Using energy well
Several practices help us use energy well.
Monitoring daily energy consumption
We should measure the energy we use each day and stay aware of how it changes; energy waste can then be kept low.
Energy auditing
Auditing means going to institutions, analysing their energy use and informing their management with recommendations and advice, encouraging people to cut energy use and be efficient.
Energy efficiency
Using the least amount of energy to supply a service, by managing consumption, is energy efficiency. It improves management and control of energy use and gives more service for less energy. It does not mean going without the service or rationing it.
Assignment 15.12
Check the electrical appliances used at home, write down their power ratings (wattage), and from them find out how much electricity they use.
For example: a 1000 W iron used for 30 minutes uses 1000 × 0.5 = 500 Wh = 0.5 kWh — half a unit, as in chapter 10.
Sustainable use of energy
Renewable energy is counted as sustainable energy: solar, wind and biomass, for example. For various technical reasons, the use of many renewable resources is still at a low level.
Natural energy in house design
- Plan for good air circulation inside the house. Direct sunlight heats the house, so windows facing east and west, especially west, are not suitable; windows facing north and south give good ventilation and natural cooling.
- Natural ventilation saves the electricity spent on air conditioning.
- Using daylight (daylight harvesting), with lamps that respond to daylight, greatly reduces the cost of electricity.
- Thick curtains reduce heat exchange, saving electricity on air conditioning.
- Rainwater harvesting is used as a way of conserving resources.
- The waste heat in the gases leaving boiler chimneys is used to preheat boilers and combustion air.
Measure, audit, be efficient
Monitoring and auditing energy use, efficient appliances, renewable sources and houses designed for natural light and ventilation all save energy.