Energy Transfer & Efficiency

Energy Transfer

Let's say you have a light which is plugged into the wall at home. You then flick the switch on. What happens? In most circumstances, it turns on a light, and you get a little heat from it too.

But what does this mean?

Basically, it means that there has been a transfer of energy, in the form of electrical power. From the switch and the plug, when it's turned on, to powering the unit (light) and also creating the heat from the bulb.

So, why does it create the heat?

This is known as wasted energy. The heat that is created is kind of like an overspill of energy. In another example, if you run a tap, and put a plug in the sink, what will happen if you leave the tap running? It'll overflow. This then becomes a waste of water. The same can be said for the energy.

While the light is turned on, this same principle can be applied. The excess energy is "wasted" in terms of being heat, and is not used for it's intended purpose as a light.

Here is a YouTube video from doodle science about how energy transfers with efficiency:

Conservation of Energy

We can conserve energy. In the light example, we can do several things to conserve energy, and even prevent energy being wasted. These include:

• changing the wattage of the lightbulb
• changing the lightbulb to an LED (Light Emitting Diode)
• switch off the light when not needed for use

If we change the wattage, it will use less energy. If you run an old bulb at 60W, and change it for an energy saver at 11W, it will save you money (in the long run), and use less energy.

Interesting fact: when you keep opening the fridge door, it lets out 30% of the cold air from the fridge, which then consumes more energy. So best to keep it shut unless necessary.

If you change lightbulb to an LED, this will also save you money, as they use minimal amounts of power, and also don't heat up.

Switching the light off when you don't need to use it, will obviously use the least amount of energy.

Efficiency

In today's modern world, we buy products that often only last a few years. This can be a bad thing, depending on the product, but also it could mean you get more energy efficient products that use less energy as a result of replacing an old appliance.

Efficiency works for both electricity, and chemical based inputs. These include everyday items like:

• boiling a kettle with the right amount of water
• dropping the temperature of your washing machine to wash in energy efficient temperatures (around 30 or even 20° Celcius)
• allowing enough room around a fridge/freezer so it doesn't overheat