Heat, water, hygiene: successfully decarbonising the food industry

A food processing facility in southern Germany faces the challenge of replacing its fossil fuel-based steam generation with a sustainable heating concept while complying with the highest standards of hygiene and production safety. It may sound like a specialised solution, but it is a common scenario in the food industry. Hardly any other sector places such high demands on heat, water and cleanliness – and at the same time offers so much potential for successful decarbonisation. In this article, we show how hygienically safe, renewable heating solutions for food companies are planned – from both a technical and strategic perspective.

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Cheese production in a small cheese dairy: large vats with cheese wheels wrapped in cloths — Hygiene is the key factor in food production. Image: Caroline Rosse for Unsplash+

Process heat in the food industry: requirements and potential

The food industry is subject to strict requirements regarding drinking water hygiene, disinfection and thermal processes, for example in accordance with DIN EN 1672-2 (hygiene requirements for food processing machinery) and HACCP guidelines (hygiene management including risk and hazard analysis).
At the same time, there is a need for process heat at different temperature levels – from 40°C for cleaning to 95°C for pasteurisation or cooking processes.
Looking at the industry's total energy requirements, up to 70% of consumption is accounted for by heat – mainly in the form of hot water or steam. And this is where a key lever for the industrial heat transition lies.
To enable companies to produce not only economically but also in a climate-neutral manner, subsidies such as BEW or EEW are also available, offering concrete and realistic opportunities for investment.

Person washing hands — Hygienically clean water at a sufficiently warm temperature is a prerequisite for effective hand hygiene.

Renewable heat sources for hygiene-sensitive applications

A common misconception is that hygienically demanding applications are only possible with fossil fuels. In practice, the necessary process heat can also be generated using renewable systems, such as:

Heat pumps powered by groundwater, waste heat or solar thermal sources
Solar thermal systems, especially those with vacuum tube collectors for higher temperatures
Waste heat utilisation from refrigeration systems or other industrial processes
Buffer storage solutions to cover peak loads and hygienic drinking water preparation

Near-surface geothermal energy combined with large heat pumps is ideal as a base load source – even for small to medium-sized businesses. The key is intelligent integration into a network system that meets hygiene requirements.

Planning hygienic hot water systems in heating networks

One of the biggest challenges in food processing plants is the safe provision of hot water in hygienically impeccable quality – for example for:

Rinsing and cleaning processes (CIP/SIP)
Product contact water (e.g. for beverages)
Hand and surface disinfection
Sanitary areas for staff

Clear technical rules apply here, e.g. from DVGW W551 on legionella prevention. Decentralised or centralised storage, the avoidance of dead legs, the choice of the right storage technology (e.g. instantaneous water heaters vs. buffer storage tanks) – all of this must be included in the planning at an early stage, especially when combined with renewable energy sources.

A heating network that also provides hot drinking water must be temperature-stable (at 55 °C), fail-safe and hygienically sound. Booster heat pumps, hydraulic concepts, storage arrangement and control technology are decisive factors here.

Many bottlenecks in a bottling plant — Hygienic filling processes are also essential in the beverage industry Image: Getty Images on Unsplash+

Energy hubs for industrial sites: what to consider

Whether for a single business or a shared site, the energy centre is the heart of a renewable heat supply. A centralised approach is particularly worthwhile in commercial or industrial areas with several businesses, e.g. as part of a local heating network.

Important points to consider during planning:

Modularity: combination of base and peak load (e.g. heat pump + biogas as redundancy)
Generator mix: sustainable combination of heat pump, solar thermal energy and, if necessary, biomass
Integration of hygiene technology: e.g. UV disinfection, fresh water stations
Monitoring & control: digital monitoring of hygiene parameters and efficiency
Eligibility for funding: e.g. within the framework of BEW M1-M3 – including feasibility studies, investment cost subsidies or subsidies for individual measures

goodmen energy has already planned several projects in the field of industrial heating concepts – both for the decarbonisation of production processes and for site development. Our experience shows that when energy centres and user requirements are clearly coordinated, economic and hygiene goals can be achieved simultaneously.

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Conclusion: Heat transition in the food industry requires a good planning

Decarbonising the food industry is feasible – provided that hygiene requirements, security of supply and temperature levels are incorporated into the planning at an early stage. Good concepts rely on renewable base load, intelligent storage strategies and hygienically safe system architecture.
With technical expertise, an understanding of industry-specific requirements and eligible concepts, goodmen energy supports industrial partners in implementing future-proof heat transition projects in the food industry.

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