Over the past week I have used our slow cooker to cook our dinners every night. It has been a busy week and I have tried to make it that little bit less chaotic by having our dinners ready as we walk in from work. During the week one of our Facebook friends asked a very good question, a question that I had never thought of asking. The question was whether having the slow cooker on for 8 hours (to cook our potatoes for dinner) would use more electricity than if I was just to bake our potatoes in the oven for an hour once I got home. I had no idea.
I asked my husband to do a little testing for me, which he did kindly and this is what he came up with.
Our slow cooker draws .4 amps on the low setting (I use this setting for most of our slow cooked meals).
.4 amps by 8 hours is a total of 3.2 amps (.768 kWs) used for the duration of our cooking time.
While our oven is heating up it draws 14.7amps. It takes our oven 15 minutes to preheat meaning a total of 3.675amps used in the pre heat stage of our cooking.
Our oven then reduces to 1.7 amps once it is at the required temperature. It would be good if it stayed at the one temperature, but it doesn't. We sat with a stopwatch and observed what the oven was doing (I know... the fun we have!). Our oven actually heats itself back up every 4 minutes and takes 2 minutes to get back up to temperature every. single. time! Every noticed that little red light turning on and off?
Anyway this made the calculations a little more tricky than the slow cooker. In the hour that it takes to cook our baked potatoes in the oven, 40 minutes of the hour the oven is drawing 1.7 amps and the other 20 minutes (when it is heating back up and down to temperature) it uses 14.7 amps again.
1.7 amps x 40 minutes = 1.139amps
14.7 amps x 20 minutes = 4.851 amps
14.7 amps x 15 minutes (preheating) = 3.675 amps
A total of 9.665 amps (2.320 kW) used baking potatoes in the oven for an hour, after preheating for 15 minutes.
The verdict: 3.2 amps used in the slow cooker versus 9.665 amps drawn from the oven OR if you want to compare the figures to your electricity bill the slow cooker used .768 kWs in 8 hours and our oven used 2.320 kWs in the time taken to cook those dear potatoes.
Moneywise: In Queensland, the current price of electricity is 25.378 cents per kWh on tariff 11. Using the slow cooker to make our dinner cost us approximately 19.5 cents whilst using the oven cost us around 59 cents.
Obviously these readings would be different for everyone depending on the size of your slow cooker and oven, but it was certainly an interesting little test that we conducted. I now know that any meal cooked on low in our slow cooker for 8 hours or less is going to use less electricity than what our oven would use just to heat up. Who knew potatoes could be so much fun!?
If you have any questions (my head is spinning too..) or disagree with any of the above please let me know.