How to save energy with LEDs – sample calculation
You do not need the gift of second sight to forecast a truly bright future for LEDs (Light Emitting Diodes). Advantages like low power consumption, long life, brilliant light radiation or low heat emission give all the aces to the diodes.
The advantages of the diodes are often praised. Yet, what is the use of dull theory? What do these advantages really tell us? A question we have asked ourselves. Thus, we present you a concrete example which precisely shows the financial difference between an LED and a halogen lamp. To answer the question as clearly as possible we list the individual expenses of these two different lamps and directly compare them against each other. This is a fictitious calculation and the individual expenses may vary. Yet, they clearly indicate were the differences are and why LEDs are worth their money.
In our example a building’s outside facade is to be illuminated with 10 spots. For our comparison, we use a common 300 watts halogen spot and a EUROLITE LED FL-24 with 24 1 watt LEDs. The spots are to light five hours a day and in the course of five years. Generally, we would like to point out that there are also quality differences with LED products which may influence the luminance and life. For our example, we use high-quality LEDs under optimum ambient conditions (temperature, etc.).
As alluded above, the numbers for maintenance and energy costs are not absolute. However, our example will demonstrate where you can save with diodes. In particular, it is maintenance, which does not apply to LED lamps at all, and energy costs. The latter are more than 90 percent higher for halogen lamps. Which is no wonder as we compare a 300 watts lamp with an LED spot with 24 watts. And despite a wattage that is more than ten times higher, we did not detect a loss of illuminating power with LED lamps. Only the purchase price of devices operated with LEDs is considerably higher. Still, the higher investment pays off. For you can save almost € 11,500 with LEDs after only five years. Absolutely convincing arguments for the use of LEDs.
| Purchase | Halogen spot 300W | EUROLITE LED FL-24 |
| Purchase price | € 15 + € 1.70 = | € 281 |
| Incl. lamp | € 16.70 x @ 10 spot = | x 10 spot = |
| Recom. sales price! | € 167 | € 2,810 |
| Energy | ||
| Energy costs | 5 h x 365 days = | 5 h x 365 days = |
| In summer/winter | 1,825 h x 0.3 kW | 1,825 h x 0.025 kW |
| Average 5 h | 547.5 kWh x 0.18 ct = | 45.63 kWh x 0.18 ct = |
| €/y 98.55 | €/y 8.21 | |
| x 10 spots = | x 10 spots = | |
| € 985.50 | € 82.10 | |
| x 5 years = | x 5 years = | |
| € 4,927.50 | € 410.50 | |
| Lamp life | Target 1000h – Real 700h | Target 50,000h – Real approx. 40,000h |
| Burning life in 5 years | 5 h per day x 365 days x 5 years | no replacement |
| = 9,125 hours | ||
| 700 h life | ||
| = 13 replacements | ||
| x 10 spots = | ||
| 130 replacements | ||
| Maintenance | ||
| Costs per lamp replacement | OMNILUX | no maintenance |
| by an electician | € 1.70 | |
| – travel costs | 0.5 h x € 36 | |
| – preparation | 0.33 h x € 36 | |
| – replacement | 0.33 h x € 36 | |
| – follow-up work | 0.33 h x € 36 | |
| – travel costs | 0.5 h x € 36 | |
| Total € 73.34 | ||
| x 130 replacements in 5 years = | ||
| € 9.534 | ||
| Summary | ||
| Purchase | € 167 | € 2,810 |
| Energy | € 4,927.50 | € 410.50 |
| Maintenance | € 9,534 | – – |
| Sum total costs in 5 years | € 14,628.50 | € 3,220.50 |
| More expensive compared to the LED spot | € 11,408 |