By Dr. Samantha Mudie, Head of Technical Development
This week it was my great pleasure to be formally interviewed for my expert opinion on the energy consumption of professional food service equipment (PFSE) in a government department for Business, Energy and Industrial Strategy (BEIS) consultation on changes to the Energy Technology List (ETL). This major research project is seeking to understand what role commercial kitchen equipment has to play in reducing greenhouse gas emissions and is currently engaging with operators and suppliers willing to share their views on the topic.
I am immensely proud and flattered that my doctoral thesis, “Energy use and reduction from commercial food preparation”, has been picked up by BEIS and the results could directly impact future policy decisions around minimum energy performance standards and energy labelling for catering appliances. Props also to Carbonxgen for affording me the time and encouraging me to make my contribution to this important study.
Much of the general public are unaware of the vast, VAST energy consumption occurring in their local pub or restaurant. In fact, before my research (sponsored by Mitchells & Butlers plc) many operators and academics were also in the dark. Focus on emissions reduction was very much on the agricultural end of the food production chain (owing to its huge GHG emissions profile through land use change and methane generation among other facets). However, when evaluating existing data on the wider food service activities of the UK (those not just from commercial pubs and restaurants but also office canteens, ministry of defence mess halls, hospital, school and care home food preparation), I initially found the energy consumption attributed to “cooking activity” to be 24 TWh per year, more than the usage of agriculture (12 TWh) and food retail (12 TWh) combined! Analysing the data in a different way I also found “hotel and catering buildings” to be the second largest energy consumers in the UK services sector (54.56 TWh).
With this mandate for further investigation and focusing more narrowly on pubs and restaurants, I analysed AMR data from over 20,000 managed sites. Electricity consumption found to be 2.73 TWh (Electricity) and 2.16 TWh (gas). Applying the average site consumption of 382,337 kWh per year to the number of pubs in the UK at the time (51,178), the study indicated that UK pub sector consumes 19.57 TWh, much greater than previous CIBSE estimates. This consumption is comparable to 1.2 million UK households! In fact, four of the operators I worked with had average electricity bills per site greater than that of the average supermarket (think about the lighting, fridge and freezer demand in a Tesco!).
PFSE ETL STUDY PHASE 1
During October, the first phase of the study sought to define the scope, definitions, eligibility requirements, performance requirements and measurement standards. This is all with the aim of identifying the top 25% of energy efficient appliances. Still, even after my 6-year project, there is no verified protocol for energy consumption data of commercial catering ovens, steamers, grills, fryers etc, leading to a large gap in knowledge around energy saving credentials of these appliances. Energy efficiency is still undefined – do we measure the oven on maximum output for an hour? On warm up, cooking at half or maximum power? How do we account for standby/pre-heat consumption? Do we use a standard food? What is a standard food? A tray of chips? A pie? A standardised food simulant? I even saw a study in the USA that used thermocoupled metal disks to simulate burgers – repeatable yes, but very far removed from real world conditions. PFSE have no energy performance regulation at all (excluding some refrigeration); even the EU Ecodesign directives only really present some standards for blast chilling and these are now getting on for 10 years old. There are also barriers around competitor’s reluctance to share data and be open about energy reduction trials.
The largest and most significant part of my research to date has centred on the creation and development of a computational model which presents power input data relative to food throughput. This is not as applicable to appliance manufacturers as the ETL study might like, but it is the first time an operator can input a menu and real food sales data per half hour, and evaluate energy consumption results in line with their typical cooking activity and service profile. In addition, the operators can simultaneously evaluate other operational impacts such as space requirements, staff training needs, cooking times and food turnover capacity (more on this to come in January…!).
The October workshop also made mention of a new ETL website and an application programme interface (E-CAT) allowing procurers and designers to use smart meter data to receive ETL product information and recommendations into their own systems. This project is now at the user testing and design influence stage.
At the workshop there was also good discussion around how business rates could be used as incentives to purchase energy efficient appliances, plant and machinery (since the close down of the enhanced capital allowance in April) and how the need scrappage schemes are critical in the move towards a circular economy.
PFSE ETL STUDY PHASE 2
The most recent phase sought stakeholder contributions to assessing energy performance and trends in the industry, Covid-19 impacts and looked at the minutia from how commercial food service outlets and their energy consumption benchmarks should be defined as a whole. (I actually published an award-winning paper on this very subject in 2016: https://www.researchgate.net/publication/291018504_Energy_benchmarking_in_UK_commercial_kitchens. Spoiler alert: it’s kWh/£ turnover NOT size (m2).)
The size of the market (currently 40,000 UK pubs) and fuel type trends in light of a move to electrification of heat in the UK net zero carbon plan were also discussed. I was able to provide my analysis and conclusions regarding staff behaviour and incentivisation. (Energy savings of up to 71% are available from staff training in relationship to certain appliances such as grills, though high staff turnover and attrition in the sector presents significant, though not insurmountable, barriers to operators investing in these programs.)
Finally, I provided my recommendations for how significant reductions in energy costs could be achieved, placing specific emphasis on how the sector could put sustainable resilience at the heart of its recovery from the devastating impacts of the pandemic. I wrote a 400-page book about this and can bore the pants of anyone for hours, but in brief this comes down to:
Full sub–metering – You can’t manage what you can’t measure and metering the food service operation on an appliance level is a great first step. Only then can the most valuable insights be gained for energy costs, but also appliance utilisation, running times and usage/behavioural aspects – even maintenance costs and avoidance of breakdowns can be achieved through granular sub-metering.
Benchmarking and disclosure – Encouraging this sector to move away from the mentally of keeping their cards close to their chest and towards shouting about what they achieve, what didn’t work for them and positioning themselves as leaders in their sector in terms sustainability attributes for competition and customers alike.
Menu modelling – Evaluating changes in the kitchen template and/or menu/service offerings impacts upon each other can see the largest cost cutting benefits in food service operations. A holistic model can look at not only the cooking of the food, but ware washing, food storage and ventilation as the bigger picture. The model provided energy, carbon and cost data for each energy reduction scenario and has identified over £2 million pounds of annual energy savings for one operator. In the words of my industrial sponsor, “it is one thing to consider an energy efficient hob, it is another to ask whether you need a hob at all”. In one restaurant chain I found that the gas usage for the hob was in excess of £250,000 a year, but only used for 3% of ingredients in the kitchen. Moving the cooking of peas, eggs and sauce to other appliances saved a quarter of a million pounds per year, with no capital cost.
Appliance specification – This is where the ETL PFSE list will help a great deal, but I maintain that menu modelling is still a necessary first step before replacing a microwave combi oven for example. Energy conscious add-ons such as weight sensitive chargrills, timers, thermostatic expansion valves, insulation and appliance internal LED lights etc should all be considered once there is an established need for categories of appliances.
Heat recovery – Once the operation is engineered to be the most efficient it can be, with the most minimal heat wastage, only then can the potential for heat recovery from appliances and extract systems be evaluated.
Ventilation – Another prompt for a holistic evaluation of the entire catering system. The selection of certain cooking appliance, such as gas fed hobs and chargrills, lead to larger ventilation requirements, bigger fans and bigger energy bills – these are often oversized too. Retrofitting demand-controlled ventilation in the form of CO2 temperature and optical sensors are a great way to save 30-50% from extraction.
Refrigeration – From utilising food simulants in order to provide accurate temperature control to free-air cellar cooling for beverage chilling, attractive return on investments of <1 year can be found from hundreds of different retrofit technologies applicable to refrigeration.
The possibilities are endless, and each requires an article, white paper or webinar in its own right! Hopefully, with government research and policy evolving in this area, we can put a sustainable recovery at the centre of the sector bounce back.
Do get in touch if you would like advice on how Carbonxgen can assist in the management of the number one controllable cost in your food service operation – energy:
Call: 01252 560 379