Energy Options - short, medium and long term

Louise Clarke, Teagasc Pig Specialist, says energy is a resource that must be used efficiently and effectively and gives us some tips to reduce energy costs.

Energy is a resource that must be used efficiently and effectively. It makes no sense to waste it. Energy prices have risen quite significantly in the last number of months and there is concern that it will become an even more significant cost in the future. Pig farms, like all businesses can spend a considerable amount of money on energy. Pig farms are energy intensive and data from the 2021 National Pig Herd Performance Report showed that the energy cost (heat, power and light) was €6.43 per pig produced (or €180 per sow per year based upon 28.1 pigs produced per sow per year). This Profit Monitor data covers approximately 43 per cent of the national pig herd. Typically, this meant that an average 600 sow integrated pig unit spent approximately €108,000 on energy cost in 2021. Today this price has further sky rocketed as current energy costs are quotes at 45c+ per kWh used versus approximately 25c KWh in 2021. For energy-intensive businesses like pig farms, these cost can be crippling.

In 2012, a Teagasc survey on 23 pig farms show a huge variation in the energy usage ranging from 18 up to 45kWh per pig produced with an average figure of 28kWh per pig produced. These audits for 23 farms included over 20,000 sows. The high variation from one farm to another suggests that a greater emphasis needs to be put on energy efficiency

Where is the energy used?

For most pig units the biggest energy requirements are used to:

1. Heat the farrowing and first stage weaner houses,
2. Ventilation systems and fans,
3. Lighting pig buildings,
4. Feed delivery and mixing,
5. Power-washing,
6. Manure pumps to mix and agitate slurry tanks.

Short term steps in trying to reduce your overall energy costs

Monitor the energy usage on your farm. This will provide the basis of good energy management. Do regular meter readings; do not just rely on utility bills. Carry out an energy audit of your farm. Energy audits will not only tell you where the energy is being used but it can also highlight areas where potential savings can be made. SEAI’s Support Scheme for Energy Audits (SSEA) offers financial support for small and medium enterprises (SMEs) to get an Energy Audit. The application and approval process is quick and easy, and in most cases, the financial support provided by SEAI will cover the entire cost of the Energy Audit. Support is issued in the form of a Voucher, which is awarded to the Applicant (the SME), who will then use it to “pay” the Auditor once the audit is complete. The Auditor will claim the cost of the Voucher from SEAI.

Benchmark your performance with industry standards. Do you know how much energy it takes to produce a pig of your farm? Research shows that there is a huge variation in energy usage on pig farms with a range of 18 to 45kWh per pig produced. Based on today’s energy cost that can equate to a substantial difference of approximately €170,000 as seen below. This difference highlights that greater emphasis needs to be placed on energy efficiency on pig farms. If we can minimise the amount of energy needed by being more energy efficient that is better because a kWh that does not need to be used is one that does not need to be produced. This will also be a positive from a carbon footprint point of view and from the country's energy statistics and reduced greenhouse gas emissions.

Table 1: Energy cost per pig produced

*Calculation based on a 600-sow unit producing 28.1 pigs/sow/year, including VAT

Understanding your electricity bill

Understanding all of the terms on your energy bill is important in order to know how to improve your energy efficiency and reduce your bills. Two terms that producers should familiarise themselves with and understand are MIC and Wattless Charges:

Maximum Import Capacity (MIC)

The upper limit on the total electrical demand you can place on the network system, so it should be high enough to meet the requirements of your business and is measured in kilovolt-amps (kVA). If your MIC is too high or too low for your needs it will cost you money:

- If the MIC is too high, you may be paying for more capacity than you actually require.

- If the MIC is too low, you may incur an 'Excess Capacity' charge

As a general guideline electrical providers would suggest that your MIC should be set at 5% above your highest electrical load in the past year. We strongly advise you to study your energy bill over a period and if you find your MIC is too high or too low we recommend that you discuss your MIC requirements with your energy provider to determine the correct MIC for your unit.

Wattless Charges

On large commercial pig farms, there are likely to be items of electrical equipment that require wattless energy to operate. Wattless energy is measured separately from your general units, and if you exceed a certain limit, during certain periods it may give rise to a separate charge. Electric power consists of two components: active power and reactive power. Active power is recorded on your normal electricity meter, and appears on your bill as general day and night units. Reactive power is also recorded by your normal meter, but will only affect you if you are a large industrial or commercial business user. This is because certain equipment common to industrial or other large businesses - such as motors or fluorescent lights (e.g. in an industrial premises) that need reactive power in order to operate. Again, it is important that you study your energy bill and see if there is an excess wattles charge regularly occurring on your bill. If so, you should contact your electrical contractor to fit power factor correction equipment. This will reduce the amount of reactive power you consume and help to avoid wattless charges on your bills.

Electric power consists of two components: active power and reactive power. Active power is recorded on your normal electricity meter, and appears on your bill as general day and night units. Reactive power is also recorded by your normal meter, but will only affect you if you are a large industrial or commercial business user. This is because certain equipment common to industrial or other large businesses - such as motors or fluorescent lights (e.g. in an industrial premises) that need reactive power in order to operate. Again, it is important that you study your energy bill and see if there is an excess wattles charge regularly occurring on your bill. If so, you should contact your electrical contractor to fit power factor correction equipment. This will reduce the amount of reactive power you consume and help to avoid wattless charges on your bills.

Medium term steps in trying to reduce your overall energy costs

Maintenance, repairs and cleaning is an essential part of reducing wasted energy. Check the accuracy of controls on your farm, check that sensors are correctly positioned and kept clean (dust, cobwebs & fly dung will contribute to incorrect sensor reading). Use the information obtained from control systems to see how the system is performing. It is critical to check if the ventilation system is working in tandem with the heating system throughout the whole unit. The ventilation system may control house temperature at a massive cost to the heat supply system if the two systems are not working in tandem with each other.

Insulation of pig buildings

The provision of heat in buildings is very wasteful if there is a poor level of insulation in the building. The walls and ceilings should be insulated to achieve suitable U values. Check the insulation to see if it has been damaged by pests. The temperature fluctuation in the pig house should also be checked by using maximum-minimum thermometers to monitor if house temperatures vary considerably between day and night-time. Is it worth replacing poorly insulated doors?

Lighting

We all know the importance of lighting throughout the different stages of production. The LED (light emitting diodes) is the latest technology in lighting and has come on leaps and bounds in the last ten years. It’s really a very commercial technology available to producers today. The light fittings are more expensive to install but last much longer and are more efficient from an energy use perspective. They do not heat and use less energy as a result. They are well worth considering in new buildings because of their lower energy requirements.

Farrowing house tips

Accurate heat control is a requirement in the farrowing house for the survival of newly born piglets.

• The ideal is to have a farrowing room temperature of 24°C once the first piglet is born in the room. This should be reduced to 20°C -21⁰C when the youngest piglet in the room is over 48 hours old.
• Pig producers may use shredded paper to supplement the heat source at farrowing rather than an infra-red bulb.
• If the average gestation period is 115 days, it is not necessary to heat up the creep area until day 113 of gestation.
• Poor temperature control can lead to unnecessary overheating of pads resulting in wasted heat production and wasted ventilation energy. This applies particularly in the first two weeks after farrowing.

Weaner and finisher accommodation tips

Ventilation and feeding systems are the main users of energy in the weaner and finisher section of a pig farm.

• First stage weaners also require a source of heat. The aim is to have newly weaned pigs kept at 28°C to 29°C initially, with a reduction of approximately 2°C in room temperature each week thereafter. However, with heavy weaning weights there may be some scope to reduce these temperatures.
• Implement dual temperature zones in houses by installing covered creep areas in weaner houses. This means that only the small area under the covered creep needs to reach 20-30⁰C, the temperature in the rest of the room can be reduced to 24°C.
• Make sure controls are properly calibrated and set to the correct temperature
• Re-insulate buildings if necessary and seal buildings to stop draughts
• With wet feeding and slurry pumping systems, choose pumps that give the best flow to energy characteristics.

On farm generators

A generator is a practical investment for all farmers. With the electricity networks set to come under more pressure this winter and an increased risk of blackouts due to electricity grid being overloaded and unable to cope with demand there is more of an interest in having your own generator on farm. There is a range of different sized generators available and the load the generator will be asked to run should determine what size of generator you buy or lease. Standby generators are the most common type of generators used on pig farms. These are diesel or gas powered generators with their own engines. In most cases, these generators are wired to automatically kick in in the event that power goes down. The downside to these generators are they are more expensive to install and a direct fuel supply is needed for them to work. However, with the crippling cost of energy now some units that are coming out of contract are using their generators as the main source of energy supply particularly during daytime rates. Speak to your Teagasc adviser to calculate the cost of running your generator to replace daytime electricity usage. However, if you are using a generator you must inform the ESB to ensure the safety of the ESB network. Most modern generators can be programmed to turn on and run for an hour or so at regular intervals. Also, it is important that generators should be tested a few times a month when not in use.

Long term steps in trying to reduce your overall energy costs

Heat pumps

A number of units have installed air-source heat pumps (otherwise known as air-to-heat pumps) to heat the heat pads in farrowing units. These systems extract heat from ambient air and use it to heat water via heat exchange systems. This can be ideal to heat water to temperatures of 55°C. The capital costs of these systems can be high, but they are effective in reducing fuel costs. 

Solar PV

Solar photovoltaic (PV) cells work on the principle that energy in the sun is converted to electricity. PV cells are used to convert solar radiation into direct current (DC) electricity. This DC electricity is then inverted to alternating current (AC) electricity for use in buildings or export to the grid. When light shines on the PV cell, an electric field is created across the silicon conducting layers, which causes electricity to flow. Solar PV is a well-proven technology and has been around for years. There is the potential to store excess energy in a battery or export it to the national grid. The technology is predictable as well in terms of the output for kW installed. Generally, solar PV will generate 20 to 50% of the farms annual requirement. It is very difficult to put in a system on pig farms that would generate 100% of the farms requirements. You would need to look into requirement around planning restrictions; roof space, etc will determine how big you can go. Once you have bought your solar PV panels, the maintenance and operating costs are small. Pig farms will require robust panel because of their environment and producers should enquire about product and performance warranties.

Funding available

• TAMS (PPIS)
• 40% grant aid on an investment ceiling up to €80,000
• 100% of electricity to be used on farm
• On farm Solar PV survey required
• Maximum size for grant aid is 62Kw (larger at own cost)
• Potential new scheme in 2023

• Better Energy Communities (SEAI)
• up to 25%
• pig farmers could become part of a local community project
• https://www.seai.ie/grants/community-grants/

• EXEED Funding (SEAI)
• Excellence in Energy Efficient Design (EXEED)
• funding of up to 50% (70% for pre-investment support)
• https://www.seai.ie/business-and-public-sector/business-grants-and-supports/exeed-certified-grant/

Conclusion

Energy is a resource that must be used efficiently and effectively. The large variation from one farm to another suggests that a greater emphasis needs to be put on energy efficiency. A lot of the savings are greatly influenced by management which is the most important aspect of energy efficiency.