How A Grid Connect Solar Power System Works

How it works video

Below is the step by step process of how a grid connected solar power system works;

  1. When sunlight hits the solar photovoltaic (PV) panels, electricity (or 'solar energy') is produced.

  2. The electricity then runs from the solar panels through an inverter.

  3. The inverter turns the power from direct current (DC) into alternating current (AC), which you can then use for electronic appliances in your home.

  4. If the appliances in your home are turned on while solar power is being produced, the power runs through the switch board and the solar power is sent to your appliances.

  5. Any appliances that are AC powered can use the solar power, including lights, dishwashes and electric hot water cylinders.

  6. Electric Vehicles (EV's) can charge up using the solar power.

  7. If electrical appliances are switched off, or if excess solar power is being produced, the power gets sent to the grid which is measured by the meter box.  Your electricity retailer applies credits in exchange for the energy you produce.  During the night, when your solar power system is not producing energy, you will draw power from the grid, which you can pay for with credits earned from exporting solar power during the day.

How Solar Power Works Diagram

How Solar Power Works Diagram NZView Larger Image

What does your power bill look like if you have a grid connected solar power system?

Each month you will see seperate line items on your bill, one is for the amount of power you have used, the price per unit and the total cost of power used (imported power).  On the second line you will see the amount of solar power you exported back to the grid, the price per unit the energy retailer is paying you, and the total credit amount you received from exporting power.  This credited amount will be subtracted from the total cost of power used. 

If the total cost for the imported power is higher than the total price for the exported power, then you will have money owing to the energy retailer.

If the total price for exporting power is higher than the total cost for imported power, then the credit will flow over to the next month. You can let credits build up or you can ask to be sent a cheque.

Find out what different energy retailers will pay you for exported solar power here.

How does a solar panel work?

If you observe the standard solar panels today, you will see at least a dozen silicon squares within the frame (solar cells).  The solar cells convert sunlight (photons) into an electrical current.

Silicon is a semiconductor, which is able to absorb a percentage of the photons emitted by the sun as they hit the solar cells. As the solar cells are bombarded with photons, the electrons are knocked loose, allowing them to flow freely.

The solar cells have an electric field that makes the loose electrons flow in one direction.  Metal contacts on the top and the bottom of the solar cell allows for the current to be fed through solar cable to reach the solar inverter. As DC electricity is created from the solar cells, the inverter converts the current into AC electricity so that it can be used by a home or business.


Check out our Components page for more information about solar panels and other solar gear.