Initially I took a reading from the meter once a week , then subtracted the past reading from the current reading to get the weekly usage. I did this in a spreadsheet. Now I use The imeasure which is a web site run by Oxford University. It does this and many more things, including gas consumption and factoring in weather conditions. I also monitor my real time using a current cost device, monitoring the whole house, plus a couple of individual appliance monitors (IAM) which provide me data about individual appliances. I can publish this data to the Internet via the current cost NetSmart unit. All these methods give me a better idea of what I'm using and where it's going.
I should explain that my household uses gas central heating as the primary source of heat and hot water. My weekly electricity usage averages 20 units a day, lower in summer , higher in winter. That is too high, I want to reduce it, but most importantly I do understand where it is going. The other thing I have come to understand is that there is no magic gadget or solution to save electricity. Many of the energy saving gadgets only affect the devices which already probably use the least electricity .
I find it useful to break down the electrical demands in my house into 3 broad groups in descending order of their. Consumption of electricity:
- Things that make things hot.
- Things that make things move
- Everything else
Things that make things move are devices with motors, pumps or compressors including vacuum cleaners, mowers, fridges, freezers, air conditioning units, sewing machines, blenders etc
Everything else includes, TVs, audio, computers, mobile phones, games consoles.
The biggest savings to be had are by changing the way you use the items in 1. , and once that is done , look at group 2, finally group 3.
Of course many items in the house are in more than one group.
A washing machine , has a heating element (group 1) and a motor to turn the drum (group 2) and a pump (group 2) and some electronics to manage the programmes (group 3). These composite devices go in the highest group they include I.e. group 1 in the example above.
As with all rules there are a couple of caveats :
1) somethings get hot as a by product of something else. For example fridges and computers generate waste heat, but it is not their primary function and I do not include them in 1.
2) conventional filament lighting, while primarily designed to create light, actually creates a great deal more heat. Most of the energy consumed is generating heat rather than light. In my model filament lighting goes in group 1
So how does this help ?
Well when considering any energy saving measure , I look to the groups and use this to decide where to spend the money. With heating items it's a question of considering programmes that use lower temperatures for shorter periods, Eco programmes etc. A tumble drier is a very heavy user of electricity. Cutting these out by hanging clothes on racks or on the line could save a lot of electricity - afterall , its in category 1 & 2 !
When considering replacing goods, paying some extra for more control in this area may be worth it. Change filament lighting to low energy CFL or LED equivalents.
Similarly in group 2. Rather than buy a gadget that , say, defeats standby mode, (group 3) It might be better to save that money and use it toward newer more efficient fridge ( group 2 )
Finally measure that save energy in group 3 are only really worth considering when you believe that groups 1 and 2 are as efficient as you can make them .