Professor of System Science, Director of the Clinical Science and Engineering Research Laboratory, Binghamton University, State University of New York

Kenneth McLeod does not work, consult, own shares, or obtain funds from any company or organization that can benefit from this article, and does not disclose any related affiliations other than academic appointments.

The State University of New York Binghamton University provided funding as a founding partner of The Conversation US.

In order to curb climate change, many experts have called for a large-scale shift from fossil fuels to electricity. The goal is to electrify processes such as heating homes and powering cars, and then use low-carbon or zero-carbon energy sources such as wind, solar, and hydropower to generate increased electricity demand.

More than 30 cities in California, including Berkeley and San Francisco, have moved in this direction, banning the use of natural gas in most new buildings. Currently, energy use in buildings generates more than 40% of San Francisco's greenhouse gas emissions.

There are direct electrical options for heating, hot water, and drying clothes in buildings, but the use of electricity in the kitchen can be more controversial. As we all know, traditional electric furnaces are slow to heat and cool. They also pose safety issues because their heating coils will remain hot for tens of minutes after being turned off.

What is a serious chef? A high-tech alternative is magnetic induction. This technology was first proposed more than 100 years ago and was demonstrated at the 1933 Chicago World's Fair. Today, magnetic induction stoves and stoves are common in Europe and Asia, but they are still a niche technology in the United States. As more and more cities and states move towards electrification, let’s take a look at the working principle of magnetic induction and the advantages and disadvantages of cooking.

I am an electrical engineer, specializing in electromagnetic field research. Most of my work is focused on medical treatment applications-but whether it is exposing human tissues or pans on electromagnetic fields to electromagnetic fields, the principle is the same.

To understand what an electromagnetic field is, the key principle is that an electric charge generates a field around it-essentially a force extending in all directions. Think of static electricity. It is an electric charge often generated by friction. If you rub the balloon on your hair, the friction will make the balloon electrostatically charged; then when you remove the balloon from your head, your hair will stand up even if the balloon does not touch it. The balloon pulls your hair with an attractive electric power.

Moving charge, like current flowing through a wire, generates a magnetic field—the magnetic field around the path of the current. The earth has a magnetic field because electric current flows in its molten core.

Magnetic fields can also produce electric fields, which is why we use the term electromagnetic field. This concept was discovered in the 1830s by British scientist Michael Faraday, who showed that if conductive materials (such as wires) are placed in a moving magnetic field, an electric field will be generated in the conductor. We call it magnetic induction. If the conductor forms a loop, current will flow around the loop.

Faraday's discovery laid the foundation for the development of electric motors. His work also shows a way to heat materials without using traditional heat sources such as fire.

All materials have electrical resistance, which means that when current flows through them, the flow is at least somewhat obstructed. This resistance causes a partial loss of electrical energy: the energy is converted into heat, and the conductor heats up as a result. In my biomedical research, we study the use of radio frequency magnetic fields to heat tissues in the body to help the tissues heal.

Unlike traditional burners, the cooking point on an induction cooker is called a stove and consists of coils embedded in the surface of the stove. In order to achieve maximum efficiency, engineers hope that the magnetic field energy generated by each stove can be absorbed by the cookware placed on it as much as possible. The magnetic field creates an electric field at the bottom of the cookware, and due to resistance, the pot will heat up even if the stove does not.

In order to obtain the best performance, magnetic induction furnaces and cooktops need to operate at a high magnetic field frequency-usually 24KHz. They also need pots made of materials that are difficult for magnetic fields to pass through. Metals with high iron or nickel content absorb magnetic fields, so they are the most effective choice for induction cooking. Iron absorbs magnetic fields more easily than nickel and is much cheaper, so iron-based materials are most commonly used in magnetic induction cookware.

Since induction stoves need to absorb a magnetic field to generate heat, they are inherently safer than traditional electric stoves. Putting your hands on the stove will not heat your hands to any noticeable degree. Because these systems heat the cookware without directly heating the stove, the stove cools down quickly after the cookware is removed, reducing the risk of scalding.

The cooker itself tends to heat up and cool down quickly, and the temperature control is very accurate-this is one of the key characteristics of the cooking value of the gas stove. Another advantage is that induction cookers usually have a smooth surface—usually glass or ceramic—so they are easy to clean.

Modern induction stoves are as energy-efficient as traditional electric stoves, twice as much as gas stoves. But this does not necessarily mean that their operating costs are lower. In many parts of the United States, natural gas is far cheaper than electricity, sometimes three or four times lower. This partly explains the wider acceptance of induction cooktops in Europe, and until recently natural gas was much more expensive than electricity.

Another factor that affects adoption is that the cost of induction cookers and cooktops is usually higher than that of traditional gas or electric stoves, although this is not the case. Chefs will have to replace aluminum pots, copper pots, non-magnetic stainless steel pots and ceramic pots, none of which will work effectively on the induction cooker. A quick check is that if the magnet sticks to the bottom of the pot, the pot will work on the induction cooker.

[The science, health and technology editors of the dialogue pick their favorite stories. every Wednesday. ]

Despite these factors, I expect that the reduction in natural gas use regulations will greatly expand the scope of use of magnetic induction stoves and stoves. These measures usually focus on new buildings, so there is no need for expensive renovations to existing houses.

Young singles and families moving into these new homes may not yet have access to many cooking utensils and may appreciate the safety associated with magnetic induction, especially if they have children. Early adopters who are willing to pay more for green energy power or hybrid or electric vehicles may not bother to spend a few hundred dollars on magnetic induction cooktops and pans.

At the national level, the United States may adopt some form of carbon pricing in the near future, which will increase the cost of natural gas. People are also paying more and more attention to indoor air pollution caused by gas appliances. More than a century after it was first proposed, the day when magnetic induction cooks in the sun may have arrived.

Write articles and join a growing community of more than 137,100 scholars and researchers from 4,211 institutions.

Copyright © 2010–2021, The Conversation US, Inc.