What is energy efficiency? How to save energy?

Energy efficiency is the goal of reducing the amount of energy required to provide products and services. For example, insulating a house allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature. The use of LED lighting, fluorescent lighting or skylights for natural light reduces the amount of energy required to achieve the same level of illumination compared to the use of traditional incandescent bulbs. Improvements in energy efficiency are usually achieved by adopting a more efficient technology or manufacturing process or by implementing widely accepted methods to reduce energy losses.

Energy efficiency is referred to as the “first fuel” in clean energy transitions as it provides some of the fastest and most cost-effective CO2 reduction options while lowering energy bills and strengthening energy security. Efficiency, electrification, behavioural change and digitalization together shape global energy intensity - the amount of energy required to produce a unit of GDP is the key measure of an economy's energy efficiency.

How to Save Energy?

Heat pumps: Heat pumps are an effective way to heat and cool your home because they move heat from the surrounding air rather than creating it. Heat pumps can also do double duty and can both heat and cool your home year-round, rather than relying on two separate systems to condition your space.
Heat pump water heaters: Your water heater is the second highest energy user in your home. On average, an ENERGY STAR-certified heat pump water heater uses 70% less energy and can help a family of four save more than $550 a year compared to a standard electric water heater.
Windows:  Energy-efficient windows are made from materials that reduce heat exchange and air leaks, which means you won't need as much energy to heat or cool a space.
Insulation:  Adding more insulation to an attic prevents warm air inside from escaping in winter. In summer, it keeps the warm air outside. With good insulation, you won't need to use as much energy to keep your home warm in winter or cool in summer.

Smart thermostats: Smart thermostats are Wi-Fi enabled devices that control the heating and cooling in your home by learning your temperature preferences and programming them to automatically adjust to energy-saving temperatures when you are sleeping or away. They can help you lower your energy bills by not spending money heating or cooling an empty home.
Computer power management:  Computers can be set to automatically enter a low-power “sleep” mode when not in use.