Skip to content

Are Microwaves More Energy Efficient Than Ovens In 2022? [Find Out All]

microwave energy efficiency

Are microwaves energy efficient? Should you be using your microwave more or less often if you’re looking to save energy? 

With energy prices going up all the time, these are a few questions I’ve been considering recently.

A microwave is a daily appliance for most households. We use ours regularly. Whether it’s reheating leftovers, warming up my morning oats or defrosting something I’ve forgotten to take out of the freezer. 

Microwaves are a versatile and handy kitchen appliance, but how do they fare when it comes to sustainability and energy use? Are microwaves energy efficient or should you use your oven more often?

Are microwaves more energy efficient than ovens?

Here’s the short answer:

Overall, microwaves are more energy efficient than ovens. They use energy more efficiently because microwaves heat food directly, are on for a short time and have a lower power supply than ovens.

It’s thought that a microwave has an energy transfer rate of 30-40% whereas an oven stove is only working on 12-14% efficiency.

I must admit, these findings surprised me a little bit.

If you want to learn more about microwave efficiency, how they use energy and how to use them in the most sustainable and responsible manner for your bills, keep on reading.

How do microwaves work?

First things first, let me break down how microwaves work and how much energy they use.

Microwaves cook food through radiation heating. This uses the power of tiny radio waves to heat up food by making each molecule vibrate and warm up.

These waves are produced by an electron tube (called magnetron) and reflected within the microwave chamber. This allows them to be absorbed by the food molecules, generating constant heat.

Fun fact: it’s because of the way this radiation affects molecules that some items, such metals, certain plastics and other items, are not microwave safe. 

As this technology relies only on electricity and heats food so efficiently, it doesn’t come as a surprise that many consider microwaves the ultimate time-saving and money-saving appliance!

Oven vs microwave energy consumption

But just how much energy can you save by using your microwave more?

Generally speaking, reheating or cooking with a microwave can save up a whopping 80% of the energy you would use with a conventional oven.

This is due to how the appliance distributes heat. 

Rather than heating up the inside of the chamber like an oven would, generating heat from underneath and dispersing much of the energy used, microwaves essentially cook food from the inside out. This results in a quicker and more efficient cooking method.

This is also the reason why, sometimes, food cooked in a microwave ends up colder in some spots. The heat distribution might be inconsistent if your food is packed onto the plate too tightly, which is one of the most frustrating things about working with a microwave!

On the other hand, ovens are notorious for being one of the most inefficient appliances to use, mostly due to their size and lack of insulation. 

How much energy does a microwave vs oven use?

An electric oven would usually use around 2000 watts per hour.

An electric oven with a fan is more efficient as the fan distributes the heat more evenly, a bit like a stove top fan does for a log burner. 

A microwave uses around 600-1200 watts (0.6kW – 1.2kW) per hour.

As you’re unlikely to be using a microwave for more than 15 minutes at a time, this is definitely the winning appliance when it comes to saving energy.

Compare this to other kitchen appliances such as an energy efficient kettle, which are powered between 2200-3000W but only used for a couple of minutes, or an efficient slow cooker with a wattage of just 200W!

At the other end of the spectrum, we have energy hungry tumble dryers which can eat up 5kW in one cycle!

Is cooking with a microwave always the most efficient option?

Still, this is not the end of the story.

According to the research we have, the amount of energy you will save largely depends on what you’re using the appliance for. Different foods and cooking methods will change the energy output of your microwave and its saving potential!

For example, a 2006 study found that cooking potatoes in a little water can save as much as 70-75% energy compared to an electric hob. However, there was little difference when heating up canned foods like baked beans.

On top of that, while both defrosting and reheating come with considerable energy-saving perks, cooking from scratch with a microwave might not necessarily be the most efficient option.

This is also the case for boiling water or other liquids, as experts agree that using a kettle is still the most energy-efficient method for boiling water. 

When we put all this data together, we can see how using a microwave might not be the be-all-and-end-all of energy-saving cooking.

It’s estimated that only 20% of everyday cooking tasks can be performed with a microwave, so it’s always better to pair microwave reheating and defrosting with other energy-saving appliances like slow cookers!

Oven vs microwave running costs

We’re facing a major energy crisis. More families than ever, including mine, are taking a closer look at their running costs to try to lower their energy bills. 

Well, here’s some good news: Not only are microwaves energy efficient, but also they’re also a whole lot cheaper to use than ovens!

Running a conventional fan oven costs an average of 45p per hour, while microwaves come in at around 32p per hour.

As you won’t be using your microwave an hour at a time, you can cut this cost to around 8p per 15 minutes.

If you have your microwave on for 5 minutes, it will cost you around 3p. 

This means that using your microwave for baking potatoes, cooking porridge, reheating leftovers and fixing up ready meals will save you plenty of money.

So, are microwaves eco friendly?

Generally speaking, microwaves are an eco friendly appliance. 

I think they’re a good energy efficient choice for a few reasons:

  • Short time on – they’re only in use for a few minutes at a time
  • No warming up – they reach temperature almost instantly
  • Less energy demanding – generally powered under 1500 watts
  • Efficient heating – heat the food itself, rather than the air around it

However, one thing people don’t think about when considering microwave sustainability is how they are disposed of. This is probably fair enough as microwaves can last many years, into decades really.

Electrical waste is one of the leading waste streams in Europe and a major cause of environmental pollution. Microwaves, like other electronic appliances, can leach toxic chemicals into the soil if they’re not recycled and dumped in the landfill instead.

Luckily, all you have to do is head over to your local Recycling Centre to dispose of your microwave responsibly!

Wrapping up: Microwave vs oven

Microwaves are more energy efficient than ovens, but they’re not a perfect solution.

Microwaves run on electricity, which is great. However, the majority of our electricity is still being powered by fossil fuels, which isn’t great. 

On top of that, their purpose is quite limited compared to what you can do with a stove or oven.

But if you make sure to use a microwave for all the small tasks it can perform more sustainably, you will end up saving plenty of energy and money.

Much like boiling water taps and slow cookers, swapping oven cooking for microwave cooking is an easy way to make your kitchen greener — as long as you don’t use them more than you really need!

Sign up to the Eco Life newsletter to get a monthly email about new content on the blog.

Don't miss out!
Join The Eco Life Newsletter!
Invalid email address
Give it a try. You can unsubscribe at any time. Check out the privacy policy.
Never spam. Always education.

If you liked that, read these blogs too…

Ben & Murphy Peaks Mam Tor

Ben is the Creator and Editor of Tiny Eco Home Life. I write and publish information about more sustainable, environmentally friendly living in and around the home.

Alongside this website, I love spending time in the natural world, living a simple life and spending time with my young family (Murphy the dog!) I round up my thoughts and recent blogs on the Eco Life Newsletter.