LED vs. Incandescent: the case for LED light bulbs in Kenya

Switch to LED light bulbs from the old ordinary incandescent light bulbs and get the benefits of new lighting technology: increased energy efficiency, reduced heat emission, reduced electricity costs, increased bulb lifespan, increased bulb durability, and increased flexibility in lighting applications.

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Increased energy efficiency

LED light bulbs are the most energy efficient of the main types of light bulbs as they consume 70 to 90 percent less energy than the more common incandescent light bulbs. LED bulbs convert more than 90 percent of the electrical energy into light while the rest is converted into heat. Incandescent bulbs do almost the opposite as they only convert about 10 percent of the electrical energy into light and the rest into heat. This excess heat from incandescent bulbs indirectly contributes to their inefficiency if air conditioners or fans have to be used to cool the heated space.

Reduced heat emission

An inbuilt system in LED bulbs reduces the effect of the low heat produced by the bulbs on the bulbs themselves and their surroundings. Incandescent bulbs overheat and emit their high heat to the surrounding air. The heat from incandescent bulbs usually makes small spaces unnecessarily uncomfortable especially in hot areas or during hot seasons. Some may argue that the heat from incandescent bulbs may be useful as a source of passive heat during cold nights. How many cold nights do you experience in Kenya? Doesn’t a sweater or a blanket work for you?

Reduced electricity costs

For most people, energy efficiency is supposed to translate into cost efficiency. How much electricity do light bulbs consume? How much does that electricity cost?

Different types of bulbs consume different amounts of electricity to produce the same brightness or the same amount of light. The traditional method of determining the amount of light produced by incandescent bulbs has been to use their wattage rating: the amount of electrical energy they consume per second. The efficiency of incandescent bulbs has not improved for many years and so wattage ratings became synonymous with the amount of light produced.

New types of bulbs, such as LEDs, are more efficient and their efficiency is constantly improving. In addition, different manufacturers produce the same type of bulb to produce the same amount of light but with different levels of energy efficiency. This makes it difficult to relate wattage ratings and the amount of light a bulb produces. A popular way to indicate the amount of light produced by these modern bulbs has been to equate their light to a similar amount of light from an incandescent bulb of a particular wattage rating. In Physics, the amount of light is actually measured in lumens (lm) and this is becoming the new standard of communicating the amount of light produced by all types of bulbs.

For example, a 60 watt incandescent and a 6 watt LED can produce the same amount of light: about 800 lumens. For every hour of use, a 60 watt incandescent bulb uses 0.06 kWh or more commonly 0.06 units of power. For easier calculations, let us compare this to a brighter 10 watt LED bulb that uses 0.01 units per hour – that is a saving of 0.05 units per hour per bulb.

Kenya Power as of September 2015 charged about Ksh. 11 to 20 per unit on average for consumption between 50 to 1500 units with the costs increasing rapidly immediately after 50 units; this being inclusive of the monthly fixed charge and taxes. Therefore, the 0.05 unit per hour represents financial savings of about Ksh. 0.5 to Ksh. 1 per hour per bulb.

If the 60 watt incandescent bulb is used for 3 hours every day for a month (30 days) it consumes a total of 60 watts x 3 hours x 30 days = 5,400 Wh or 5.4 kWh or more commonly 5.4 units of power. The brighter 10 watt LED bulb used for the same 3 hours every day for a month (30 days) consumes a total of 10 watts x 3 hours x 30 days = 900 Wh or 0.9 kWh or more commonly 0.9 units of power; therefore saving 4.5 units per bulb every month. The 4.5 units represent financial savings of about Ksh. 50 to Ksh. 90 per bulb every month. If in a house, 5 bulbs are used at the same monthly rate, financial savings of about Ksh. 250 to Ksh. 450 are attained by switching to LED bulbs.

Minimum electricity cost savings per bulb based on less efficient brands of LED bulbs and low electricity unit cost of Ksh. 11
Amount of light produced (lumens) Amount of electricity consumed (watts) Cost of electricity consumed per hour (Ksh.) Hourly cost savings (Ksh.) Monthly cost savings at 3 hours average daily use (Ksh.)
Incandescent LED Incandescent LED
450 40 5 0.44 0.06 0.39 34.65
800 60 8 0.66 0.09 0.57 51.48
1,100 75 13 0.83 0.14 0.68 61.38
1,600 100 20 1.10 0.22 0.88 79.20
2,600 150 28 1.65 0.31 1.34 120.78

 

Maximum electricity cost savings per bulb based on more efficient brands of LED bulbs and high electricity unit cost of Ksh. 20
Amount of light produced (lumens) Amount of electricity consumed (watts) Cost of electricity consumed per hour (Ksh.) Hourly cost savings (Ksh.) Monthly cost savings at 3 hours average daily use (Ksh.)
Incandescent LED Incandescent LED
450 40 4 0.80 0.08 0.72 64.80
800 60 6 1.20 0.12 1.08 97.20
1,100 75 9 1.50 0.18 1.32 118.80
1,600 100 16 2.00 0.32 1.68 151.20
2,600 150 25 3.00 0.50 2.50 225.00

Increased bulb lifespan

LED bulbs last more than 40 times longer than incandescent bulbs. Incandescent bulbs burn out after about 1,200 hours of use while LED bulbs do not burn out but rather their light output decreases by 30 percent after about 50,000 hours of use. Frequent switching on and off also has no effect on LED bulbs unlike in the case of incandescent bulbs where their lifespan may be shortened.

Increased bulb durability

Incandescent bulbs are made of fragile glass while LED bulbs are usually made of plastic-like materials which make them more durable. This is especially important when moving from house to house as it give you one less fragile thing to worry about.

Increased flexibility in lighting applications

Light has a colour temperature: the yellowness to blueness of light. This colour temperature range is measured in Kelvins (K) with the lower the Kelvins the more yellowish the light and the higher the Kelvins the more blueish the light. Incandescent bulbs have a yellowish light of about 2,700 K. This colour temperature of light is referred to as ‘warm white’ or ‘soft white’ in LED bulbs. Unlike incandescent bulbs, LED bulbs come in a much wider colour temperature range: 2,700 K to 6,500 K. At about 4,100 K, the colour temperature is referred to as ‘cool white’ or ‘natural white’ as the light has no discernable colour other than white. ‘Daylight’ is used to refer to blueish light from LED bulbs rated 5,000 K as the light emitted is similar to daylight during a clear blue sky at noon.

The light from LED bulbs can also be varied in many different ways. LED light is naturally directional and focused but can also be made to be omnidirectional like light from incandescent bulbs. LED bulbs also come in other different shapes and sizes: candle or flame tip, globe or bathroom light, tube light, spot light, flood light, high bay etc.

LED-light-bulb-variety

Check out some of the LED light bulbs currently available for sale in Kenya. If you have bulb holders not in use in your house or place of work, this is the perfect opportunity to buy and use LED bulbs to see their benefits for yourself.