I’ll cut to the chase for those of you who want the bottom line. If you want the most even heat in a residential cooktop possible regardless of drawbacks, get either multiple-ring gas or an induction cooktop that has dozens of little induction coils. Those tend to cost quite a lot, though. For everyone else, if you can afford it, get induction, as it strikes a great balance, though the upfront cost is still relatively expensive. If you can’t afford induction, get gas (assuming you already have the gas line and ventilation ready to go). If you can’t get either, get electric radiant, and if you can’t get that, get electric coil (same thing as electric radiant, but harder to clean). Also consider hybrid induction-gas ranges if you have a piece of induction-incompatible cookware you absolutely can’t let go of, or use woks a lot to stir-fry, as most induction cooktops struggle with both. Frankly, though, I’d rather just get a portable gas stove for those situations.
I’ve used a lot of different cooktops. I grew up in a home with a natural gas range. From college through the present, I have lived in various apartments and dormitories, all with electric-coil ranges. I had a girlfriend with a smoothtop electric radiant range. Then I bought a series of portable induction cookers1 as well as an Iwatani Corporation of America ZA-3HP Portable Butane Stove (I reviewed the ZA-3HP here). For this article, I rely on my experiences as well as U.S. Department of Energy data on appliances.2 I’ve summarized my findings in a table below. If you want to know how the table was constructed, just keep reading after the table.
|Electric Coil||Electric Radiant||Electric Halogen||Induction||Gas|
|Speed/Responsiveness||Very Poor||Very Poor||Fair||Excellent||Excellent|
|Accuracy/Repeatability||Very Poor||Very Poor||Very Poor||Excellent||Fair|
|Personal Health Cost||varies||varies||varies||varies||varies|
|Utility Bill Cost||varies||varies||varies||varies||varies|
|Life Cycle Cost||varies||varies||varies||varies||varies|
TYPES OF BURNERS/HEATING ELEMENTS
Electric Coil and Disc
Some materials are more electrically conductive than others. Running electricity through copper wire (high conductivity) means little resistance (energy that is wasted as heat). But running electricity through a strong resistor means the resistor will throw off tons of heat and allow just a trickle of electricity through. NiChrome is such a resistor; it’s a rust-resistant nickel-chromium alloy with high melting point (~2500F) used in electric coil ranges, hair dryers, and toasters. This NiChrome wire is what powers electric coil heating elements.
Note that a solid metal hotplate-style heating element is possible, but the problem is that solid electric plates heats up even more slowly then electric coil, so for purposes of this article, we’ll ignore solid metal hotplates.
Electric Halogen (rare)
Rectangular Tungsten-halogen lamps shine infrared (thermal) energy into the bottom of your cookware. The lamps are covered by glass/ceramic. In some cases the lamps have radiant coils round the halogen elements to heat the perimeter of the burner circle. There are also circle-shaped lamps (Haloring) that use circular lamps for better efficiency. Basically you are getting an easier-to-clean, more responsive, slightly more efficient (75.3%) electric coil stove that may heat more evenly. Note that shiny metal reflects infrared, so the dirtier your cookware, the better they may perform using this technology. Electric halogen is rare, but I’m including them for sake of completeness.
You get electric coil heating elements covered by a smooth glass/ceramic cooktop. The heat energy radiates upward into your cookware. Basically you are getting an easier-to-clean electric coil stove with slightly lower efficiency (71.5%, probably because the energy has to punch through an insulating layer of glass/ceramic before reaching your cookware).
This is a video of how induction cooktops are made:
This is how induction works: Electricity is run through coils of wires. This creates a magnetic field. Residential induction cookers are only powerful enough to use with ferromagnetic cookware (cast iron, carbon steel, and most stainless steel cookware manufactured today; although the truth is, induction also technically works if you have thin enough foils of copper or aluminum, but so thin as to be impractical for cooking, and there is one exotic Japanese residential induction cooker that works with aluminum and copper, albeit inefficiently and at huge cost). The magnetic fields interact with the ferromagnetic cookware to produce eddy currents at the bottom of the cookware, which results in tons of heat (with no risk of electrocution, for those who are wondering).
In theory the process is 100% efficient conversion of electricity to heat on the bottom of your cookware, but in reality, efficiency is below 100% because the induction cooker’s electronics need some power, cooling fans need power, copper wire is not a superconductor, etc. The exact efficiency will vary depending on the cooker and the cookware material but is in the ~80% range.3 All of this is sealed off underneath a glass/ceramic cooking surface.
What is unique about induction is that the heating element is the cookware itself. In every other case, you have a relatively hot heating element pushing heat into relatively colder cookware (relative to each other). This heating method relies on the second law of thermodynamics: if the heating element is ever hotter than the cookware, heat flows into the cookware, and vice versa.4 With induction, thee heating element IS the cookware, so varying the power level instantly varies the cookware’s heat, similar to natural gas–but even better. With natural gas, even if you shut off the gas, there will be a split second of hot gases dispersing underneath your cookware, plus the grates above the natural gas burner will continue to inject heat into the cookware for a few seconds. With induction, if you shut off the induction cooker, the cookware will immediately start to cool down.
Some people may fear that they need “special” cookware to use induction, and by “special” they mean expensive. That is not exactly true. It’s true that most copper and aluminum cookware do not have integrated magnetic stainless bottoms and will not work on induction, but most stainless steel cookware made since the 2000s will work with induction and are quite affordable. Why? Because Europe and Asia make a LOT of cookware, and induction is very popular there. US stores carry mostly EU and Asian cookware, and even if you insist on buying made-in-USA, you will find that even American makers of stainless steel cookware (Vollrath, Regal, All-Clad, etc.) have jumped on board; it’s rare that any stainless they make is not induction compatible. This is in part due to self-interest: magnetic stainless is CHEAPER to make than non-magnetic stainless (nickel is 200+ times more expensive than iron, and it is the addition of nickel that makes cookware stainless non-magnetic).
Please note that the amount of magnetic energy rapidly tapers off by distance, so that cookware must be extremely close to the coils for maximum efficiency. Many people like to use a paper towel or newspapers to cover their glass/ceramic to make for even easier cleaning and to prevent scratches, and that will not materially affect cooking efficiency. However, anything thicker than several sheets of newspaper may noticeably degrade your cooking efficiency, and many induction cookers have safety shutoffs where the burner turns itself off if you lift the cooking vessel more than about a quarter inch above the glass/ceramic cooktop.
The silver lining to this proximity requirement: induction is safe for those with pacemakers at normal cooking distances, meaning, don’t put your heart directly above an induction cooker if you have a pacemaker. And induction cookers are typically built with safety sensors so that the cookers will not heat small objects like spoons, in addition to the safety shutoff as described above.
Those who are unsure about induction may want to visit a showroom or simply buy a small, cheap, portable induction cooktop and see how things go from there. You might find some used, or you can go with popular models like this: Max Burton 6200 Deluxe 1800-Watt Induction Cooktop. They are 1800W, which is roughly equivalent to a 13,000 Btu/h gas burner, which is on the high end of typical residential gas burners in the U.S.
Please note that cheap portable induction cookers usually produce lots of watts with small heating elements. This means a lot of heat gets concentrated near the middle of cookware bottoms, so cheap portable induction cookers are not appropriate for use with large-diameter cookware at full power. The larger the diameter of the cookware’s bottom, the more you want to stay away from using max power. Most portable cookers’ manuals will have recommendations. For instance, the Tru Eco manual recommends cookware no larger than 10 inches in diameter at the bottom, which I think is reasonable at 1300W.
Natural Gas (and Propane, Butane, etc.)
“Natural gas” is just another name for methane. Propane and butane are other common flammable gases used for cooking, but natural gas is more commonly piped to homes. They each have different heating values (amount of combustion heat per volume, holding temperature and pressure constant), but they all rely on the same principle that humans have used for thousands of years: control the amount of fuel being burned. More fuel means more fire. More fire means more heat. Place a cooking vessel above the fire to absorb the heat. In order to suspend cookware above fire, you can use a grate of heat-resistant material or a spit. (Since we are talking about indoors cooking, we usually mean a grate.)
One upside to gas is that it’s quick and responsive to fuel changes. Dialing the heat up or down means changing the temperature of the cookware within seconds.
Additionally, gas is unique in that flame heats the base of cookware directly, but hot gases billow out from underneath the base and also heat the sidewalls of cooking vessels. This can be a blessing when such an effect is desired and can help even out heating. In fact, multiple-ring gas burners can be extremely even-heating. The same effect can be a curse, such as when using a high flame with cookware that has thin steel sidewalls. In such cases, the hot gases rolling up over the thin steel sidewalls may overwhelm the ability of steel to disperse heat, resulting in sidewalls that are much hotter than the base of the cookware (which presumably has a thick layer of heat-conductive material to absorb heat and prevent hotspots). To avoid this scorched-ring effect, turn down the heat. If you can’t turn down the heat for some reason, then consider buying cookware with heat-conductive sidewalls such as thick aluminum, copper, or cladded designs with inner cores of aluminum and/or copper. Also consider buying disc-base designs where the disc goes all the way to the edges without tapering off, such as Demeyere Atlantis. As a last resort, you could also use a large flame tamer to blunt the flames by turning your gas burner into an electric hotplate. But the cheapest solution is to simply turn down the heat so you don’t get a scorched-ring effect. This also retains the responsiveness of gas.
Some people like how you can still cook on gas if the power goes out. This is an important advantage in some places where the power is unreliable or if the power may stay off for quite some time. However, don’t lose hope if you have an electric range (coil, induction, halogen, or radiant)! You can buy an inexpensive butane burner such as the Iwatani Corporation of America ZA-3HP Portable Butane Stove referenced above as a backup burner for power outages. You may also use it on camping trips to boot. Even cheaper butane burners exist, if you are willing to tolerate lower maximum heat and and a less-flat heat output profile over the life of a butane canister.
Also, curvy cookware like woks do not work well with flat heating surfaces. In that case, if you do not have a gas range, you can either buy an expensive curved induction cooker specifically for woks, or you could buy a portable butane burner (see above, and note that Iwatani produces a 15,000 Btu/h that should be more than enough for the occasional need for gas. (The regular version is 12,000 Btu/h which is already plenty powerful.)
The converse is also true, to some extent. A natural gas range may be supplemented with a portable, countertop induction cooker to handle boiling, steaming, and other such energy-intense tasks. The induction cooker will waste less heat (thereby heating your kitchen up less) and potentially save you money in direct energy costs as well. (See above in Induction for further comments about cheap, portable induction cookers.)
Electric coil/halogen/radiant is about 73.7-77.7% efficient. In all three cases, you must have metal-to-cookware contact to get thermal conductivity. If your cookware is not flat or has scratches, that means air pockets, and air is a horrible heat conductor that reduces efficiency. DOE estimates for electric coil cooktops that the cooking efficiency is 73.7%. Using reflective drip pans to reflect infrared radiation back up into the cookware results in an efficiency increase of ~1% for a total efficiency of 74.4%. So don’t bother cleaning your drip pans too often, unless it’s for other reasons like looks or hygiene. On the other hand, flatter heating elements help to improve contact between cookware and heating element and therefore boost efficiency to 76.9%. Combining reflective drip pans and improved contact conductance results in an efficiency of 77.7%. However, DOE cautions that the actual efficiency is probably less than that, because their test block of aluminum is extremely flat (flatter that most cookware), so it’s unlikely that flatter heating elements will do much for most cookware: “Because of the block’s very flat surface, test efficiencies will be higher than those obtained from field measurements using “real” cooking vessels. Increases in efficiency that can be obtained by improving the contact conductance under DOE test conditions will not be realized under field conditions.” Radiant and halogen are come in at 71.5% and 75.3% efficient in the DOE report, respectively. They both use smoothtops so they already have very flat heating surfaces for thermal conduction.
Induction is about 80% efficient.5 The actual efficiency of induction can vary depending on the exact cooktop and cookware in question.
DOE found natural gas cooktops to have 39.9% cooking efficiency, assuming 9000 Btu/h burners and pilot lights. Going to thermostatically controlled burners and electronic ignition (instead of pilot lights) does nothing to help cooking efficiency, though it saves money over the course of the year because no gas is being burned in the pilot light. Going to sealed burners does increase efficiency to 42.0%. DOE found that using reflective drip pans increased efficiency by ~0.1%, so do not worry too much about reflective drip pans. Apparently natural gas produces less infrared radiation to reflect than electric coils.
SPEED AND RESPONSIVENESS
Most cookware can’t handle very high heat as they are nowhere near as “even heating” as you hear cookware manufacturers claim. Some cookware can’t even heat evenly on medium heat. So you should generally heat or pre-heat your cookware on medium heat or lower. That said, there are times when you want maximum heat/speed, most commonly for when you want to boil water or generate steam. In general, induction is fastest, followed by gas, followed by electric coil/halogen/radiant, as we’ll see below.
Electric Coil/Halogen/Radiant – On the low end you will find 2,100 watt burners; on the high end, 3,000 watts. Electric coils vary in efficiency (see above), but we’ll assume 75% efficiency on average. So that 2,100 watt burner is really only delivering 1575 Joules/second–eventually. (1 Watt = 1 Joule/second.) A 3,000 watt electric coil/halogen/radiant burner will deliver about 2250 Joules/second–eventually.
What do I mean by eventually? Except perhaps for halogen, heating elements take a long time to heat up and cool down, which means they are less responsive and more prone to overshoot. When you first turn on an electric coil burner to max, the energy warms up the heating coil, which absorbs a lot of heat. Your cookware sitting on the coil will get some heat as well, but it won’t be getting anywhere near the rated wattage even factoring in efficiency losses. Only after an electric coil element gets hot does it deliver all the energy its supposed to be delivering (again, factoring in efficiency losses). Similarly, if you shut down an electric coil element that has been on for a while, the residual heat in the coils will continue to heat your cookware for a long time–even half a minute or more if it was on high and glowing red.
Induction – Even low-end induction ranges produce 3,400 watts with their largest burners. High-end units? 3,700 watts. Assuming 84% efficiency, a 3,000 watt induction burner delivers 2520 Joules/second, and a portable 1800W induction burner delivers 1512 Joules/second. A 3,700 watt induction burner will deliver 3108 Joules/second, higher than most gas or electric coil/halogen/radiant burners.
There is no warm-up time for induction because the cookware itself is being heated; you get all of those Joules immediately when you turn on an induction burner at maximum power. When you turn down the power, you get immediate response as well, except for situations where you heated the cookware for so hot and long that the glass/ceramic itself is higher than the temperature you subsequently want the cookware.
Natural Gas – The Btu rating is for gas burners is British Thermal Units per hour. A low-end gas range’s largest burner will be around 9,100 Btu/h; a high-end gas range’s largest burner will be around 20,000 Btu/h. A typical residential gas range is somewhere in the middle, at about 12,000 Btu/h.6 Unfortunately, natural gas burners are only about 39.9-42% efficient depending on whether they are sealed or not, with sealed burners having 42% efficiency and unsealed 39.9% (let’s say that overall, gas ranges have 41% efficiency for sake of argument). The rest of the energy doesn’t heat cookware but instead goes into heating the air in the kitchen or is seen as visible light. So that 9,000 Btu/h burner is really only delivering 9,000 x 0.29307107 x 0.41 = about 1,081 Joules/second of heating power to your cookware. Similarly, a 20,000 Btu/h burner only delivers 2,403 Joules/second.
Most natural gas burners have small grates which absorb some amount of energy before rising to such a high temperature that they no longer impede heat delivery. Similarly, once you turn off a gas stove, the temperature drops after only a few seconds, during which time the grate cools down (by injecting heat into your cookware) and hot gases disperse.
In general, fast heating is more important than fast cooling, because you can always take a hot pan off the stove and put it onto a cool surface, such as an unused burner.
Induction wins by a mile, followed by electric halogen smoothtops, electric radiant smoothtops and electric coil, and gas.
Since induction heats the cooking vessel directly, the glass/ceramic top never gets hotter than the cookware. Furthermore, glass/ceramic is a poor thermal conductor and takes a while to heat up, so for short cooking sessions it may not even reach the temperature of the cooking vessel. On the downside, glass/ceramic also takes a while to cool down as well, by radiating heat and by thermal convection via air. Most induction cookers have fans that assist in cooling the electronics beneath the smoothtop, which may also help cool down the smoothtop from the other side. Lastly, if a pot gets knocked off an induction burner, most if not all cookers will automatically shut down that burner since no cooking vessel is detected. Induction does have one weird weakness, though, which is situations where someone with a pacemaker leans over the burner so closely that it impacts the pacemaker. For normal cooking distances, though, that should not be an issue.
Electric halogen smoothtops should theoretically be relatively safe as well, especially if their heating elements do not get as hot as the cookware and cool down quickly. Unfortunately data is scant on that front.
Electric radiant heating elements do get hotter than the cooking vessel, also heating up the glass/ceramic smoothtop more, so the higher temperatures present more of a hazard. They also cool down to safe temperatures more slowly than induction because the smoothtop is heated to a higher temperature in order to transfer heat to the cookware. Electric coil heating elements have the same problem as electric radiant, though in theory they should cool down faster since there is no heat-retaining glass/ceramic in the way. However, the coils are exposed and can burn the unwary.
Gas produces open flames which may burn the unwary. On the plus side, most creatures, including pets, know better than to touch objects that emit heat and light. A bigger concern is gas leaks and what happens if a child or pet accidentally or intentionally turns on the fuel supply without igniting it. Methane is naturally odor-free, so utilities typically add odorant so that one can smell a gas leak and take appropriate action. But that requires a human to smell that odorant and turn off the fuel supply. The incidence of gas-related home explosions is low, so I don’t want to scare anyone, but on a relative basis it is hard to argue that gas is not the least-safe among safe choices.
If you are counting long-term/chronic risks, natural gas has additional risks because natural gas contains traces of impurities and may also burn incompletely (that is, produce something other than water and carbon dioxide, both of which are harmless in the quantities typically found in kitchens). Some of these non-H2O/CO2 products may be carcinogenic or have other negative effects (e.g., incompletely-burning gas can produce carbon monoxide instead of carbon dioxide; breathing in lots of carbon monoxide can lead to suffocation), so always turn on your range hood to ventilate. If you do not have a range hood, crack open a window and let the gases escape that way. Note also that heated food itself can emit things that may not be that great to breathe in, so you should turn on your range hood even if you are using induction or some other electric option.
Electric coil burners are cheap and have nasty negatives, but durability is not one of them. They are simple and effective; very little can break. If your electric coil burner breaks, it may be due to a manufacturing defect such as wires not touching properly.
In the case of electric halogen and radiant burners, glass/ceramic smoothtops may chip or shatter, especially if you bang on them hard enough or expose them to massive thermal shock, such as boiling water on them and then dumping a bunch of dry ice on them. This is a problem for any smoothtop cooktop. Solution: don’t abuse your cooktop!
Natural gas burners are durable and need little maintenance, though burners may become clogged and ignition devices may fail (pilot light or electric). Avoid spilling any food or liquid onto the burner (obviously). Try to avoid aluminum burners if possible. Brass resists high heat better without melting or deforming. Both are decently corrosion-resistant. Stainless steel is perhaps the best material: resists high heat, easy to clean, and corrosion-resistant. It also costs the most, unfortunately.
Induction is new-ish to North America, but it’s popular in Europe and Asia, where energy costs are higher and thus fuel costs matter more. I have had some trouble finding data on durability written in English, though what I have found implies that induction may be as reliable as other cooktops, especially for newer units.7 I’m also going to assume that if induction were unreliable, it would not be so popular in Europe and Asia. Induction suffers from smoothtop breakage issues like electric halogen/radiant, though perhaps less so because the temperatures are likely to be lower because the cookware is being heated directly, rather than heating something above the temperature of the cookware and then having that hot material heat the cookware. Cooktek has an amusing video where they drop a 10-pound (4.55 kg) bowling ball onto their portable stockpot induction cooker from higher and higher distances until it finally breaks (I’m guessing that the final drop was about 4 feet, or 1.22 meters):
ACCURACY AND REPEATABILITY
Induction is digital and in theory should be repeatable every single time. So if you find that setting X for Y minutes lets you cook Z perfectly, you can just memorize that formula and get the same results each time. However, note that cheap induction cookers with only 10 heat settings or fewer may present difficulties in simmering, as even the lowest setting may be too high. Thankfully most induction ranges, and even some portable induction cookers, come with 20 or more settings that allow for finer control. If you need more than 20 settings, look into getting the Vollrath 59500P Mirage Pro Countertop Induction Range, 14-Inch which has 100 settings.
Other electric may have digital controls, but most cheap ones have analog controls that prevent exact repeatability. On the plus side, analog means you have no gaps between power settings. However, due to thermal inertia, non-induction electric may over- or under-shoot your target temperature unless there are sophisticated electronics that try to “coast” their way to the proper temperature.
What I mean by thermal inertia: since electric coils must be heated to a higher temperature than whatever you are heating in order to transfer heat, this means that if you cut off power to the coil when the vessel you’re heating reaches x degrees Celsius, the coil will continue to inject heat into that vessel and thus raise the temperature above x degrees Celsius. Overshoot may last several seconds and several degrees. That’s probably not enough to ruin most foods, but such overshoot can ruin delicate foods like confections and sauces. Advanced electric coil/radiant cooktops may come with electronics that try to cut off power before your object reaches x degrees Celsius, in order to avoid overshooting your temperature preset. A low-tech, alternative solution is to lift the object off the coil when the object reaches x degrees Celsius, and setting it on an unused coil that is at room temperature. Natural gas stoves have much faster responsiveness–when the flame goes off, the heat almost immediately starts to plummet in the vessel you are heating as the hot gases dissipate and the hob cools down. Induction is even faster, since the cooking vessel itself is the heat source; when you turn the power off, the cooking vessel immediately starts to cool down.
Natural gas can be digital in theory, but in practice I have only ever seen analog controls. This makes it harder to repeat the exact same heat level each time but also means you have no gaps between power settings. Furthermore, some gas burners can not easily simmer because the flame goes out when the fuel supply goes too low. This can be fixed using a small plate of cast iron such as this Ilsa Cast Iron Heat Diffuser, but then you are basically turning your natural gas burner into a solid electric burner instead, with the lack of responsiveness that entails.
Non-smoothtop cooktops require more maintenance, whether it is cleaning drip trays or wiping off burned food stuck onto the areas adjacent to the heating elements. Anyone who has burned things onto drip trays knows how difficult it can be to scrub off carbonized food. Some people resort to using oven cleaners or replacing the trays periodically with new ones. I simply switched to induction smoothtops.
Anyone with a smoothtop already knows how much easier it is to clean than enamel or metal. This is somewhat less-true for electric halogen/radiant because those two still heat up the glass/ceramic so much that food can get burned onto the glass/ceramic. But induction smoothtops are a breeze to clean, because only the area directly beneath the cookware gets really hot. This is because the cookware’s bottom is the heating element, and it takes a long time to heat up glass/ceramic; in contrast, electric halogen/radiant burners heat the glass/ceramic to a temperature greater than what you want your pot to be. For instance, if you are boiling water on induction, the glass/ceramic will never be hotter than 212F/100C at sea level at room temperature. In fact, the glass/ceramic will take a long time to get anywhere near 212F/100C. But for electric halogen/radiant, the glass/ceramic has to be GREATER than 212F/100C in order to transfer enough heat to make your cookware hot enough to boil water. In fact, the temperatures are usually MUCH greater, to ensure that more than a dribble of energy makes it through to the cookware.
Induction also has a secret weapon for easy cleanup beyond the smoothtop surface: you can make a cover of rags/newspaper/paper towel/etc. and place it on the smoothtop. (I prefer uncolored, unscented paper towels because I don’t want to breathe vaporized ink.) Despite the popular book Fahrenheit 451, there are many kinds of paper, and paper does not necessarily ignite at 451F; in fact, some brands of parchment paper are rated to to last for hours at 450F in ovens. In my experience, high-heat searing will brown a paper towel a bit, but you can simply replace the paper towel. (I haven’t tried a real towel, but presumably a damp towel can take even more heat. Just be careful to use a thin enough towel that you still get most of the power, because the magnetic field diminishes extremely rapidly. Anything more than a few millimeters is asking for trouble.) Anything less than about 400F will not char the brand of paper towels I use (Costco Kirkland, but there is nothing special about them), so you could use the same paper to to fry eggs or saute vegetables for days or weeks without a problem. Here’s a video describing what I’m talking about (starting at 1:40):
KITCHEN ENVIRONMENT COSTS
In theory, induction is the most efficient method of heating up just your cookware and the food in it, though in practice it’s merely on par with electric coil. Electric coil/halogen/radiant varies but is around 75%. Natural gas is about 41% efficient. All that waste heat has to go somewhere. If you have a good ventilation system, this is not as big of an issue, but those with poor ventilation are going to suffer hotter kitchens and the higher air conditioning bills that may result. Some people might argue that waste heat is not really wasted in cold wintertimes, but the point is, you do not get a choice with non-induction: you must take the heat whether you want it or not. It’s better if you have the option of heating your home or not, e.g., if you have an induction cooker and also a dedicated heating system or space heater if you really want that heat. Options are good. If you have no dedicated heating system or space heater, consider boiling water on your stove. It’s not necessarily that efficient, but it does circulate hot, moist air around the home.
GLOBAL ENVIRONMENT AND LIFE CYCLE COST
This is a tough one. I don’t know if there is a clear answer to this. Let’s start with global environmental costs first.
Global Environmental Costs
Environmentally, initial construction probably favors simple electric coils and natural gas ranges. Electric coils of NiChrome are relatively cheap, which is part of why they are ubiquitous. Natural gas ranges aren’t complicated, either; they basically need to channel gas around without melting. Other electric requires smoothtops, which cost extra environmentally. Induction uses rare earth minerals that we import from China, at some environmental cost as well.
Considering only environmental operating costs, natural gas and electricity don’t come for free. There is some environmental cost of drilling and fracking (for natural gas). Natural gas has gotten lots of bad publicity from fracking, much of it unwarranted but some of it warranted. Similarly, electricity is often produced by burning coal, natural gas, or oil. Even when it’s not, about a fifth of US electricity comes from nuclear fission power plants with (literally) tons of radioactive waste awaiting long-term disposal in a radioactive garbage dump that we still don’t have. (In the interim, the spent fuel rods are often stored on-site at the nuclear power plants.) Fission nuclear power also emits lots of carbon dioxide, contrary to popular belief, due to the huge amounts of concrete and metal used in plant construction, energy-intensive mining of uranium ore, and security, transportation, and disposal costs, plus clean-up costs for uranium mill tailings. Much of the rest of US electrical power comes from hydroelectric power, which has its own environmental issues with dams and affecting fish spawning and such. That leaves geothermal, solar, wind, and ocean power, all of which have their own issues (e.g., requiring rare earth minerals, disrupting desert habitats, etc.) but which are arguably the least-damaging sources of electricity.
Complicating issues is how electricity is often produced far away from urban centers, meaning it must be transported via transmission and distribution wires, with 7 percent of the energy wasted in the process on average. For instance, a state-of-the-art combined-cycle natural gas power plant may burn natural gas, converting ~55% of the energy into electricity, which is transmitted to your electric range with seven percent in line losses, for 51.15% efficiency up to that point. Depending on whether you use electric coil/halogen/radiant or induction, your overall efficiency is about 38% (eletric coil, halogen, radiant) to 46% (induction).
Compare this to natural gas that is produced and sent over natural gas pipelines to your home: line losses are only a few percent, even including the cost of powering compressor stations that push the gas to you. But then you get just 42% efficiency at the burner tip, for an overall efficiency of ~40%. This is comparable to the overall efficiency in the natural gas power plant scenario above for electric coil/halogen/radiant.
Personal Health Costs
Even if you do not care about the environment, there are possible human costs as well from the kitchen environment factors (above). I have not seen DOE do a study on how many deaths, injuries, cancers, etc. are caused by poor ventilation combined with natural gas combustion products (nitrogen dioxide, carbon monoxide, etc.), for instance. Ditto for studies on what effect the production/mining/refining of various metals has. On the plus side, waste heat is unlikely to kill you or cause cancer.
Utility Bill Costs
The answer to the question of what cooking method is most energy-efficient from an utility bill perspective is not as important as other questions, because cooking accounts for only 4% of American home energy consumption according to a US Department of Energy’s 2010 report.8 Besides, that question way too complicated to answer. I know some journalists attempt to make sweeping generalizations, but it really depends a lot on how much electricity and natural gas (or propane or butane or whatever you use as cooking fuel) costs in your service area, whether you have tiered rate structures in your utility bill or not, and what your current load is. Furthermore, appliances are supposed to last for a long time, and the relative costs of electricity and natural gas today may change–actually, they WILL change–over the years.
I’ll give you a real-life example:
Recently a friend bought a house and asked me if I recommended a gas or electric dryer, which are comparably energy-efficient. He already had a gas line hookup so that was not an issue. His local utility is PG&E, which has tiered rates as an energy-conservation incentive, meaning that he pays about $0.13/kWh for the first few hundred kilowatt-hours (the baseline varies depending on time of year and region), then $0.15/kWh for the next chunk of kilowatt-hours, leaping up to almost 32 cents/kWh on Tier 3, and 36 cents/kWh beyond that. (You can see PG&E tiered rates for 2013 here. Although not every PG&E residence is on E-1 tariff rates, most are. Some residences use less-common rates like Time of Use rates, but we’re getting into too much detail here, so I’ll stop.) Based on his historical energy usage, I knew he used enough electricity to push him into Tier 3. Thus if he bought an electric dryer, each time he used it, it would cost him 32 cents/kWh.
In contrast, PG&E residential gas service is only slightly tiered, without the huge leap from 15 cents/kWh to 32 cents/kWh, so he would likely pay about a buck per therm, or the equivalent of about 3.5 cents/kWh. So an electric dryer (32 cents/kWh) would cost my friend an order of magnitude more to run than a natural gas dryer. Even if he somehow managed to use less energy (buy more energy-efficient appliances, conserve energy, etc.), PG&E’s Tier 2 electric rate is 15 cents/kWh which is still much, much higher than 3.5 cents/kWh.
It was a no-brainer for me to recommended the gas dryer for fuel cost reasons alone. Furthermore, I thought it would be wise for him to reserve a little electric capacity in case he decides to get a more powerful air conditioner or something. I have no idea what his house’s maximum electrical load is, but as we as a society rely more and more on electricity-eating devices, it seems prudent to leave a some capacity in reserve, just in case.
This one example should give you some idea of why it’s hard to make a blanket statement like “induction costs less to operate.” You may or may not live in PG&E’s service territory, with the same baseline or not, with tiered rates or not, with comparable natural gas rates or not, etc.
In any case, I would not worry too much about cooking impacts on utility bills, given that cooking is a minor energy user in the home (see above). You are better off worrying about buying a more-efficient refrigerator or upgrading your insulation instead. If we were to discuss cooktop operation costs, then we might as well include other small costs like the cost of replacing drip pans, or the time/effort/money cost of cleaning drip pans vs. wiping off smoothtops, because that is the level of cost difference we’re talking about here. (By the way, I am ignoring ovens for the time being, but ovens vary greatly in efficiency and cost as well, so if you are in the market for a range, you may want to consider oven-related variables like cubic foot capacity, rackspace, etc. Oven cooking is much less energy-efficient than stovetop cooking, but they will give you steady, even heating.)
Upfront and Installation Costs
Finally an easy topic! Low-end electric coil and gas ranges tend to be cheapest (~$360 including the oven). Low-end electric radiant costs a lot more ($2,000+). Low-end induction ranges go for as low as $1400 including oven. Halogen electric is rare and I do not see it sold often, making it hard to estimate cost. If you want high-end, though, prices are all over the place. You can have crazy situations like electric radiant ranges costing $2,880 and being outperformed by induction and gas ranges costing half that or less.
Of course, if you do not have a natural gas pipeline hookup and proper ventilation, you may have to add several thousand dollars to the upfront cost–perhaps more. If you do not have the amperage for high-end electric, you may have to pay thousands for that.
Summary of Life Cycle Costs
I think it’s safe to say that there is no definite answer for which technology gives the best life-cycle costs, including or even excluding environmental costs. About the only thing for sure is that a natural gas range that uses pilot lights is wasteful, because pilot lights consume almost as much gas as cooking, over the course of a year. Put another way, pilot-light gas stoves use almost twice as much gas over the course of a year as electric-ignition gas stoves.
Electric coil is pretty quiet. Assuming quiet cooling fans or no fans, electric halogen/radiant should be quiet as well. Induction would be as quiet if it weren’t for the “induction buzz” that results from heating metal via induction coils throwing off magnetic fields at high frequency. Still, that buzz should be drowned out by your ventilation fan. Natural gas can be pretty quiet as well; you can hear the roar of the flame at high settings on high-end gas ranges, but your equally-high-end ventilation system should drown out much of that roar.
By the way, for those who are curious what a full-scale induction cooktop sounds like, start this video at about 3:42:
COMPATIBILITY WITH COOKING VESSELS AND COOKING STYLES
The most flexible heat source is gas. A flame not only heats where the flame hits, but hot gases (chiefly water vapor and CO2) also roll up from beneath the cookware, up the sides of the cookware, heating from the sides as well. This makes gas ideal for things like stir-frying with woks, or for warped (bent) cookware that would not stay flat for smoothtops and would not make good contact with electric coil heating elements. Gas is compatible with all cookware materials. And a natural gas range does not shut itself off if cookware is lifted up. For those who like to “jump” their food, this is important.
If there is a downside to gas, it’s with disc-based cookware. Hot gases that roll up from the bottom of the cookware may be fine or even desirable for things like woks and cookware with thick sidewalls, but cookware with thin sidewalls may get burned rings. This is when too much heat enters from the sides, scorching a ring around the perimeter of the pan. I’ve seen this happen with my parents’ stainless steel pan with a bonded aluminum disc bottom, even though they try to keep the flame from getting too high.
The next-most flexible option is some form of electric coil, halogen, or radiant. The large thermal inertia of the heating element means they take a while to heat up and to cool down, which is not ideal when you want to boil water quickly, preheat a pan, or rescue food that is starting to overcook, but electric coil/halogen/radiant works with all cookware materials and does not have a scorched-ring problem, either.
Induction is perhaps the most demanding heating method: virtually all residential induction cookers are restricted to cast iron, carbon steel, and magnetic stainless steel. On the other hand, most stainless steel made in Europe and Asia today are induction-compatible, including most stainless steel cookware sold in the USA. Furthermore, a thin layer of magnetic stainless steel attached to aluminum or copper can make the entire cooking vessel induction-compatible. Some older and cheaper models of induction cookers turn themselves off right after lifting a pan from the cooker, but more advanced cookers give you a grace period of a few seconds before auto-shutoff. Induction’s lightning-speed responsiveness and high power output makes it ideal for quickly boiling water.
It is difficult to generalize because cooktops come in so many varieties, but in general, electric coil and electric radiant produce very even heat, not because they are so inherently even, but because they are so slow to heat up and cool down that it gives cookware a long time to spread heat around while they wait. (Solid metal disc hotplates are even slower to heat up and cool down; think of them as electric coils with the gaps between the coils filled in.) Electric halogen is faster but seems to have disappeared off the market; if you get one, try the circular-bulb variety which promises even heating without resorting to a perimeter coil. In any case, once electric coil/halogen/radiant has gotten up to temperature, it is less-even.
Midrange gas and induction cookers have one heating ring per burner. If the burner is turned on high, an “O” shaped ring of high temperatures may result, since the cookware can’t spread heat fast enough to prevent hotspots.
High-end gas works around this problem by having multiple rings: a little ring and a larger ring, producing a little “O” within a larger “O” that should help even out heat.9
Similarly but to a more extreme degree, the highest-end induction ranges do not have a few big induction coils, but dozens of little coils. The cooktop detects cookware and activates the little coils immediately below the cookware. This produces many little “O” rings of heat that should result in a bunch of little “O” shapes in the cookware and thus result in more even heating than having one big coil doing all the work. However, such high-end induction ranges are so expensive (over $5,000) that they are apparently out of production now.
- The Tatung Induction Cooker TICT-1500W, All Clad Electric Induction Burner, the Cooktek MC1800, the Duxtop 9100MC, the Vollrath Mirage Cadet, and the Vollrath Mirage Pro ↩
- TECHNICAL SUPPORT DOCUMENT FOR RESIDENTIAL COOKING PRODUCTS, VOLUME 2: POTENTIAL IMPACT OF ALTERNATIVE EFFICIENCY LEVELS FOR RESIDENTIAL COOKING PRODUCTS (Docket Number EE-RM-S-97-700) by Lawrence Berkeley National Laboratory, Environmental Energy Technologies Division Technology and Market Assessment Group, Accessed at http://www1.eere.energy.gov/buildings/appliance_standards/residential/pdfs/cookgtsd.pdf ↩
- Various studies have estimated efficiencies ranging from 80 to 84% depending on testing methodology. ↩
- http://en.wikipedia.org/wiki/Second_law_of_thermodynamics Statistically it is possible that heat flows from cold to hot, just like it is theoretically possible that all of the atoms in your body spontaneously decide to teleport to Mars and back, but the odds are essentially zero at kitchen-sized scales. The odds are still close to zero even at microscopic scales. ↩
- I’ve done my own test that shows that induction is not more efficient than electric coil, for boiling water, though induction might be more efficient for shorter cooking tasks. ↩
- On Amazon, as of 2015, the cheapest gas range produces 9,000 Btu/h. A typical gas cooktop or range produces more like 12,000 Btu/h. A high-end gas range might produce 20,000+ Btu/h. ↩
- See, e.g., http://news.google.com/newspapers?id=NYw1AAAAIBAJ&sjid=qggGAAAAIBAJ&pg=7164%2C6472771 (or http://articles.sun-sentinel.com/2006-04-07/lifestyle/0604050628_1_induction-cooktop-viking-induction-magnetic-cookware if that does not work) quoting two home appliance retailers stating that induction quality and reliability and technology have improved over time. See also http://www.usatoday.com/story/tech/2013/07/02/reviewed-induction-range-column/2480239/ and http://www.consumer.org.nz/reports/induction-cooktops/reliability (the link is now broken, but the report said that after 5 years, all types of cooktops including induction had comparable failure rates of ~10%). ↩
- http://energy.gov/energysaver/articles/tips-your-homes-energy-use citing the US DOE’s 2010 Buildings Energy Data Book, Table 2.1.1 Residential Primary Energy Consumption, by Year and Fuel Type ↩
- For example, General Electric produces gas ranges with “Tri-ring” burners with this feature. http://www.geappliances.com/appliances/range-stove/tri-ring-burner.htm ↩