The government of Jamaica has embarked on a $1.2b energy reduction program, which will involve among other things, replacing fluorescent lamps with LED Lamps.
They have also indicated that the over 90,000 plus street light across Jamaica, which mainly consists of the highly efficient high pressure sodium vapour lamp will be replaced by LED lamps. Note efficiency of a lamp is noted as lumens/w or lm/w and is a measure of how much light is produced per watt consumed.
Now we all know that LED are energy mizers and a such, from a a simple payback period it easy to determine that this appears to be the correct move on the part of the government.
The problem I have with us undertaking such projects however, is we often don’t do the complete analysis and then are left scratching our heads trying to figure out, why our projections did not work out.
Now there are a couple of roads across Jamaica road network that are currently using LED street lamps, these are the recently upgraded roads in Montego Bay just outside the town center and leading to the Lucea.
The most recent road to have LED street lamps replacing High Pressure sodium Vaopur (HPS) is the recently upgraded work from the harbour view round about all the way across the new bridge and ending where Bull Bay begins. (East St Andrew)
Now LED street lamps do not come cheap, but the energy they save when properly installed and controlled makes than a worthwhile investment in a place like Jamaica, where our energy cost is in the region of US$0.40 per kwh.
So as part of my investigative work I decided to drive along this roadway( Harbour View) in the day as well as in the night and make some observation, which I could then use to determine if we are likely to be successful in our quest for energy savings.
During the day I noticed that at least 2 of the over 36 lamps where on all the time, which I am going to surmise is the result of a defective photocell. Now I am aware that not everyone who reads my blog is a technical persons so I will define what this and how its suppose to work in non technical terms.
A photocell, which is that “blue” thing you see sitting on top of these street lamps is nothing but a device to turn on and turn off the street lamps depending on ambient light intensity (brightness). So the photocell (switch) turns on the light when it gets dark and turns off the lamp at daylight. These are built in a manner than when they fail the lamp(light) will remain on to tell us that it has failed.
So here we have installed at great cost the lowest energy consuming street lamp that money can buy, then pay someone to installed it, yet we fail to get the benefit required due to the failure of a cheap US$10.00 part being used to control the lamp.
Now the cost to run these LED street lamps 24hrs per day = consumption per fixture x #hrs run per day x cost per kwh.
Assume the LED lamps were are using are rated at 100w = 0.1kw
= 0.10 x 24 x 0.40
= US$9.6 per day or J$820
= $24.6K per mth
= $295k per yr for a single lamp highly efficient lamp.
The other thing I observed was that during the night at least 3 lamps did not come on at all, which presents a safety risk at these dark spots for pedestrians coupled with the fact that we are not getting the benefit of what we are paying for, since JPS charges for every street lamp, whether it functions or not.
So from my simple drive through, we can see that energy efficiency and cost reduction will not simply come from replacing HPS with LED street lamps . Neither will the calculated savings in the offices be realized simply by replacing the lamps, it will only come by adding good controls to ensure the we reap the benefits of our investments.
More to come…
Courtesy: Illumination in Focus.
The above was presented as part of the Rio +20Rio+20 summit in Rio de Janeiro, Brazil ( Our PM was in attendance).
The above shows the savings of Street LED trails done in 12 of the world’s largest cities.