Renewable Energy 101

The Basics

Renewable Energy is energy that comes from a source that is renewable, that is it can be renewed or replenished within a relatively short period of time usually within a human's lifetime.  The wind, sun and plants are all sources of Renewable Energy.  Coal, Oil and Uranium not renewable forms of energy as they can take millions of years to be produced again.   

Types of Renewable Energy:

• Solar

  • Solar Photovoltaic (PV) – Panels convert sunlight into electricity.

  • Solar Thermal – The sun heats water inside panels to be used for domestic hot water.

  • Passive Solar Heating – Home heating energy is provided by way of light energy from the sun mainly through south but also east and west facing windows.

• Wind

  • Turbines convert energy from the wind into electricity.

• Biomass

  • Biodiesel – a clean burning, renewable fuel created from one of many sources such as canola oil and soybeans.  It can be used as a substitute or blended with Petroleum Diesel.    

  • Ethanol – a cleaner burning, renewable fuel created from one of many sources such as corn and wood.  It can be used as a substitute or blended with Petroleum Gasoline.    

• Micro-Hydro

  • A turbine creates electricity from the flow of water.
     

 Basic Home or Cottage RE Diagram:

Components:

Photovoltaic (PV) Array: PV arrays are made up of a group of solar modules or solar panels.  Solar cells convert solar energy into Direct Current (DC) electricity. 

Inverter: Converts Direct Current (DC) electricity into Alternating Current (AC) electricity.  Most electrical products in the home are made to run on AC current.

Battery: Stores energy in the form of DC electricity. 

Charge Controller: Controls the electrical current that runs between the Solar Panels and Batteries.  Its main functions are to prevent the batteries from being overcharged and also to prevent the batteries from being discharged at nighttime through the solar panels.

Terminology and Equations:

Power, in watts = Current, in amps x Voltage, in volts (P = I x V)

Voltage, in volts = Current, in amps x Resistance, in ohms (V = I x R)

AC: Alternating Current, i.e. Electricity from an inverter or the power company. 

Amp-Hour (Ah): Amps multiplied by hours, often used to specify the storage capacity of batteries.

Autonomy: The amount of time in which the batteries can store energy to run you house without replenishment.   Also called the days of storage. 

DC: Direct Current, i.e.  Electricity from a battery or solar cell.

Net Metering: A system where you are able to feed electricity into the electrical grid when you produce excess and get electricity from the grid when you are can’t produce enough yourself.  You then pay the net amount of your bill but often don’t get compensated if you produce more than you use.     

Off-grid: You are not depending on the provinces power lines for electricity, you are self-sufficient.  You will need your own energy storage system (batteries).

Watt-hour (Wh): A unit of energy found by multiplying watts by time, in hours.  Kilowatt-hours (kWh), or one thousand watt-hours are often used in power bills.