Modern water faucets are often designed to feel like there is an endless supply of water available while they actually restrict the amount they deliver. This has long been touted as a good environmental feature, but people have grown used to hearing about it. They might take it for granted that their sink faucets or shower heads will deliver an economical amount of water, so they seldom see it as a path to energy efficiency. They have moved past that, and the trend today is to take a look at the efficiency of heating their water for a shower of luxuries.
While energy efficiency in water heaters has come a long way, they can still be fairly inefficient. Most of them use tanks where the water is kept at the desired temperature, but it could sit there for many hours during the day or night. Most people only use hot water for meals and washing, so the appliance is heating water while they work or sleep. This is now seen as an inefficient way to have hot water come out, but the options are limited.
The need for immediate hot water has always been there, but it took a long time before electricity was available to heat the water. Putting a pot of water on the fire was often the way it was made in ancient times, but heaters today have enough capacity to warm much more. On demand systems have become available for homeowners, and they are becoming more popular. They only heat the water when the tap is turned on, so they avoid the cost of heating it when it is not needed.
There are many ways to create energy savings in the modern world, and changing the way water is heated is now one of them. While it can be expensive to install, an on demand system can last for years while heating only the water really needed.