happen. Thorium fuelled nuclear power Thorium is a fuel that can be used in nuclear reactors but 24  Silicon Chip produces very little nuclear waste and what there is, has a half-life of hundreds of years, rather than millions. Thorium reactors are what is called sub-critical, so no runaway reaction can occur. Furthermore, Thorium is 10 times as abundant as uranium and Australia has huge reserves of it. Maybe, and certainly if you search on the web you can find plenty of criticism and opposition to the idea. Having said that, Norway, which currently bans the use of nuclear power, is now investigating it. Obviously the jury is out – but who knows, it might be that a more benign form of nuclear power will emerge. Our journey In the beginning I talked about how much energy various domestic appliances activities use and how we could reduce it. Some surprises included: • While taking a shower you are using the energy equivalent of 240 light bulbs. • Leaving a light on every night for a year uses as much energy as driving from Melbourne to Sydney. • All those devices on “standby” are huge wasters. • Electrically boosted solar water heating is worse than gas. • Fluorescent lights are not necessarily low energy! • Leaving them on never saves energy. • Low voltage halogen downlights are the worst. • “50W” low voltage halogens consume around 62W each when transformer losses are taken into account • “36W” fluorescents consume close to 50W each when ballast and other losses are taken into account. • Compact fluorescent lamps (CFLs) are efficient compared to incandescent lamps but perhaps not the panacea the government claims them to be. After having given you the bad news ,on how much energy everything uses, we saw how, by making the right choices and spending a bit of money, one could do a lot better. But we also learned about the dishonest practices of the electricity suppliers and how to get wise to their tricks. We learned that various “low energy” appliances use more energy sitting there doing nothing than doing their job. On the third leg of the journey, I introduced a real liability, space heating and how even there, improvements could be made. By using a combination of all tactics, our household managed to get its CO2 emissions down to one quarter of the “business as usual” scenario. On this last leg we have moved on to deal with energy usage over which we have less control by using methods such as carbon offsets. Even then, there are choices to be made and some of them make more sense than others. Finally we moved into the arena of government policy and discovered (surprise!) that the government actions and the technologies they support don’t make a lot of sense. I hope I have alerted you to some of the foibles we are led to believe. As informed citizens we can do a better job. SC siliconchip.com.au