Electrical Power Misconceptions (Part 1)

PART ONE OF THREE PARTS

With these three posts, I hope to explain some of the misconceptions people have about the generation and supply of electrical power.

The invidious task I have is to try and counter the insidious creeping malaise that is slowly infecting us all, that being how solar power and wind power can be easily implemented so we can forever shut down those coal fired power plants that are contributing to global warming climate change by emitting Carbon Dioxide (CO2) the single greenhouse gas that we are told is contributing to a disaster of unparalleled proportions. I try and explain these things from the point of view of showing what the consequences will be.

The difficult part of my task is to explain something that is quite technical by its very nature, and to then try and reduce that highly technical content to something that can be easily understood. The problem is that the other side has effectively reduced that technical content to tiny sound bytes that make it all sound as if it is quite a simple thing. The public is unaware of the technical aspects, and have believed what they are being told without understanding the dire consequences, or just how marginal these forms of electrical power generation are, and in fact, cannot replace those large coal fired power plants.



The explanation of those technical aspects has led some readers to perceive that I have another agenda, not because I actually have that agenda, but that they just cannot understand those technical aspects when they have been confidently told that it is in fact quite a simple thing to do, and because of that, then anything I say in explanation goes completely against what they have heard and read from sources who themselves have no idea just how technical it really is.

So, what I will again try to do with these posts is to try and explain the complexities of some of those things that are really just misconceptions. Keep in mind that if something is repeated often enough, then it reaches such a huge audience, that it then becomes the truth, making it harder to explain the reality of the facts behind it.

In the previous post I explained how the Solar option has been made to sound like it is the saviour in a situation like this, and how the simplicity of the argument has been accepted.

To follow on from that, I offer this simple idea that has gained traction here in Australia, so much so that it is actually looked upon as an attractive option.

The idea is to place a gazillion mirrors or solar cells in one of the hot deserts in Central Australia where the Sun shines all the time, (even at night it seems) and the power generated from this will be enough to power the whole of the Australian Continent.

That throws up the first of the misconceptions. If something of this scale was done, (and let’s actually pretend a ridiculous idea like this could be implemented) then it’s just a matter of connecting all of Australia to that huge plant with the one gigantic electrical grid.

The same can be said of what President Obama first mooted during the election campaign, and then again since he has taken Office, and has also been included as part of the Economic Stimulus Package, that being that work should start on what has been termed ‘A Smart Grid’.

The Smart Grid.

The idea of this is that realistically, the whole of the U.S. can be interconnected together so that all the power plants in the U.S. can supply all the power requirements for the whole of the U.S. the idea being that power that is surplus in some areas can be used in areas where they may be a deficit, or the threat of an approaching deficit, thus lessening the need for some of those power plants, the main targets being those large coal fired power plants.

It’s a great idea but is actually impossible.

The nature of electrical power is that it cannot be transmitted across the vast distances that the intent of the statement might suggest. This is because no matter how close to perfect that the wire conductors are, there is always a voltage drop along those wires because of the inherent electrical resistance of those wires.

On a smaller scale this can be demonstrated with an everyday electrical item used in some households.

In the U.S. your electrical power supply is 115 Volts AC supplied at 60 Hertz, while here in Australia, we use 240 Volts AC supplied at 50 Hertz. So electrical items used in the U.S. cannot be used here in Australia and vice versa.

I use the example of an electric line trimmer that some people use to trim the edges of their lawns. These electric line trimmers have been known to have the electric motors burn out, mainly because the people using them have no idea about how electrical power is used by the items attached by power cords to the ‘hole in the wall’, the idea being that if the hole in the wall supplies that 115 Volts, then it will be available at the item itself, which is no problem inside the house, because there are plenty of power points and any item is usually placed close to that point, negating the need for long extension leads.

However, outside the house, it is different. There is usually only one point outside, or one in the garage, so to trim the edges with one of these items, you actually need an extension lead, and sometimes a long one if you wish to reach all the far points of the lawn and gardens. An average length extension lead will suffice in most cases as the voltage drop along its length still leaves enough voltage to run the electric motor in items like this within the limits of the motor itself.

However, if you use a long extension lead, then some people might find that the trimmer runs slower, and some with really long leads find that the trimmer does not even turn over at all. Further to this, some will actually burn out the electric motor that drives the whizzing line.

Why this happens is that even though the power at the wall is a dedicated 115 Volts, there is voltage dropped across the length of the extension lead, so at the motor in the tool itself, that voltage can be considerably reduced to the point that instead of driving the electric motor, it tries to turn it over, but the voltage is just too low, and the electric motor overheats, and eventually burns out, usually accompanied by an expensive brown odour.

The same applies on the much larger scale with high tension electrical transmission lines. Even though the voltage is of an incredibly high value some of that voltage is lost in the transmission. When it arrives to where it is used, sub stations have huge transformers to transform that power from the incredibly high number back down to the 115 Volts for the area supplied locally from that substation.

The concept being proposed leads into the idea that large solar plants can be constructed in areas where the Sun does shine constantly and the power generated can then be used across the whole of the grid, giving the impression that huge solar plants in places like Death Valley could effectively power areas in the North East where the largest amounts of power are used. The same would apply for those large wind towers. Put them all in really windy places, and then transmit the power the vast distances where it can be used.

It just cannot be done, no matter how smart the grid.

The power used in those areas actually needs to be generated in areas close by where it is actually used.

Hundreds of miles ….. yes.

Thousands of miles ….. no.

Some States actually source their power from neighbouring States, but the idea of a solar plant in Arizona providing power for Maine is totally out of the question.

If the grid is updated at immense cost, then it is true that savings in transmitted power versus delivered power can be found, and in some cases, where the grid has been allowed to degrade because of decades of inaction from Governments both State and Federal, then the upgrade of that grid will see more power available to consumers. However, that amount is still only at the margins, and while overall power consumption in the US steadily increases by around 2.5% a year, any amounts of ‘new’ power coming on line and available to consumers does not cover the slowly decreasing amount of available as older plants reach the end of their lives. This is again a problem of Governments that have become complacent and not willing to invest in new power plants over the years, and now have reached the stage where those old plants have reached the end of their useful life, and there is nothing new to replace them with, because now, well intentioned people will veto any new plant of a large kind.

So, the underlying ‘suggestion’ that a smart grid can connect everybody to every plant is erroneous.

In the next post I will deal with some of the other aspects of electrical power generation that have been reduced to sound bytes that lead people to believe one thing when in actual fact, the opposite is the case.