Komorowski’s Korner – LED Lights VS HPS – Attention Mayor Kilger and Cornwall City Council – Cornwall Ontario, October 22, 2009

Mayor Kaneb Drive – An Opportunity to save Tax Dollars

The decision to build the bypass road from Second Street East to Marleau will be welcomed by most commuters. It will take a lot of the traffic heading to the industrial complexes in the north east of the city, relieving the delays on McConnell, and reducing the traffic through residential streets such as Lynwood and Glengarry.

From an energy saving point of view, this is a win-win situation. Quite simply, a faster drive with fewer stops for traffic lights and other delays means less gas is burned, reducing our costs and the amount of CO2 and other pollutants. The new road will also have sidewalks and a bike path. But is the city going far enough to reduce energy usage?

The new road will have street lights, like any other road in Cornwall, or indeed anywhere. Who can argue the wisdom of having good street lighting. It increases safety and reduces crime. But at what cost?

Cornwall, like almost all municipalities in Ontario, uses orange High Pressure Sodium (HPS) bulbs to light the streets. Until recently, this has been the most cost effective system, providing a relatively high level of usable light for the amount of power consumed. It’s not perfect, as the orange tint to the light does not render other colours especially well, but after all, we’re not trying to illuminate the National Gallery.

However, safe, bright street lights do not have to be HPS systems. Recently, several towns in Nova Scotia completely eliminated HPS bulbs, and are using LED lighting instead.

LED lights use about 37% of the electricity HPS lights use for a similar light output. Put another way, we could have 3 LED lights for every HPS light without significantly raising our power consumption. Granted, LED lights are relatively expensive compared to HPS, but as more and more municipalities start to use them, these costs will come down due to economies of scale. Another bonus is that LED lights have a 20 year life span, compared to 3 years for HPS.

So why not install LED lights on the new bypass? Assuming a light every 25 metres, there would be 48 lights from end to end. Over 20 years, this would save us about 250,000 kWh of power. The savings on the city’s electric bill would be about $27,000 (assuming the city pays $0.08/kWh), and the savings in maintenance costs would be over $60,000. And this is for only 48 lights along a 1.2 kilometre road. How many HPS lights does the city have? If all the current HPS lights are phased out over the next three years, we could save millions of dollars and reduce our CO2 emissions by thousands of tons.

There’s another benefit, too, for our children and grand-children, who will have to live in this world long after we’re gone. Over the next twenty years, these 48 LED lights are going to pump about 100 tons less carbon dioxide into the atmosphere than their HPS counterparts. Not a great saving when you consider the global problem, but we have to start somewhere. And just think: if we put a small windmill on top of each light, we could reduce our costs and CO2 pollution even more!

This Saturday, October 24, local Cornwall Citizens will be meeting to take action on climate change. Let’s be there to support them, before it really is too late. Check the CornwallFreeNews article at http://cornwallfreenews.com/2009/10/350-org-local-group-takes-action-cornwall-ontario/

If you want to learn more about LED Street Lighting, here are a couple of links:

http://thechronicleherald.ca/NovaScotia/1145301.html and http://www.ledroadwaylighting.com/

To contact the Mayor or City Council click the names below.

  • Bob Kilger, Mayor
  • Kim Baird, Councillor
  • Denis Carr, Councillor
  • Bernadette Clément, Councillor
  • Syd Gardiner, Councillor
  • Glen Grant, Councillor
  • Mary Ann Hug, Councillor
  • Elaine MacDonald, Councillor
  • Mark MacDonald, Councillor
  • André Rivette, Councillor
  • Denis Thibault, Councillor
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    1. A single kilowatt-hour of electricity will generate 1.34 pounds (610 g) of CO2 emissions. Assuming the average light bulb is on for 10 hours a day, a single 40-watt incandescent bulb will generate 196 pounds (89 kg) of CO2 every year. The 13-watt LED equivalent will only be responsible for 63 pounds (29 kg) of CO2 over the same time span. A building’s carbon footprint from lighting can be reduced by 68% by exchanging all incandescent bulbs for new LEDs in warm climates. In cold climates, the energy saving may be lower, since more heating would be needed to compensate for the lower temperature.

    2. Well you might save some money by switching to LED lighting, but I doubt you will save on CO2 emissions. What you have to remember is it takes days to get the big power plants even started. It is impossible to regulate power production from hour to hour. You either produce it or you don’t. So you have to base power production on the high of the day which is during the day. Turning your air conditioning down during the day is more important.

    3. Thank you Burton Haynes and glassbowl.

      Burton, I’m not sure where you’re getting your figures from, but according to my calculations, 1 Kwh generated from coal would produce about 1.35 kilograms of CO2. According to Wikipedia, 1 Kwh produces about 2.25 lbs (roughly 1 kg). These differences could be due to estimating the combustion and mechanical efficiency of the generating stations. In any case, if you are talking about coal fired generation, your figures are, unfortunately, optimistic. Oil and natural gas, however, are less polluting than coal.
      Typically in Ontario, about 75% of electricity is generated from Nuclear and Hydro sources, and are green (at least in the sense of CO2 production). Therefore, in Ontario, the CO2 per Kwh would be roughly 250 grams.

      Glassbowl: Power stations don’t typically start and stop on a dime, but “days” is an exaggeration. A gas fired plant can come on line in a matter of minutes. One of the major reasons for Smart Meters is to lessen the peak demand by encouraging consumers to use less power during the daytime when there is a high demand for electricity, and more at night and weekends, when demand is lower. Leveling the demand curve means fewer generating stations are needed to supply the peak demand.
      If you study electricity rates in Europe, you’ll find that very often there is a massive difference between high peak and low peak rates.

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