Monday, 04 March 2019 08:14

Why energy efficiency matters

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Refrigeration is generally the third-highest energy user on a dairy farm. Refrigeration is generally the third-highest energy user on a dairy farm.

Energy management is a key way dairy farmers and sharemilkers can cut costs and improve profits.

That's the message from the Energy Efficiency and Conservation Authority (EECA).

Improving the energy efficiency of your farm will reduce operating costs and greenhouse gas emissions, and build a more sustainable business long term.

It will also improve returns for investors, improve productivity, free-up cash to re-invest in the business, add value for the end consumer and be better for the environment. 

Taking a proactive approach to improving efficiency puts more control in the hands of the farm owner who can make cost savings and better overall decisions about energy use.

The main electrical loads on dairy farms are hot water heaters, rotary milking platforms, lighting and pumps (vacuum, water, pre-cooling, wash-down, milk, effluent).

Before considering specific components of farm energy efficiency, consider these simple energy savers that often get overlooked. 

1. Turn off all machines, monitors, equipment and lighting when not in use; preset switch timers can assist. 

2. Use energy efficient light bulbs, and fluorescent instead of incandescent lights. 

3. Use natural light where possible (e.g. clear Perspex corrugated sheets). 

4. Ensure cow comfort in and around the milking shed to reduce effluent discharge which costs money to remove. 

5. Bury or insulate coldwater pipes from pump to refrigeration unit. Don’t lash a cold and hot water pipe together. 

6. Check that every ICP number on electricity invoices matches with a real meter on the farm. 

7. Take your own meter readings from time to time and match them to the invoiced reading. 

8. Know what tariffs you are on and, where possible, feed energy loads into off-peak tariff times. 

The first step in reducing onfarm energy use is to understand where the energy is being used. 

Nearly 90% of dairy sheds’ energy use goes on refrigeration, pumps and water heating. 

Irrigation systems, when used, typically account for at least 70% of electricity usage. Having a clear picture of what energy is being used and where, and how much it costs, enables two key things: being able to monitor, measure and show savings, and being able to target energy-saving efforts in a prioritised and structured way.

A dairy shed energy audit is a good way to start.

“Trying to improve energy efficiency without understanding the current situation is like trying to reach a destination without knowing where you’re starting from,” says EECA. 

“An audit is a snapshot of your energy expenditure at a fixed point in time and is the first step to planning improvements. Without an audit, whatever good strategies you put in place, it will be hard to measure their success.”

At its most basic, energy use in the dairy shed is measured and analysed over a fixed time. 

A detailed report is provided detailing where the energy is being used, what savings can be made, the unit cost of these measures and the payback period. 

Additional services could include analysing billing, matching of invoiced readings to actual meters, re-design concepts or a whole farm audit. 

The energy challenge

Refrigeration is generally the third-highest energy user on a dairy farm.

Although chilling the milk prior to pickup is essential for food safety and quality, the energy saving measures listed below show where savings can be achieved. 

Refrigeration is often an important aspect of many industrial processes so measures developed in other industries can often be adapted to the dairy farm. Benefits include less likelihood of grades due to plant machinery failure and possibly large energy savings. 

Optimising refrigeration plant performance is a specialised skill. While service companies may need to do certain tasks, you can schedule regular system checks, do regular maintenance (e.g. cleaning condensers and evaporators) and challenge the service provider on issues like vat and pipe insulation, plant room ventilation and refrigerant charge.

Benefits

An audit draws a picture of energy use and costs that allows you to plan changes with a strategy in mind. 

Documentation makes measuring savings and ongoing monitoring easier and more accurate than relying on invoices alone. 

External consultants can offer specialist knowledge (including payback periods, challenges and supplier information) and have a wide knowledge of available and emerging technologies. 

Local advisors or contractors appreciate the constraints and complexities of your farm and region and are often farm managers themselves. 

Constraints

Whether to invest in a whole farm audit or solely the milking shed. 

Whether to do the audit yourself or employ a contractor/energy consultant. Available solution / technology 

A consultant will usually list his recommendations and associated costs for you to consider. 

Smart meters may be fitted to monitor how much energy is being used by individual components.

 
 

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