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Australia is going solar – or at least that’s what we’re told by Government agencies, environmentalists and corporate spin doctors. But if you take a really good look look at what’s on offer, arereally you getting at what’s on offer, are you getting a good deal? a good deal? Solar Power for All: Does it Add Up? By Ross Tester 8  S 8  Silicon iliconCChip hip www.siliconchip.com.au www.siliconchip.com.au A ten-panel “plug&power” rooftop system from Pacific Solar. This would be capable of generating 1.5kW and cost between $10,000 and $15,000. Photo courtesy Pacific Solar. W ith much fanfare and breastbeating, several initiatives have been announced to convince Australians to generate their own electricity, simply by placing photo-voltaic (or solar power) panels on their otherwise-wasted roof space. Of course, there is nothing particularly new about generating electricity from the sun. Photo-voltaics have been known about – and used – for many decades. There are two main reasons that it has taken a recent boost in profile: (1) “Green” is fashionable. Concern about the environment has escalated dramatically in the last decade to the point where some people are prepared to pay extra for “green” power. (2) Perhaps even more importantly, vast improvements have been made in the efficiency of photo-voltaic cells in recent years. And with the amount of money being poured into R&D, it is expected this will continue. Coupled with this is a very significant reduction in cost – as volumes rise, costs should continue to fall. “Greenhouse” gases If you say something often enough www.siliconchip.com.au and loud enough, most people start believing it. Could this be the case with the so-called “greenhouse effect”? The theory, albeit very abridged, goes something like this: we humans produce too much carbon dioxide. The two main culprits of CO2 production are (of course) that evil monster, the car, along with fossil-fuel (mainly coal) burning power stations. Problem is, no-one wants to give up their car or turn off the air conditioner! This large amount of CO2 acts like a one-way valve for sunlight (and therefore heat) entering our atmosphere and striking the earth. The earth heats up, which will eventually cause polar ice caps to melt which in turn will cause oceans to rise, flooding low-lying areas. Another consequence is a major change in climatic conditions. Cut the CO2 emissions and we’ll cut the greenhouse effect. It’s that simple. The point is, it is still JUST a theory. Most people are firmly convinced it is fact, simply because there are so many people telling them it is fact. We even have Government departments and agencies set up to deal with the “problem”. However, there are many experts around the world who don’t believe the greenhouse effect is the one true gospel. Many refer to it as the “greenhoax” effect. In 1995, skeptical scientists signed the Leipzig Declaration on Global Climate Change, stating that they “cannot subscribe to the so-called ‘scientific consensus’ that envisages climate catastrophes and advocates hasty actions.” But their voices are generally not heard amongst the incredibly sophisticated PR machine of the environmental lobby. The greenhouse effect is taught in schools as fact. The alternative point of view – that climate change is a natural phenomenon – barely rates a mention. Yes, there is some evidence of global climatic change. That proves the theory, of course – except that there is also evidence that the Antarctic continent is colder now than it has been since records were started! Whoops – better ignore that one! And in the overall scheme of things, we’re still only talking the blink of an eye in not just human history, but the March 2002  9 Wind and water: two of the most prolific and abundant forms of renewable energy. At right is Australia’s largest wind farm near Albany in Western Australia. Below is the turbine hall of a hydro-electric power station. No wonder they call it “clean” power! into the decaying material underground. While not truly renewable energy (it must run out in time!) it is relatively non-polluting (in fact, it uses and therefore removes a potentially polluting gas).    Another form of bio-energy burns the waste material from a production process (eg, the bagasse left over from sugar-cane crushing) in a similar manner. In many instances, this also produces steam and other energy for use in the plant – socalled “cogeneration.” Courtesy Western Power. history of our planet. Who is right? Only time will tell. In the meantime, it does make sense to try to limit the amount of CO2 and other pollutants entering out atmosphere from power stations – if only to make us feel better about the air we breathe! And that’s where “clean, green” renewable-energy electricity comes in. Green power Photovoltaic cells are not the only way to produce non-polluting electricity. There are four main ways to do it: (a) Wind-generated power – this has started to make an impact in Australia recently with several “wind farms” established in relatively-constantly-windy areas. The advantage is that the wind is free, if not constant. One disadvantage, apart from fairly low output per generator, is reportedly the swishing noise of the blades for people living within a few kilometers!    To show just how far wind farms 10  Silicon Chip have come, in January this year it was announced that the world’s largest wind farm, a 520MW, 200 turbine installation, would be built off the coast of Ireland at a cost of more than $1 billion. Proponents claim that wind farms will be able to produce more than two thirds of Europe’s electricity by 2020.    Incidentally, the first grid-connected wind farm in Australia was opened at Crookwell, NSW in 1998. At 4.8MW it doubled the previous wind generation capacity in the country! For more information on the Crookwell wind farm, see the January 1999 SILICON CHIP.    The largest wind farm in Australia is currently the 21.6MW plant at Albany, WA, with twelve 1800kW turbines on 65m towers.    (b) Bio-energy – burns the methane gas created during the natural decomposition of organic material to drive a turbine. Several bio-mass power stations have been established on the sites of old rubbish tips, tapping (c) Water-generated power – immediately, most people think of hydro-electric and for the most part (at least in Australia) they’d be right. However, the “green power” people will not allow their power to be sourced from any new dam or river diversion so this option is now, for all intents and purposes, at its peak (upgrades to existing hydro-electric facilities are allowed). Turbo installations range from backyard, hobby types (perhaps on a stream flowing through a rural property) producing perhaps a couple of hundred watts, to giant dams with huge flows of water, producing many megawatts. There is another source of water power, as yet relatively unknown in Australia, and that is tidal. In many places in the world (including the north-west of Western Australia) tide heights are measured in tens of metres and this inflow and outflow can be used to generate electricity via a turbine. The disadvantage is that the flow stops, builds, reaches a peak, stops, builds in the opposite direction, reaches a peak and stops again, twice every day. Due to lack of flow around high and low tide, electricity of any significant magnitude can only be generated for perhaps half to two-thirds of each six-hour cycle. An ocean wave converter generator is reported to be currently under construction (or at least in planning) off the coast of Portland, Victoria. (d) And, of course, solar power, where in most cases the electrical energy is created through sunlight striking a photo-voltaic cell. Until quite recently, the amount of power generated this way was either very www.siliconchip.com.au small or very expensive – but this is changing. It is solar power we are looking at in this feature. Before we leave this introduction there are two other forms of solar power generation which bear mentioning. The first is where a large “field” (perhaps several hectares) of sun-tracking mirrors (called a “heliostat”) focus the sun’s rays on a steam-producing boiler (usually high on a tower). This in turn drives a turbine, generating electricity. Such systems are in use overseas. The temperature at the focal point of the mirrors can be extremely high – many thousands of degrees! The second form of solar generation, still somewhat in the “theoretical” stage but likely to appear this decade, is a huge solar-powered “chimney”, incredibly tall (a kilometre or more) and 5km wide at the base. The sun heats air at the base which rushes up the chimney, driving turbines on the way. Such a project, which will have a peak output of 200MW, has recently been announced for Ned’s Corner in far north-western Victoria. But this is not quite the solar installation for a suburban house! Solar for all There is no doubt about it – the “push” for solar power is gaining momentum (even if the installation is not quite keeping pace). It received quite a “kick along” prior to the 2000 Olympic Games when 629 buildings in the Olympic Village (now the suburb of Newington) as well as the 19 lighting towers on Olympic Boulevarde were fitted with solar power modules from BP Solar. You may have seen recent television adverts supporting the “solar for schools” project – in fact, there are now more than 25 schools listed as “generators” of electricity via their solar panels. Few, if any, would be significant net producers of power; they would use all the power they generate themselves (thereby reducing their energy bills). They are somewhat fortunate in that most, if not all, of their power demand occurs during daylight hours. When you have large expanses of roof space (and often, in the case of schools, elevated roof space at that, away from shading of trees and other buildings) there is room to fit large numbers of solar panels. The rule is simple: the more panels, the more power. On the downside, naturally, the more panels, the higher the initial cost. But even with a large installed solar capacity, can a school – or even a house – generate enough electricity to make it an economic proposition? You be the judge. One product/company which caught our attention (after much media fanfare!) is “Plug&Power” from Pacific Solar. This company, by the way, is a spin-off from the University of NSW which provided the intellectual property. The company’s vision is “to have developed solar cells seen across the rooftops of the world”. While this is a laudable objective, their claim that “the majority of households have enough sunshine and roof area to produce their entire energy needs” bears closer examination. Its solar panels measure 1.68m x 0.84m (1.41 square metres). Each ELAN Audio The Leading Australian Manufacturer of Professional Broadcast Audio Equipment Featured Product of the Month PC-BAL PCI Format Balancing Board Interface PC Sound Cards to Professional Systems Not only do we make the best range of Specialised Broadcast "On-Air" Mixers in Australia. . . We also make a range of General Audio Products for use by Radio Broadcasters, Recording Studios, Institutions etc. And we sell AKG and Denon Professional Audio Products For Technical Details and Professional Pricing Contact Elan Audio 2 Steel Crt South Guildford WA 6055 Phone 08 9277 3500 08 9478 2266 Fax email sales<at>elan.com.au WWW elan.com.au One of the first modules produced on Pacific Solar’s pilot-line. These 30cm x 40cm modules were sufficiently large for researchers to address most of the issues involved in scaling up technology to commercial size of up to 1m2. Photo courtesy Pacific Solar. www.siliconchip.com.au March 2002  11 its payback period beats me!) Note that none of the grid-connected systems (as far as we are aware) have any form of storage – ie, no batteries. This means you cannot get any power from your system at night, nor anything significant when it’s raining (or even heavy cloud). When it does produce power, you either use it – or sell it. Selling your electricity The owner of this house in Sydney’s inner west “is interested in a sustainable future”. He chose Plug&Power because of the “low maintenance, design and modular construction”. Pic courtesy Pacific Solar. comes complete with its own inverter and is capable of generating 150W in direct sunlight mounted at the right angle on a north/north-east-facing roof. Pacific Solar maintain that the average house in Sydney has enough roof area to allow 21 modules (29 square metres). These are capable of producing around 3.2kW (maximum). Their examples, to give them credit, are based on a probably-more-realistic 15-module, 2.25kW system. According to accepted figures, there is 1500kWh/kW of solar energy available in Sydney per annum. With a 95% efficient panel mounting (28° angle, north-east facing) that reduces the figure to 1425kWh/kW. Their figures assume an annual electricity usage of about 6800kWh in a year. The 15-module system is capable of producing nearly half the annual usage (1425 x 2.25 = 3206kWh). But is that realistic? And what happened to the earlier claim of “to produce their entire energy needs?” I know that in my own case, the 6800kWh is very much understated. My last four electricity bills shows it’s closer to 10000kWh. And that’s for a two-person household (albeit all-electric, with a pool). On the face of it, to produce 10000kWh “to provide all my energy needs” I would need to have not 21 12  Silicon Chip modules but 46. That’s some 66 square metres of roof area which have to face the right direction – north! Admittedly, about 30% of this energy is for hot water and you wouldn't use solar electricity to heat water (you’d simply use a solar heater). But that would take away some of my roof space . . . What cost? So far, we haven’t looked at costs – let’s do so now. To install a solar power system, you’re up for anywhere between $5000 and $30,000, depending on size (of system) and the supplier. Large systems may go even higher (we’ve seen quotes for $50,000). Now before you fall of your chair, it’s not quite that bad because the Australia Government has a rebate program to encourage more people to install solar power. There are various rebates depending on the size of your installation. A small installation is worth $5.00 per watt of installed solar capacity while a larger one is worth $7500 plus (in NSW) $2.40 per watt over 1500W. The program, which is available to all owner-occupiers, runs out in 2004. There are some conditions, one of which is an agreement to keep the system running for at least five years. (Why on earth you would spend all that money and pull it out way inside If you install a system which generates more power than you can use, in many cases you can sell the excess back to your power company. Some energy suppliers apparently do not yet have a firm policy on this but of those that do, the majority will pay you (or give you a credit on your bill) at the same rate as you currently pay for electricity. In at least one case, it’s much more generous than that: the Northern Territory’s Power and Water Authority sell power to you at 12.9c per kilowatt-hour but will buy power back from you at 16.9c per kilowatt hour! Hey, let’s move to Darwin! In some cases the power companies will charge you extra to install either a special bi-directional electricity meter (normal meters cannot run backwards) or install an “outgoing” meter which is read in conjunction with your normal “incoming” meter. The first is subtracted from the second to achieve your power usage. Payback period Putting in a solar system is not going to make you rich in power savings. In fact, it’s probably not even going to break even. Let’s look at the sums: Say the system you put in costs $20,000. Take off the full Government rebate and you’re still paying more than $11,000. If your current electricity bill is, say, an average of $200 per quarter, $11000 is equivalent to 55 quarters – almost 14 years – before you recover your investment. Take into account interest lost or paid and it’s probably more like 20 years. Even discounting a tad for the pittance you’ll receive in energy credits, you’re still well over 18 years before it starts paying for itself. Given that the average Australian family will move house at least once (and probably twice or more) in that www.siliconchip.com.au Better ways to save “greenhouse” gases So installing a solar system on your roof may not be the way to go. But you still want to do something about reducing greenhouse gases. What can you do? There are plenty of things you can do and they will also give you a big payback in terms of reduced energy bills. Here are some of them: (1) Buy a new car. No, we are serious. If your car is more than ten years old, you should buy a new one, to help the environment. Can’t afford a new car? Well, then you certainly can’t afford “plug&power” or any other of these schemes either. (2) Get rid of your lumbering full-size 4WD. We cannot understand how anybody who is concerned about greenhouse gases can justify driving these monstrosities. Typically, they use 80% more fuel than a big car such as a Commodore, Falcon, Mitsubishi Magna or Toyota Avalon. And full size 4WD vehicles use at least twice the amount of fuel compared to medium-size cars such as Ford Lasers, Toyota Corollas, Mitsubishi Lancers etc. safer than 4WD vehicles. OK, so you want a 4WD for your bush holidays. Fine. Buy a small car and hire a 4WD during your holidays – you will still save heaps. (3) Buy a new fridge. If you don’t have air-conditioning or a swimming pool, your refrigerator’s electricity use is a major part of your electricity bill. New refrigerators are much more efficient than your old unit, especially if it is more than ten years old. By the way, put your old fridge on the next council cleanup for recycling. Don’t use it as a beer fridge or give it away for the same use – you do want to see electricity saved, don’t you? (4) Get rid of your freezer. Most households simply don’t need a separate freezer. You’re better off using fresh meat anyway. Instead, buy the largest refrigerator which will fit into your kitchen and use the freezer compartment in that. (5) Replace your old dish-washer. New machines use less water and consume less power. They’re much quieter, too. with a gas system. It may not be cheaper to buy or to run, but it will produce less greenhouse gases. (7) Use gas heating or a reverse-cycle air-conditioner for your home heating in winter. Gas heaters are far more expensive to buy than electric radiators but they produce less greenhouse gas to give the same (or more) heat. The same comment goes for a reverse-cycle air-conditioner. They cool in summer, as well. (8) Install a solar hot water system. This list is not comprehensive but if you really want to spend some money to reduce your greenhouse gas emissions, these are the intelligent decisions you can make. OR you can invest your money in “green” companies. If you have lazy $5000 or more laying about, why not invest it in companies which are committed to a “green” outlook. Apart from being much cheaper to drive (and therefore more greenhouse-friendly), new cars are much (6) Use gas hot water. When your electric hot water system fails, replace it There are quite a few such companies listed on the Australian Stock Exchange or you can invest in an “ethical” managed fund. That way, you benefit the environment and hopefully, make a profit as well. 18 years, you will probably never get out of the red! Can’t afford a big system? Here’s one being marketed at the moment: Pacific Solar’s "Member’s Pack”. It comprises a three-module system along with a Sunlogger (keeps track of energy generated), a Sundown program for your PC and a regular newsletter. It costs just under $6000 (and that’s after the government rebate) but the one thing you can be sure of is that you won’t ever generate much power to sell! They claim this system “on average will supply enough electricity over a year to run the lights, television, video, microwave and toaster of the average house. . .” Oh yeah? Let’s see: the three-module system at best generates 450 watts. But that doesn’t happen from dawn to dusk. Nor does it happen when it’s cloudy or rainy. We mentioned the accepted figure of available solar energy in Sydney is 1425kWh/kw per annum. With the 450W system, you’re going to produce 641kWh per year (.450 x 1425) OK, so you have this 641kWh per year to play with. Now let’s see. In order – lights in an average home, say 10 rooms with an average 75W globe; 750W. Television: oh, about 250W. Video: a modern one, say 50W. Microwave: about 1000W. Toaster (even a measly little one): 800W. All that comes to a smigeon under 3000W. Naturally, not everything is going to be on all the time. The average Aussie TV set is on for 5 hours a day. 5 hours x 365 days x 250 watts = 456kWh per annum. Most people leave their videos on constantly – 440kWh. The toaster may only get a workout for 10 minutes a day (if that) – 48kWh and the microwave perhaps half an hour a day – 182kWh. Lights, of course, vary all over the place and are usually only on for 5-6 hours a night. Let’s then assume that one third of the lights will be on at any one time – say 22kWh (probably a bit conservative because most light usage will be in the kitchen/ living/lounge room areas). That’s 456 + 440 + 48 + 182 + 22 . . . 1200kWh (1.2MWh) per annum, in round figures. Now when I was at school (it was a couple of years ago and things might have changed . . .) 1200kWh into 640kWh doesn’t go (even if I did fail maths!). So who is kidding whom? www.siliconchip.com.au March 2002  13 Solar panel installations do not have to be roof-mounted. This one is on a frame in the back yard and has the added advantage of being able to turn to track the sun, keeping the angle at the optimum for virtually the whole day. Incidentally, buying that 1200kWh from your electricity supplier at 10c per kWh will cost you the princely sum of $120. Makes the $6000 installation cost of the solar system looks pretty sick, doesn’t it? 640kWh would of course cost about $64 so you’re looking at a payback period of, oh, about 100 years give or take. Of course, all this assumes that energy costs will stay around where they are now. While most fuels have risen dramatically in recent years, electricity is one which has shown admirable restraint. Again, I remember from school in the (late!) sixties, we used a figure of 5c per kilowatt hour in maths problems. Today my power bill says I pay 9.38c per kilowatt hour – not bad for forty years of often double-digit inflation! But that’s not to say our electricity costs will not increase in the future: they probably will. Then there may be some better cost justification for domestic solar power. Costs of the solar panels themselves will almost certainly continue to fall. Not only due to costs of production but also due to the huge amount of R&D investment, solar panels will not only get cheaper in the future, they will get more efficient at converting the sun’s energy into electrical energy. And Pacific Solar, among others, are getting pretty excited about thin film solar panels which are expected to start appearing about the middle of this decade. This second generation PV technology is expected to more than halve the cost of manufacture. 14  Silicon Chip While we're talking of the future, let me throw this one in: all the reading I’ve done on this subject tells me that heat is one of the biggest problems with solar panels. So why not produce a solar panel which is water cooled – presto, a solar water heater built into the photovoltaic panel? Sounds feasible, don’t you think? Another random thought (I have plenty of those): it seems to me that cladding a roof (with tiles, iron, etc) then placing the solar panels above that is a waste of roof cladding. Why not make a solar panel which IS the roof cladding? But I digress . . . The environment Most of the “case studies” I have read involve a significant environmental commitment on the part of the homeowner installing solar power. They wanted to “do their bit” for the environment and were willing to pay to do it. Australians today are generally much more environmentally conscious than their parents or grandparents. In those days there was scant information about the environment; there was even less effort to improve it. Today, that’s all changed. We recycle our garbage as much as possible. We try not to pollute our waterways. We’re conscious about dirty car exhausts. And so on. People today get a “warm and fuzzy” feeling about doing the environment good. Even if they are sometimes misinformed or even misguided, that doesn’t hurt anyone and may leave the planet a better place for our children! If you believe in the greenhouse effect and want to minimize CO2, fair enough. Each Plug&Power module installed (or similar product from other suppliers) prevents almost 250kg of CO2 from being generated in a coalfired power station each year. Wow! (Yes, I am being facetious . . .) A 10-module installation (1.5kW) will save over 60 tonnes of CO2 over the system’s 25-year life. Again, in the overall scheme of things this isn’t going to achieve much at all. There are much better ways to reduce energy use and therefore “save the environment” (see separate panel). Despite the intense efforts of the Government and industry to promote solar energy for homes, the Australian Bureau of Statistics has indicated recently that the use of renewable energy, especially solar power for domestic purposes, has actually declined. Perhaps consumers are thinking more with their wallets than their SC hearts? References: (These are just some of the websites where you’ll find information on solar power for the home. Google "solar power" and you’ll get thousands more!) Pacific Solar ("Plug&Power" is their trademark): www.pacificsolar.com.au BP Solar: www.bp.com/bpsolar Western Power (WA): www.westernpower.com.au Citipower (Melbourne): www.citipower.com.au Energy Australia (Sydney): www.energyaustralia.com.au An excellent educational site for school projects, general information, etc: www.env.qld.gov.au/sustainable-energy/publicat/ Links to hundreds of solar power sites: www.pv.unsw.edu.au/solpages.html The "Greenhoax" effect: www.geocities.com/Yosemite/7915/Greenhoax.html (or Google "Greenhoax effect") www.siliconchip.com.au