Council Energy Efficiency

Sustaining Our Towns was pleased to recently deliver workshops designed to support Councils to improve energy efficiency of their facilities. This would not only bring cost savings but also carbon reductions. These workshops were held in Cooma, Queanbeyan, Young and Goulburn in late June 2011.  The energy efficiency workshop was led by Tooraj Arvejeh, Senior Sustainability Engineer with Advitech. Lighting consultant Julien Freed assisted.

Download the full Efficiency Efficiency for Councils presentation (Note 7 MB PDF)

Download the full Lighting Efficiency for Councils presentation (Note 2 MB PDF)

A summary of main points coming out of the sessions

Know your bills

  • Commercial energy bills provide users with valuable information that is vital to planning energy efficiency measures
  • Network or demand charges are often significantly larger than the actual energy use. These charges are projected to rise (by 18% in the one standard example provided in the sessions).
  • Check the Power Factor on your energy bills; if it is not close to 1.0 then it may be worth investing in Power Factor correction equipment
  • Kwh is the total amount of power you have used in a period (equivalent to the total tank size/volume if comparing to water use)
  • KVA is the rate at which you use power (equivalent to the litres/minute – or tap size – if comparing to water use)
  • Peak demand charges are based on KVA and are for the moment you use the most power in a single billing period, not the average demand over the whole billing period
  • Peak demand charges can be a significant proportion of your bill and you should focus on measures to decrease peak demand if this is the case
  • Ask your service provider to provide you with 30 minute interval data for your site to see how energy is used over time and identify opportunities for efficiency measures
  • 30 minute interval data can also help to calculate your baseload power at a site (the power that is still consumed while the facility is not in use e.g. overnight to run servers or fridges)

Reducing energy costs

  • The suggested priority list is firstly behaviour change, then lighting, reducing baseload power,  and finally air heating and cooling
  • Always start with behaviour. Look at 30 minute billing to identify baseload and peaks. Investigate where this use can be decreased through process changes.
  • Install power factor correction (suppliers are able to determine your new power factor with equipment installed so you can calculate projected savings). Note that power factor correction does not reduce energy use but will reduce the amount you pay for power.
  • Distribute electricity consumption throughout the day and where possible move to off peak periods

Lighting

  • To design effective lighting, it is valuable to understand lighting measurements. These include the total amount of light (lumens), the intensity at a given angle (candela), the amount falling onto a surface (lumens) and the surface brightness (candela/m2)
  • Lighting is critical to a productive work environment. Ensure any lighting changes satisfy the Australian Standard 1680 for public lighting
  • As billing is for Watts (which is volt x amps), a low voltage lamp may not be low power
  • In standard fluorescent lighting the newer T5 or 16mm lamps are the newer and more efficient option to the T8 or 26mm. There are converter kits available but seek advice as to whether a complete replacement may be a more cost effective option
  • LED’s are the lighting of the future; the technology is still in relative infancy but is bound to advance fast over the coming years
  • There are a range of LED standards; invest in higher quality lights from known lighting companies. Investigate sales claims against manufacturer information
  • Avoid 5mm bullet / bubble LED’s for lighting as they are designed as indicator lights on devices, not for illumination applications
  • LED options are ideal for public lighting (efficient, low replacement need, no mercury, excellent quality of light)
  • Investigate sensors (light or movement) as part of a holistic energy strategy
  • Lighting tips include:
    • First light the space evenly across vertical and horizontal surfaces using ambient lighting
    • Then task light the important surfaces and objects above the ambient light level
    • Avoid glare (including daylight) and shadows
    • Consider surface colours (darker will absorb more light)
    • Use quality luminaires that control the light produced. This minimises waste and therefore improves efficiency
  • A commercial building retrofit can expect a 30 – 60 % reduction in lighting related energy use with a 3 – 5 year simple payback. Also lower operating costs including reduced maintenance costs
  • As LED technology develops, the very bright light will be reflected off surfaces (indirect lighting)

Baseload Power

  • Baseload power is the power used when a facility is not operating for business (e.g. overnight and/or over weekends)
  • Generally this is the power used to run things like fridges, servers and security lighting
  • The easiest way to identify baseload power use is to ask your energy provider for 30 minute interval data for the site
  • This will allow you to quantify the proportion of energy used to run the site during ‘downtime’
  • Baseload should not be more 20-30% of your energy use at the site; if it is more than this you should try to identify why
  • Investing to reduce excess baseload power use can often be achieved by behavioural and systems changes

Heating and cooling

  • The best way to produce energy and demand savings is to consider the operation of the entire chiller plant using an integrated approach.
  • Energy and demand savings are achievable through improved operation and maintenance of the plant as well as through efficiency retrofits
  • Obtain data on Heating Degree Days (HDD) and Cooling Degree Days (CDD) from the Bureau of Meteorology. This assists in calculating when the outside air temperature was above or below a base temperature
  • Use HDD and CDD to determine weather dependent and non-weather dependent energy consumption. If weather dependent consumption is significant, assess the building insulation and air heating/cooling efficiency
  • Types of systems to investigate include:
    • central systems
    • roof top (packaged) units
    • split systems (suited for warm climates, low electricity price and high gas price)
  • Energy saving opportunities are to replace with:
    • better sized units (not oversized)
    • more efficient
    • variable refrigerant flow (VRF)
    • gas powered (reduces demand charges)
  • Chillers use one of four types of compressors, reciprocating, screw, centrifugal or scroll. The application is dependent on cooling capacity
  • Consider retrofitting with a heat exchanger to recover energy
  • If natural gas is available, consider tri-generation to produce energy, heating and cooling
  • If available, gas powered heating and cooling is worth investigating particularly to reduce peak demand issues

Financial justification for efficiency projects

  • Reducing greenhouse gas emissions can be profitable and offer a good return on investment (ROI)
  • The ROI on energy efficiency will improve with rising energy prices
  • Efficiency measures are often low risk compared to other projects and quantifiable payback can usually be measured
  • Having an asset management plan is key to identifying where efficiency can be planned for and allows financial justification
  • Energy efficiency may be a lower cost way of increasing the bottom line than seeking things like rate increases; weigh up energy efficiency project costs against the cost of acquiring income from alternative sources (e.g. from Council business ventures and/or stock market investment)
  • Separate the additional investment required to get an enery efficiency dividend from an asset renewal or replacement activity from the base investment required to a achieve a like-for-like renewal; this should make it easy to demonstrate a good ROI on the energy efficiency investment and sell the more efficient technology as a good business decision
  • Use benchmarking as a way to identify where your efficiency may have room for improvement (scorekeepers such as Planet Footprint can provide comparisons)

This is an example of a Simple HVAC Calculation Sheet that demonstrates the payback period for investment into energy efficiency for four different types of air conditioners.  This is the best way to promote more energy efficient measures to Council.

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