It’s easy to presume when we see bright neon lights that they must use a lot of electricity.  The dazzling neon glow is so intense that it can be seen even in daylight and it seems logical that so much light can only be achieved by using a lot of energy.  So it is surprising to find that neon lights are actually very energy efficient.

How Neon Lights Work

I am not a scientist so this is a very simplified explanation that will probably have physicists choking on their coffee.  A traditional light bulb works by heating up a thin strip of metal.  Tungsten is the usual metal used as it melts at a very high temperature.  When it gets hot enough, the metal strip will emit light.  In normal circumstances, the tungsten would catch fire when it gets this hot so to prevent this happening it is enclosed in a glass shell filled with an inert gas, usually argon. A lot of the energy used to by a light bulb is wasted as heat, as you can tell if you touch a light bulb that has been on for a while.

Neon lights work in a completely different way that does not waste energy producing heat, which is why a neon light is always cool to the touch even if it has been on for hours.  A neon light is made up of a glass tube filled with neon gas and sealed with electrodes at each end.  When an electric current is fired between the two electrodes it ‘pulls’ an electron away from a neon atom.  Neon is an inert gas, which means it doesn’t really react to or combine with other elements very much and it is reluctant to let go of its electrons.  When an electron, now known as a free electron,  escaped it becomes negatively charged so it is pulled towards the positive electrode.  The neon atom that has lost its electron, now known as an ion, is now positively charged so it is sucked toward the negative electrode.  So you have neon atoms, ions and electrons crashing into each other and the ions and free electrons recombining to makes full neon atoms and all this creates a lot of energy that we see as light.

A light bulb needs to continually heat its tungsten element to create light.  However, although a big surge of energy is needed to start the process of neon emitting light, once it has started it is pretty much self-fuelling and needs very little energy to keep going. An electrical transformer steps up normal voltage to between 2000 volts and 15000 volts to get a neon light started.  This means that neon lights actually use much less energy than a traditional light bulb and are therefore more energy efficient.

How Much Energy Does a Neon Light Use?

To keep things simple let’s use watts to measure how much energy a neon light uses.  If you have a neon light that is a foot long it will consume between 20 to 40 watts.  Things such as how thick the tube is and what kind of transformer is used will affect the amount of energy used.  Most traditional light bulbs are between 75 and 100 watts.  A fluorescent light uses twice as much as a neon light.

Will Leaving My Sign On Save Money?

Surprisingly the answer is yes! Remember there’s an initial burst of energy needed to get the neon glowing but after that it is very energy efficient process with no energy being wasted as heat.  So leaving it on will actually cost you less than turning it on and off.  Great news if you are using it as an advertising sign.

Are LED Neon Lights More Energy Efficient?

The latest advancement in neon lighting is LED neon.  LED stands for Light Emitting Diode.  The non-physicist’s explanation for how they work is that a diode has one side full of electrons and the other side with hardly any electrons.  The over-full side of the diode send electrons rushing to the other side but they have to go through something called the p-n junction.  This junction is opened by applying power (electricity) to it and when the electrons squeeze through they give off light.  Just like traditional neon lights, no energy is wasted creating heat so LEDs are much more energy efficient than a traditional bulb and they don’t get hot when in use.  They are also more energy efficient than traditional neon lights because they don’t need a big surge of power to get the electrons moving.  To create about the same amount of light a traditional bulb uses 75 watts, a neon light uses 20 watts and a LED neon uses about 14 watts.

The shift to using LED neon has made neon signs much more affordable.  As well as being cheaper to use they are also cheaper to make.  This is good news for a business thinking of using a neon sign to advertise their business.  It has also led to neon signs being used in interior design as using cheaper, safer LED neon makes them a practical choice.