How Much Electric Does a Slow Cooker Use

The slow cooker has made a comeback in recent years as more people look for affordable, energy-efficient ways to prepare home-cooked meals. Known for its gentle, consistent heat and convenience, this simple kitchen appliance can simmer stews, soups, and curries for hours with minimal electricity use. But just how much electric does a slow cooker use compared to an oven or hob? Understanding its consumption can help you appreciate why it has become a staple for energy-conscious households in the UK.

Average Power Consumption of a Slow Cooker

Most slow cookers use between 150 and 300 watts of electricity on their low setting and between 250 and 500 watts on high. These figures can vary slightly depending on the size of the appliance, the manufacturer, and the model. For example, a small 1.5-litre slow cooker might use around 150 watts on low, while a large 6-litre version could draw closer to 300 watts.

Although these wattages may seem modest, slow cookers are typically used for several hours at a time. Even so, their low power rating means that running one for eight hours consumes roughly 1.2 to 2.4 kWh of electricity. Based on an average UK electricity rate of 30 pence per kWh, that equates to around 36 to 72 pence for an entire day’s cooking. This makes slow cookers one of the most cost-effective appliances in the kitchen, especially when compared with ovens that can use ten times as much electricity in the same period.

Comparing Energy Use with Other Cooking Appliances

Electric ovens generally draw between 2,000 and 3,000 watts, meaning that a single hour of oven use can consume as much electricity as a slow cooker uses over an entire day. Electric hobs also use significant power, typically between 1,000 and 2,000 watts per ring, depending on the heat setting.

Microwave ovens are more efficient for very short cooking times but are not suitable for preparing slow-cooked meals. When you consider that a slow cooker can produce a family dinner for under 50 pence of electricity, it becomes clear why it has become so popular as households look to manage energy costs more effectively.

How a Slow Cooker Works

A slow cooker, or crockpot, uses a heating element around a ceramic or metal pot to maintain a steady low temperature, typically between 75°C and 95°C. This allows food to cook slowly and evenly over several hours without boiling. The lid traps moisture, preventing evaporation and retaining heat efficiently. Because of its insulated design and steady operation, very little energy is wasted.

The appliance cycles on and off during operation to maintain a constant temperature. This means that even though it runs for a long time, it does not draw full power continuously. The result is an exceptionally energy-efficient cooking method that suits stews, casseroles, soups, and even desserts.

Cooking Times and Energy Efficiency

Cooking times in a slow cooker range from 4 to 10 hours depending on the recipe and temperature setting. The longer cooking duration might seem like it would use more power, but because of the low wattage, the total energy consumption remains low.

For instance, a 250-watt slow cooker running for 8 hours uses 2 kWh, costing around 60 pence at current electricity rates. A comparable meal cooked in an electric oven for 1.5 hours at 2,000 watts would use 3 kWh, costing around 90 pence. If you use the slow cooker three times a week instead of the oven, you could save £45 to £60 per year on electricity.

The consistent heat of a slow cooker also means there’s no need to preheat, further reducing wasted energy. Some modern models include timers or automatic “keep warm” functions that maintain safe serving temperatures while using minimal power.

Factors That Influence Power Use

Several factors can affect how much electricity your slow cooker uses. The size of the appliance is the most obvious—larger cookers consume more power to heat greater volumes of food. However, they are still efficient because they can prepare larger portions, reducing the need for multiple cooking sessions.

The heat setting also plays a role. Cooking on the high setting generally shortens cooking time but increases hourly power consumption. For most meals, using the low setting is more economical and delivers better flavour and tenderness.

Opening the lid frequently during cooking can increase energy use because it releases heat and moisture. Each time the lid is lifted, the temperature drops, forcing the cooker to draw more power to restore heat levels. Keeping the lid on ensures steady cooking and maximises efficiency.

Slow Cooker Sizes and Power Ratings

Mini slow cookers of around 1.5 litres typically use 120 to 160 watts, ideal for one or two people. Mid-size models between 3 and 4.5 litres use around 200 to 250 watts, perfect for families of three or four. Large 6-litre slow cookers, popular for batch cooking or entertaining, may draw between 300 and 350 watts.

Choosing the right size for your needs is important. Using a large slow cooker to prepare small portions wastes energy because it heats more space than necessary. On the other hand, overfilling a small cooker can lead to uneven cooking and safety issues. Aim to fill your cooker between half and three-quarters full for best results and maximum efficiency.

Slow Cookers and Modern Smart Features

Modern slow cookers often come with features that make them even more efficient and convenient. Programmable timers, temperature sensors, and automatic switches can help control energy use. Some models can be operated remotely via smartphone apps, allowing you to start or stop cooking without being at home.

These features not only improve convenience but also prevent unnecessary electricity use by ensuring the cooker switches to “keep warm” mode or turns off entirely once the food is done. The “keep warm” setting typically uses around 100 watts or less, maintaining food at a safe temperature for several hours at minimal cost.

Using a Slow Cooker Efficiently

To get the best value from your slow cooker, plan meals that make full use of its capacity. Cooking in bulk and freezing leftovers is one of the most energy-efficient ways to prepare meals. The slow, gentle heat helps preserve nutrients and tenderise tougher cuts of meat, making it possible to use cheaper ingredients without sacrificing quality.

Using fresh rather than frozen ingredients can also improve energy efficiency. Adding frozen items can extend cooking time and increase electricity use as the appliance works harder to reach optimal temperatures. Similarly, avoid placing a cold ceramic insert directly into the cooker from the fridge, as the sudden temperature change can delay heating and reduce efficiency.

Cost Comparison Example

Let’s take a practical example. A 3.5-litre slow cooker rated at 200 watts, used for 8 hours, will consume 1.6 kWh. At 30 pence per kWh, the total cost of cooking is just 48 pence. If you use this appliance three times per week, the monthly cost will be around £6, and over the course of a year, roughly £72. In contrast, using a standard oven for similar meals three times per week could cost £130 or more annually.

Even at higher energy rates, the difference in cost remains significant. For households trying to save on bills without compromising meal quality, the slow cooker offers excellent long-term value.

Environmental Benefits

Aside from saving money, slow cookers are better for the environment because of their lower power use. By consuming only a fraction of the electricity needed by larger appliances, they reduce carbon emissions and overall household energy demand. Using a slow cooker during off-peak hours or alongside renewable energy sources, such as solar panels, further enhances its eco-friendly benefits.

The reduced need for reheating also contributes to energy savings, as food prepared in a slow cooker often stays warm for hours after the appliance is switched off.

Conclusion

A slow cooker is one of the most energy-efficient appliances in any UK kitchen, typically using between 150 and 300 watts on low and around 250 to 500 watts on high. Even when cooking for 8 to 10 hours, it consumes only about 1.2 to 2.4 kWh, costing less than 75 pence per meal.

By using the low setting, keeping the lid closed, and cooking in bulk, you can enjoy hearty, home-cooked meals for a fraction of the cost of using an oven. For homeowners looking to manage household energy use more effectively, ensuring your electrical sockets and wiring are up to date allows you to run efficient appliances like slow cookers safely and confidently while keeping bills low and meals delicious.