Wednesday, 23 September 2009

Light Matters

Deputy Phil Rondel (St John) raised a question about floodlighting Victoria College:

Would the Minister advise what action, if any, he has taken to review the floodlighting of Victoria College and indicate what savings, if any, could be made to the school's annual electricity bill, should this practice be curtailed, for use by Victoria College towards the cost of other school resources.(1)
 The Minister, Deputy James Reed, replied:
On 10th March 2009, during Questions in the States, Deputy Rondel raised the subject of floodlighting at Victoria College. At that time I advised members that floodlighting had proved to be effective as a security measure at the College, as well as being appropriate for a prominent and historic building. I did not undertake to 'review the floodlighting at Victoria College', as implied by Deputy Rondel in his question, and remain of the view that the use of floodlighting is justified.
As indicated in my previous answer, the cost of floodlighting is minor in relation to the total cost of electricity for the school, and is considered to be cost-effective in terms of deterring vandalism and theft.(1)

But what is the cost? It is not just Victoria College that is lit - Parish Churches and the Castles are also lit up at night. This floodlighting was put in place many years ago, and I don't know when it has been updated. If it has not been, it could be quite energy inefficient. There is now available low energy Halogen lighting for spotlights, for example  (2)

Alternatively there are even forms low energy LED floodlighting with new technology to give the same degree of brilliance as older floodlights, but at a fraction of the cost. One such example is the Stringray LED Floodlight, of which the details are as follows(3):
Stingray LED Floodlight
Created: 08 April 2009 by Advanced LEDs
Typical applications:
External building floodlighting
Existing technology to be replaced : 150 and 250 Watt Halogen floodlights

A revolutionary new LED floodlight. This is the LED replacement for the150 and 250 watt floodlights. The performance far exceeds any otherequivalent high powered LED floodlight on the market. This uniqueluminaire can be fitted with combinations of ultra high power LEDs andin corresponding combinations of colours to give complete control overthe colour of projected light from either advanced leds own high powerRGB control system or through DMX interface.

Key Benefits,Features & Energy Savings 
Low maintenance and energy efficient
Low energy product.
Also on the subject of lights, there is an interesting note on street lighting in the 2008 Minutes of Enfield Energy Committee. This is a town in the USA (New Hampshire), which is looking at energy savings, and has noted the methods used by another town to achieve this end. Some interesting snippets:
Alisa offered information on Jaffrey, New Hampshire which is in the process of reducing the number of streetlights in their town.  The number of streetlights in their town is comparable to what we have in Enfield. The methods used by the Jaffrey Energy Committee involved taking late night tours of the town to collect information on necessary lighting at intersections and crosswalks.  The Jaffrey committee found that money would be saved by removal of 61 of their 225 streetlights and installation of lower wattage bulbs in those remaining.  The Jaffrey committee will consult with other towns for information on lower wattage.  They are looking for the balance between saving money and energy and keeping the town lit. (4)
Rich provided information on types of light bulbs, rated in lumen, from the Nationalgrid web site.  He noted that changing from mercury vapor to high pressure sodium bulbs would provide an energy cost savings, however, the initial installation would be costly.  High pressure sodium bulbs can be identified by a yellow hue while mercury vapor bulbs have a bluish glow.  There may be an individual preference in light "color".(4)

The Jaffrey plan (5) looked at the Street lights following a set of specific guidelines (6):

Goal: to identify and meet street lighting needs in Jaffrey so that only that lighting (measured in brightness and color) that is necessary is provided, and the lighting that is provided consumes the least fossil fuel derived energy of the available alternatives at the lowest possible cost.

Intersections: In general, there should be streetlights sufficient to signal the location of each intersection of major public roads where there is significant vehicular traffic.

Sidewalks: In general, there should be streetlights sufficient to illuminate sidewalks in densely populated areas where there is significant pedestrian movement.

No Wasted Light: The light provided by each street light should be no more than what is necessary to accomplish its purpose, should not illuminate the night sky, and should not shine into neighboring windows or yards.

Energy Efficient Lighting: The Towns new street lights should be state-of-the-art in terms of the light (lumens) provided per watt of energy consumed and in terms of their long-term durability and maintenance needs.

Consistent Lighting: In general, there should be one consistent type of street light, providing light of the same color (whether yellow-looking as in high pressure sodium lights or white-looking as in metal halide lights), used throughout Town.

I wonder if any assessment like that has been done in St Helier or St Brelade, for example, which are well lit areas, but probably have not had a detailed survey done of the lights for some time. When was the last time - if at all - such a survey was carried out? Are our street lights, like those of Jaffrey, USA, using low wattage lights?

These considerations come into the Jaffrey "Masterplan", which also notes that

In many areas of Jaffrey, street lighting utilizes technologies dating back 20-30 years or more. In some areas street lighting produces annoying glare by shining into pedestrian or driver fields of view. Excessive and unwanted light shines directly on property beyond the intended target and unwanted atmospheric lighting contributes to sky glow. Older lighting technologies utilizing mercury vapor lamps and high pressure sodium lamps offer poor color rendering qualities as compared to more modern metal halide systems.

Today's lighting systems employ design and efficiency features that were virtually unknown as little as 10 years ago such as optical controls that maximize lighting in targeted areas while minimizing undesirable glare and light "trespass". Modem lighting technologies are producing lamps that are more energy efficient by utilizing "pulse starting systems" and moving away from incandescent and mercury vapor lighting to more efficient and color balanced metal halide systems.

Returns on modern street lamping capital costs whether new or retrofitted are more quickly realized because of reduced energy usage and proper layout design reduces the frequency of lamps required for the same level of lighting in a targeted area.

A well planned street lighting program to replace and/or retrofit existing old technology lamping would be a desirable venue to pursue for Jaffrey and the accelerated return on investment would be well worth the initial capital cost.

Now that's what I'd like to see as part of our own St Helier "Masterplans"!

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