PERFORMANCE CONSIDERATIONS

Lighting

Although a small percentage of total energy use, lighting is an important part of most EPC contracts. 

Firstly, it is relatively easy and cost effective to implement lighting energy upgrades, as technologies are improving all the time (new lamps, fittings and controls) and many lighting installations are very inefficient.  The huge improvements reported from USA and Europe are not generally available in Australia as we have lower lighting levels to begin with, hence less equipment to upgrade, however substantial savings (typically 20 –40% and up to 80% in some cases) can be found.

Secondly, lighting is a relatively simple technology to understand (compared with HVAC for instance).  Upgrading the lighting sends a very obvious message to staff, patients and the public that the facility is serious about reducing its energy use.

Thirdly, because lighting consumes electricity, not gas, it has a disproportionate impact on greenhouse emissions . Coal fired electricity emits around 5 times the greenhouse gas per unit of energy than natural gas, so saving a unit of energy in lighting has 5 times the impact of reducing a unit of gas used in  HVAC or water heating for example.

General techniques applied in the lighting upgrade of these facilities included:

• Replacement of rapid start ballasts in fluorescent fittings with energy efficient low loss ballasts.  This then also allows the use of more economical and readily available standard fluorescent lamps instead of the special rapid start lamps.  Standard lamps are cheaper to buy, are available widely rather than from limited suppliers, and last longer. Combined, this results in lower operating costs for energy and reduced maintenance costs for lamp replacement.

• Replacement of inefficient fixtures such as incandescent lamps with compact fluorescent lamps.  This also involved replacement of whole fittings where a simple lamp replacement was not possible.  Compact fluorescent lamps are now well accepted as the standard lamp for general lighting duty in areas where the appearance of the 1200 long fluorescent lamp and its enclosure is considered unsuitable.  This generally includes public areas where a more “domestic” appearance is required.  Compact fluorescent lamps use only 20% of the energy of a tungsten lamp and last five times as long so, as for the rapid start example above, there are savings in energy and maintenance costs to be taken into account.  As an example of the reduced energy consumption of compact fluorescent lamps, compare the following:

Table 2 Comparison of lamp types

(for approximate equivalent light output)

* depends on style of lamp

•  Installation of lighting control systems such as occupancy detectors, time delay switches, dimming equipment and photoelectric cells.  There is now a wide range of proven automatic and semi-automatic lighting control technologies that are cost effective when correctly applied.  These range from simple day timers  which turn lights off after hours to whole building digital control systems integrated with other building controls such as HVAC and security, with costs ranging from a few dollars to hundreds of thousands of dollars. Considerable skill is required for selecting the correct type of lighting control systems for each situation. Inefficient systems can result from:  

1. Poor quality equipment, either inadvertently or as a result of taking the cheapest price, and

2. Selecting the wrong technology.

A simple example of the latter has been occupancy detectors which have a mixed, but largely undeserved reputation for being unreliable.  Broadly there are two types, infra-red and ultra-sonic; using the wrong one can result in unwanted operation or worse, no operation at all.  Using a lighting controls specialist avoids these problems.

Example:  a lighting upgrade at Parramatta Linen Service comprised de-lamping in areas with excess lighting, new control equipment, new reflectors and dimming.  Prior to the work the annual electricity used by the lighting system was estimated at 359,079 KWh by measuring for 2 weeks and extrapolating over a full year.  This is s standard technique.  When the modifications were completed the electricity consumption was similarly measured over a period of 2 weeks, resulting in estimated savings of 93,365 KWh or 26%.

Heating Ventilating And Air Conditioning

Heating, Ventilating and Air Conditioning, commonly referred to as HVAC, is the major energy user in most commercial, institutional and industrial facilities.  It usually provides the greatest opportunity for energy savings as almost all HVAC installations in Australia rank poor to fair when they are assessed for efficiency, greenhouse impact and overall effectiveness.  Energy reductions of 10-20% are common under an EPC, with reduced maintenance, increased effectiveness and lower emissions also contributing to the benefits achieved by a sensible upgrade.

HVAC improvements include Boilers, (for space heating and domestic hot water), and automatic control systems, as well as the more common features such as pumps, fans, chillers and cooling towers.

EPC’s are particularly effective when applied to HVAC systems, as they can also be used to renew old and out-of-date equipment, replacing it with newer plant and systems which not only perform more effectively but last longer as well.  This means that a major capital cost item, often difficult to fund (such as the replacement of aging plant), can be carried out as part of an EPC, paid for from the total operational savings from the project.

For this project, the HVAC associated actions accounted for 95% of total energy savings.  The major strategies implemented were:

• Decommissioning of existing coal fired at Bathurst and Mudgee Hospitals, and a diesel fuel oil boiler at Blayney Hospital, and installation of gas fired boilers.  This required the installation of a new gas service to the site for Bathurst and Mudgee Hospitals. It is normally impossible to justify the cost of these conversions based on energy savings alone. Indeed, for coal boilers it is probable that the energy costs will actually increase, due to the very low cost of coal.  However, the financial benefits come from operational costs savings, the most significant of which is the transfer of full-time boiler attendants to other duties.  The salary cost savings are substantial, especially when the additional on-costs are included, and are the normal financial drivers behind the project.  This is a very good example of the importance of capturing all benefits from a project, be it an EPC or a normal project.  EPC projects frequently do not proceed because the proponent fails to identify all the quantifiable, and often intangible, befits from the proposal, and hence fails to convince the decision maker to implement the project.

• Installation of direct digital controls for space heating, air handling units, and general mechanical systems at Bathurst Base Hospital.  Some hospitals had poor building automation and some of the smaller hospitals had none at all.  Without some level of computerised control, HVAC energy use is totally dependent on the skills and daily commitment of the operator. This will vary over time, and depending on the operator,  and is unlikely ever to match the expertise and fast response of even a simple electronic system. There are many examples, where automatic systems have been installed but  have never been fully commissioned and failed to deliver results.  One of the benefits of an Energy Performance Contract is that if these systems don’t deliver the guaranteed savings, then the contractor doesn’t get paid. This ensures the HVAC systems run at maximum efficiency once installed.

• Most of the systems installed were end-use heating controls.  This not only provided measurable  energy savings,  but also improved the internal comfort conditions within the hospitals benefiting staff, patients and visitors.  These benefits cannot be quantified, however  international evidence suggests that such improvements have a significant monetary value by reducing absenteeism, improving staff productivity and, in health care establishments, improving patients well-being and recovery rates.

• Installation of infra-red electric heaters with time delay function in place of inefficient, electric oil column radiators, plus the installation of thermostats to room heaters to provide more efficient localised space temperature control, thereby reducing energy waste.

Power Factor Correction

Power factor is a measure of the efficiency with which electricity is used on a site.  A Power Factor of 1 is the ideal, most commercial businesses run somewhere between 0.7 and 0.95.  Poer Factor is usually improved by installing banks of capacitors at the main electrical switchboards.

Power factor correction is not of itself an energy saving project, however, it is a significant energy cost saver where there is a charge (or penalty) for low power factor.  In these cases the closer the power factor is to unity (1) the lower the total electricity charge.  This technique can also increase the capacity of existing electrical distribution systems so it may sometimes be a way of accommodating increased electrical load without the capital expense of additional wiring and switchgear.

For this contract power factor correction units were installed to increase the Power Factor at sites such as Bloomfield and Blayney Hospitals, from 0.85 to 0.98. 

Water Saving Devices

Water is often overlooked as a cost saving opportunity, largely due to Australia’s long history of free water and lack of awareness of the significant costs involved in water and sewerage charges. There is often little understanding of the ways in which these charges can be reduced. Strategies for reducing water costs include:

Reducing total water use by:

• Installing flow control devices to taps and showers (see table 3 below);

• Collecting and recycling rainwater;

• Collecting and recycling ‘grey’ water from baths and hand-basins (not always possible in Hospitals); and

• Identifying and repairing water leaks.

 Reducing waste charges by:

• Using less total water;

• Collecting and reusing on site, and;

• Limiting trade waste to sewer, e.g. by collecting and removing by tanker.

Recommended water flow rates

For the  AHS sites, an inspection revealed that tap and shower fittings at the hospitals were inefficient, and inlet and outlet seals on toilet cisterns were in poor condition and in need of repair. As a result, water was unnecessarily wasted. Water conservation measures implemented were:

• Installation of control valves;

• Installation of toilet cistern modifiers;

• Replacement of “O” rings and tap washers; and

• Installation of automatic flush control systems to toilets.