Food and beverage manufacturing is synonymous with high energy costs and waste outputs. Total Construction’s Engineering Construction Group managing director Rob Blythman explains how factories need to be individually appraised for the best environmentally sustainable and economically efficient fitout. This article was first published in Food & Drink Business July/August 2020.
Food and beverage processing facilities are highly energy intensive. Producing the heat required for industrial production consumes high volumes of gas and or electricity, which comes at a hefty price. Energy usage accounts for at least 15 per cent of total operation costs for food and beverage manufacturers.
With high power costs looking likely to remain a norm in Australia, reducing reliance on the grid and generating energy onsite is an increasingly attractive option. Reducing reliance on traditional forms of energy can help save on operating costs.
Water consumption and waste production are also high, so improving efficiency in all these areas is critical for companies looking to improve their bottom line.
There are a number of renewable energy technologies that can reduce reliance on the grid, but it is essential a company weigh up the costs and benefits of the available options before rushing ahead with costly installations.
The same applies with a F&B manufacturing facility build and fitout. Sometimes the best fit is not always obvious.
For a recent food manufacturing build, we undertook a detailed analysis for the client whose brief was a plant that was energy efficient and affordable.
The client would have a relatively high energy consumption, particularly electricity, and they would also be using significant amounts of water through production. We looked deep into the client’s options that would make the facility more sustainable without blowing out the cost.
Powering up
When exploring the options for onsite power generation, it was quickly established that solar panels with battery storage would be greatly beneficial. With ample roof space solar panels would cut back the facility’s demand on the grid during the day.
Sizing the panels correctly was a key consideration. Excess power produced would be exported back to the grid, reducing potential returns due to the low prices offered from the retailer. But installing battery storage would increase the proportion of renewable power used, something that would be favourable during peak usage periods.
For this client, solar was a no-brainer. It made sense from an economic perspective and battery storage is becoming increasingly affordable.
We looked at co-generation, the generation of high-temperature heat and electricity from a single source, but it was rejected due to questionable reliability of supply and the investment needed for a back-up source of generation.
We found that it was pretty hard to make co-gen work for them, economically speaking. It would have cost a similar amount to power from the grid, which meant a good return on the co-gen investment would have been difficult. Also, the substantial increase in the price of gas over the last five years made co-gen less attractive.
When we were looking at the site’s gas requirements solar-powered hot water was deemed a viable alternative to co-gen with minimal cost impact. Alternative methods of gas supply, such as onsite biogas and hydrogen generation via anaerobic digestion and solar-powered electrolysis, were also considered. While they have great environmental benefits, the costs were too high.
Waste not
The plant would be creating a lot of food waste, which in turn created the opportunity to produce gas from the waste using anaerobic digestion. Again, it was an expensive proposition.
Relatively speaking, this particular factory didn’t require all that gas just for water heating, so it didn’t make sense for them to spend $1.5 million on a special plant to achieve something they would not use.
We had a similar result when it came to water management. We were shocked by the feasibility study results.
For this client, when it came to working out how the facility could better manage its water usage, we found using recycled water was not a viable option. In fact, the cost of potable water was so cheap that other options couldn’t compete.
In terms of sustainability, we thought that collecting rainwater from the roof would be a good idea. The facility has quite a large roof area but the cost of a rainwater tank and the space it would take, coupled with the cheap price of potable water, made it economically inefficient.
Health and safety regulations require any water used in production must be potable, so collected rainwater cannot be used unless treated. But the process and cost of treating it for re-use outstrips the cost per megalitre of supplied potablewater.
Most councils will force manufacturers to install retention tanks for rainwater. In these cases, it makes sense to find uses for the rainwater so that it is a benefit for the manufacturer and environment.
When it came to the facility’s wastewater discharge, it was determined that a dissolved air flotation (DAF) plant would be the best option.
A DAF dissolves airs in water under high pressure then releases it at atmospheric pressure, causing solids to float to the surface with the bubbles, where they are removed.
An emerging technology for the processing of solid waste where micro-organisms digest the food waste into a liquid product that can be discharged into the sewer was found to suit the needs of the plant, as it would dramatically reduce waste disposal costs.
This method allows environmental sensitivity and operational costs savings.
This is a good example of how particular technologies and methods, while not always suitable for some operations, can be beneficial and sensible in others.
Each client needs to be assessed individually on their usage of gas, power, the amount of food waste produced, and the amount of water they have to recycle.
It is not a case of saying other technologies are unworkable and that solar is the only way to go, you have to weigh each option and determine which one suits an individual client and their particular needs.
The choice needs to be bespoke for the operation and based on decisions made after a comprehensive business analysis process.
