What are Renewable Energy Certificates (RECs)?

In response to climate change, and to encourage the development of renewable energy, wholesale buyers of electricity such as retailers are required to source a portion of their power from renewable sources. This is demonstrated by the purchase of Renewable Energy Certificates (RECs) which must be surrendered to the Office of the Renewable Energy Regulator.

One REC represents the generation of 1 MWh (megawatt-hour) of electricity. As the total electricity produced by your Clear Solar power system depends on the amount of sun that falls on your roof, the number of RECs created by your system depends on its size and a factor linked to your postcode. The sunnier your postcode, the more RECs you can create. On installation, you can create RECs equivalent to the anticipated amount of power that your system will generate over the next 15 years.

RECs can be sold through companies that are authorised to deal in them. Our base prices assume that you assign the RECs created by your system to us. We then sell them, and this reduces the out of pocket cost of your system.

Why would I want to keep my RECs?

If you do not create RECs for your system then wholesale buyers of electricity will need to buy RECs from elsewhere, so by keeping your RECs you may be encouraging further investment in renewable energy.

What’s a kW and a kWh?

kW stands for kilowatt, or 1,000 watts. It is a measure of power. Your Clear Solar power system is rated according to the number of watts it can produce in full sun. kWh stands for kilowatt hour. It is a measure of energy. If you ran a 1 kW electric heater for one hour, it would use 1 kWh of energy. Electricity companies bill you a certain amount per kWh you use.

Will a 1 kW system generate 1 kW of power?

The short answer is “no”.

Manufacturers of solar panels rate their output under standardised conditions, often referred to as Standard Operating Conditions (SOC) or Standard Temperature and Conditions (STC). This test is designed to be a convenient method of comparing the performance of panels under laboratory conditions. In the real world, solar panels perform differently and some panel manufacturers also provide figures for panel performance under Normal Operating Temperature and Conditions, sometimes referred to as NOTC.

The main influence on the output of a solar cell is its temperature. The standard test measures the output when the actual solar cell is at a temperature of 25oC and illuminated with 1,000 watts per square metre. The cells, being a dark colour, heat up in the sun. Typical operating temperatures are around 40oC, and at this temperature power output most cells produce around 20-30% less power than they generate at 25oC. Also, atmospheric conditions mean that the amount of energy falling on the cells will rarely be 1,000 watts per square metre. A 1 kW system installed at the top of a mountain with an air temperature of around zero might come close to matching Standard Temperature and Conditions.

Small losses of power also occur at the inverter (3-6%), and any dirt on the solar panels may also lead to a small additional loss. In the real world, a 1 kW system (as measured under Standard Temperature and Conditions) is likely to have a peak output of between 700 and 800 watts.

In line with world practice Clear Solar’s systems are rated according the panel specifications determined under standard conditions. However, the important figure is how much electricity your system actually produces. Our calculation of the daily output of each system is based on real performance under conditions experienced in southeastern Australia. Higher performance can be expected in sunnier parts of Australia.

How much electricity will my system produce and how much CO2 will it keep out of the atmosphere?

The following table provides a guide for systems located in Melbourne. Higher performance will be achieved in sunnier locations. (Update for larger systems)