How Solar Power Works
Solar Photovoltaic – how it works
Solar photovoltaic (PV) panels are usually found on the roof of many homes and businesses. The panels harness the sun’s energy to generate zero emission electricity. Light energy is converted directly into electricity by transferring photon energy into electrical energy. The conversion takes place within cells of specially fabricated semiconductor crystals.
While it might be true that solar cannot generate electricity all the time, it does generate electricity when it is needed most – during peak demand hours of the day, such as hot, periods when we all run air-conditioners.
Having solar panels is like having a mini power station on your roof. PV electricity is generated at the point of demand – where people live and work, which means there is no need to transfer the energy long distances across expensive infrastructure.
Which way should I face my Solar Panels?
The sun rises from the East and passes through the Northern part of the sky, then sets back down on the West in the afternoon. Most experts have, in the past, advised clients to install the solar panels on the north facing area of the roof. When there was a 60c Gross Feed in Tariff this was a logical approach.
But times have changed and now, Forster Solar and Lighting has a better option. With Net Metering and the meagre feed in tariffs available there is another way to maximise your solar solutions.
Here’s what the team at Forster Solar and Lighting believes is a more productive solution.
Under the current system in NSW, consuming your own power is worth four to five times the value of exporting unused power back to the grid. If you are not home in the middle of the day to consume the power, you get very little return on each kilowatt hour (kWh) produced.
By putting your panels on a West facing roof, you will lose between 12% and 18% production overall compared to facing them North, but if you are home in the afternoon to consume the power instead of exporting it – then it may be a better option.
Here’s the maths – in real terms, for a 1.5kW system facing North your average daily production would be about 6kWh per day. Production would peak in the middle of the day when no one was home, and you would end up exporting power for a return of 6c-8c per kWh.
With a West facing array, the worst case scenario would be that your average production for that system would be about 5kWh. More importantly, your peak production would be shifted to later in the day, and you would be making more power when you need it most – after school and work.
To make up for the 6 cents you may miss out on, you would only need to consume an extra 0.2kWh at the end of the day from your West facing array.
A North facing array would not have been producing power or was producing less than you were consuming at this time of the day. Makes sense, right?
(By the way, these figures are based on a standard billing rate of 31.1 cents per kWh. If you are on time-of-use billing and not at home during the day, this idea makes even more sense.)
If you are purchasing a 3kW system or larger, Forster Solar and Lighting suggests an inverter with two maximum power point trackers would be the best option. You can utilise more than one roof space, perhaps splitting your system so half faces East and half faces West, or have a North and West combination. Your overall production would still be down over a North facing array, but you may find that you are able to consume a greater percentage of the power produced, thus saving more money. The key is to make sure that the system you purchase suits your individual needs.
Who are you going to call to get that expert advice? Forster Solar and Lighting, of course.
And remember: consumption is the key to making the most of your solar!