As energy bills have skyrocketed, air fryers have skyrocketed in popularity amid reports that they are cheaper than electric ovens. But now a leading university professor has tested deep fryers, pressure cookers and ovens to determine which are more energy efficient in different scenarios.
Amin Al-Hababeh is Professor of Intelligent Systems Engineering at Nottingham Trent University. He took a scientific approach to figuring out when is the best time to use the device.
If you look closely at energy vampires in any home, they have one thing in common: warmth. This means cooking can be one of your biggest expenses, along with electric heaters and warm water for washing and radiators. So what are the most effective things you can do in your kitchen to cut down on your energy bills?
At home, I conducted a series of small experiments comparing the energy efficiency characteristics of various appliances and ordinary cookware.
The savings and payback period of all of the changes below will depend on food, fuel and technology. But in general, using more efficient kitchen technology will lower your energy bills.
To understand my conclusions about pasta, rice and potatoes, let’s look at the basics of energy consumption. Whether you use natural gas or electricity, energy consumption is measured in kilowatt hours (kWh). It takes about 1 kWh to boil 10 liters of water in a kettle at room temperature. An electric heater with a power of 1 kW (1000 W) consumes 1 kWh in one hour.
Deep fryers save about two-thirds of the energy compared to electric ovens. (Amin al-Khabaiba – provided by the author).
My deep fryer consumes about 68% of the electricity used by my oven. I froze 500g chips in the oven at 200°C. The fryer uses 0.43 kWh and takes 18 minutes, while the electric oven uses 1.35 kWh and takes 32 minutes. This can be explained by the large size of the oven and the fact that it must be preheated.
Making 500g of potato chips a day, an air fryer could save a British family around £114 a year. This is based on electricity and gas prices set at £0.34/kWh and £0.10/kWh respectively as part of the October 2022 energy price cap.
The boiler used only 0.03 kWh to keep warm, boiled 200 ml of water and cooked 150 g of rice, which took 2 hours (one person). A typical pot only takes 15 minutes but consumes 0.18 kWh. Thermopots save 83.3% of energy. 600 grams of rice a day saves about £74 a year.
When cooking a batch of pasta, the energy required to boil water is 0.09 kWh, which allows you to cook pasta in 30 minutes. Cooking the same pasta in a regular frying pan requires 0.26 kWh of electricity. This saves 65.4% of energy. With one meal a day, a family of four saves around £84.
I cooked 1kg of potatoes and used electricity in every test. A regular frying pan uses 0.65 kWh in 30 minutes, a pressure cooker uses my 0.42 kWh in 20 minutes, and a slow cooker uses about 0.59 kWh and cooks potatoes in two hours.
Using a pressure cooker in the UK saves about £28.50 a year on electricity. Save £7.40 a year on a slow cooker, but save even more by cooking at lower temperatures for longer. However, if you have a gas stove, a pressure cooker can save up to 81% on energy costs compared to a conventional frying pan.
Based on current average market prices: around £15 for a small insulated pot (£100 for a family), £70 for a home deep fryer, £50 for a pressure cooker and £35 for a slow cooker.
Suppose a family cooks once a day for a year. For air fryers and electric ovens, the payback period for chips for one meal a day is about 7 months. After a £70 investment, you won’t see any real savings for 7 months. However, you will save £114 per year.
Efficient cooking is about reheating food, not cooking. The image below is an infrared image showing the heat loss when cooking pasta in a regular pan. Most of the energy goes off the sides of the pan instead of reheating your dinner.
Heat dissipation shown by infrared camera, lighter colors show higher temperatures (Amin Al-Hababeh – courtesy of the author).
Think about the energy prices in the country you live in. In the UK, gas prices represent around 30% of the cost of electricity, and based on prices as of October 2022, the daily flat fee is only around 60% of the fixed cost of electricity.
So, for the same amount of heat, theoretically using a gas oven should be about 70% cheaper. Electrical equipment is more efficient because heat is distributed and controlled more efficiently. But who is the consumer champion? Electricity is estimated to eventually double the cost of oven gas.
Furnaces are a different story. The induction cooker uses the magnetic field of the cooker directly. Induction cookers save energy in two ways. The stove itself does not heat up, so no heat is lost. The heat is transferred to the pot through the magnetic field without heat escaping to the environment. But you will need a black metal pan.
As a final tip, keep in mind that using high heat on liquids that are already simmering will not speed up cooking as the temperature of the liquid will not change. If you like hard-boiled eggs for breakfast, turn down the heat as soon as the water boils.
This article is republished from The Conversation under a Creative Commons license. Read the original text.
Post time: Oct-31-2022