Lesson 2 - Environmental Sustainability

We have learnt that it is imperative we reduce carbon emissions, and that there are both environmental and economic benefits in doing so. Within our brewing operations, there are two main ways of achieving this:

1. Being more efficient with the energy we use

2. Using or generating low or zero carbon energy

Brewery energy sources and carbon emissions

Breweries typically generate heat energy on-site in boilers using primary fuels such as gas, oil or coal. Electricity, on the other hand, is usually purchased from national grids, even though some breweries generate a proportion in-house. The variety of fuels we use to power our processes create different emissions.

Table: Carbon emissions of various fuels to illustrate difference in carbon footprint

As shown, burning coal has the greatest carbon emissions, while biogas from waste water has minimal emissions. This latter fuel is a crucial way brewers can reduce direct carbon footprint using waste water treatment with anaerobic digestion and biogas capture to create an energy source from this waste. However it is important to note that although biogas is much more carbon friendly, it normally comes with very heavy levels of sulphur contamination. Consequently, the biogas has to be cleaned before it can be used in a boiler.

Electricity will have a different carbon footprint, depending on how it has been generated. The table below shows the carbon emissions associated with grid electricity from several locations globally.

Table: Examples of carbon emissions of grid electricity from different countries to illustrate difference in carbon footprint

Electricity purchased from the grid will have a different carbon footprint depending on the mix of fuels and energy types used to generate it in each country or location. For example, in the UK, the carbon emissions from one MJ of energy is less than that of India as less coal is used in generating electricity for the grid.

It is possible to purchase zero carbon electricity either directly from energy companies on a green tariff or by several other types of purchasing agreements.

How much energy?

The amount of energy required per hL of beer we produce varies between breweries based on:

• The age of the brewery – whether it is old or modern

• The size of the brewery – whether it produces a large or small annual volume

• The type of products being brewed

• Packaging types being filled – cask, keg, returnable glass bottle, non-returnable glass bottle, can or polyethylene terephthalate (PET) bottle

• Location – ambient air temperature and water temperature

• The management systems that are in place (more on this later)

Benchmarking data indicates that breweries energy use can range between 0.75 MJ/L to 2.21 MJ/L, with carbon emissions ranging between 48 and 187 g/L. While data from craft brewery benchmarking in North America indicates the smaller breweries may use up to 15.33 MJ/L.

Smaller breweries are typically, although not always, less efficient in converting energy, water and other resources into beer than larger breweries, i.e. smaller breweries  producing less beer tend to use fewer resources overall, but they may use more resources per hectolitre beer they produce.

This is due to economies of scale.  As breweries or processes become larger, they are often able to utilise more sophisticated or automated machinery. Additionally, as brewing at any level is fundamentally done in batches, producing more beer per batch will result in less energy (and water) being used per batch. There is, of course, a limit to economies of scale: very large breweries can become less efficient if they grow in complicated ways or do not run at their full capacity.

Further reading on benchmarking studies:

https://www.bieroundtable.com/work/benchmarking/

https://www.brewersassociation.org/wp-content/uploads/2019/01/2017-Sustainability-Benchmarking-Report.pdf

Main energy consuming activities

Just as there is variation in total energy use across breweries, the main energy consuming activities will vary within a brewery. The following tables provide some examples of the main brewery energy consuming activities.

Table: Main thermal energy consuming activities in a brewery by percentage

Table: Main electrical energy consuming activities in a brewery by percentage

Best available techniques

In some countries, breweries may need to adopt Best Available Techniques (BAT) to achieve any necessary environmental permits. BAT describes the best available techniques for preventing or minimising emissions and impacts on the environment.

‘Techniques’ include both the technology used and the way the installation is designed, built, maintained, operated, and decommissioned.

Examples of processes which require high energy inputs where BATs have been developed include:

• Mashing
• Wort boiling and cooling
• CO₂ recovery plants
• Fermentation
• Pasteurisation