So on with the show. Most will have about 3 days worth of readings now. Here is how my calc table looks (click to enlarge)
I have been at work the last two days, and in my absence and to my surprise our total kWh per day has gone up, not down like I expected! WTF? 20.7 kWh in the last 24 hours! I have been unable to figure it out for two whole days, and thought someone was stealing our electricity or that one of the meters was wrong.
After questioning Kim, it suddenly dawned on me. About a year ago we refurbished the kitchen and purchased a duel fuel oven. We can cook with natural gas or electricity. I was hedging my bets come energy descent and wanted to get the most out of the oven. Also, I can cook with gas even when there is no grid connection.
Kim had been cooking in our duel fuel oven using the electric oven setting which uses at least 3000 watts, and she had it on for 45 minutes on Tuesday, and over an hour today! We normally use the oven on natural gas, however she finds the electric bakes muffins, bread, and biscuits better. It uses a massive amount of what I thought was our humble daily energy requirements.
So it was time for my very own family meeting tonight, and we discussed when the best time to cook with electricity was (after sunset to maximise export and the feed-in tariff), and to cook as many things as she could during the same time. In other words, fill the oven up when using electricity! We discussed the pros and cons of using electricity vs natural gas. She also agreed to do laundry at night and hang it outside in the morning. This conversation reminded me of a few tips that I can share today.
- Think about energy usage by room. Do a mental audit of all electrical items in the room. If needs be, right down the items for future reference.
- Look for waste and educate others as we go along.
- Don’t spend any money until you assess your/family behaviours. Try simple efficiency first of all.
- Remember, it is easier and cheaper to save electricity than to generate.
- Use a microwave for cooking, they’re more energy efficient than conventional ovens
- Stir or turn food in the microwave often to ensure the heat spreads evenly – speeding up the heating process.
- When cooking on the range make sure you use the lids on your pots. You don’t need to use as much energy to get the same result.
- Make sure the seals in your oven fit properly. The seals should hold a piece of paper in place when the oven door is closed. We replaced ours about 2 months ago because the manufacturer found a fault with the design and sent us a free replacement.
- Use small appliances for small tasks e.g. use the toaster not the oven for toasting.
- Use the correct size pot for the element or burner, it is more efficient and you don’t waste heat.
- Avoid cooking food that is still frozen. Defrost it in the fridge or use the microwave.
- Avoid opening oven doors when cooking – each time you do the internal temperature drops by at least 15°C.
- Use appropriate cooking temperatures
- Cook several dishes at once in the oven.
- Electric ovens are usually rated between 2400 – 3200 watts, so an hour of cooking you would use 2.4 – 3.2 kWh.
- An electric stove element is rated between 150 watts for the low setting up to 1500 watts for the high setting.
- A Microwave (1000W) actually uses about 1600 watts on the high setting.
- An electric grill is rated at 2200 watts.
- An electric jug is rated between 2000-2400 watts
- A toaster can be rated between 1800 – 2200 watts.
OR you could buy a solar oven.
Mine arrived last night.
Linda Woodrow says
I know with our stand alone solar system, I can afford to use anything electronic or with a small motor almost as much as I want – music, computer, radio, blender, food processor. I can use things with big motors frugally – washing machine, vaccuum, compressor fridge. But I can’t use things that use electricity to create heat at all – they just use too much power. So we have a gas stove and oven, and I love it. I’d add to your tips, try a pressure cooker. They cut cooking time back by two thirds, which saves a lot.
We have gone down a couple of kW over the three days – but we started at 36 (remember the bit about living in cold, dark wintery Canada?), and are only down to 33 – this could be something as simple as one teen skipping their shower, or me not doing a load of laundry. Whatever, I’ll take it as progress that one of the teens actually turned OFF the kid computer before they went to bed – without being asked. I practically did a happy dance 🙂
@ Frogdancer. Great work! Do you have a link to the product? I have been interested in one for a while now.
@ Linda. Nice to get a different perspective on off-grid energy usage. It just confirms that using electricity to heat things is very inefficient.
@ Dawn. Well done on convincing teenagers to do anything other than sleep and eat 😉
Hi Gavin, I can also add that we use a slow cooker for roasts in summer, also because we don’t like to overheat the kitchen, and the woodstove all winter. I very rarely use the oven, but then I also don’t bake (although the slow cooker or bread maker can also be used for baking). I don’t like use the microwave much ither – a bit paranoid about what those waves are doing to the food.
We have noticed this also and tried to use our wood fired oven in the winter. Thats not viable where we live in the summer though. As we bake all our own bread and cook evrything from scratch I’ll have to think more about this. I dont think microwaving is a real option for lots of other reasons and our oven is new so we wont be getting a gas one any time soon.
Planning the baking and baking at night may be the best I can do.
Can you show the tab from your sheet where you key in your figures as well? I think I was reading the wrong numbers on mine, and just wanted to get a guide on whether I’ve now figured out whether I’ve got it right now. Then, if all OK, I get to see how I’m travelling.
We quickly realised that the oven was one of our biggest energy users. My daughter loves chicken nuggets cooked in the oven, and we were in the habit of putting the oven on to preheat, then coming back much later to put the nuggets on.
Now we set a timer when we put the oven on to preheat, and we’re using far less. Sometimes the simple things can really make a difference, without having to change your lifestyle drastically.
Love your blog – first time comment from me. I wanted to point out that your power usage calculations for ovens is probably overstated. The oven will only be drawing maximum power until it reaches the desired temperature. The heating element then shuts down until the thermostat trigger point is reached, at which time it starts up again. If your oven is well insulated and sealed, the actual usage will be well below the theoretical amount.
This in no way diminishes the sense of using it as efficiently as possible, in the ways you have described 🙂
Btw, this is also true for other ‘intermittent’ loads, such as fridges and air-cons. You can figure out how often your fridge cycles by listening to it!
Cheers for now,