Energy in the Kitchen

Topic 5: Energy in the Kitchen

Overview

Kitchens are all about heating and cooling food, often at great speed all at once! To do this and still save energy; you can increase the efficiency of your appliances and change the way you use them.  On this page we introduce some ways that can help you to do this.

Kitchen activities use energy in the preparation and storing of food, and in the clearing up afterwards. The size, purpose and numbers of people using your kitchen will all influence how much energy can be conserved through small changes to daily habits, and / or one off purchasing to increase the efficiency of some appliances. Energy saving should be practical and do-able for all kitchen users, and help make the kitchens healthier environments to work in. In this topic we focus mainly on users of commercial kitchens, and include suggestions for self-catering lets too.

Make a Plan

After reviewing the information in these pages its best to draw up a short plan of action to test different ways to save energy.  When you do this, ensure to consider all potential kitchen users, and if possible talk to everyone involved before you start drawing up and implementing your energy and water saving plans. Ask yourself, your staff (and guests of self-catering lets, if they agree to participate in a short questionnaire) if the plans are workable, and what might prevent them from working in practice? Use that experience and feedback to agree on a plan all kitchen users are happy with.

Using Appliances Efficiently

Your energy consumption will be influenced by how you use appliances. Below we give an overview of some energy saving actions and habits in the kitchen. You might already be implementing some, others might require more consideration. Reducing energy usage in the kitchen will help ensure a healthy and comfortable working environment for all kitchen users.

Appliances: Check the energy rating on all your appliances. The current most efficient rating is A+++.  Typically choosing an A+++ fridge freezer over an A+ unit will save you about £200 in energy bills over the lifetime of the product. However, as the energy rating is based upon classification by size, choosing a smaller fridge will use less energy than a larger fridge with the same energy rating. If replacing appliances, look for the product with the best energy rating for the size you require.

If you are considering replacing appliances, you may be able to get a tax break by choosing from the Energy Technology List. Here you can find cellar cooling equipment and display refrigeration equipment for pubs and restaurants, but not domestic style kitchen equipment. If you are looking for domestic appliances then have a look at the Energy Savings Trust’s list of appliances by category.

Fridges and freezers:

Fridges and freezers are on constantly, so the efficiency of these appliances is important. Here are some tips for using your existing appliances efficiently:

  • Only open the doors of fridges and freezers for the minimal time. Ensure food is cold before putting it in the fridge and freezer. Minimize the use of ice machines and adjust settings to dispense less ice. Try asking if customers would like ice, especially in the winter!
  • Defrost the freezer regularly.
  • Ensure the seals on your fridge and freezer doors are tight, and replace if necessary.
  • Ensure the fridge and freezer are set to the appropriate setting – too cold will waste energy and too warm will mean food goes off prematurely. 5°C is recommended for most foods, but it will depend on what you are storing in your fridge or freezer. Find out the specific recommended temperature for your goods and make sure your fridge and freezer are set to this temperature.
  • Placement and location: Fridges and freezers will operate more efficiently when they are placed in the coolest places. If practical, ensure they are not next to the cooker, and ideally out of direct sunlight. Keep them at least 10 cm from the wall.
  • Check the condenser coils for dust – this reduces their efficiency, so if they are dusty turn the fridge/freezer off and give them a gentle brush. The condenser coils are found on the back of the fridge.
  • Review your fridge and freezer space requirements. Rather than have two half-full units, combine them and turn off the unused unit until it’s needed again.
  • Defrost frozen food in the fridge overnight: defrosting food in advance typically halves the cooking time.

Dishwashing:

Check the energy rating of your dishwasher. If you are considering purchasing a new one, consider energy and water consumption per load, and run times.

  • Try to only use dishwashers on full load
  • Where practicable, use the eco programme if you have one.
  • Pre-soaking utensils and dishes in cold water saves using hot running water
  • Always wash up in a bowl or sink with a plug not under running water. Soak item in a bowl not under running water. You will save energy and water too.

Taps: do you know the flow rate of your taps?

  • Taps in kitchens should have a maximum flow of 10 litres per minute.
  • You can install dual-flow taps in your kitchen, so that you can have the benefit of water saving taps, and full flow when you need to fill saucepans or basins quickly. Have a look at Topic 1 for more information.
  • If you use hot running water, could you save water by using basins instead?

Electric cookers and ovens:

How long does your oven take to pre-heat? Could you turn them on later than usual? Ovens will not heat up faster if you set them to a higher temperature, they will instead heat up past the temperature you actually need, wasting energy. Make sure you set them to the temperature you need. Make a note of how long it took to get to temperature and in future only turn on your oven early enough to get to temperature.  You might want to monitor your energy using your OWL energy monitor and see if you can make savings just like the Island Bakery has.

Only switching cooking appliances on when they are needed will also reduce the overall heat in the kitchen. This will help the kitchen to be a healthy and comfortable environment to work in, reducing stress.

Hobs can waste a lot of energy if you are not careful. Make sure when you are cooking to always use a lid on the pans and once the water is boiling to turn down the heat and/or move the pan to a smaller ring. The water temperature is the same if it is lightly boiling or vigorously over boiling, but the energy waste is higher if it’s over boiling. Doing this will also reduce the humidity and heat in the kitchen making the working environment much more pleasant.

Wonderfully, a Cambridge educated engineer has conducted an experiment and calculated the difference between boiling potatoes with a lid, and without. This demonstrates the saving very clearly. For more information, such as the number of potatoes, do have a look at her blog.

Extractor fans / cooker hoods:

Extractor fans and cooker hoods can help keep the kitchen environment healthy for all the kitchen users.

  • Ensure to clean your range / cooker hood often to keep it working well.
  • When specifying or installing extractor fans, make sure it has a variable speed drive (VSD) as standard. All new fans should but make sure to double check. A VSD should also be on all new pumps and motors. A VSD matches the speed of the fan to the use, so rather than the fan running 100% all the time the VSD reduces the speed to match demand. The fan can be linked to either a humidity or CO2 sensor in order to control its speed. More often they are linked to a simple dial in the kitchen which is controlled by staff. If this is the case, make sure it is not left running on high unnecessarily.

Do you know how much energy each appliance uses?

You can work roughly how much each appliance costs you each month by using your OWL and filling in the energy monitoring sheet  that we talked about in the Energy Monitoring topic page. Refer to the guide if you need any help filling it in.

Alternatively, if you want to track a particular appliance you could use a dedicated plug-in energy monitor (like this one for example). These  cost between £7-20 each or you may be able to borrow one from Ben Robbins. Some plug in energy monitors will record and store consumption over a period of time for a particular piece of equipment. This is really handy if you are trying to test different ways of changing behaviour for particular appliances, say an oven. Use it normally for a week and check the consumption. Then clear the data, change what you are doing and check again another another week.

Communicating to Guests or Staff

Pointers and tips for:

  • Staff and kitchen users, (Food and Drink Sector) : when discussing changes with kitchen users, you could include it in a discussion about what would enhance the kitchen working environment. Many of the energy efficiency changes are about reducing excess temperature, which can contribute to a healthier work environment.
  • Ask staff to try out different behaviors and test different ways of working. Try running an energy saving week with your staff and challenge them to see how much energy they can save, promise them a reward at the end of it! Ask them to reflect on what they found easy or more difficult.
  • Guests in self-catering accommodation – Below we have put some suggested text to personalise and include in welcome packs for self-catering accommodation. Bear in mind that some research shows that guests are not necessarily as conscious of energy and environmental issues when they are on holiday as when they are at home, so encourage and enable them to help you / the Islands achieve a good energy rating.

Dear Guest,

As part of the Smart Energy Islands project, the community of the Isles of Scilly is working together to reduce energy consumption by at least 5%. We invite you to share in this challenge with us. Here are some actions we have taken (list them). Join us in taking part by trying the following:

  • Cover pans with a lid when cooking. Its quicker and uses less energy
  • Only fill the kettle with the water you need
  • Turn off lights when not in use
  • Turn off towel heaters when you go out in the morning

Thank you’

Green Kitchen Standard

Soil Association Certification and Carbon Trust have joined forces to create the Green Kitchen Standard, a new certification which recognises caterers that are taking positive steps to sustainably manage energy, water and waste. This scheme gives information on the standard. Although this seems to be currently aimed at larger establishments like hospitals, its still worth a watch if you are running a large kitchen:  You can watch the Green Kitchen standard webinar for more info: (44 min).

Sustainable Menus

Being energy efficient in the kitchen needn’t just stop at cooking. Have you considered the energy efficiency of the food its self? Different food have different environmental impacts and embodied energy and carbon. This is why you might have heard about ‘meatless mondays’ and other campaigns to reduce meat eating. Meat, in particular beef, is really carbon intensive compared to other foods.

This chart is taken from research into the full ‘cradle to grave’ life cycle assessments of different foods. This means they research environmental impacts from the planting, land use, growing, harvesting, transporting and consuming of different foods. Life cycle analysis is a complex field, and there are many ways to cut this particular cake (no pun intended). But the basic point to take away is the relative impacts between different foods. Lamb is the highest due to the land used in sheep farming. Chicken is the lowest impact meat, while cheese is higher than pork. Have a look at the bar for potatoes, its almost all cooking. Which ties in nicely with the chart above about keeping a lid on cooking pans.

We are not suggesting you tell your customers what to eat, but providing them the option to choose a low impact meal would really reinforce your green credentials.