Saving Energy on WA Dairy Farms
Saving Energy on WA Dairy Farms
Saving Energy on WA Dairy Farms
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SAVNGENERGY<br />
On <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong><br />
This project was jointly<br />
funded through a<br />
collaborati<strong>on</strong> between<br />
<strong>Dairy</strong> Australia,<br />
Western <strong>Dairy</strong>, and<br />
Department of Agriculture,<br />
Fisheries and Forestry<br />
Western<br />
DAIRY<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <strong>on</strong> <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong> 1
Foreword<br />
The cost of electricity accounts for a significant proporti<strong>on</strong> of a dairy farm’s shed cost. <strong>Dairy</strong> farmers are under pressure<br />
from the rising cost of electricity and an increased focus <strong>on</strong> carb<strong>on</strong> emissi<strong>on</strong>s, with carb<strong>on</strong> legislati<strong>on</strong> to be introduced<br />
in July 2012. Real opportunities exist for dairy farmers to better c<strong>on</strong>trol their energy costs while simultaneously reducing<br />
greenhouse gas emissi<strong>on</strong>s.<br />
Western <strong>Dairy</strong> actively support dairy farmers in their bid to reduce the energy costs associated with milking. They recently<br />
assisted 22 dairy farms to complete a dairy energy use audit. Many of the farmers who took part in these audits are already<br />
reaping the benefits of having identified areas for improvement, and have invested in changes to their dairy. The audits<br />
found that while no two dairies were the same, milk cooling, milk harvesting and hot water producti<strong>on</strong> were the areas of<br />
highest energy use. The audits also revealed that while larger herds tend to have ec<strong>on</strong>omies of scale, similar herd sizes<br />
had significant variati<strong>on</strong> in energy costs at the dairy. Similar results have been found in the eastern states. Focussing <strong>on</strong><br />
ways to reduce energy c<strong>on</strong>sumpti<strong>on</strong> for milk cooling, harvesting and hot water producti<strong>on</strong> provides the greatest gain for<br />
improving energy efficiency.<br />
13% HOT<br />
<strong>WA</strong>TER<br />
43% MILK<br />
COOLING<br />
5% SHED LIGHTS<br />
&<br />
9% STOCK<strong>WA</strong>TER<br />
5% FEED<br />
3% CLEANING EFFLUENT<br />
&<br />
22% MILK<br />
HARVESTING<br />
Electricity usage from energy<br />
audits of <strong>WA</strong> dairy farms<br />
<strong>Dairy</strong> Australia has recently acquired $1 milli<strong>on</strong> in Federal Government funding aimed at helping dairy farmers use energy<br />
more efficiently. This funding will give 45 Western Australian dairy farmers access to complimentary energy audits. <strong>Dairy</strong><br />
farmers are urged to c<strong>on</strong>tact Rob La Grange <strong>on</strong> 0448 939 344 or email at rob@westerndairy.com.au to register their<br />
interest in this program.<br />
Western <strong>Dairy</strong>’s aim in producing this publicati<strong>on</strong> is to present tips, technologies and ideas for reducing energy use in the<br />
dairy. It also provides examples of farmers who have implemented some energy optimising ideas to reduce dairy running<br />
costs. It c<strong>on</strong>cludes with a checklist that brings together some simple things you can check to ensure your dairy is using<br />
energy efficiently. This publicati<strong>on</strong> focuses <strong>on</strong> improvements that are relatively low cost, have short payback periods, and<br />
can be implemented in most dairies in <strong>WA</strong>.
C<strong>on</strong>tents<br />
2 Electricity at the <strong>Dairy</strong><br />
2 <strong>Dairy</strong> energy audits<br />
3 Tariffs and energy supplies<br />
4 Negotiating a price<br />
4 Alternative energy retailers<br />
5 Demand resp<strong>on</strong>se programs<br />
6 Hot Water Systems<br />
6 Solar hot water systems<br />
7 Thermal heat recovery<br />
9 Heat pumps<br />
10 Milk Cooling Systems<br />
10 Plate coolers<br />
11 Cooling towers<br />
13 Improved refrigerati<strong>on</strong><br />
14 Milk Harvesting<br />
14 Variable speed drives<br />
18 Big Ticket Items<br />
18 Solar power<br />
19 Wind power<br />
19 Green cleaning systems<br />
20 <strong>Dairy</strong> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <str<strong>on</strong>g>Saving</str<strong>on</strong>g>s Checklist<br />
21 References and c<strong>on</strong>tacts<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <strong>on</strong> <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong> 1
Electricity at the <strong>Dairy</strong><br />
• Take advantage of off peak power to heat water, mill and mix grain and transfer feed and pump effluent.<br />
• Finish milking before 8am during the week.<br />
• Check that off peak timers are set correctly.<br />
• If you spend more than $10,000 per year <strong>on</strong> electricity, c<strong>on</strong>sider negotiating a c<strong>on</strong>tract with Synergy.<br />
• C<strong>on</strong>sider changing your electricity provider.<br />
<strong>Dairy</strong> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> Audit<br />
The first step to reducing the amount of power you use in the shed is understanding how much you use and what equipment<br />
uses the most. There are several <strong>on</strong> line tools that can help you calculate your dairy energy usage and identify the areas<br />
where efficiency gains and savings can be made.<br />
CowTime <strong>Dairy</strong> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> M<strong>on</strong>itor<br />
www.cowtime.com.au/<str<strong>on</strong>g>Energy</str<strong>on</strong>g>M<strong>on</strong>itor/index.aspx<br />
Synergy<br />
www.synergy.net.au/for_business/small_medium_business/energy_audit.xhtml<br />
What Wattage?<br />
You can check the wattage <strong>on</strong> motors and multiple<br />
the kilowatts (kW) by the run time to calculate the<br />
kilowatt hours (kWh) of energy usage. For anything<br />
that requires 240V you can measure the energy<br />
c<strong>on</strong>sumpti<strong>on</strong> by using an energy c<strong>on</strong>sumpti<strong>on</strong> metre.<br />
They simply plug into the power point and then you<br />
plug the equipment into the metre – it turns into a real<br />
time power m<strong>on</strong>itor. It tracks the power used and can<br />
display the instantaneous voltage or current being drawn<br />
as well as the peak levels that have been drawn.<br />
Costs start from $30.<br />
2
Tariffs and <str<strong>on</strong>g>Energy</str<strong>on</strong>g> Supplies<br />
Tariff and supply arrangements vary from dairy to dairy. The table below illustrates five different supply arrangements<br />
available from Synergy, Western Australia’s default electricity supplier.<br />
Review your power bill and make particular note of the units used during <strong>on</strong> peak (M<strong>on</strong>-Fri 8am-10pm) and off peak<br />
(M<strong>on</strong>-Fri 10pm-8am and weekends) periods.<br />
Tariff Supply Charge ($/day) Arrangement<br />
Peak (cents/unit)<br />
Off Peak (cents/unit)<br />
R1 Business Time of Use 1.56 27.41 8.45<br />
R3 Business Time of Use<br />
Fifty<br />
2.14 37.48 11.54<br />
K1 Home Business Plan 0.40 21.87<br />
(first 20 units/day)<br />
27.41<br />
(21-1650 units/day)<br />
L3 Business Plan Fifty 0.495 First 1650 units/ day 32.40<br />
P13 Business Time of Use 3.08 32.91 8.98<br />
Types of Electricity Meters<br />
Electromechanical Dial Meter – These meters have four, five or six dials.<br />
Digital Display Meter – Has a six digit display similar to the odometer of a car.<br />
Electr<strong>on</strong>ic Meter (types may vary) - Electr<strong>on</strong>ic Meters have a six digit display register which scrolls through different tariff<br />
rates. Some electr<strong>on</strong>ic meters c<strong>on</strong>tinuously scroll through the different channels, pausing <strong>on</strong> each channel for a period<br />
of six sec<strong>on</strong>ds. Other electr<strong>on</strong>ic meters have a fixed display that requires you to repeatedly press the reset scroll butt<strong>on</strong> to<br />
display all rates depending <strong>on</strong> the tariff.<br />
Time of Use or SmartPower Meter - Synergy offers time of use meters. These meters allow customers to access time<br />
based pricing. By moving usage from an expensive time period (Peak) to a less expensive time period (Off Peak) you can<br />
reduce electricity costs. The service charge for time of use is c<strong>on</strong>siderably higher than the normal service charge and must<br />
be taken into account when calculating the savings.<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <strong>on</strong> <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong> 3
Negotiating a Price<br />
It is worth c<strong>on</strong>tacting your energy supplier in an effort to negotiate a better deal for your electricity requirements.<br />
For example, if you spend more than $10,000 a year <strong>on</strong> electricity you are eligible to move to a Synergy Business Plan or<br />
n<strong>on</strong>-standard c<strong>on</strong>tract. These c<strong>on</strong>tracts c<strong>on</strong>tain different terms and c<strong>on</strong>diti<strong>on</strong>s to a ‘standard’ c<strong>on</strong>tract and may include<br />
variati<strong>on</strong>s in price, fees, charges, c<strong>on</strong>tract length, payment opti<strong>on</strong>s and early terminati<strong>on</strong> and exit fees.<br />
www.synergy.net.au/business_quote.xhtml<br />
N<strong>on</strong> Standard C<strong>on</strong>tracts – What can you save?<br />
Many dairy producers are investigating the opti<strong>on</strong> of moving to a n<strong>on</strong>-standard c<strong>on</strong>tract in order to save <strong>on</strong><br />
their electricity costs.<br />
In writing this brochure several dairy farmers were c<strong>on</strong>sulted <strong>on</strong> their experience in negotiating a c<strong>on</strong>tract for<br />
a better electricity price. In most cases the c<strong>on</strong>tract was for a 12 m<strong>on</strong>th period. An example of the new pricing<br />
arrangement in a n<strong>on</strong> standard c<strong>on</strong>tract can be seen below.<br />
<str<strong>on</strong>g>Energy</str<strong>on</strong>g> Price (c/unit)<br />
Supply Charge<br />
On Peak<br />
Off Peak<br />
(c/day)<br />
N<strong>on</strong> standard 34.20 8.16 307.75<br />
Standard 37.48 11.54 214.00<br />
For <strong>on</strong>e dairy farmer who had negotiated a n<strong>on</strong>-standard c<strong>on</strong>tract, the savings <strong>on</strong> the n<strong>on</strong>-standard c<strong>on</strong>tract<br />
compared to the standard c<strong>on</strong>tract, for <strong>on</strong>e billing period of 68 days, was $580 dollars. Across a year this<br />
represents $3133 in savings, all for the cost of a ph<strong>on</strong>e call and some paperwork.<br />
Alternative <str<strong>on</strong>g>Energy</str<strong>on</strong>g> Retailers<br />
The majority of dairy businesses use Synergy to supply their power as<br />
they are the default electricity suppliers for <strong>WA</strong>. As a result of government<br />
policy to allow more competiti<strong>on</strong> in the energy industry, some customers<br />
are now able to choose their electricity retailer. The Ec<strong>on</strong>omic Regulati<strong>on</strong><br />
Authority, who are the independent ec<strong>on</strong>omic regulator for Western<br />
Australia, state that if you are a Western Power customer and use more<br />
than 50 MWh of electricity per year (approximately $12,600), then you<br />
can choose an alternative retailer. Current choices are Synergy, Alinta<br />
and Perth <str<strong>on</strong>g>Energy</str<strong>on</strong>g>.<br />
Synergy<br />
Alinta<br />
Perth <str<strong>on</strong>g>Energy</str<strong>on</strong>g><br />
www.synergy.net.au<br />
www.alinta.net.au/business/electricity-products<br />
www.perthenergy.com.au<br />
4
Paying You for Power<br />
As demand for electricity c<strong>on</strong>tinues to rise, utilities and grid operators c<strong>on</strong>tinue to look for ways to increase the electric<br />
grid’s capacity. Where <strong>on</strong>ce the <strong>on</strong>ly opti<strong>on</strong> was to fire up costly backup plants, power providers can now look to energy<br />
users to relieve the grid of excess demand at critical times.<br />
What is Demand Resp<strong>on</strong>se?<br />
Demand resp<strong>on</strong>se is simple: peaking demand triggers a dispatch across the grid. Your business resp<strong>on</strong>ds by reducing<br />
electricity usage for a few hours. You receive a payment from EnerNOC for your participati<strong>on</strong>. You also receive regular<br />
payments year-round just for being <strong>on</strong>-call during normal grid operati<strong>on</strong>. They have an intuitive, web-based applicati<strong>on</strong>,<br />
DemandSMART, which enables commercial, industrial, and instituti<strong>on</strong>al entities to receive payments for participating in<br />
demand resp<strong>on</strong>se programs.<br />
EnerNOC provides demand resp<strong>on</strong>se capacity to the South West Interc<strong>on</strong>nected System in Western Australia, while helping<br />
businesses maximise payments for participating.<br />
How Does it Work?<br />
1. When a demand resp<strong>on</strong>se is anticipated you are notified via ph<strong>on</strong>e/email that the demand resp<strong>on</strong>se event is going to begin.<br />
2. At the start of demand resp<strong>on</strong>se you cut or reduce your power usage according to your pre- determined energy<br />
reducti<strong>on</strong> plan.<br />
3. Before, during and after the event you have the support of EnerNOC staff to ensure that you achieve the highest level<br />
of performance, payments and satisfacti<strong>on</strong>.<br />
4. You receive quarterly payments for your participati<strong>on</strong>.<br />
www.enernoc.com<br />
Payment for Power is Painless<br />
Ross Woodhouse, who farms at Scott River, is involved in the<br />
EnerNOC DemandSMART program. He commits to 24 hours across<br />
a year in which he will turn off power. The demand resp<strong>on</strong>se usually<br />
occurs between 4-6pm during which time he uses a generator to<br />
c<strong>on</strong>tinue milking. He is given 12 hours advanced warning to prepare<br />
and then is paid 50c/kWh plus an annual fee for the power that he<br />
is not using. Joining incentives in the first year of the program<br />
saw Ross paid $26,000. In subsequent years this had dropped to<br />
approximately $17,000 per year. The profitability of being involved<br />
in this scheme will depend <strong>on</strong> the cost of generating the power<br />
yourself and whether there is a capital expense involved. In Ross’s<br />
case he did not buy the generator specifically for this program but<br />
already had it for back-up power.<br />
Photo courtesy of CSBP<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <strong>on</strong> <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong> 5
Water Heating<br />
• Minimise the volume of water used to wash the plant and vat. Wash at the lowest temperature possible without<br />
compromising hygiene.<br />
• Use a thermometer to m<strong>on</strong>itor hot water inputs and outputs.<br />
• Install a water heater with capacity for all daily wash requirements so that all heating can occur <strong>on</strong> the off peak tariff.<br />
• If a time of use tariff is in place, install a timer to ensure water is <strong>on</strong>ly heated during the overnight off peak period.<br />
• Install a hot water pre heating device such as a heat recovery unit or solar hot water heater so that most of the heating<br />
can occur without using extra electricity.<br />
• Insulate pipes to reduce heat loss.<br />
• Keep storage tank out of breezeways and drafts.<br />
• Use the best quality water available – high levels of minerals or organic matter reduces heating performance.<br />
Solar Hot Water Systems<br />
In most cases producing hot water for the dairy using a solar hot water system is the best move financially and<br />
envir<strong>on</strong>mentally. There are two types of solar hot water systems, flat panel collectors and evacuated tube solar collectors.<br />
Flat plate collectors have copper pipes running through a glass covered collector, often c<strong>on</strong>nected to a water storage tank<br />
<strong>on</strong> the roof. The water thermo-siph<strong>on</strong>s in and out of the tank, heating the water.<br />
Evacuated tubes use a glass tube with a vacuum inside and copper pipes running through the centre. The copper pipes are<br />
c<strong>on</strong>nected to a comm<strong>on</strong> manifold which is c<strong>on</strong>nected to a slow flow circulati<strong>on</strong> pump. This pumps water to a storage tank below,<br />
heating the hot water during the day. The hot water can be used at night or the next day due to the insulati<strong>on</strong> of the tank.<br />
Flat Plate<br />
Evacuated Tube<br />
Less expensive ($10,550*) More expensive ($11,039**)<br />
Operates most efficiently in the<br />
middle of the day<br />
More sensitive to frost causing<br />
damage to the collectors<br />
Heavier<br />
Can heat water to a higher temperature as they have a greater surface area<br />
exposed to the sun at any <strong>on</strong>e time (40% more efficient)<br />
Can be used in sub zero and overcast c<strong>on</strong>diti<strong>on</strong>s (can extract heat out of the air<br />
<strong>on</strong> a humid day).<br />
Risk of overheating as the water reaches its maximum temperature in the tank<br />
the pressure and temperature valve automatically activate and release some<br />
water to allow for cold water to come back in reducing the temperature build up.<br />
The number of tubes needs to be matched to the quantity of water to be heated<br />
to minimise the risk.<br />
Lighter – some lightweight designs can be mounted <strong>on</strong> walls and even poles.<br />
Requires a smaller roof area.<br />
Less corrosi<strong>on</strong> than flat plate systems.<br />
Are durable and broken tubes can be easily and cheaply replaced.<br />
Quotes obtained from www.dpi.vic.gov.au/agriculture/dairy/energy-in-dairy<br />
*Solar Dynamics – 3 x 300L storage tanks with no internal boost, six flat panels and three manifold kits.<br />
** Apricus Australia - 90 evacuated tubes and heat pipes, three manifold kits.<br />
Photo courtesy of SCE <str<strong>on</strong>g>Energy</str<strong>on</strong>g> Soluti<strong>on</strong>s<br />
6
Boosters<br />
In the cooler m<strong>on</strong>ths a solar hot water system will not provide water sufficiently hot enough to clean the milking machine so<br />
an electric booster is required for both flat plate and evacuated tube systems. It is recommended that water is kept below 90°C<br />
entering the line (under vacuum) to prevent steam from damaging the vacuum pump but will still need to be hot enough to<br />
achieve an effective clean of the milking machine.<br />
Washing Regimes<br />
Is there a better way?<br />
• Check the temperature of the wash water in the drum as the wash cycle commences (it should not exceed 85°C).<br />
• During recirculati<strong>on</strong> the drum should be around 20% full as the wash water returns. If it is more then smaller wash quantities<br />
should be c<strong>on</strong>sidered.<br />
• Investigate detergents that work effectively at lower temperatures.<br />
• Use a chemical sanitiser in the final wash cycle to reduce hot water demand.<br />
• Capture the final rinse for use next time.<br />
Factors to c<strong>on</strong>sider when installing solar hot water system at the dairy<br />
• Tank sizes are limited to 315L or 440L. Costs increase dramatically when more tanks are needed (CowTime research shows<br />
that each cluster requires seven litres of water per wash. Use this to calculate the volume of hot water required).<br />
• Correct installati<strong>on</strong> and mounting is critical to success. The roof needs to be str<strong>on</strong>g enough to hold the system. The collector<br />
should be mounted to face north or the amount of energy that can be captured is reduced. The tilt angle should be the latitude<br />
of the installati<strong>on</strong> site.<br />
• The higher the quality of collectors in the system the hotter the water produced.<br />
• If your gas/electric hot water system has plenty of life in it, c<strong>on</strong>sider retro fitting collectors, pump and c<strong>on</strong>troller to an existing<br />
storage tank. The retrofit opti<strong>on</strong> can save large amounts <strong>on</strong> installati<strong>on</strong> but eliminates the need to replace an existing hot<br />
water cylinder.<br />
Thermal Heat Recovery Systems<br />
A large amount of waste heat generated during milking can be harvested and used. Sources include the plate cooler, refrigerati<strong>on</strong><br />
systems and some vacuum pumps. Heat recovery systems are available that capture the heat from the milk refrigerati<strong>on</strong> system<br />
and use it to heat water (to 50°C to 60°C). The system sits between the compressor <strong>on</strong> the milk vat and the air cooled c<strong>on</strong>denser<br />
to extract the heat during milk cooling. The hot refrigerant gases with high pressure from the compressor are transported to<br />
the heat recovery system where the heat is released into the cycling water in the system. Most of the commercial units available<br />
have 450 L capacity. This water can then feed into the hot water system. Using water to remove heat from the refrigerati<strong>on</strong><br />
system is more efficient than using air so improves the efficiency and life of the compressor.<br />
Advantages<br />
Disadvantages<br />
Free energy from the refrigerati<strong>on</strong> system Capital expense ($7000-$11,000)<br />
Can reduce milk refrigerati<strong>on</strong> costs if properly designed Poorly designed systems can result in water that is too<br />
hot and reduce the overall efficiency of the refrigerati<strong>on</strong><br />
C<strong>on</strong> prol<strong>on</strong>g the life of the compressor<br />
Difficult to recover heat from the large volume of warm<br />
In some cases can get water to greater than 75°C<br />
water generated from the plate cooler (without insulated<br />
storage)<br />
*informati<strong>on</strong> from CowTime<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <strong>on</strong> <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong> 7
Cost<br />
A recent project from DPI Victoria developed a hypothetical case study dairy farm in south Gippsland to estimate the<br />
cost of energy saving technologies. The case study assessed the cost associated with a heat recovery system to heat<br />
700 litres of water to 65°C. The preheated water entered the electric hot water service to heat to 90°C overnight. The<br />
energy saved under the system was 41kWh which equated to $2905 saved in the first year. The capital investment of<br />
the system was $7375 plus $3000 for installati<strong>on</strong>. The system was a profitable investment which recouped the initial<br />
cash outlay and will cost less than business-as-usual in year five. After year five the system would be a cheaper<br />
alternative to electric hot water. At the end of year ten the system was $16 800 better off than business-as-usual and<br />
had an internal rate of return (IRR) of 27 per cent.<br />
Factors to c<strong>on</strong>sider when installing thermal heat recovery systems<br />
• Correct installati<strong>on</strong> <strong>on</strong> the existing milk cooling system to achieve target water temperatures<br />
• The volume of the water tank and volume used during and between milkings.<br />
• The amount of milk to be cooled will determine how much heat can be captured.<br />
• The network water temperature.<br />
• Type of refrigerant gases and the c<strong>on</strong>figurati<strong>on</strong> of the installati<strong>on</strong>.<br />
• Combining an evacuated tube solar hot water system with the thermal heat recovery system. This can be an<br />
opti<strong>on</strong> that will reduce dependency <strong>on</strong> electricity but the complexity of combining the different systems will need<br />
to be c<strong>on</strong>sidered.<br />
Heaps of Hot Water<br />
Bob and Jacqui Biddulph realised that heating up to 1600 L of<br />
water, to wash their 44 stand rotary in Cowaramup, formed a<br />
big part of their electricity bill. Participating in Western <strong>Dairy</strong>’s<br />
<str<strong>on</strong>g>Energy</str<strong>on</strong>g> Audit program c<strong>on</strong>firmed that the decisi<strong>on</strong> to purchase<br />
an <str<strong>on</strong>g>Energy</str<strong>on</strong>g> Recovery System (ERS) was the right <strong>on</strong>e.<br />
The dairy already had two 800 L Wils<strong>on</strong> hot water storage<br />
tanks which heated up cold water during off peak periods.<br />
This was complemented by the installati<strong>on</strong> of two 550 L<br />
Delaval <str<strong>on</strong>g>Energy</str<strong>on</strong>g> recovery tanks which heat water using the<br />
waste heat generated from the vat compressors. The ERS<br />
system cost $12,500 (45 per cent was installati<strong>on</strong> of electrics<br />
and plumbing) and at current electricity rates (not counting<br />
rising rate increases) the payback period will be 3 years.<br />
Bob has been very happy with the result. “We recently<br />
measured surplus water from the heat recovery tank and it<br />
varies between 60°C and 73° C. This means that the electric<br />
hot water system <strong>on</strong>ly has to heat it another 20 - 30°C before<br />
it is ready for washing out the milking machine” Bob said.<br />
An analysis of their electricity bills estimates that the Biddulphs<br />
are using approximately 18 per cent fewer units of electricity<br />
than for the same period last year, despite milk producti<strong>on</strong> over<br />
that same period being up 20 per cent. Bob has been unable<br />
to quantify the savings accurately, but he feels that the milk<br />
cooling system is working more efficiently with the compressor<br />
shutting off earlier, despite this year’s l<strong>on</strong>g hot summer.<br />
Bob and Jacqui had toyed with various ideas in the last few<br />
years for reducing costs associated with heating water but<br />
felt that the heat recovery units gave them the ‘biggest bang<br />
for their buck’. The ERS also allows for quick access to hot<br />
water through an outlet direct from the tanks. This has<br />
proved handy for washing calf buckets and general cleaning,<br />
and means that water is not sourced directly from the hot<br />
water storage tanks.<br />
8
Heat Pumps<br />
A heat pump can reduce power c<strong>on</strong>sumpti<strong>on</strong> and costs by preheating large volumes of water to 60°C. A solar heat pump<br />
works like a refrigerator in reverse. The compressor <strong>on</strong> the heat pump transfers heat from the surrounding air to water<br />
held in an insulated tank. The water from the heat pump is then transferred to the hot water heater so it can be heated to<br />
the required temperature required to wash the milking machine. They are not a substitute for the hot water system.<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g>s of approximately 40 per cent can be made with heat pumps To heat 800 L of water to 85°C savings ranged from<br />
$700 for off peak hot water systems to $2500 where there is no off peak hot water at the dairy (Ewen Report).<br />
Facts about Heat Pumps<br />
• Most have a volume of 340 L, however 400 L and 1000 L<br />
tanks are also available. Two or more tanks can be installed in<br />
manifold to supply large volumes of hot water.<br />
• Tanks are made of stainless steel, copper or ceramic lined steel.<br />
• Compressor motors are usually small drawing 0.7 kW to 4.2<br />
kW depending <strong>on</strong> the model and size of the unit.<br />
• Smaller units run off single phase and large models will<br />
require three phase power.<br />
• Of the energy required to heat the water, two thirds comes<br />
from the heat in the air, and the remaining <strong>on</strong>e third from the<br />
power used to drive the compressor.<br />
Manufacturers recommend that heat pumps should be<br />
operated during the warmer part of the day when they<br />
will work most efficiently as the ambient temperature<br />
is highest. They can operate at night as they do not<br />
require direct sunlight to work. Some heat pumps<br />
have been designed to work in ambient temperatures<br />
ranging from -10°C to +40°C.<br />
Cost<br />
The Ewen Report indicates that three tanks in<br />
manifold with a capacity to heat 800 L of water costs<br />
approximately $12,000 including installati<strong>on</strong>. If there is<br />
no off peak power supply at the dairy, installing a heat<br />
pump to pre heat water can save up to $2500 each year.<br />
In this example the payback period was five years.<br />
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Milk Cooling Systems<br />
• Switch to time of use metering where morning milking activities are completed by 8am.<br />
• Use a plate cooler with a single pass of cool water that is not recirculated unless it is re-cooled ie with cooling tower.<br />
• Ensure plate cooler is the correct size for the volume, pressure and milk flow rate. This will ensure effective cooling of<br />
milk so vat compressors are not running for extended lengths of time.<br />
• C<strong>on</strong>sider double bank plate coolers where the coldest source of water flows through the first plate cooler. The sec<strong>on</strong>d<br />
plate cooler can use glycol or chilled water to cool the milk even further. It is beneficial if the chiller can be run during<br />
off peak power.<br />
• Have your plate cooler regularly serviced by a technician.<br />
Cooling milk from 35°C to 4°C accounts for the biggest proporti<strong>on</strong> of total dairy energy costs (43 per cent in <strong>WA</strong> audits). Designing<br />
and operating an efficient milk cooling system can reduce energy demand and operating costs. In many cases the technology,<br />
such as plate coolers, is not new but needs to be evaluated to ensure it is working efficiently and not costing you m<strong>on</strong>ey.<br />
Plate Coolers<br />
Plate coolers are an extremely cost effective way to cool milk, but in many cases are poorly utilised. There are several<br />
factors that impact <strong>on</strong> the effectiveness of plate coolers.<br />
Flow Rates<br />
The system needs to be designed according to the peak flow rate of milk<br />
expected from the milk pump. Providing an even flow of milk from the milk<br />
pump by installing a variable speed drive will help make the plate cooler system<br />
easier to size and make efficient use of the cooling water. Using a transfer<br />
(rather than pressure) pump is a preferable way to supply the cooling fluid.<br />
Surface Area<br />
The latest plate coolers are designed to have more surface area giving them<br />
greater heat exchange capacity which improves their cooling efficiency.<br />
Different types of plate coolers require different flow rates for the cooling<br />
medium. The standard ‘M’ and ‘P’ series plate coolers operate <strong>on</strong> a ratio of<br />
2.5-3 L of water to 1 L of milk passing through the cooler. Newer industrial<br />
models work <strong>on</strong> 1.5–2 L water to 1 L of milk.<br />
Plate Compressi<strong>on</strong><br />
Plates that are too tight restrict flow so aim for 3 mm for each plate and gasket.<br />
Plate Cleanliness<br />
C<strong>on</strong>taminants of either the water or milk that adhere to the plates will affect<br />
the heat exchange capacity, flow rate and efficiency of the plate cooler.<br />
Source Water<br />
The temperature of the source water is the greatest limitati<strong>on</strong> to plate<br />
coolers. In winter when water temperatures are low plate coolers operate<br />
very efficiently. In summer, when water temperatures increase, there can<br />
be very little margin between the water temperature and milk temperature.<br />
This means the vat will do the majority of the chilling which uses a lot of<br />
electricity, usually at peak tariff rates.<br />
Plumbing<br />
To maximise heat transfer the water should flow through the plate cooler in<br />
the opposite directi<strong>on</strong> to the milk.<br />
Informati<strong>on</strong> sourced from CowTime<br />
10
Is your plate cooler doing the job?<br />
The best way to check if your plate cooler is up to the task is to compare the temperature of the milk leaving the plate<br />
cooler with the incoming temperature of the cooling water. A plate cooler working properly should cool milk to within 2°C<br />
of the incoming cooling fluid ie if water coming into the plate cooler is 18°C then the temperature of the milk should be<br />
about 20°C.<br />
Step 1 Identify water inlet and milk outlet pipes.<br />
Step 2 Apply strip thermometers to water inlet and milk outlet pipes and measure the temperature of the water and milk<br />
during peak milk flow as it exits the plate cooler.<br />
Step 3 If you get more than 3°C difference there is room to improve the performance of your plate cooler.<br />
Step 4 Measure the flow rate of water leaving the plate cooler. This is d<strong>on</strong>e by timing how l<strong>on</strong>g it takes to fill a 20L bucket<br />
when the pump is operating at normal speed and flow rate. If the water is being recycled or recirculated into a tank<br />
put the bucket under the discharge pipe. For example if it takes 13 sec<strong>on</strong>ds to fill a 20L bucket the flow rate is 20<br />
÷ 13 = 1.5 L/sec).<br />
Step 5 Measure the time taken to fill the bucket with milk at the vat entry point while the milk pump is working at capacity<br />
(ie all cups <strong>on</strong>). If it takes 40 sec<strong>on</strong>ds to fill a 20 L bucket the flow rate is 20 ÷ 40 = 0.5 L/sec. If it is not possible to<br />
measure during milk, simulate using water at a later point.<br />
Step 6 Divide the cooling fluid flow rate by the milk flow rate to determine the ratio. Using the numbers menti<strong>on</strong>ed in<br />
steps 4 and 5 the flow rate would be 1.5 ÷ 0.5 = 3. The water flow rate is 3 times the milk flow rate or 3:1.<br />
Informati<strong>on</strong> sourced from CowTime<br />
How hot is it?<br />
There are two quick and easy ways to test the temperature of either milk or water running in and out of the plate cooler.<br />
Thermometer Test Strips - temperature difference is easy to measure by applying strip thermometers to the water inlet<br />
pipe and to the milk outlet pipe. Cost $4.<br />
Digital N<strong>on</strong>-C<strong>on</strong>tact Infrared Thermometer Gun – can measure surface temperature of hot, hazardous or hard to reach<br />
objects. Simply point the red light at the pipe/object to be measured and pull the trigger to get a quick temperature<br />
reading. They are a great tool for around the farm. Cost start at $30.<br />
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Cutting Costs at Scott River<br />
Ross Woodhouse milks 1100 cows in a 60 stand rotary <strong>on</strong> his Scott River property. The ever increasing cost<br />
of electricity, and a desire to improve efficiency, prompted Ross to make several key changes to his dairy.<br />
After a particularly hot summer Ross realised that the vat was struggling to reduce the temperature<br />
of the milk, c<strong>on</strong>sistently producing the error message ‘too slow to cool’. After c<strong>on</strong>sulting Kim Norwell<br />
from DeLaval, it was decided that the plate cooler needed an overhaul. It was cleaned and serviced and<br />
ten more plates were added to improve its cooling efficiency. In additi<strong>on</strong>, a filter was put <strong>on</strong>to the water<br />
supplying the plate cooler to ensure any c<strong>on</strong>taminati<strong>on</strong> from leaves and sludge could not inhibit the flow<br />
through the plate cooler. With the plate cooler now taking more heat out of the milk, the vat has less work<br />
to do reducing electricity costs.<br />
Ross has also looked to make further savings by installing a VSD <strong>on</strong> his vacuum pump and negotiating<br />
a better deal <strong>on</strong> his electricity supply. He has been able to negotiate a new two year c<strong>on</strong>tract with Perth<br />
<str<strong>on</strong>g>Energy</str<strong>on</strong>g> to supply his electricity requirements at a competitive rate, with peak electricity being reduced by<br />
5c/kW. He is also part of the EnerNOCS demand resp<strong>on</strong>se program.<br />
Bring in the Expert<br />
Testing the efficiency of your plate cooler is an important first step that you can do yourself. If you have ascertained<br />
that there is a problem it may be a good idea to call <strong>on</strong> the services of a skilled technician. They will be able to clean<br />
the plates (a harder job than it looks) and ensure the plate cooler is reassembled properly. They will also be able<br />
to advise <strong>on</strong> resizing, extra pumping capacity, additi<strong>on</strong>al cooled water storage or a complete dismantle and service.<br />
The additi<strong>on</strong>al capital and cost of the servicing should be compared to the cost of an inefficient plate cooler. The<br />
cost of an inefficient plate cooler can run into the thousands of dollars a year depending <strong>on</strong> milk producti<strong>on</strong> and the<br />
difference in temperature of the water and milk entering and exiting the plate cooler.<br />
12
Cooling Towers<br />
If you discover that the water entering your plate cooler is too warm, a cooling tower could be a c<strong>on</strong>siderati<strong>on</strong>. They also allow<br />
for water from the plate cooler to be cooled so it can be recirculate without jeopardising milk cooling. Cooling towers can be very<br />
effective at cooling water in areas of low humidity.<br />
A cooling tower is a heat rejecti<strong>on</strong> device. A cooling tower relies <strong>on</strong> evaporati<strong>on</strong> to remove heat from the water. The tower<br />
allows a small porti<strong>on</strong> of the water being cooled to evaporate into a moving air stream to provide significant cooling to<br />
the rest of that water stream. The heat from the water stream transferred to the air stream raises the air’s temperature<br />
and its relative humidity, and this air is discharged to the atmosphere. Water can be cooled to within 5°C of the wet bulb<br />
temperature* in a tower that is properly designed.<br />
• Cooling towers are a relatively cheap technology.<br />
• They do not work well <strong>on</strong> days of high relative humidity and high wet bulb temperatures.<br />
• They can reduce the temperature of the water entering the plate cooler improving its efficiency and reducing the<br />
cost of milk cooling. Check the temperature of the water entering the plate cooler to see if a cooling tower could<br />
be an opti<strong>on</strong>.<br />
• Bore and well water will have a relatively stable temperature all year round but the temperature may rise c<strong>on</strong>siderably<br />
in hot weather depending <strong>on</strong> how this water is stored.<br />
• Positi<strong>on</strong>ing, burying, screening or planting shade around tanks are opti<strong>on</strong>s to help insulate.<br />
• Mechanical-draft cooling towers rely <strong>on</strong> power-driven fans to draw or force the air through the tower and are more<br />
effective than natural draft cooling towers.<br />
*Wet bulb temperature is measured using a standard mercury-in-glass<br />
thermometer, with the thermometer bulb wrapped in muslin, which is<br />
kept wet. The evaporati<strong>on</strong> of water from the thermometer has a cooling<br />
effect, so the temperature indicated by the wet bulb thermometer is<br />
less than the temperature indicated by a dry-bulb (normal, unmodified)<br />
thermometer against the warming effects direct sunlight.<br />
Improved Refrigerati<strong>on</strong><br />
A new product, the Mysticool Max, is an add-<strong>on</strong><br />
comp<strong>on</strong>ent that can help to improve the performance<br />
of milk vat refrigerati<strong>on</strong>. It is a valve that changes the<br />
liquid dynamics of the refrigerant gas allowing more<br />
of it to come into c<strong>on</strong>tact with the copper and cooling<br />
plates. This reduces the temperature faster and more<br />
efficiently. It also enables temperatures to be held more<br />
c<strong>on</strong>sistently. It can be installed without altering any of<br />
the other system comp<strong>on</strong>ents. The starting cost is $2400<br />
+ GST with return <strong>on</strong> investment between 9-36 m<strong>on</strong>ths.<br />
www.sce-energysoluti<strong>on</strong>s.com.au<br />
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Milk Harvesting<br />
• Investigate variable speed drives for vacuum pumps (best suited to blower type vacuum pumps) where there is sufficient<br />
excess vacuum being produced for the motor to be able to reduce power output.<br />
• Reduce milking times where possible.<br />
• C<strong>on</strong>sider variable speed drives for large water pumps.<br />
In many dairies vacuum and milk pumps operate at a c<strong>on</strong>stant speed which is required to create a desired vacuum or flow<br />
rate. Power savings of 40-75% can be made when a variable speed drive (VSD) is fitted to the vacuum pump (Ewen Report).<br />
Further savings can be made when VSDs are fitted to the milk pump as it can improve the efficiency of heat exchange through<br />
the plate cooler.<br />
A VSD uses a sensor in the vacuum line to detect changes in pressure and then adjusts the speed of the pump motor to<br />
match the demand for vacuum or flow rate. This lowers energy c<strong>on</strong>sumpti<strong>on</strong> and emissi<strong>on</strong>s. There is less wear and tear<br />
<strong>on</strong> the motor and noise levels are lower during milking. One VSD can c<strong>on</strong>trol up to three motors at <strong>on</strong>e time and they can<br />
work with both three phase and single phase power supplies.<br />
VSDs can be fitted to new or existing pumps. Vane and blower vacuum pumps are the two most comm<strong>on</strong>ly used vacuum<br />
pumps. Blower vacuum pumps are more efficient than vane pumps but are more expensive. VSDs are better suited to<br />
blower vacuum pumps as they can operate at lower revoluti<strong>on</strong>s than vane pumps and still maintain sufficient vacuum.<br />
They are usually quieter and have a l<strong>on</strong>ger life. Some vane pumps are not suited to VSDs if the revoluti<strong>on</strong>s can not be<br />
lowered without wearing out the pump. They will also require additi<strong>on</strong>al lubricating oil which will be an added cost.<br />
VSD <strong>on</strong> VACUUM PUMPS<br />
Advantages<br />
Only uses energy needed to meet the load <strong>on</strong> the milking<br />
system<br />
The l<strong>on</strong>ger the milking time the better the savings<br />
Reduces noise in the dairy<br />
Reduces wear <strong>on</strong> the motor and pump prol<strong>on</strong>ging their life<br />
Disadvantages<br />
Capital expense<br />
Not every<strong>on</strong>e can repair them. Requires yearly servicing.<br />
Typical pay back times range from 4-7 years depending<br />
<strong>on</strong> how many hours/day they are used for<br />
*informati<strong>on</strong> from CowTime<br />
VSD <strong>on</strong> MILK PUMPS<br />
Advantages<br />
Can give better milk cooling due to more c<strong>on</strong>stant rate of<br />
milk flow.<br />
Enables better matching of precooled water to daily milk<br />
volume which can save water<br />
Reduces the need for a ‘choke’ <strong>on</strong> the milk line which<br />
may have an impact <strong>on</strong> milk quality<br />
Disadvantages<br />
Capital expense<br />
Typical pay back times for VSDs range from 2.5 to 5 years<br />
depending <strong>on</strong> daily milk volume and the expected<br />
improvement in milk cooling efficiency.<br />
Not every<strong>on</strong>e can repair them. Requires yearly servicing.<br />
*informati<strong>on</strong> from CowTime<br />
14
Factors to c<strong>on</strong>sider before installing VSD <strong>on</strong> milk and/or vacuum pumps<br />
• Existing pump – Blower vacuum pumps are generally more efficient than a vane pump. The working c<strong>on</strong>diti<strong>on</strong> of the<br />
pump can influence potential savings particularly <strong>on</strong> older pumps.<br />
• The size of the dairy relative to the number of cows being milk influences potential savings where the greatest gains are<br />
made <strong>on</strong> l<strong>on</strong>ger running times.<br />
• When the size of the pump is not matched to the size of the shed ie a small pump relative to the requirement of a large<br />
shed provides opportunity to save m<strong>on</strong>ey by upgrading the pump and installing a VSD.<br />
• Have the VSD correctly installed by a qualified technician. The full energy savings are often not achieved if VSD are<br />
installed without filter protecti<strong>on</strong>s and comp<strong>on</strong>ents and not tested to ensure it is operating efficiently.<br />
• Different vacuum pumps with the same motor size can have different air c<strong>on</strong>sumpti<strong>on</strong> due to the layout of the system.<br />
Leakage of air in the system as a result of incorrect installati<strong>on</strong> can also reduce efficiency.<br />
• Greater energy savings are possible where the pump can operate at lower RPM ie a 1400 rpm motor than can be geared<br />
down to 700 rpm will benefit from adding a VSD. If the pump can <strong>on</strong>ly be lowered to 1100 – 1200 RPM there is relatively<br />
little benefit from installing a VSD. Motor speeds should not be lowered below the minimum operating requirement of<br />
the motor as the motor will wear out prematurely.<br />
Cost<br />
Cost will vary depending <strong>on</strong> the make, country of manufacture and whether the VSD is pre- programmed for the model<br />
and type of vacuum. The EWEN project quotes prices (ex GST) for VSD that range from $2300 for a 4 kW motor/pump to<br />
$10,500 for a 22 kW motor/pump.<br />
A recent project from DPI Victoria developed a hypothetical case study dairy farm in south Gippsland to estimate the cost<br />
of energy saving technologies. An ec<strong>on</strong>omic analysis of installing a VSD <strong>on</strong> new and existing pumps is outlined in the table<br />
below. The most profitable opti<strong>on</strong> was installing a VSD kit <strong>on</strong> an existing blower vacuum pump. New blower vacuum pumps<br />
were profitable investments but new oil vane pumps would not recoup the initial costs by the end of year ten.<br />
Existing Pump<br />
New Pump<br />
VSD <strong>on</strong> vane VSD <strong>on</strong> blower VSD <strong>on</strong> new vane VSD <strong>on</strong> new blower<br />
Net present value<br />
(7% discount, 3% inflati<strong>on</strong><br />
<strong>on</strong> cash flow)<br />
Internal Rate of<br />
Return (real)<br />
Years to breakeven<br />
(before interest and tax)<br />
$10,336 $18,789 -$833 $2,102<br />
34% 51% 6% 9%<br />
4 years 3 years >10 years 10 years<br />
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VSD Gets Thumbs Up at Benger<br />
After shifting their dairy operati<strong>on</strong> from the Fergus<strong>on</strong> Valley to Benger in 2006, Michael and Sophia Giumelli, who milk 380 cows<br />
in a 20 unit double up herringb<strong>on</strong>e, began looking at ways to reduce electricity costs in the dairy. Installing a variable speed drive<br />
<strong>on</strong> the milk pump appeared to be <strong>on</strong>e of the areas where big savings could be achieved.<br />
In December 2011 a variable speed drive was fitted to the existing DeLaval LVP4500 blower type vacuum pump at a cost of<br />
$5000. While the direct savings of installing the VSD have not been able to be m<strong>on</strong>itored directly, Michael and Sophia have<br />
noticed savings in their power c<strong>on</strong>sumpti<strong>on</strong> compared to the same time last year.<br />
“When you compare last m<strong>on</strong>th’s power bill with the same time last year we are using about 4000 units less of electricity.<br />
Our power bill has come down, even though the price of power has g<strong>on</strong>e up so we are pretty happy,” Michael said.<br />
The Efficient Water <str<strong>on</strong>g>Energy</str<strong>on</strong>g> and Nutrients (EWEN) project involved m<strong>on</strong>itoring the energy c<strong>on</strong>sumpti<strong>on</strong> following the installati<strong>on</strong><br />
of a VSD <strong>on</strong> the same vacuum pump found that without the VSD the motor would be running at full load and drawing a 37 kWh/<br />
day. This adds up to 13,500 kWh each year at a cost of $2650. Installing the VSD reduced energy costs by 65%.<br />
16
One of the significant advantages of installing the VSD has been a reducti<strong>on</strong> in the noise in the dairy at milking time.<br />
“Since we have installed the VSD it is very quiet in the dairy. The <strong>on</strong>ly time you hear the motor is when a set of cups is kicked off<br />
and vacuum pump has to speed up to alter the vacuum. We can’t quantify the effect of reduced noise but we know it is definitely<br />
a big plus,” Michael said.<br />
Michael has also envisaged that there will be less wear and tear <strong>on</strong> the pump reducing maintenance costs in the future.<br />
Michael and Sophia are investigating other energy savings including a heat recovery system to complement the existing<br />
electric hot water system. In the short term, Michael and Sophia have negotiated better rates for their power by entering into a<br />
n<strong>on</strong>-standard c<strong>on</strong>tract with Synergy.<br />
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Big Ticket Items<br />
Solar Power<br />
Solar photovoltaic panels c<strong>on</strong>vert energy from the sun into electricity which reduces reliance <strong>on</strong> energy sourced from the<br />
grid and reduces carb<strong>on</strong> emissi<strong>on</strong>s. The savings that can be achieved by c<strong>on</strong>verting to a solar system will depend <strong>on</strong> the<br />
size of the solar panel (kW), the feed in tariff, when you supply excess electricity, and current electricity tariffs <strong>on</strong> individual<br />
farms.<br />
A solar power system c<strong>on</strong>sists of photovoltaic panels made up of a c<strong>on</strong>nected group of photovoltaic cells to form a usable<br />
size and output. Typically sunlight produces 1 kW per square metre. A 1m 2 efficient panel can c<strong>on</strong>vert as much as 15-21<br />
per cent of this 1 kW to electricity. The panels are c<strong>on</strong>nected to an inverter which makes the generated electricity suitable<br />
for dairy use.<br />
Factors to c<strong>on</strong>sider<br />
• Any system larger than 4.5kW will need energy distributor approval and the farm needs to have three phase power.<br />
The size of the transformer at the farm will determine the allowable size of the solar panel system.<br />
• Electricity is <strong>on</strong>ly fed back into the grid if there is an excess produced. The proporti<strong>on</strong> fed back into the grid is highly<br />
variable between days and between farms.<br />
• The quality, orientati<strong>on</strong> and tilt of the panel will determine the maximum electricity generated from the system.<br />
• Some farmers may be disadvantaged through losing their off peak entitlements or by having increased base tariffs.<br />
• The expected energy savings will depend <strong>on</strong> the electricity price particularly <strong>on</strong> the standard feed in tariff <strong>on</strong> systems<br />
larger than 5kW as savings are based <strong>on</strong> your current tariff.<br />
• The quality of the solar panel will influence the effectiveness of c<strong>on</strong>verting sunlight into electricity particularly under<br />
limited sunlight.<br />
A recent project from DPI Victoria developed a hypothetical case study dairy farm in south Gippsland to estimate the cost<br />
of energy saving technologies. They compared a 5kW and a 30kW system <strong>on</strong> a dairy farm using 84 000kWh of electricity in<br />
the last financial year. Based <strong>on</strong> off peak and peak prices the cost of electricity for the whole farm was $14,960.<br />
Cost<br />
For the case study farm the cost of a quality 5 kW solar panel was $13,100 exc. GST and 30 kW was $75,000 exc. GST.<br />
These prices included installati<strong>on</strong> and reducti<strong>on</strong>s through the solar credit scheme. Most systems will require new metering<br />
costs associated with installing the solar panel system to the grid and an independent electrical inspector fee ($400).<br />
Do they Pay?<br />
An ec<strong>on</strong>omic analysis of the solar panels <strong>on</strong> the case study farm found that they were both profitable as they were better<br />
than the business-as-usual opti<strong>on</strong> at the end of year ten. The 30kW system was more profitable than the 5kW system<br />
despite the larger capital outlay. This is due to the larger annual savings and a greater increase in the tariff between years<br />
in line with a ten per cent increase in market value of electricity.<br />
Net present value<br />
(7% discount, 3% inflati<strong>on</strong> <strong>on</strong> cash flow)<br />
5 kW solar system 30 kW solar system<br />
$6,805 $41,159<br />
Internal rate of return (real) 14% 14%<br />
Years to breakeven<br />
10 Years 9 years<br />
(before interest and tax)<br />
18
Wind Power<br />
Wind turbines c<strong>on</strong>vert kinetic energy from the wind into mechanical energy to produce electricity. The turbines generate<br />
electricity suited to c<strong>on</strong>versi<strong>on</strong> to single phase 240 V AC (between 400W and 10kW output). The wind power market is still<br />
developing in Australia and turbines suitable for dairy farm requirements will become more prevalent.<br />
For more informati<strong>on</strong> www.worldwidewindturbines.com<br />
Green Cleaning Systems TM<br />
Green Cleaning systems are milking machine wash systems that operate at low temperatures, re –use the cleaning<br />
soluti<strong>on</strong>s and are energy efficient. They comprise of an automated cleaning unit that is capable of capturing, storing<br />
and re-using the wash soluti<strong>on</strong>s. They use chemicals that are specifically designed for re-use and to work at lower<br />
temperatures (less than 50°C). Heating of the wash soluti<strong>on</strong>s utilises energy from renewable sources such as solar & heat<br />
recovery. The storage tanks are well insulated to minimise any heat losses.<br />
The same wash program can be used at every washing and the c<strong>on</strong>trol unit m<strong>on</strong>itors the c<strong>on</strong>centrati<strong>on</strong> of the cleaning<br />
soluti<strong>on</strong> and doses as required. Capital outlay for a Green Cleaning system range from $25 000 - $40 000 depending<br />
<strong>on</strong> dairy size and the existing system. They have been dem<strong>on</strong>strated to be more profitable than c<strong>on</strong>venti<strong>on</strong>al cleaning<br />
systems, particularly <strong>on</strong> large and new dairies.<br />
For more informati<strong>on</strong> www.agvetprojects.com.au/greencleaning<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <strong>on</strong> <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong> 19
Cow Time <strong>Dairy</strong> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <str<strong>on</strong>g>Saving</str<strong>on</strong>g>sChecklist<br />
Hot Water Systems<br />
YES NO<br />
Is the off-peak time clock meter set correctly at the power box<br />
(weekdays 10:00pm-8:00am and all weekend)? ________________________________<br />
Is the hot water system protected from the weather and kept dry? _____________________<br />
Does the capacity of the hot water system match the daily requirement for milking<br />
(without using the daytime booster)? ______________________________________<br />
Are the sacrificial anodes in the hot water service checked regularly? ___________________<br />
Is the hot water unit free of hot spots? _____________________________________<br />
Is the hot water system flushed regularly to remove sludge or mineral build up? _____________<br />
Are the metal pipe c<strong>on</strong>necti<strong>on</strong>s into the hot water service well insulated? _________________<br />
Have you reviewed you washing regime with your chemical reseller to look for opportunities to<br />
reduce costs (ie reduce hot water volumes required)? ____________________________<br />
Does the hot water system deliver hot water into the CIP barrel at 75 to 85°C? Check by comparing<br />
the morning hot wash temperature with the thermostat setting and adjust. ________________<br />
Do you commence morning wash up after 8am? If cold water enters the hot unit before 8am it will<br />
be heated up unnecessarily ___________________________________________<br />
Have you eliminated hot water leaks and wastage? ______________________________<br />
Do you c<strong>on</strong>serve heat by <strong>on</strong>ly filling the CIP barrel immediately prior to cleaning the machine? _____<br />
Does the hot water system boil at night? ___________________________________<br />
Milk Cooling<br />
Pre Cooling<br />
Has the plate cooler been correctly sized for the job? _____________________________<br />
Are you using the coldest water available? ___________________________________<br />
Do you have an even flow of milk through the plate cooler? _________________________<br />
Does the water and milk flow in opposite directi<strong>on</strong>s through the plate cooler? _______________<br />
Does the water flow rate exceed the maximum milk flow rate by at least 3:1 for ‘m’ type plate<br />
exchangers (2:1 for industrial types)? _____________________________________<br />
Refrigerati<strong>on</strong> Plant<br />
Is the refrigerati<strong>on</strong> unit protected from rain and direct sunlight? ______________________<br />
Is the c<strong>on</strong>denser located to take advantage of prevailing winds/allow unrestricted airflow around the unit? _ _<br />
Is the vacuum pump exhaust positi<strong>on</strong>ed far enough away to prevent oil build up <strong>on</strong> c<strong>on</strong>denser fins? ___<br />
Are c<strong>on</strong>denser cooling fins clean and undamaged? ______________________________<br />
Is the compressor and refrigerati<strong>on</strong> motor clean and free of oil leaks? ___________________<br />
Does a qualified refrigerati<strong>on</strong> mechanic undertake annual maintenance? _________________<br />
<strong>Dairy</strong> Equipment<br />
Are annual tests carried out by a technician to check vacuum regulati<strong>on</strong>, airflow, leaks, drive belts etc? ___<br />
Is the vacuum pump motor clean and well ventilated? ____________________________<br />
Do you clean your light tubes and fittings annually? ______________________________<br />
Have you replaced incandescent lights with energy efficient fluorescent bulbs and/or metal halide lights? _ _<br />
20
Need More Informati<strong>on</strong>?<br />
Western Australia <strong>Dairy</strong> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> Audit Project Summary<br />
A summary report which presents the outcomes, observati<strong>on</strong>s, results and recommendati<strong>on</strong>s as determined by the<br />
Western <strong>Dairy</strong> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> Audits. Copies available by c<strong>on</strong>tacting Western <strong>Dairy</strong> <strong>on</strong> (08) 9525 9222.<br />
CowTime<br />
A nati<strong>on</strong>al dairy industry project aimed at making milking easier. It encompasses milk harvesting research and extensi<strong>on</strong><br />
from when the cows leave the paddock for milking right through to cleaning up the milking shed. www.cowtime.com.au<br />
Victorian Department of Primary Industries Report<br />
Ec<strong>on</strong>omic Analysis of Technologies to Reduce <strong>Dairy</strong> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> C<strong>on</strong>sumpti<strong>on</strong> www.dpi.vic.gov.au/agriculture/dairy/energy-in-dairy<br />
The Ewen Project<br />
Efficient Water <str<strong>on</strong>g>Energy</str<strong>on</strong>g> and Nutrients Project, Nick Bullock and Associates - Fact sheets and case studies <strong>on</strong> energy use<br />
in dairies <strong>on</strong> the Mid North Coast of NSW www.nickbullock.com.au/facts.php<br />
<strong>Dairy</strong>ing for Tommorow – <strong>Dairy</strong> Self Assessment Tool<br />
To help you identify areas for improvement in all areas of dairying www.dairyingfortomorrow.com/index.php?id=98#<br />
<strong>Dairy</strong>ing for Tommorow - “RRR” Reduce Reuse and Recycle at the <strong>Dairy</strong> Shed 2007<br />
Series of factsheets <strong>on</strong> improving energy use at the dairy www.dairyingfortomorrow.com/index.php?id=52<br />
Useful C<strong>on</strong>tacts<br />
Western <strong>Dairy</strong><br />
Rob La Grange<br />
<strong>Dairy</strong> Industry Development Specialist<br />
Tel: +61 8 9780 6294<br />
Mob: 0448 939 344<br />
Email: rob@westerndairy.com.au<br />
Esther Price<br />
PO Box 341<br />
Mundij<strong>on</strong>g, Western Australia 6123<br />
Tel: + 61 8 9525 9222<br />
Mob: + 61 (0)418 931 938<br />
Email: esther@westerndairy.com.au<br />
www.westerndairy.com.au<br />
<strong>Dairy</strong> Australia<br />
Level 5, IBM Centre, 60 City Road<br />
Southbank, Victoria 3006<br />
POSTAL ADDRESS:<br />
Locked Bag 104, Flinders Lane, Victoria 8009<br />
Tel: + 61 3 9694 3777 | Fax: + 61 3 9694 3733<br />
Memberline: 1800 004 377<br />
C<strong>on</strong>sumerline: 1800 655 441<br />
www.dairyaustralia.com.au<br />
<str<strong>on</strong>g>Saving</str<strong>on</strong>g> <str<strong>on</strong>g>Energy</str<strong>on</strong>g> <strong>on</strong> <strong>WA</strong> <strong>Dairy</strong> <strong>Farms</strong> 21
This project was jointly<br />
funded through a<br />
collaborati<strong>on</strong> between<br />
<strong>Dairy</strong> Australia,<br />
Western <strong>Dairy</strong>, and<br />
Department of Agriculture,<br />
Fisheries and Forestry<br />
Western<br />
DAIRY