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What is Solar Self Consumption?

To understand the topic we need to look into how a grid connected solar power system functions. We will discuss this in detail below.

For those of you that want a 1 sentence answer here you go;

Solar Self consumption is the percentage of solar production that is consumed by you directly from the solar array. 

For those that are looking for a more detailed answer, see below.

Solar Panel

Step 1. Solar Production. 

Solar electricity is created when the solar panels absorb the suns rays during the day. Technically we use a term called PEAK SUN HOURS (PSH). In a place like Adelaide for example in summer there are up to 12hrs per day of sun and in winter there is as little as 2hrs of ‘usable’ sun.  To calculate solar self consumption we need to understand how much electricity your property uses during the peak sun hours (PSH). 

Solar Inverter

Step 2. Conversion from DC to AC. 

The solar panels generate DC Electricity. An inverter is installed to ‘invert’ DC electricity to AC electricity (the type of electricity we use). Your inverter is connected to BOTH your household electricity circuits and your Utility Grid. 

More recently with the uptake of batteries, it’s becoming more common that you would have a hybrid inverter which is also connected to batteries for what is known as ‘increased self consumption’. 

Self Consumption House

Solar Self Consumption In the home. 

The solar energy produced from your solar panels in Australia* will first supply the electrical needs within your home. So the more you are using electricity within your home during peak sun hours the higher rate of solar self consumption you will achieve.

Many households feel like they don’t use any energy during the day. Whilst this is true in some cases, the below needs to be considered when calculating self consumption. 

  1. In summer the sun is still creating solar electricity until 9pm in some places. 
  2. Your appliances will still use some energy during the day even if you are out (if they are not switched off). 
  3. On weekends some households will be home more during the day and do household chores during that time, which use electricity – i.e. washing, vacuuming, home improvements. 
Business Solar Self Consumption

Business Solar Self Consumption. 

Businesses are commonly open and using the bulk of electricity during the day when the sun is shining. This can create great ROI for businesses. Even businesses that run 24hrs can still benefit from solar, although only when the sun is shining unless they install a battery. 

Whilst businesses are commonly using energy during the day and can directly draw that energy straight from the solar panels. Some things to be mindful of are; 

A. Does the business run up until 9pm? During summer the panels will still generate power right up until sun set. If a business closes at 5pm this will change a self consumption calculation. 

B. Does the business run 7 days per week? A lot of businesses only operate 5 or 6 days per week. If the business is not a 7 day site, then it is important to allow for opening days as well as opening hours when you make a solar self consumption calculation. 

Electricity Grid

Step 4. Utility Grid. 

If you do not have a battery installed to ‘increase self consumption’ then any excess energy is sold to the utility grid if your energy retailer or Network allows it. 

The amount that an energy retailer will pay you is around 1/3 of what you would pay for the electricity from them. 

Some Networks/ Energy Retailers will only allow a certain amount of electricity to flow in to the grid. We will talk more about that in another section of our glossary and FAQ pages.