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Problems with Electricity Supply

"Energy, Emissions and All That"

Now there's a subject, I might not manage to fully cover this topic in a mere 1,200 words so I hope you don't mind if leave out the section of thermo nuclear fission and the bit about the behaviour of rocket motors in the oxygen free environment of space.

Energy is pretty useful stuff. Imagine trying to get out of bed in the morning if there was no such thing as energy? Breakfast would be pretty boring too, no cup of coffee, no toast.

But energy is becoming a bit of a problem isn't it? We use so much of the stuff and there are more and more people in the world doing such important things as powering their electric nasal hair clippers, squirting water in the air because it looks pretty and making snow for skiing centres in Saudi Arabia.

There is an ever increasing demand for energy. The world population continues to expand (I notice a group in Jakarta consider family planning to be a heinous plot by the West to take over the world) and there is a worldwide commitment to raising people out of poverty, 40% of the Indonesian population we are told, now that is a lot of people. How many more washing machines, refrigerator, televisions and motor cycles will this mean have to be supplied with power?

It is becoming more and more obvious here in Indonesia that PLN simply cannot keep up with demand. They are trying though, why only last week a nice little PLN man came round asking if I had any spare electrons. He said they'd run out and were doing a bit of a whip around to rustle a few up.

Recently a major power blackout hit most of Bali. News from Java is that there are serious problems and we have been warned of rolling blackouts through the next few months. With a serious lack of infrastructure planning in Indonesia we can only expect things to get worse. The supply voltage is dropping to very low levels and this can damage electrical and electronic equipment notably air conditioner control circuits to say nothing of the tempers of grumpy old men.

The building industry continues apace with new villas going up everywhere and most, I have to say, are not designed to be energy efficient. Many people arriving in Bali are used to unrestricted supplies of electricity and expect unreasonably large amounts of power to be available to their nice new villas. The bad news for them is that this will have to change. Word on the grapevine is that it is getting much harder to get a PLN supply connected particularly if you want more than 7,700 watts.

The hard reality of PLN's crisis is that we are all going to be affected by it. The fact is that we do not need to use such large amounts of energy, all we need to do is get a lot smarter in how we use it. Up until now most decisions have been made based purely on a financial basis and here in Indonesia electricity is subsidised by the government and is very cheap. Low prices are not a great incentive to help reduce demand but are essential when there are so many very poor people around.

Perhaps we should start to think more about where our energy comes from, the form it is in and how efficient it is to use. While we are at it we could also consider the closely related issue of how dirty it is. In spite of living on top of volcanoes our power in Bali comes from burning coal – very dirty stuff.

Every now and again I pick up a newspaper and see yet another advert for an “Emissions free” car. I find myself pondering on how such a vehicle may be powered. My conclusion is that if it is truly “emissions free” it is obviously one of those cars you park in your driveway to show off to the neighbours but you never actually drive.

There are some bright sparks in this world that think that if you plug a car into an electric socket then it is emissions free, where on earth do they think the electricity comes from? The fact is that a car charged up through a plug socket may be cheaper, thanks to the low cost of subsidised electricity, but to declare it emissions free is rather like saying that Rolf Harris's wobble board is a classical instrument.

Why? Well it all goes back to some basic physics. The basic rule of energy - “Energy can neither be created not destroyed but can be merely changed from one form to another.”

Something we should all understand is that it requires a lot of energy to convert energy from one form to another. Boy scouts very quickly find out about the effort required to boil a bit of water, collecting wood, rubbing sticks together and all that.

(I must warn you that the next paragraph is very long and you might find it really, really boring. Perhaps now is the time to go and get a nice cup of coffee).

So where does the power come from to power our electric car ? Well it starts with diesel powered excavators digging coal out of the ground in Kalimantan, electric powered machinery crushes and sorts it and sends it on electric powered conveyors to storage piles at a loading dock. Diesel powered scoops then put the coal onto electric conveyors to load it into barges. The diesel powered barges carry the coal across the sea of Java to Surabaya where electric powered equipment unloads it onto storage piles on the dock. Diesel powered scoops pick up the coal and put it onto electric conveyor belts which take it to the power station where electric powered crushing equipment crushes it into a fine powder which is then blown with electric fans into the power station furnace where it burns to convert it into heat energy (much of which goes up the chimney) but some is transferred into water to boil it to produce pressurised steam. The steam is then fed into turbines which turn electric generators to produce electricity. The now pressureless (and therefore useless) steam is fed into cooling towers to cool it down and convert it back into water expelling vast amounts of heat into the atmosphere. The electricity is now fed down long transmission lines from Surabaya to Bali and, through leakage, a lot of electricity is lost along the way. Finally the energy arrives at our plug socket. We plug the car in and the energy flows into our car being converted into chemical energy stored in our car battery. We now get in the car and switch it on. The chemical energy is converted back into electrical energy which goes to the electric motor where it is converted into mechanical energy to drive the car along the road.

I have a sneaky suspicion that this is not emissions free. Mind you, the way PLN is going, an electric car will certainly be emissions free during blackouts!

If we think about the form our energy is in and what we use it for this may lead us to alternatives. Firstly in Indonesia electricity is produced from coal and coal has a very dirty reputation as far as emissions go. It is an understatement to say that the efficiency of Indonesian coal fired power stations is probably not as high as it could be. A lot of energy is wasted when we produce electricity.

Note the process, we burn coal to make heat which then pressurises steam, we use the steam to create mechanical (kinetic) energy to drive turbines, we use the rotation of turbines to generate electricity, which is then used to heat water for our cup of tea. This seems like a mindbogglingly inefficient process which of course it is. Wouldn't it be more sensible to burn a bit of gas to produce the heat for our tea (or for our shower for that matter)? Even better heat it with the sun.

For some things, such as lighting, television sets and computers electricity is, of course, the only choice. Relatively speaking these items do not tend to use a lot of energy. In contrast the functions that tend to use the largest amounts of electricity are those that use mechanical or heat energy such as electric kettles, water heaters, water pumps and compressors for refrigerators and air conditioners. Unless you have two hundred lights in your garden it is the heating and mechanical functions that need most attention in finding alternatives.

The ideal is to stay within the form of energy we require. The sun gives us heat and so is best for heating things (solar hot water heaters). Wind and water movement gives us kinetic energy which is good for pumping water or driving machinery. The windmills and watermills of old were very powerful machines, energy was free and no emissions.

Are we getting smarter I ask myself? Well yes we are and a heatpump / air conditioner is an interesting example. The electricity is used in these machines not to create heat but to move heat. A heat pump takes only a quarter of a kilowatthour of power to generate a kilowatthour of cooling (air conditioner) or heating (heatpump).

Major hotels in Bali these days are saving very large amounts of money (to say nothing of emissions) by replacing oil burning boilers with heat pumps to provide their hot water.

Second best is to convert our energy only once. Burn gas to produce heat to cook.

Use photovoltaic cells to convert solar radiation directly into electricity for electronics or lighting.

Use wind or water movement to generate electricity. There are exciting developments happening in many parts of the world. In some parts of Indonesia there are very small scale hydro electric systems being installed capable of powering whole villages.

We are living in a time of great change, unfortunately the motivation for this change is necessity. Now is a good time to really start looking at our energy use. PLN are, in fact, playing their part and motivating us to take action. Next issue we might look at where we use most energy and perhaps find some alternatives.

Copyright © Phil Wilson August 2009
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