Energy Efficiency Of Low Voltage Lighting

One of the major advantages and most attractive features of low voltage lighting is the relatively high energy efficiency and low power consumption in comparison to standard incandescent light bulbs.

This of course translates into lower energy usage, lower electricity bills and more money in your pocket at the end of the month.

However, as there are many different types of energy saving light bulbs on the market, which one you choose to use in your home will largely determine what sort of savings you will experience.

Although, since all the energy efficient bulbs use less power than regular incandescent bulbs, whichever one you choose to use for home lighting is still going to save you money.

Below you shall find a comparison of the different types of low voltage indoor lighting, and their respective energy efficiency rating. But to begin with, let’s look at the energy efficiency of a standard incandescent light bulb as that is what most people will be upgrading from.

Incandescent Light Bulb

Standard incandescent bulbs typically have an energy efficiency rating of about 5-10%. As a result, 90-95% of the energy used by the bulb is wasted, most of which is lost as heat.

This is why regular light bulbs get so hot after they have been on for awhile. In fact, incandescent bulbs can get so hot that you could easily burn yourself on a 100 or 120 watt light bulb that has been left on for a few minutes.

One of the main reasons why incandescent bulbs are so inefficient is because they have a very thin filament. This provides a lot of resistance to the passing electrical current, which subsequently causes the bulb to produce a lot of radiant heat.

So in terms of energy efficiency, incandescent bulbs would have to be given an F rating as they are the least energy efficient form of domestic lighting and the most expensive to run.

Halogen-Tungsten Lighting

Although halogen-tungsten light bulbs have a similar energy efficiency rating as incandescent bulbs (around 15%), they are classified as low voltage lighting because they consume far less power than incandescent bulbs.

Rather than being fed directly from the mains electricity supply, tungsten-halogen lights operate at a non lethal 12 volts.

However, in order to do this, they must first be connected to a transformer which supplies the appropriate voltage, although some newer halogen lights now come with built in transformers.

Halogen-tungsten lights have a much thicker and more robust filament that provides less resistance to the passing electrical current compared to the filaments found in regular incandescent bulbs.

This thicker filament allows the bulb to run hotter and produce more light whilst using less power than incandescent bulbs.

Newer generation halogen-tungsten lights, often referred to as energy saving halogen light bulbs, are even more energy efficient, typically consuming around 30% less electricity than regular halogen lights.

We give halogen lights an energy efficiency rating of C. They are more energy efficient and use less power than regular incandescent bulbs, but are still based on the same type of lighting technology which means they can never be as energy efficient as other types of low voltage lighting.

Low Voltage Fluorescent Tube Lights

With an energy efficiency rating of around 60%, fluorescent tubes were for a long time the most energy efficient low voltage lighting solution available.

As a result of their high energy efficiency, fluorescent tubes are cool to the touch and generate very little heat.

In fact, this is a quick way to determine how energy efficient a light bulb really is, as generally, you will find that the cooler something runs the more energy efficient it is because the less energy it is wasting as heat.

Fluorescent tubes employ a mixture of argon and mercury as a means of generating light. This means that they have no filament which can burn out which subsequently makes fluorescent tube lighting extremely long lasting.

Due to their low power consumption and high energy efficiency, fluorescent tubes are given a grade B energy efficiency rating.

Note: Although some fluorescent tubes can have an energy efficiency of around 60%, it is important to note that this can depend on the quality of the lighting equipment.

Some fluorescent tubes for example, can have an energy efficiency of as little as 15%, although this tends only to be the case for the lower quality or older tubes. Newer and higher quality tubes, should have an energy efficiency of or approaching 60%.

Furthermore, lighting reflectors may be used behind lower powered fluorescent tubes to reflect light that would otherwise be lost behind the tube.

If a high quality lighting reflector is used, a lower rated fluorescent tube will be able to produce almost the same amount of luminosity as a higher rated fluorescent tube without a reflector.

Compact Fluorescent Light Bulbs (CFL)

Compact fluorescent light bulbs are being heavily promoted as an energy efficient low voltage indoor lighting alternative to incandescent bulbs, and for good reason.

Compact fluorescent bulbs use a similar technology to fluorescent tubes, which gives them a relatively long lifespan and an energy efficiency rating of about 50%.

Because of this high energy efficiency, a 20 watt compact fluorescent light bulb can produce as much light as a 100 watt incandescent bulb. In other words, you would need five 20 watt energy saving bulbs to use up the same amount of electricity as one 100 watt standard incandescent bulb!

As the most popular type of low voltage indoor lighting, fluorescent bulbs are cheap, easy to obtain, and when used to replace incandescent bulbs, can result in a noticeable reduction in electricity bills.

On average, using a CFL energy saver bulb will save you about £2.50 or $4 per year per bulb on your electricity bills in comparison to if you were using an incandescent bulb. If you have 10 bulbs in your home, you could be looking at a saving of £25 or $40 a year. Not bad for just changing your light bulbs!

As compact fluorescent bulbs are slightly less energy efficient than fluorescent tubes, we give them an energy efficiency rating of B-.

LED Lighting

LED lighting is perhaps the most exciting development in low voltage indoor lighting. LED bulbs have an extremely high energy efficiency rating, which as the technology improves, should reach around 80%.

Like the fluorescent tube technology, LED lights are cool to the touch but are much smaller and have more than double the lifespan of the larger fluorescent tubes.

Another advantage of using LED bulbs is that they are very environmentally friendly. However, this is not only because they use so little power, but because of how they are made.

LED lights do not contain any toxic heavy metals in them such as mercury which is found in fluorescent bulbs. So when your LED bulb does reach the end of its lifespan, you won’t have to worry about it polluting the environment which is a concern with fluorescent bulbs.

Low voltage indoor LED lighting certainty is the way of the future, although at present, cost and design limitations have somewhat hindered their acceptance into the domestic market.

But rest assured, as the technology improves and the cost of production falls, LEDs will soon become commonplace throughout the majority of countries in the world.

Considering the fact that lighting accounts for approximately 20% of the worlds electricity usage, the switch to LED lights could therefore have a massive positive impact on our environment.

Being the lowest power user and the most energy efficient, LED bulbs get a grade A energy efficiency rating.

They are certainly the best type of light bulb to use if you want to reduce your electricity bills and help save the planet, but at present, their relatively high cost will mean that most people will be using the compact fluorescent bulbs until LEDs start to drop in price.