Building Construction, Renovation, Maintenance & Advice

Costs Of Solar Power

"Coffee Pooak"

Have you ever wondered where all that whisky comes from? You know what I mean, when you see a label saying Robbie McSquirter's 200-year-old aged in the cask malt whiskey doesn't it ever strike you that 200 years ago old Robbie McSquirter could hardly have anticipated the sort of worldwide demand that might be generated from a television image of some sultry tart(an) drooling over a bottle of Robbie's best paint stripper, indeed Robbie had never even heard of a sultry tart(an).

Would he have sat there thinking “in 200 years some smooth talking international marketing bar steward is going to require two squillion barrels of aged whisky, I'd better put a couple of extra casks aside.”

So where does it all come from? How do they instantly produce large volumes of personally blended aged whisky.

Where does all the coffee luak come from?

In a similar vein we have to consider how production can keep up with demand for the world's most expensive coffee, which has increased a zillionfold in only the last few years. I've even started to see this perky percolation in the coffee equivalent of tea bags. How could this be? Considering such coffee is passed through the bowel of the civet cat, ramping up the output so to speak is not an easy task.

Perhaps the poor little civets are being asked to eat a little more, perhaps some little coffee farmer is pushing beans down their throats, even so the enormous increase in production of this so-called wonder coffee lends us to suggest that either there are thousands of farmers all over Sumatra busy ramming beans down the throats of harmless little civets and feeding the poor little blighters with laxatives to speed things up or perhaps someone is having a lend of us. Could it be that just rubbing a few beans in some cat poo might be considered good enough for a public that doesn't know any better.

Now there is a new product to consider. We now hear that coffee is being passed through the bowel of the elephant to improve its flavour. Think of those hard-working folk that spend their days trawling through piles of elephant's do da (“Hello love, your tea’s ready, have you had a busy day at the orifice?”) who report that most coffee beans become damaged in their passage through the elephant’s passage and so you have to search through rather a lot of do da to get only a small number of beans.

To make such things commercially viable, of course, you have to go for mass production, not an easy task when the whole process depends upon bowel movements. Volume sales go up, more money is made, more research gets done, production costs come down, prices come down leading to volumes going up and before you know it every elephant all over the world will be eating coffee beans. There just won’t be enough elephants now will there? At least it might help to save them from the poachers and pianists.

Mass production reduces costs

Mass production now there’s a thing. Our whole world started to change dramatically in 1726 when the first cotton mills introduced the world to serious mass production. These days economies run on it and products survive or fail on it. We only have to think of the astronomical scale of the launch of an iphone or an ipad. Think of the logistics of launching a new smart phone and having to have around 5 million in stock ready to go on launch day.

The basic motivating factor is that mass production brings costs down dramatically. If you can increase sales sufficiently you can invest in more sophistication in the manufacturing department. In some cases mass production doesn’t manage to take its course. A case in point is in the field of solar electric power. It has been around for some time now but somehow the cycle of demand fuelling research to bring the cost of photovoltaic cells down doesn’t appear to have happened sufficiently to make solar panels viable.

Demand is not yet sufficient to make solar panels economically viable

Photovoltaics are semiconductors that convert solar radiation (sunshine) into electricity. As we know photovoltaic materials are used to make solar cells which are assembled into solar panels. These form the basis for photovoltaic solar power generation systemsUnknown to most of us photovoltaic systems are very common in many households in remote areas of Indonesia. These have been installed by the national power provider, PLN, in remote areas that do not have mains power distribution. These systems tend to be very small and only provide some rudimentary level of lighting.

In developed countries photovoltaic systems have been around for quite a while and are becoming used widely for situations where mains power is not readily available such as street lights, signs and traffic lights. Takeup of these systems for home power generation, however, is still at very low levels owing to the high cost of installing systems relative to the low levels of power such systems can generate.

Technology keeps advancing both in the generating capacity of solar panels and in the development of electrical equipment that uses lower levels of power. More specifically with the recent availability of high quality LED lighting we can reduce the power we need to light our homes and workplaces.

How efficient are solar panels?

Let us look at some basic considerations.

How much sunshine do we have? If you live in Australia where the solar radiation is higher than in most other parts of the world solar power is most effective.

Latitude has a major impact on solar power generation, the further away from the equator you are the lower the sun is in the sky and the more atmosphere the sun’s rays must pass through to get to you. To collect as much solar radiation as possible solar panels should be tilted to be at right angles to the sun’s rays. In Bali we are 8 degrees South of the equator so solar panels should be tilted 8 degrees to the North.

Time of the day is just as important and most power is generated in the middle of the day when the sun is directly overhead.

Add to these factors cloudy skies and air pollution levels which both reduce solar radiation levels reaching your panels and we see that the theoretical maximum power output of a solar panel is seldom achieved and in addition panels must be kept clean and should not be vulnerable to shadows from trees or buildings. For calculation purposes we can assume that in Bali close to the equator we can expect to get 4.5 hours of effective sunshine per day.

A typical solar panel (depending on size and efficiency) can generate up to 200 watts of power in full sun. As we have said we can expect 4.5 hours of full sunlight a day giving us a total power generation from one panel of 900 watthours or 0.9 of a kilowatt hour (kWh) each day. Like all generation systems we have to expect inefficiencies which we can expect to multiply up to losses of around 45%, our panel will effectively give us around 500 watt hours of electricity per day.

To put this into perspective a one PK air conditioner (an average bedroom size) will use around 750 watts of power so in a full day on a sunny day our solar panel will generate enough power to run our air conditioner for only about 40 minutes. To run one air conditioner for 8 hours we will need 12 solar panels.

Solar electric systems are good for lighting but not electric motors

Generally speaking photovoltaic systems are not good for supplying the power for electrical equipment that use electric motors such as pumps, air conditioners, refrigerators and washing machines or items that have electric heating elements such as water heaters, hair driers electric kettles and washing machine heaters.

Lighting and electronic controls such as security systems, however, are another matter and one solar panel can power 9 high power 5.5 watt LEDs for 10 hours, suddenly for certain applications solar power is starting to look viable.

Hybrid systems

This also opens the opportunity for installing hybrid systems that use different power sources for different purposes so, for example we can combine gas for cooking, mains electrical power for pumps and air conditioners and solar for heating water and lighting.

Solar power generation is one area where technological advances have been disappointingly slow probably due to a lack of serious investment or will. New developments are progressing with a new type of photovoltaic being worked on that promises to boost the amount of power one solar panel can generate. If we could get over the “hump” in this initial developmental period and get the mass production cycle going we might start to see more development and lower prices but don't hold your breath, for some reason progress seems to be slow.

Unfortunately unlike the civet cat laxatives don't work on solar panels.

Copyright © Phil Wilson 2013
This article or any part of it cannot be copied or reproduced without permission from the copyright owner.

17 July 2017 Copyright © Mr Fixit,
Jl Bypass Ngurah Rai, Gg Penyu No 1, Sanur, Bali 80228, Indonesia
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