There are a lot of house hold electric stuffs that use transformers. For example, speakers, mobile or torch chargers, modems, cordless phones, radios and many more. Usually after their main use, e tend to keep them as it was, that is plugged. If you want to charge a mobile phone, you connect it to the charger and get it fully charged. Later you disconnect the mobile, but forget to switch of the plug. You may also do it purposely. But, little do we think about the amount of power these transformers consume. According to a recent study, there is a minimum of 4 transformers plugged in each home every minute of our life, either connected to the device or not. Not only do they cause power loss without the device connected, but it also happens while connecting the device.
When connected to the device, the transformer, apart from supplying the required power to the device, also emits power in the form of heat. You may think that the power loss may not be large. The transformer releases up to a maximum of 5 Watts. This may be a very small amount. But, what would be the added amount of power loss when about 5 or 6 of them are ON for the entire time. That means almost 30 Watts of power is wasted throughout. If 1 KWH costs you 10 cents, that means you are wasting almost 10 cents for 24 hours. That is equal to about $40 annually. This $40, when calculated for about 100 million households in one country alone costs 4 billion dollars!! If transformer connected components from all the countries are added together, you get almost $780 billion dollars. Just think how far the world could change with this much money.
So, take special care while using components. Never forget to OFF the switch or disconnect the device from the socket.