Energy saving case studies

Hotel phase 1 - Lobby, Public areas, and Corridors

A medium-sized hotel initially looking at all the Lobby, Public areas, and Corridors, these lights were left on, on a 24/7 basis. There were 152 x 50-watt bulbs and 212 x 35-watt bulbs with virtually no other Electricity usage in these areas

Quantity Watts Watts used KWH Day Month Year Cost Day Cost Month Cost Year
152 50 7600 7.6 182.4 5548 66576 £22.80 £694 £ 8,322
212 35 7420 7.42 178.08 5416.6 64999 £22.26 £677 £ 8,125
            Totals £45.06 £1,371 £16,447

 

Quantity Watts Watts used KWH Day Month Year Cost Day Cost Month Cost Year
152 4.6 699.2 0.70 16.78 510 6125 £2.10 £ 64 £ 766
212 2.6 551.2 0.55 13.23 402 4829 £1.65 £ 50 £ 604
            Totals £3.75 £114 £1,369

 

The savings by switching to LED'S just in these areas was an incredible £15,078 a year, saving 92% from the original cost.

This was when the cost of electricity was 12.5p Per KWH and while the percentage saved remains the same, the savings in £'s increases as follows when the price of energy goes up.

Electricity Price per kWh Savings
£ 0.125 £ 17.762.65
£ 0.15 £ 18,093.25
£ 0.16 £ 19,299.47
£ 0.17 £ 20,505.69
£ 0.18 £ 21,711.91
£ 0.19 £ 22,918.12
£ 0.20 £ 24,124.34

 

Now we know LED bulbs are more expensive to purchase than standard ones; however, LED bulbs work for years on average running for between 25,000 – 50,000 hours before they need to be replaced.

So, if you bulbs run on a 24/7 basis equals between 3-6 years, standard & Halogen bulbs last between 2,000 – 4,000 hours, which means those on 24/7 would need to be replaced 2-4 times a year. If we take an average non-LED bulb needs replacing say every 3000 hours, almost three replacements are required a year. Over three years, this is at least nine replacements, so these cheap bulbs ultimately cost more than the LED bulb equivalent. This does not take into account the time spent replacing the bulbs, which in this case that amounted to over 1000 light bulb changes a year. On top of the 90% saving on the electricity bill, you will see other savings in staff costs as you won't be replacing 1000 bulbs per year.

Hotel phase 2 - Bedrooms

After the incredible savings seen on the public areas, the hotel immediately went on to do the bedrooms

Here are the findings on the bedroom switch over to LED Lighting.

Before:

Room Type No Bulbs Per room Total Bulbs Watts Watts Used KWH Day Month Year Cost Day Cost Month Cost Year
Standard 52 10 520 50 26000 26.00 208.00 6,327 75,920 £41.60 £1,265 £15,184
Superior 30 12 360 50 18000 18.00 144.00 4,380 52,560 £28.80 £876 £10,512
Family 8 18 144 50 7200 7.20 57.60 1,752 21,024 £11.52 £350 £4,205
Suite 4 22 88 50 4400 4.40 35.20 1,071 12,848 £7.04 £214 £2,570
Std Bath 90 5 450 35 15750 15.75 63.00 1,916 22,995 £12.60 £383 £4,599
Suite Bath 4 10 40 35 1400 1.40 5.60 170 2,044 £1.12 £34 £409
                  Spend £102.68 £3,123 £37,478

 

After:

Room Type No Bulbs Per room Total Bulbs Watts Watts Used KWH Day Month Year Cost Day Cost Month Cost Year
Standard 52 10 520 4.6 2392 2.39 19.14 582 6,985 £3.83 £116 £1,397
Superior 30 12 360 4.6 1656 1.66 13.25 403 4,836 £2.65 £81 £967
Family 8 18 144 4.6 662 0.66 5.30 161 1,934 £1.06 £32 £387
Suite 4 22 88 4.6 405 0.40 3.24 99 1,182 £0.65 £20 £236
Std Bath 90 6 450 2.6 1404 1.40 5.62 171 2,050 £1.12 £34 £410
Suite Bath 4 10 40 2.6 104 0.10 0.42 13 152 £0.08 £3 £30
                  Spend £102.68 £286 £3,428

 

On Lighting alone, this exercise would reduce their annual bill by over £34,000.

All other Electrical usage was looked at, but the remaining use was minimal, or there was no desire to change anything else. However, they were about to changes their TV'S. With 102 in the property, they had a choice between LED'S or carry on with LCD'S while the savings were minimal a 32inch LED tv uses about 50 watts of energy versus 60 watts of power for an LCD. Even so, this would save them 16% on energy use when TVs were being used. Based on 6 hours a day usage that would be circa £400 a year