What Potato Growers Can Do To Improve Energy Efficiency

With energy prices rocketing in recent months, potato and vegetable growers face soaring increases in production costs as we enter the energy intensive storage period. This will have a severe impact not only on margins but on cashflows in the months ahead. Reviewing existing facilities and processes to maximise energy efficiency has never been more important to try and mitigate some of the cost increases. Here are a few suggestions you could apply within your own enterprise which can be put in place relatively quickly and cheaply

Review Your Store For Leakages

Leakages from stores mean that fans and cooling systems have to work much harder or longer to achieve the desired temperatures and airflows- requiring more energy and costing more money.

There are several areas growers can look at:

1. Check your seals: Take the time to check that all doors create a seal when closed. The building itself should also be structurally sound with no gaps in the building fabric e.g. around joints or around fans and ducts.

2. Check your insulation integrity: Internally, insulation needs to be fully intact and effective. Attention should be paid to areas with any joints between building elements e.g. walling and roof as well as any internal edges such as around doors or fans and individual panels. Vermin can also cause damage to insulation and any areas damaged should be repaired as soon as possible.

3. Thermal imaging: Is your store really as good as you think? The use of thermal imaging cameras can identify any leakages from the store- possibly revealing areas not previously identified or less visible as those previously discussed.

4. Review insulation thickness: Check the thickness of insulation and upgrade where necessary to minimise the transfer of heat from within the store to the outside and vice versa. Roof insulation should be at least 75mm thick in refrigerated stores and 50mm in ambient stores and the better a store is insulated, the less chance of condensation forming. Potato Store Manager’s Guide, AHDB.

Leakages and gaps can be addressed fairly simply in many cases- from the fitting of flaps to vents, the fitting of gaskets to personnel doors to using cans of spray foam to fill any gaps in insulation around ducts etc. For smaller gaps the use of sealant of draughtproofing strips can be effective.

More Efficient Ventilation and Cooling

Ventilation and cooling systems need also work as effectively as possible and growers should consider the following.

1. Service your systems thoroughly Systems should be serviced and well maintained, with controls checked to ensure they are working as they should. This includes making sure the system is free from dust and debris that could interrupt airflow or the effective working of flaps etc.

2. Calibrate your temperature controls Even a small difference between recorded and actual temperature can result in increased costs through unnecessary energy use.

3. Fit variable speed drives (VSD) to motors. VSD can match the demand of the system to the power that is needed by varying the output speed of the motor. These have been proven to significantly reduce energy consumption and work by allowing a more continuous, lower rate of airflow to circulate compared to periods of no airflow punctuated by power-hungry short periods of high-speed fan use.

4. Remote monitoring: Remote monitoring and control systems also give growers the ability to adjust conditions in the store where necessary as well as acting as a warning of any problems.

Optimise Power-intensive Activities

Storage sheds and potato handling are power intensive activities, again growers can review their current systems to look for savings.

1. Upgrade your motors: How efficient are the motors on equipment on grading and handling equipment? – can the motors be changed for a more efficient versions or should the machine itself be replaced.

2. Consider renewables: Is there scope for renewables or alternative power sources to partly replace expensive electricity used from the grid? This can range from the installation of solar panels to the fitting of hydrolysers to forklifts to even considering the use of diesel generators.

3. Efficient lighting: Can the lighting in the building be replaced with more efficient LED alternatives? LED lighting uses much less energy than more traditional Tungsten lamps or fluorescent bulbs and tubes.

Efficient Store Management

Store management can also play a role in energy consumption and the following can help reduce energy consumption.

1. Keep doors shut whenever possible: Stores should be loaded as quickly as possible with strip curtains helping maintain temperatures during periods of frequent traffic in and out of the store.

2. Upgrade your equipment: Upgrading to take advantage of the latest advances in SMART technology can allow machinery to operate when it is most energy efficient. Such as taking advantage of low-tariff periods or using sensors for defrosting cooling systems.

3. Clean potatoes: Potatoes should be lifted as cleanly as possible – lumps of soil and stones disrupt airflow through the box, not only wasting energy but also compromising quality.

4. Plan your layout: To work effectively, potato stores rely on good airflow to ensure satisfactory ventilation. Plan filling of the store and stacking of boxes to achieving optimum circulation of airflows for both drying and cooling. Poor layout can mean that equipment has operate longer to achieve desired temperature or remove condensation.

Consider An Energy Audit

This would identify where most power is consumed, provide suggestions to reduce usage and offer action points listing potential costs and benefits. Measuring power usage is also important for monitoring and the installation of meters and sub-meters can facilitate this.

Taking some time now to look for store leakages and reviewing store equipment and processes is crucial to optimising energy efficiency and mitigating costs during these challenging times.

If you have further questions, please contact the FAS helpline for advice and support:

Email: advice@fas.scot

Call: 0300 323 0161