Re-energising pig production

Barry began by highlighting an energy audit that showed large variations between best practice energy consumption and typical energy use across a range of pig-production activities. In farrowing units, for instance, where energy is required for heating, lighting and ventilation, the figure for best practice, measured in kWh/pig produced (kilowatt per hour per pig produced) is believed to be 4kWh. But typical industry energy-use figures for the same activities are double the best-practice target. Likewise, the discrepancy between best practice and industry norm energy use for the weaning stage is significant. The best-practice target is set at 3kWh/pig which is a third of the average figures being achieved in pig units. Those contrasting figures on energy usage point to an opportunity to improve energy-use efficiency through improved management as well as upgrading the energy performance of pig production buildings. Barry outlined a series of upgrading options to reduce energy use, including:

• Enclosing creep areas;
• Switching to more energy-efficient lighting;
• The introduction of high-efficiency pumps, aerators and separators; and
• Improving insulation and ventilation, as well as fitting more efficient fans in units.

Solar

On the other side of the energy equation, the Teagasc expert explored options to reduce the energy unit costs through the adoption of renewable-energy sources on pig-production farms. Solar is becoming the ‘go-to’ option for many businesses and private homes as government policy has finally got the message that moving consumers from fossil-based energy to renewable sources needs significant support and incentive. Even allowing for the fact that energy costs have retreated somewhat from the extraordinary highs of the past twelve months, Barry emphasised that over the longer term, electricity prices are trending upwards. He pointed to the now well-proven solar technology as an obvious cost-effective alternative energy source for high-use pig-production facilities. Solar adoption also accords with the Government's policy to electrify heating and transport. For all businesses there is the benefit of being able to legitimately claim kudos for environmental awareness and reduced carbon use.

Cost-effective investment

Barry provided valuable advice to pig producers considering investing in solar energy production. He detailed the differences in performance and longevity between the two types of monocrystalline solar panels. Panel robustness is another consideration, given that they will be placed on farms where dirt, dust and gasses are part of the surrounding environment. Even the location, near the sea, for example, should influence panel choice. Long-term warranties need to be closely scrutinised, as Barry advised. Ultimately, the condition of roofs on which these panels will be placed, perhaps for several decades, needs to be assessed in detail for stability during installation, maintenance and operation over many years. Ground-based solar panels can be a viable alternative installation option.

Key solar considerations

In considering the adoption of solar panels to maximise the value of solar-produced electricity on a pig farm, the farmer needs to consider all aspects including, though not exclusively the cost/benefit. Barry provided guidance in making these decisions. The best return on investment, as he confirmed, is to use the generated electricity in the business as it is being generated. Storage imposes limitations including increased cost. Practicalities that must be understood include the fact that a solar PV system only generates energy during daylight hours, with a peak production around noon. Solar systems do produce energy during all daylight hours but produce five times more electricity, on average, on a mid-summer’s day than during the December/January period. While the Government has relaxed some planning requirements for solar installations, a checklist is advised, according to Barry, as to whether an individual business requires planning or not depending on circumstances particular to the business in question. There are also limitations on how large the installations can be in order to qualify for a planning exemption. Orientation of roofs is sometimes overlooked in considering a solar installation. The difference, however, in energy production between a southern and a northern orientation, is essentially the difference between a cost-effective and a cost-ineffective installation. Grid connection for the export of electricity is now generally available, after much foot dragging by ESB Networks for several years. Electricity export potential should be considered by anyone placing solar panels on the roofs of their farm buildings, Barry said.

Cost effectiveness

Assuming all the structural, orientation and consumption factors are optimal, Barry produced several examples of the electricity cost savings to be gleaned from a solar installation. He provided payback timescales and, importantly, a calculation of the carbon offsets from a solar installation. Turning this carbon offset into hard cash is something businesses in general and pig producers in this instance, will have to advance in the future. As food processors, buyers, consumers and governments increasingly insist on data around carbon use, there has to be a push for this lower carbon footprint food production model to claim a premium in the marketplace. It cannot be acceptable that demands for higher environmental standards and lower carbon inputs, which often carry increased production costs, do not have these additional costs reflected in the product price.
Heating is a large component of energy use on pig farms and Barry broadened his energy-options presentation by outlining the potential of on-farm biomass-based energy as a heat source. His ultimate assessment of farm-based energy production was that the opportunities for renewable energy production on pig units are considerable, provided such key factors as roof space and demand for space heating are adequate. Rising electricity prices reduce the payback timescale for solar PV, he added. Barry also advised consideration by pig farmers because they are high energy users and, therefore, particularly exposed to price fluctuations, and potentially some future instability in the energy market, to provide cost competitive and dependable energy to their farms.