What Are 3 Things That Use Energy To Make Light?

There are several common types of electric lighting that use energy to produce illumination in homes, businesses, and public spaces. Understanding the key differences between these lighting technologies can help consumers make informed choices to reduce energy consumption and costs. This article will explore three major categories of electric lights—incandescent, fluorescent, and LED—looking at how they work, their energy efficiency, environmental impact, and costs. With this knowledge, you’ll be better equipped to choose the right type of lighting for your needs.

Table of Contents

Incandescent Light Bulbs

Incandescent light bulbs are one of the oldest and most basic electric lighting technologies still in use today. They produce light by heating a tungsten filament with an electric current inside a glass bulb filled with an inert gas.

When the tungsten filament is heated by the electric current, it starts to glow white-hot, producing visible light. The hotter the filament gets, the brighter the light it emits. However, most of the energy consumed by an incandescent bulb is released as heat rather than visible light. Only about 5-10% of the electricity used by an incandescent bulb is converted into light, while the rest is converted into infrared radiation or heat.

This inefficient design is why incandescent bulbs tend to have a short lifespan and high energy costs compared to newer lighting technologies like LEDs. But their simple design also makes them inexpensive to produce and durable. Overall, the lighting principles behind incandescent bulbs have remained largely unchanged since Thomas Edison patented the first commercially viable design in 1879.

Fluorescent Lights

Fluorescent lights work by passing electricity through a tube containing argon and a small amount of mercury vapor. This generates invisible ultraviolet light that excites the phosphor coating on the inside of the tube, causing it to glow or fluoresce and produce visible light.

Specifically, the electric current flows between two electrodes at opposite ends of the tube. The electrodes heat up and vaporize the mercury, creating mercury atoms that produce ultraviolet light when excited by the electric discharge. The ultraviolet light is then absorbed by the phosphor coating, causing it to emit photons in the visible spectrum that provide illumination.

Different blends of phosphors emit different colors of visible light. Cool white fluorescent lamps mix phosphors to create a bright white light suitable for offices and workshops. Warm white fluorescents use less blue/green phosphors to produce a more yellowish light. There are also phosphor blends to produce different colors for decorative fluorescent tubes.

Overall, fluorescent lights require less electricity to produce light compared to incandescent bulbs because the phosphors can convert ultraviolet light into visible light more efficiently. However, fluorescents do use some energy to initially excite the mercury vapor and generate the invisible ultraviolet light.

LED Lights

LED stands for light-emitting diode. LED lights are the most energy efficient lighting option available today. Unlike traditional incandescent light bulbs that use electricity to heat a filament until it glows, LEDs produce light in a fundamentally different way.

LEDs are made from materials called semiconductors that can conduct electricity under certain conditions. When voltage is applied to an LED, electrons are able to flow through the semiconductor material. The movement and collisions between electrons generates energy in the form of photons or particles of light. This process is called electroluminescence.

The color of the light emitted depends on the type of semiconductor material used. By combining different semiconductor materials, LEDs can be tuned to produce various colors of light, from warm white to cool daylight tones. This makes LED lighting extremely versatile for many different applications.

Comparison

When comparing different types of light bulbs and fixtures, there are a few key factors to consider:

Incandescent bulbs

Pros:

Inexpensive to purchase upfront

Instantly bright when turned on
Warm, familiar light quality

Cons:

Very inefficient – 90% of energy is given off as heat
Short lifespan of 750-1000 hours
Higher operating costs over time

Fluorescent lights

Pros:

Much more energy efficient than incandescent

Longer lifespan of 6,000-15,000 hours
Lower operating costs over time

Cons:

Higher upfront cost
Contain mercury which requires special disposal
Some find the light quality harsh or flickering

LED lights

Pros:

Extremely energy efficient – uses up to 90% less energy

Longest lifespan of 25,000-50,000 hours
Lowest operating costs over time
Compact and durable

Cons:

Higher upfront costs currently
Light quality varies – some find it harsh

Energy Efficiency

When it comes to energy efficiency, LED lights are generally the most efficient option. This is because LEDs convert most of the energy they consume into light, whereas incandescent bulbs convert a lot of energy into heat. Specifically:

LED bulbs convert about 80% of energy input into light
Fluorescent lights convert around 65% of energy input

Incandescent bulbs only convert about 10-15% of energy input into light, with the rest turning into heat

So LED lights require significantly less electricity to produce the same amount of brightness compared to other options. For example, an LED that gives off the same light as a 60W incandescent would only require 8-12W of electricity. This translates into major energy savings over the lifetime of the LED bulb.

There are a few reasons why LEDs are so much more efficient:

They produce directional light, so very little is wasted
The semiconductor material used glows when electricity flows through it, so very little energy is lost as heat
They last longer, spreading energy use over more hours of operation

For these reasons, switching to LED lighting is one of the most impactful steps for increasing energy efficiency in homes and businesses.

Environmental Impact

The environmental impact of different types of lights can vary significantly. Here’s a look at some of the key considerations:

Incandescent bulbs are not very eco-friendly. They use a lot of electricity and generate quite a bit of heat, which can increase energy usage for cooling. They also have a short lifespan, so they need to be replaced frequently, creating more waste. However, they can usually be recycled.

Fluorescent lights are more energy efficient and have a longer lifespan than incandescent bulbs. However, they do contain mercury, which is hazardous if released. Proper recycling is important to prevent mercury pollution. Fluorescent lights also use small amounts of rare earth metals that need to be mined.

LED lights are the most energy efficient option and can last for years. They contain no mercury. However, some contain rare earth metals. And while LEDs themselves are not toxic, the manufacturing process can generate some hazardous waste. Recycling LEDs properly is important.

Overall, LED lights tend to have the least environmental impact over time, while incandescent bulbs tend to have the most. But all types require conscientious recycling to minimize their footprint.

Cost Comparison

When comparing the costs of different types of lights, it’s important to consider both upfront costs and ongoing operating costs. Here’s a look at how the costs of incandescent, fluorescent, and LED lights compare:

Incandescent bulbs are cheap to buy, typically costing less than $1 per bulb. However, they are expensive to operate because they are very energy inefficient, wasting 90% of energy as heat. This amounts to higher electricity bills over time.

Fluorescent lights cost more upfront, around $2-$8 per tube. However, they use about 75% less energy than incandescents and can last 6-12 times longer. This makes them cheaper to operate in the long run despite higher upfront costs.

LED lights are the most expensive upfront, costing around $10-$25 per bulb. But they last 25+ times longer than incandescents and use at least 75% less energy, making them the cheapest to operate over time. Their long lifespan offsets their high initial costs.

So while incandescent lights are cheapest initially, fluorescent and especially LED lights save significantly on energy costs in the long run. The energy savings make the higher upfront cost worthwhile over time.

Usage Guidance

When choosing which type of light to use, consider the purpose, location, and your priorities.

Incandescent bulbs provide a warm, cozy light that’s ideal for living rooms, bedrooms and other areas where ambiance is a priority. However, they are very energy inefficient, so avoid using them in high-traffic areas that require lots of lighting.

Fluorescent lights are best for kitchens, basements, garages and workspaces where bright, energy-efficient illumination is more important than ambiance. They also work well in office buildings and retail stores.

LED lights strike a nice balance between energy efficiency, lifespan, and light quality. They work great for accent lighting, task lighting, outdoor lighting, and in bathrooms or laundry rooms. LEDs are versatile for both home and commercial use.

Consider switching to more energy-efficient LEDs or fluorescents where possible. Use incandescents sparingly, mainly for ambiance in low-use areas. Choose the right light for the space based on your specific needs.

Conclusion

In summary, the three main things that use energy to produce light are incandescent light bulbs, fluorescent lights, and LED lights. Each has its own advantages and disadvantages.

Incandescent bulbs are inexpensive to buy but inefficient, wasting 90% of energy as heat. Fluorescent lights are more efficient and last longer, but may flicker and contain mercury. LEDs are the most energy efficient and long-lasting, but expensive upfront.

When choosing a light, consider energy use, lifespan, light quality, environmental impact, and costs. LED lights are generally the best option, using up to 90% less energy than incandescent bulbs. Fluorescents are also efficient, best for large indoor spaces. Incandescents are cheap but inefficient, best avoided.

By understanding the differences between lighting technologies, we can make informed choices to reduce energy waste. Choosing efficient bulbs saves money and lessens environmental impact over time.