Calculating the energy efficiency of different cooking modes is complex, as it is influenced by many different factors. A study in the scientific journal Food Policy has noted that it is important to consider energy conversion when calculating efficiency. Converting coal-powered energy into electricity, for example, is stated to be less energy efficient than converting energy produced from the combustion of natural gas.
- Ben Morelli summarises the findings of the Food Policy study in the Yale Environment Review, suggesting that – generally – the most energy efficient means of cooking on the stove is by cooking on an electric induction stove (using electricity derived from natural gas). Induction hobs are therefore also cheaper - Uswich state that they use 57% less energy than gas hobs in generating heat energy.
- Fan ovens are more environmentally friendly than conventional ovens, because they allow heat to circulate more easily, speeding cooking times.
- In terms of using other appliances, generally modern devices such as rice cookers are more energy efficient than using an oven/stove. Pressure cookers save time and energy by cooking food at very high temperatures. Uswich states that slow cookers are similarly energy efficient, using just a little more energy than a traditional lightbulb.
- According to the Food Policy study, microwaves tend to be more energy efficient than using an oven/stove, but only when used to heat small amounts of food for a short period.
New, increasingly energy efficient appliances are always being developed. See, for instance, how the Welsh company Clyne Energy have designed a ‘LoCooker’ heater that uses steam to minimise energy loss.
In terms of developing countries, a study by Sunil Malla and Govinda R. Timilsina cited these energy conversion ranges for different modes of cooking:
| Fuel source | Conversion efficiency range (%) |
| Traditional stoves (open fire or mud) | Fuel wood | 13-18 |
| Crop residue (eg. straw, leaves) | 9-12 |
| Dung | 12 |
| Charcoal | 10-22 |
| Improved biomass stoves | Fuel wood | 23-40 |
| Crop residue | 15-19 |
| Charcoal | 20-35 |
| Biogas | 50-65 |
| Advanced stoves | Coal (inc coal gas) | 7-47 |
| Kerosene | 35-55 |
| Liquefied Petroleum Gas (LPG) | 42-70 |
| Natural Gas | 54-60 |
| Electricity | 75 |
(data copied from Table 1 in section 3.2 of Malla and Timilsina study)
N.B. 'Improved' stoves are those that have a better efficiency and/or lower emissions than traditional stoves. 'Advanced' stoves are available in the market and are based on non-biomass energy sources.
Bibliography:
American Council for an Energy-Efficient Economy, 'Energy Saving Tips', SmarterHouse (2015)
GOV.UK, 'Energy efficient cooking: LoCooker steams ahead' (16 September 2014)
Hager, T. J. and R. Morawicki, 'Energy consumption during cooking in the residential sector of developed nations: A review', Food Policy, 40, (June 2013) 54-63
Malla, S. and Timilsina G. R., 'Household Cooking Fuel Choice and Adoption of Improved Cookstoves in Developing Countries', The World Bank Development Research Group (June 2014)
Morelli, B., 'How cooking method and practice affects energy consumption', Yale Environment Review (January 2014)
Uswich, 'Energy-efficient cooking', Uswich (2020)
