Smarter energy use

 

The Smarter energy use on Australian dairy farms program completed in June 2015. It provided ~1,400 on-farm energy assessments (~21% of dairy farms across Australia), practice resources for assessing and improving energy efficiency and a national analysis of energy use on-farm. Resources and reports can be accessed here.

Key characteristics of energy use in Australian dairy farms:

  • The national average energy use was 48 kWhr/kL of milk, with a range of 31 to 66kWhr per kL milk.

  • The type of dairy does not affect energy use except for automatic, small rotaries (<150) and large walk throughs (>300), which all have higher energy use compared to others with a similar herd size. However, there is a herd size impact on energy use, i.e. dairies with larger herd sizes have lower energy use per kL milk.

  • There is no regional impact per se except that there is a different mix of sizes of dairies captured by energy assessments in the regions.

  • Annual energy costs per business were highly variable and ranged from $1,663 to $121,722.

  • The three main energy cost components are hot water, milk cooling and milk harvesting. These components make up on average 81% of each business’s energy use. This is equivalent 40 kWhr/kL of milk for most dairies and 60 kWhr/kL for automatic dairies.

Source: An independent analysis of the National Database of energy assessments conducted on 1,396 dairy farms between 2012-2015 (RMCG 2015).

By conducting on-farm energy assessments, more than half (55%) of the participating farmers identified savings of less than $2,000 per year. About 40% of properties had potential to save a modest amount ($2,000–$10,000), while substantial savings (up to $29,000) were identified for a small (5%) proportion of the assessments.

The most commonly identified savings were associated with:

  • Improved functioning of equipment for milk cooling, including function of the plate-cooler and the compressors on the vats and using cooler water sources

  • Pre-heating hot water for hot water systems, using heat exchange units (where appropriate) and using correct water temperatures

  • Installing variable speed drives (VSDs) on vacuum pumps.

Cows and irrigation  Video: Variable speed drives
How VSDs can reduce power consumption by as much as 75% 

In addition to energy savings, for some farms there were further dollar savings to be made with electricity billing arrangements and changeover to time of use contracts. Although these do not reduce energy use, they can substantially reduce total bills.

Note that regional analysis of the on-farm energy assessment data was also undertaken and made available in a series of fact sheets.

  • Opportunities for reducing energy use

    The on-farm energy assessments identified that to reduce energy use, and consequently lower energy costs and greenhouse gas emissions, farmers need to both reduce demand and improve efficiency.

    Reducing demand can be realised through implementation of some/all of the following actions: insulation (against heat gain or loss), utilising natural attributes (for example, re-installing the first stage heat exchanger has the potential to save ~5,000 kWh and $1,060 per year), sizing systems to suit, reducing/avoid wasting (for example, turning off lights when not needed) and/or utilising renewable energy sources.

    Improving efficiency can be realised through implementation of new technologies (for example LED lighting and VSDs), better design, improved maintenance (for example, regular cleaning of filters) and/or use of high efficiency motors.

    The first step is to start measuring energy use and potential areas of inefficiency. Undertaking an energy audit would provide a good first assessment, as well as identifying goals, for potential energy savings. Alternatively farmers should consider assessing the costs of the three main cost components (hot water, milk cooling and milk harvesting) against regional benchmarks (found in regional fact sheets on Reports page).

    Practical advice on reducing energy use on-farm can be found in the national resources booklet Saving energy on dairy farms.

  • Renewable energy opportunities
    Stand-alone renewable energy systems

    With costs falling and take-up rising of solar and other renewable energy systems, businesses are increasingly interested in storing the energy they produce to maximise its benefit and reduce their bills.

    Renewable energy’s main challenge is that its use is restricted to when the renewable resource is available (e.g. when the sun shines or the wind blows). Storage allows more of that renewable energy to be retained so it can be used on-site at a later time – and further reduce electricity consumption from the mains power grid.

    Unfortunately, given the complexity of renewable energy and storage technology, there is no easy or quick way to answer the question of “how much storage do I need at my site and what will it cost?”

    The only way to properly answer this question, which maximises the chance of implementing a cost-effective project at any given site, is to undertake a feasibility analysis – taking into account that site’s specific consumption patterns, electricity tariffs and solar resource.

    Please note: That both renewable energy and storage technologies continue to evolve – with storage prices predicted to drop dramatically in the coming decade. Make sure you consult an expert about your individual business to see whether renewables and storage is a viable option for your farm.

    For more information download the Fact sheet: Feasibility of stand-alone renewable systems.

     

    Methane digesters (biogas)

    Some large dairy farms and feedlots may produce sufficient manure from dairy effluent to make biogas generation from methane an option.

    Despite dairy farm waste being a good resource for biogas production, there are currently few working examples of biogas technology in Australia’s dairy sector. Biogas technology not only supplies renewable energy, but in addition the technology can simplify waste management, reduce odour and GHG emissions, and improve fertiliser value of manure and other by-products.

    Biogas technology does not have to be complex or difficult to operate, but it does need to be tailored to the specific needs of the farm in terms of farm management, waste characteristics and biogas use.

    Before you can develop methane capture and use projects, you need to answer the following questions:

    • What type of anaerobic digester suits the operation?

    • How much biogas will it yield?

    • How do the costs and benefits compare with conventional alternatives?

    For more information see Fact sheet: Biogas feasibility and Emissions Reduction Fund method - Destruction of methane generated from dairy manure in covered anaerobic ponds.

  • Reduce pre-farm embedded emissions

    Production/manufacturing efficiencies in other industries could reduce the embedded emissions in farm inputs. By selecting products that are addressing their emissions, dairy farmers can reduce emissions from across the supply chain.

    Conversely, farmers need to ensure any management changes do not just move emissions off-farm; for example, if increased grain feeding and/or increased nitrogen use (pasture quality) is implemented to reduce methane, then more off-farm inputs, with a higher overall level of embedded emissions, will be used.

    These are not considered ‘farm emissions’ for accounting purposes.

  • Drivers and barriers for smarter energy use

    In total, the Smarter energy use program engaged 1,399 (900 from Round 1 and 499 from Round 2) farmers directly with personalised energy assessments and action plans, and engaged a further 930 (492 from Round 1 and 438 from Round 2) farmers at workshops and field days, further disseminating energy efficiency information to a wider audience.

    The evaluation showed that from the sample of 192 farmers interviewed, by participating in the program:

    • 100% increased knowledge and awareness;

    • 90% changed energy management practices or behaviour on farm; and

    • 79% changed their attitudes towards energy use.

    The key driver for dairy farmers to participate in the program was the likelihood of saving money through reduced power bills, but evaluation results reveal the program has significantly increased awareness of energy use in the dairy.

    The evaluation demonstrated that the program has encouraged many dairy farmers to undertake simple efficiency measures such as turning off lighting and equipment when it is not in use, as well as plan for longer term energy efficient strategies such as upgrading of dairy shed machinery. There is already evidence of equipment purchasing decisions being influenced by the project and this is likely to become more widespread as financial pressures ease or as existing equipment and machinery ceases to function. Evaluation showed that key areas that farmers had made changes or planned to as a result of participation in the project, were in milk cooling, water heating and lighting. Costs associated with replacing existing equipment and machinery is the main barrier to implementing recommended changes, particularly where equipment is still functioning.

    Some barriers to adoption were identified in the project. The major barrier to adopting strategies and technologies on a farm is the cost of infrastructure. The evaluation found that 55% of farmers interviewed said that the cost associated with replacing existing equipment and machinery is the major barrier to implementing recommended changes. If a more rapid rate of change of energy use on-farm is desired grants or rebates may need to be offered.

    In line with widespread satisfaction with the program, only 11% of evaluation interview respondents were able to recommend improvements. Those who could typically suggested the following:

    • Supply additional information to ensure farmers are on the most suitable tariffs (8% of respondents mentioning);

    • Include irrigation systems in future assessments (5%);

    • Provide information on renewable energy systems (5%); and

    • Provide a list of knowledgeable tradespeople able to carry out recommended work (5%).

    Dairy Australia is working on implementing these recommendations.

    See Reports page for full list of all outputs and resources developed through this program.

  • Key outcomes from Smarter energy use program

    The Smarter energy use on Australian dairy farms program was developed to assist farms to realise their potential for energy savings by conducting energy efficiency assessments. The project was administered by Dairy Australia with funds provided under the Australian Government Department of Industry and Science Energy Efficiency Information Grants program.

    Since 2012 this program has successfully delivered 1,400 energy assessments, covering ~21% of dairy farms across Australia (RMCG 2015). For each individual energy assessment, information on energy use and potential savings were captured and collated for broader analysis within a National Database managed by Dairy Australia.

    The program has also hosted 15 energy efficiency workshops and the development of a set of national information resources. The resources developed and disseminated included: Saving energy on dairy farms booklet; 8 case studies; 14 fact sheets; and the collation and analysis of the on-farm energy assessment data within a National Database.

    The program also successfully achieved desired outcomes at a project and program level, including increasing knowledge and awareness of reducing power consumption in the dairy, changing energy management practices on-farm and changing farmer attitudes towards energy consumption, as evidenced in the independent program evaluation.

    Undoubtedly this project is the most comprehensive in the country - no other industry has engaged with so many farmers. Similarly, no other industry has such a comprehensive database of energy usage figures.

    The Smarter energy use program activities finished on 30 June 2015.

  • Lessons from dairy farmers

    The Smarter energy use program developed eight (8) case studies from participating farmers:

    1. Revisit of NSW farm assessments (analysis of energy savings made since investment in Variable Speed Drives)

    2. The Van Diemens Land Company, Tasmania (multiple dairy farms in NW Tasmania case study)

    3. Matthew and Allison Cahill, Rathdowney (robotics case study)

    4. Brendan Martin, Bamaum, Murray (reducing energy use in milk cooling and water heating)

    5. Pat McDonald, Tygalah, NSW (Skype assessment case study)

    6. Energy monitoring of inefficient dairy farm (TAS case study)

    7. Using interval data recording to measure power use (WA case study)

    8. Buying better power and negotiating tariffs (WA case study).

    These case studies and fact sheets are all available via the SEU project website or via Reports page.