WHAT IS ALTERNATIVE ENERGY?
As Eskom struggles to find their feet, battling load shedding, not enough generating capacity and an ever growing demand, there is mention at every corner about ‘alternative energy’. So what is this all about?
Traditionally, alternative energy refers to an energy source that has no undesired consequence as what fossil fuels and nuclear energy have. An energy source that is aimed at reducing our dependency on fossil fuels. Over time, this definition has changed. In our current South African environment with all the discussion and controversy surrounding Eskom and load shedding, ‘alternative energy’ has taken on the meaning of ‘anything other than power supplied by Eskom’.
Alternative energy covers a wide range of products and services with a variety of different uses; from generators, keeping the lights on during load shedding, to LED lighting for lowering electricity consumption to battery packs with the aim of completely eliminating Eskom from your monthly budget and going off the grid.
Most forms of alternative energy are classified under ‘natural’ or ‘renewable energy’. Such types would include solar power, hydroelectric power, wind energy, geothermal energy as well as ocean energy. Each of these alternative energy types are completely renewable, meaning they will not run out and can be reproduced again and again with little to no pollution.
With the state the world is in and the way things are going with pollution rising and global warming, maybe its not a bad idea to go completely renewable.
Probably the most common form of alternative energy, solar power is a major market right now. With products from calculators using tiny solar power panels all the way though to big houses using solar power to run their entire home to go completely off the grid, the use of harnessing the suns natural energy is almost limitless.
There are two types of solar energy, active and passive. Passive uses position, duration and the sun’s rays to achieve its goal of heating something specific or a particular area. This is similar to you taking a mirror and reflecting it onto someone or something.
Active solar energy works differently by using photovoltaic cells (PV cells) to covert the sun’s energy into electricity. It doses this through its structure. A solar panel is made up of a bunch of silicon based materials called PV cells that absorb the suns light, causing the electrons to move in a direction, known as current. This current is in the form of direct current (DC), which would need to be changed to alternating current (AC). This conversion is done through an inverter.
Because the electrical output of one single cell is too small, they are arranged in a certain way and grouped together to form an array, which is then able to give much more output and meet a greater demand for power.
This form of alternative energy has far greater global energy potential than any other type and is extremely effective, clean, renewable and, once all your hardware is in place, free and limitless.
An essential part of installing an alternative energy system is the inverter. But to understand what an inverter does, one must first understand the difference between alternating current (AC) and direct current (DC) and how they work.
Electric current is the flow of electric charge carried by electrons. In this example, we’ll use a battery powered torch to explain.
Direct current; this can be thought of as a line of ants/electrons all moving in one direction. Suppose we connected a battery to a torch and turned it on, all the electrons pass through, getting refuelled by the battery and dispersing their energy on the light bulb and returning to the other end of the battery.
If you took the battery out and put it back in the other way (assuming it could fit), the current would flow exactly the same, in direct current, but the opposite way. That’s the only difference.
Alternating current works by continually changing the direction of the current; 50-60 times per second. Now lets assume you were fast enough to change the battery around 50-60 times per second, allowing the electrons to only move a very small distance before changing to the other direction, you would in essence be, a mechanical inverter of sorts. Instead of electrons running through a circuit to generate power, they would be running on almost the same spot.
An inverter does just that, but nowadays without having to manually switch directions of the current. It takes DC and electronically converts it into AC, electronically ‘changing the battery around’. A very important point to note is that the inverter does not actually produce any power, the power is provided from the dc source.
Almost all appliances run on AC and therefore require an inverter. The only thing left to find out is where to get yourself an inverter?
Wind, the movement of air from one area to another. A natural movement of the elements. But what about harnessing this movement as a form of alternative energy to help power our lives?
Wind is created when one area is heated up by then sun. The hot air rises, which results in a low pressure cell. Cooler air rushes in to fill that gap, therefore creating wind. In areas that are particularly windy by nature, wind farms are erected to harness this natural energy to turn it into usable electricity.
So how does a wind turbine turn an element into a form of alternative energy? Wind turbines work on a very simple principle, the opposite to a fan, in fact. Instead of using electricity to make wind, it uses wind to make electricity. The wind turns two or three propeller-like blades which spins a shaft that’s connected to a generator to make electricity. Limitless, clean alternative energy.
As of June 2014, with over 200 000 wind turbines in operation, wind power was making up for about 4% of the world’s total electricity usage and its capacity had expanded to an estimated 336 Gigawatts and is on the rapid increase. Maybe with more effort and reseach, we’ll see the majority of the world being powered by alternative energy.
GENERATORS AND ALTERNATORS
The mention of generators has become somewhat of a daily occurrence in today’s South African lifestyle. They have become a necessity, in fact, to maintain the regular flow of business and ensure continuation of revenue. To most people, a generator is just something that keeps the lights on when Eskom doesn’t, but it goes a bit deeper than that.
Firstly, following the famous words of Albert Einstein; “’Energy cannot be created or destroyed, it can only be changed from one form to another”, it’s important to note that a generator does not create electricity. It works in the opposite to an electric motor. Rather than spinning when electricity is applied, a generator makes electricity when parts inside it are spun.
So, by attaching a generator or alternator (which works on a very similar principle) to a moving part is what creates the electricity, providing you with a source of alternative energy. Put in more practical terms, take a wind turbine, for example. The wind turbines blades catch the wind and turn a rotor which is connected to a shaft. The shaft is attached to a generator which turns mechanical energy into electrical energy.
Most of today’s generators are used to combat load shedding and are driven by an engine which is powered by a fossil fuel. The combustion of this is what creates the mechanical energy which is then converted into electrical energy, used as a solution to load shedding.
There is a lot more to generators, but let’s keep it to the basics for now.