Generally, most of the kettle companies paid scant regard to ethical issues, having very few ethical policies in most areas.
Most of the electric kettle companies did not have any kind of publicly available conflict minerals policy, and were therefore given a worst rating. The only exceptions were Russell Hobbs and Philips, which got a best, and Panasonic and Siemens, which got a middle.
Most companies had no mention at all of their use of toxic chemicals and so got a worst rating, apart from Groupe SEB (Tefal) and Philips which got a middle rating.
Of the 25 companies covered, only Philips scored a best rating with seven of them scoring a middle rating in this category, and the rest scoring worst mostly for having no mention of their environmental impact at all.
Supply Chain Management
The same is true of protecting workers’ rights in their supply chains. Most companies did not even mention workers’ rights. Only four of the companies did which is particularly disappointing in an industry where outsourcing of production to lower wage countries is endemic.
Hob kettles vs electric kettles
With an electric kettle, the element is immersed in the water so there’s very little heat loss. This is also the case with a hob kettle on an electric induction hob. Whereas with a kettle on the gas stove, energy is wasted heating up the body of the kettle and bits of the stove.
So, at the point of use, an electric kettle or electric hob kettle is more energy efficient than a gas hob kettle.
But that’s not the whole story. We also need to consider the efficiency of the energy supply process. Power stations are only about 30% efficient in converting primary fuels to electricity, whereas burning gas directly is 60% efficient. There are also energy losses from the electricity power lines during transmission.
However, with a gas hob kettle, the efficiency gains you get from burning natural gas directly are probably offset by the inefficiency of the flame on a gas hob.
An electric kettle or hob kettle still has the edge until you look at its carbon footprint. Electricity generates one and a half times more carbon dioxide than gas (see the cookers guide). Electricity is also more expensive than gas.
But, if you are using renewable energy that you have generated yourself at home then there will be no CO2 emissions or transmission losses from using an electric kettle. If you don’t generate your own electricity, you could at least (notionally) get rid of the CO2 emissions by choosing a green electricity supplier that sources 100% renewable energy.
It’s swings and roundabouts! Gas hob kettles have the edge in the end, but the savings are fairly minimal both in terms of price and CO2.
The downside to hob kettles is that they don’t turn themselves off, so you can overboil them, so always choose a hob kettle with a whistle. The worst thing is that they don’t usually have minimum-level, easy-to-use water gauges. Manufacturers of hob kettles need to take responsibility for this oversight and incorporate water level gauges to help consumers use less energy.
Energy use in electric kettles
Pretty much every household has a kettle, and kettles use a surprising amount of energy. The 2012 annual electricity consumption of kettles in the UK was roughly 34% of the total consumption attributed to cooking. This explains the well-known energy demand surges caused by putting the kettle on during the ad breaks of favourite TV shows.
But unfortunately, unlike the other guides in this magazine, there is a lack of any energy efficiency labelling for the kettle. The EU should extend labelling laws to cover all products that consume energy in use.
Since we last looked at kettles in 2010, a couple of insulated kettles have come onto the market which do reduce energy use. But generally, there has been slow technological progress in improving kettle efficiency relative to other domestic appliances. One of the main ways to increase energy efficiency of kettles is in the way that we use them, for example by not overfilling them. And to this end, manufacturers need to go some way in trying to help us out.
Saving energy with electric kettles
The number one way to improve the energy efficiency of kettles is to stop overfilling them. It is really important to only boil the amount of water you actually need. You can do that if a kettle has a minimum water fill level marked on it. But some kettles, especially kettles that are wider at the bottom, have a minimum fill level that is typically 500 ml, too much if you just want one cup. A mug is about 350 ml whilst a tea cup is about 250 ml, so look for ones with those levels as a minimum.
If there is no fill guide on the kettle, a glass one will at least allow you to see how much water you are boiling.
Unfortunately, hob kettles don’t tend to have easy to read water gauges on them – they usually just have a ‘max fill’ line on the inside.
Ideally, all manufacturers should only be making kettles with clear and low minimum fill gauges. Perhaps that should be a legal requirement?
Use variable temperature settings
You can also save energy by using a kettle that has variable temperature settings. Not all hot drinks need boiling water. Rather than wasting energy by boiling the water and waiting for it to cool down a little, you can use exactly the right amount of energy to get the temperature you want.
Tea experts suggest the following ideal temperatures for teas:
- white and green teas are best at 70°C,
- black and oolong teas need water around 85°C,
- herbal infusions need 100°C water.
According to Best Buy coffee company Cafédirect, for coffee, the ideal is between 92 and 96°C, never boiling.
Many of us put the kettle on to boil and then forget about it once it has switched itself off, meaning that we need to reheat the water, using even more energy. But if you use an insulated kettle it will take less energy to reboil the water, if you do need to.
Vektra receives an extra Product Sustainability mark because all of its kettles are insulated. Severin receives a half mark because it only makes one insulated model.
Insulated kettles are essentially thermos flasks and kettles combined. Vektra guarantees that the water will stay hot for up to 4 hours after it is first boiled. Testing has shown that after 2 hours the water is at 80°C, hot enough to brew a cup of tea, and after 4 hours will be at 68°C. Because less energy is lost through the body of the kettle, an insulated kettle also uses less energy to boil than a standard kettle.
The Vektra kettles have a maximum water level indicator on the inside of the body, not a minimum fill level, but it matters less if you overfill because you don’t need to reboil the water. The Severin has an outside water gauge with a 200 ml minimum fill level.
Both produce models with variable temperature control, which indicate the current water temperature as well as letting you set it for different types of tea or coffee.
Where to buy our recommended brands
Prices range from £60-£100 for a Vektra kettle. The Vektra 4 (£100) has variable temperature control. They are available online from Vektra or Ethical Superstore website
Other recommended brand Severin has a kettle that costs £58 and can be purchased from the Ethical Superstore website
There isn’t really an option for boiling water without a kettle. Saucepans, even with lids on and a flame that fits the pan, are less efficient than a purpose-made, hob kettle. 
What about using a microwave? According to Tom Williams, a researcher at the National Renewable Energy Lab, a microwave is less efficient than an electric kettle or electric hob kettle. Most of the energy is lost in the process of converting electricity to microwaves.
Metal, glass or plastic?
Even if a plastic kettle is Bisphenol A (BPA) free, user forums complain that there is initially a taste of plastic in the water with a new plastic kettle. Plus, it’s probably best to avoid putting more unrecycled plastic into the environment so opt for a stainless steel or glass one which can be recycled.
Boiling water taps
As the name suggests, boiling water taps provide instant hot water without the need to switch on the kettle or boil a pan on the hob. A boiling water tap needs to be plumbed in alongside or instead of your standard kitchen sink taps so there is a cost attached to that of a couple of hundred pounds at least, plus the cost of a plumber. They are plumbed into a separate water tank heated by electricity.
Manufacturers claim that boiling water taps use much less energy and water than a kettle and therefore cost less to run. They provide hot water much more quickly and easily than a kettle and make it much easier to add just the amount of water you need.
But Andy Smale, technical director at Expert Energy, a group of independent energy consultants, calculated that the difference in energy and cost savings were in fact minimal and any financial savings are not enough to recoup the initial costs. Plus, you could start using boiling water for unnecessary purposes therefore increasing your environmental and financial costs.