Welcome to the FREE technical Q&A consulting service

This technical Q&A service is designed to answer all public lighting related queries that cannot be answered by perusing the Sustainable Public Lighting Toolbox.

The service is:

• FREE
• FAST
• FORWARD THINKING

ICLEI Oceania is working with public lighting experts, Ironbark Sustainability, to offer all councils participating in the Cities for Climate Protection Program friendly and helpful advice on all your public lighting queries. 

To use the technical Q&A service call (03) 9660 2244 or email us to discuss your public lighting query.

Please note: 

• Most Q&As will be published on the website and will name the Council only with their permission
• The service is attended Monday to Wednesday. Communications received at other times via email or voicemail will be responded to within three working days.

For general Frequently Asked Questions see the FAQ page.

This service was launched in September 2008.

• Lighting technologies
• Approvals
• Reporting
• Other

Manufacturer claims about T5s in cold temperatures: An urban Victorian Council, January 2009

Question:
I have recently been told that the T5 operates at a lower luminosity in colder temperatures. How can I validate these claims?

Answer:
It is true that the T5 experiences some reduction in light output (as do most fluorescent technologies) as the temperature decreases. Research carried out by VSPLAG demonstrated that this reduction only had a marginal impact on spacing of the lights. These spacing calculations consider a range of inputs including luminaire design, reflector design, lumen depreciation over time as well as the starting lumens (which is the relevant item to alter for temperature variation). In fact, at Zero degrees Celsius, the T5s still have better spacing characteristics than the current 80W Mercury Vapour B2224 luminaire. See the Q&A, T5s in Cold Temperatures, below.

A lot of information, half truths and rumors are circulating about newer lights. When situations such as this arise the onus should be put on the organisation making the claim to prove it. If they can't, or the information is unclear then independent advice should always be sought before the prevailing facts are used to make decisions.

T5s in cold temperatures- ACT Government, September 2008

Question: Could you please advise the temperatures that the T5 luminaires and globes work efficiently? I wish to confirm that in cold climates the T5 loses much of its light output.

Answer: T5s start in temperatures down to -5 degrees C and the non-amalgam variety have temperature sensitivity. However amalgam T5s, like those being trialed in South-East Queensland, do not depreciate in cold temperatures. Note that even the non-amalgam T5 lights when down to -5 degrees C have superior spacing than that of the commonly used B2224 luminaire. When compared to the new Urban luminaires the spacing is equivalent or better at 0 degrees C and slightly lower (2m for 15m road reserve width) at -5 degrees C.

Also, the trade off is that technologies such as Mercury Vapour and High Pressure Sodium are voltage sensitive so their light output is up to 30% lower in peak hours, whereas compact flouros and T5s are not voltage sensitive.

The VSPLAG Technical Report will assist you further.

The viability of LEDs compared to T5s: An Urban  Victorian council, October 2008

Question: Are LEDs a viable option instead of T5s for public lighting?

Answer:  LEDs in residential street lighting (or minor roads) are currently around 3-5 times the cost of T5s, CFLs and other efficient lights (and 8-10 times the cost of standard MVs). They have lower lighting levels for the same amount of energy used compared to T5s and some other technologies. The repair options for LEDs are very expensive, with several of the manufacturers stating that the entire light fitting needs to be replaced every 10-15 years in comparison to every 20-30 years with current fittings.

When comparing the specifications of a major brand of 30 watt LED public light to a standard T5 it can be concluded that the LED provides 35-40% of the light output of the T5 while using the same amount of energy.

Also, LEDs are typically made overseas while the T5 and the 42W CFLs are still manufactured in Australia.

LEDs might be a viable option in the future for minor road lighting but are certainly not at the stage where councils could make plans to roll them out.

For major road lighting, some of the newer batch of LED's are providing comparable light output to energy use as the higher wattage lights such as 150 and 250W HPSs. However, cost and experience in the field require that further testing and life cycle costing be completed before recommending their use for large scale roll outs.

Choosing technologies for bulk change over, A rural NSW council, November 2008

Question:
The distribution business has offered its customers three choices for bulk change over.

1. T5 32 watt
2. CFL 47 watt
3. MV80 95.8 watts

They have advised that T5s and CFLs have higher OMR costs and shorter life and suggest the Mercury Vapour is a good choice.

Answer:
The T5 and 42W CFL do not have shorter lives. This is based on experience in Victoria since 2004 and in NSW since 2002. It is true that the CFL and T5 are more expensive to buy (around 50-100% more) and typically the OMR costs are more expensive (around $5-15 is normal).

It is clear the T5 is the preferred option from a sustainability perspective (around 68% energy and greenhouse savings). The CFL is also much better than the 80W MV (50% savings) and can be used in top entry decorative luminaires.

If Council has specific targets for energy and greenhouse savings then the savings from a bulk change over need to be weighed against the purchase of Green Power as an alternative. In Victoria (where this has been modeled) the bulk change over option is preferable. Modeling for this council would be useful and the following information would be of use for this.

Currently the OMR costs proposed by the distribution business for the energy efficient lights are very high (refer to SSROC's submission to the AER). From an economic perspective alone it is unlikely the T5 and CFL will provide significant long term savings if the costs proposed by the distribution business, and listed in the SSROC letter, are agreed to by the Australian Energy Regulator. E.g the energy savings from the T5 change would be around $20 per light and the tariff for the T5 is listed as $45 higher than the 80W MV. If the tariff was the same as the other distribution business's (Integral) price then the project would be likely to have a payback within the life of the luminaires. Proper and transparent technical data is available from the VSPLAG Technical Report- noting that some information has been updated since then. This technical information is likely to influence the tariff greatly.The other key point to consider is the cost of the actual bulk change. This will greatly influence any project viability.It may be useful to investigate the gains that could be made by working between councils and distribution businesses as has been done in Victoria.

Comparison of T5 and MV light output: A rural Victorian council, September 2008

Question:
Will T5 lights provide the same light output as 80 watt Mercury Vapour (MV) lights?

Answer:
The Australian Standards (AS/NZS 1158:2004) provide guidance around the spacing requirements of different lighting schemes. These requirements take into consideration information on pole height, light output, luminaire (light fitting) design, light output depreciation over time and the protection rating of the luminaire.
Using these spacing calculations is the best way to compare the light output and design characteristics of different luminaires.

There are various types of luminaires but when comparing the main types that use 80 watt MV lights to those that use 2x14 watt T5s the spacing is equivalent.

Therefore a 2x14 watt T5 can replace an 80 watt MV light and still meet the recommendations of the Australian Standards.

Note* This is not the case for the higher output 2x24 watt T5 which allow greater pole spacing than the 80 watt MV and direct replacement can result in over lighting.* The 42 watt CFL also provides similar spacing characteristics to the 80 watt MV.* In some situations, such as where lighting is being replaced on decorative poles in new estates more detailed analysis will be required before specific recommendations can be made.

For further information about the lighting technologies mentioned in these Q&As see the following links: LEDs, CFLs, T5s.

Approvals for efficient street lights: A rural Victorian council, March 2009

Question:
Our council has been approached by suppliers demonstrating LED technology for street lighting. Have LEDs, or other types of efficient public lighting, been approved by distribution businesses for use in the distribution grid?

Answer:
The lights that are most progressed in the Victorian technical approvals process are the Pierlite T5 and the Sylvania CFL. Some LEDs and other types of fluorescent lights have started this process.

LEDs tend not to be as competitive (in terms of energy efficiency) as other minor road lights but there may be a case for their use in major roads in the near future. Noting this is changing rapidly but it would take at least 3 years for a minor road light to become available for councils that competes with the T5 and the CFL.

NGERS reporting requirements for councils: An Urban South Australian council, November 2008

Question:
What are the reporting requirements of local councils under the NGERS legislation for public lighting? 

Answer:
There are two aspects to think about when considering reporting under the NGERS  framework.

The first is whether or not the entity has operational control. NGERS captures organisations under this definition, which states that the entity has operational control if they have the power to make policies that affect the organisation. As councils do not have the authority to create policies that affect the operation of distribution businesses they are not likely to be the entities that are liable to report.

The second aspect is the emission threshold of the scheme. The reporting requirements are really only relevant for street lighting if they result in emissions of over 25,000 tonnes of Greenhouse gases, or use of 100 terajoules of energy each year. To put this into perspective - the Council with the largest number of streetlights in Victoria (Casey) emits around 13,000 tonnes of GHG from street lighting.

So only the very largest of councils (such as Brisbane City Council) will find NGERS to be an issue for street lighting. Even at the 50 Kilotonnes level for all emissions most councils would not require to report under NGERS.

Note also that energy efficient streetlighting technologies and practices typically can save around 40-50% of the energy used so this would lead to even fewer Councils requiring to report under NGERS.

The Australian Local Government Association (ALGA), has released a Briefing Paper on National Greenhouse and Energy Reporting Scheme, Carbon Pollution Reduction Scheme and Complementary Measures (September 2008) to address implications and opportunities for ALGA and its members.

Switching off public lighting for Earth Hour: City of Fremantle WA, January 2009

Question:
Our council is considering switching off public lighting for Earth Hour. What are the logistical and safety concerns associated with switching off street lighting?

Answer:
1. Logistics.
The ability of a council to switch off public lighting depends on the particular switching options that are available. Park and car park systems are commonly metered and operated by council, who would be able to switch them off centrally either through a timer or a mechanism at the switchboard. For unmetered street lights, which make up most public lighting, it may be very difficult to turn lights off without individually removing the lamps of each light or installing control systems. Some street lights are switched centrally via a switch wire - though this is unusual.

There are instances Australia and abroad where lighting is either not provided or is provided at very low levels, especially rural areas of Australia. Prior to the use of PE cells in the 1970's switch wires and timers were used throughout Australia. This resulted in a range of time settings that included turning lights off at night (after 11 or 12pm). When PE cells came in this local switch off changed to a standard sunset to sunrise time setting. Maribyrnong Council in Melbourne removes around 10 lamps surrounding an inner park for a Christmas festival for one night each year. The local distributor (Jemena) removes these lamps during the day and reinstalls them the next day. The developer of the location has accepted responsibility for the liability issues in this case. Eaglemont, an inner city Melbourne suburb designed by Walter Burley Griffin, has no street lights in a bid to reduce unsightly street scapes caused by poles and wires. Their electricity needs are supplied through the back of the property.

There are many examples of cities and counties overseas turning off street lights, or dimming them, during the night. The NAGA PLAP2 Test report, June 2008, discusses some examples of switching off in the UK. Note that these systems typically use sophisticated control systems to enable time switching to occur. Recent developments of PE cells enable this turn off to occur through the PE cell control.

2. Safety concerns.
Research shows that lack of lighting is likely to lead to increased vehicle accident rates. There is conflicting evidence around whether it leads to increased crime. It is probable that a wide range of issues add to increased crime levels- lighting is one of these issues and a region by region approach is best.

The International Dark Sky Association works to achieve the lowest possible level of lighting in order to improve the view of the night sky. They provide evidence that suggests artificially lit night skies have some health risks, including cancer, as well as the obvious greenhouse and environmental concerns. An article by National Geographic covers some of the issues and examples of action by councils from the USA.

3. Liability and standards.
It is not mandatory to adhere to Australian Standards for street lighting (AS 1158), meaning street lighting can be switched off. However, if lights were switched off it is likely that the distribution business would require council to assume liability for accidents of crimes that occur during this period.

4. Best options.
In summary the main issues are technical and from a liability perspective. If these issues are managed or easy to deal with (i.e. for metered situations this is relatively easy) then taking action to turn lights off is straight forward though can be expensive.