By Kelvin Kemm
The Sun has mystified mankind for centuries. In days long gone, primitive people worshiped the Sun or a Sun God. But much more recently, in the later 1800s, people were still mystified because by then science had advanced a great deal and physicists had acquired a significant understanding of thermodynamics and energy. They knew that thermodynamics states that energy can neither be created nor destroyed, and it can only be converted to another form. They also knew how to calculate the heat emitted from burning coal, wood, or anything else.
Astronomers and physicists had also come to the realization that the Sun was billions of years old and appeared to be going strong for a few billion more.
The physics calculations of the time showed that the Sun should be impossible.
The calculations showed that the Sun could not possibly have burned for millions of years, let alone billions, and that it was destined to burn out soon.
But mysteriously, it was doing just fine. The year 1900 arrived, and five years later, some young upstart physicist started to say crazy impossible-sounding things. He made wild claims. His name was Albert Einstein.
He came up with a crazy equation; E= mc2. This said that energy obtained (E) was equal to the mass of anything (m) multiplied by the speed of light squared (c2). This comes out at a huge number. In fact, it tells you that something like an ordinary household brick, if converted to energy, would drive a large ship around the world over 100 times.
The equation applied to nuclear power. It said that you could turn atoms into energy, that is heat and light. This equation appeared to contradict the laws of thermodynamics.
Using that equation showed that the Sun was not burning stuff like coal, it was turning its own atoms into energy. It was a giant nuclear reactor.
Finally, physicists could explain the age of the Sun.
A few years later, Einstein was awarded the Nobel Prize… he got it for explaining how solar panels worked. That was something he sort of did in his spare time, when he was not figuring out how the Sun stayed alive.
So, all the solar power arriving at the Earth is actually nuclear power, from a giant nuclear reactor.
When the Sun’s rays arrive at the Earth’s surface, it is possible to get about 20% of it to turn into electricity. At lunchtime, the Sun’s rays are about one kilowatt per square meter.
Any energy which makes engineering and financial sense should be used. So, we should use solar power, but its use must be governed by sense and reality, not by fantasy and dreams.
That means real economics employing real engineering.
You only get solar power when the Sun shines. Furthermore, you only get the maximum when the Sun is directly overhead. Before morning teatime and after afternoon teatime, you only get about half because the sunlight is coming in at a steep angle. Therefore, much less falls on the square meter. Try this with a flashlight on the lounge wall.
So, the best thing to do with solar power is to use it where it is appropriate and for an appropriate purpose. What people need to do is to find usage patterns which match the natural solar patterns. Alternatively, use solar in remote locations in which it would be impractical to run electric cables from any other source. For example, power a radio repeater station which is far out in a remote area, or open and close an electric farm gate.
Those are low current requirements yet are most valuable applications.
So let us look at higher current applications. How about pumping water into storage tanks on a farm or industrial site? In such an application it is not necessary to pump all day, so it is fine if the pumps only work when the Sun is shining.
Let me propose another idea, a company manufacturing wooden furniture. Let us assume that it is run using only solar power. In the morning, the workforce comes in and measures up the wood, draws pencil lines. I have to start at some point in the cycle. Then after morning teatime, as the Sun climbs in the sky, they start to use cutting and drilling machines which need electricity. This goes on with shaping and sanding until around afternoon teatime. Then, they stop the machines and start to glue and screw all the prepared parts together. Then, there is varnishing, painting, and adding the metal handles and locks. Meanwhile, they have charged a small battery bank. They go home. The next morning when they arrive at work, the battery will supply electricity for some lighting, computers, and tea and coffee. So the cycle goes.
Unfortunately, politics and fantasy have intruded into solar power to such a degree that people are trying to force solar power to perform functions for which it is not suited. You cannot run an electric train on solar. You can’t drive a steel foundry on solar. You can’t risk open-heart surgery in a theatre run entirely by solar, nor can you run a mine.
The large solar arrays that we are seeing are there because politics is telling you that they will ‘save the planet,’ but in fact, they are quite dangerous to an electricity grid. That is because they can create huge instability into a system, resulting in a crash. That is what happened in Spain recently. Huge solar arrays also create a significant system-management problem. For a system controller, it is obviously far more difficult to try to manage hugely varying amounts than it is to manage a far more continuous, reliable source of supply.
I am all in favor of using solar, but don’t force it to perform functions for which it is clearly not suited. At the end of the day, excuse the pun, it is the consumer who pays for all the mismatches.
