MEASUREMENT of ENERGY USE

• Electrical energy (Hydroelectric) - For lights, appliances, air conditioners and sometimes heating. This type of energy is measured in KILOWATT hours (kWh).
  

• Heating energy (Fuel Combustion) - In some buildings, heating is created by burning fossil fuels like natural gas or oil. This type of fuel consumption is measured either by VOLUME (cubic measurement or gallons), or by GIGAJOULES (GJ)*. One cubic metre (m3) is almost as big as a regular kitchen stove, and for natural gas it is equal to approximately 0.0038 GigaJoules (Billion Joules).

*What is Energy? = A measurement of the ability of something to do work. The base metric unit for energy is the Joule (J).

*What is Power? = A measurement of the rate of energy transfer. The base metric unit for power is the Watt (W) and it is equivalent to 1 Joule transferred in one second (J/s).

• By FLOORSPACE AREA: (Square feet (ft²) or square metres (m²)) - This measurement is called the ENERGY USE INTENSITY, or how much energy is required for the size of a building or apartment. The unit of measure is kilowatts / square metre (kW/m²) or kilo Btu's* / square foot (kBtu/ft²). You'll see this used when designers are trying to figure out the best efficiency strategy, getting the lowest energy use per square area as possible.

*What is a 'Btu'? British Thermal Unit = The energy required to make a 1 degree increase in temperature in 1 pound of water. This unit of measure is still used for furnaces, BBQ's and other heating equipment.

THE COST of ENERGY $$$

When you use electricity or turn on your heating, you're charged an hourly rate by an ENERGY PROVIDER. The provider is making sure that the distribution of energy is consistent and reliable, and they maintain the energy GRID - wires, towers, transformers, gas lines, oil pipelines, etc..

Electrical energy is generated mainly by some force acting on turbines that spin, transferring mechanical energy to electrical generators and out to the grid.

ENERGY SOURCES:

• Water power - water flows through dams
• Nuclear power - nuclear fission (splitting atoms) heats water, creates steam
• Coal, oil and gas - fuel burning heats water, creates steam
• Wind power - wind pushes giant windmill turbines

And the power sources that don't use spinning turbines...

• Solar collectors - sun light excites molecules in panel cells, creating electrical current.
• Geothermal - Pipes with refrigerant flowing through them use stable below ground temperatures to heat or cool a home.

SPECIAL NOTE: NET ZERO ENERGY buildings use renewable energy sources (i.e. solar, wind, geothermal) to generate power that offsets the power consumed by the building. Basically, power consumed minus power generated = zero energy.