{"id":5978,"date":"2015-03-04T04:45:40","date_gmt":"2015-03-03T18:45:40","guid":{"rendered":"https:\/\/gold-coast-solar-power-solutions.com.au\/?p=5978"},"modified":"2024-05-02T20:24:08","modified_gmt":"2024-05-02T10:24:08","slug":"reactive-power-and-solar-power","status":"publish","type":"post","link":"https:\/\/gold-coast-solar-power-solutions.com.au\/posts\/reactive-power-and-solar-power\/","title":{"rendered":"Reactive Power and Solar Power"},"content":{"rendered":"

Reactive Solar power factor<\/h2>\n

Recently we have had a number of customers here on the Gold Coast approach us about reactive power and solar power systems. It sounds like some unscrupulous sales people on the Gold Coast and Brisbane are trying to use Energex’s changes in regards to reactive power and solar power inverters to add some fear into their sales pitches. Let’s have a look at what’s going on and try to separate the fact from the fiction.<\/span><\/p>\n

New Energex Rules with Reactive Power and Solar Inverters<\/h2>\n

From the 1st of October 2015 Energex introduced a ruling that makes it mandatory for every solar power inverter greater than 3kW<\/strong> in size to have reactive power control set to 0.9 lagging. Energex have the following to say about this: “The performance of both the network and solar inverter systems can be improved by enabling the reactive power control functionality on some inverters. This occurs because it lowers the voltages and reduces, or potentially eliminates nuisance tripping and may therefore increase the total amount of power exported to the grid.”<\/p>\n

As a result, the new Energex standard requires that all solar power systems capable of exporting more than 3kVA must have a Power Factor (reactive power) Control setting activated at a designated value of 0.9 lagging.<\/p>\n

What Does 0.9 Lagging Reactive Power Mean?<\/h2>\n
\"Reactive

Reactive Power and Solar Power demonstrated in a chip packet, the chip packet is a certain volume but how much is actually of use to you?<\/p><\/div>\n

This is where it starts to get a little complicated, so grab your thinking cap and hold on!
\nHave you ever heard of kVA, Power Factor and kW?
\nkVA (kilovolt-ampere), also called Apparent Power.<\/strong> This is a unit of electric power equal to 1000 volt amps. This is calculated by Voltage x Amps. So a 5 kVA solar inverter at full power output would be working at 240V x 20.83A, that equals 5000VA, or 5kVA.
\nPower Factor (pf)<\/strong> is a ratio (a number from 0 to 1) of true, or real power and apparent power. In the case of a 1.0 power factor (also called unity power factor), the real power equals the apparent power. In the case of a 0.5 power factor, real power is approximately half that of the apparent power.
\nkW (kiloWatt), also called True Power or Real Power<\/strong> This is a unit of electric power equal to 1000 Watts. In the past it has normally been used to list the power rating of the solar inverters, and is still accurate to be used to list the power rating of solar panels, but with a Power Factor of anything other than 1 it is no longer an accurate measure to use for solar inverters. kW are calculated by Voltage x Amps x Power Factor, so a 5kW rated solar inverter set to the new Energex requirements of a lagging power factor of 0.9 would equal the following: 240V x 20.83A x 0.9pf = 4500W, or 4.5kW, but the inverter still has a 5kVA rating!<\/p>\n

What all this means at the end of the day is that any new solar power system with a solar inverter larger than 3kVA will have to be set to a reactive power rating of 0.9 lagging, and as all current residential electricity meters only measure kW not kVA this means that when a 5kVA inverter is producing 5kVA of power then 500 watts of the generated solar power will provide no realised benefit. The top 10% of the inverters output when working at peak power production will provide no realised benefit to the systems owner due to the lagging power factor, this is the difference between kW (which is measured by the meter) and kVA (which is produced by the inverter).<\/p>\n

With Reactive Power Is It Still Worth Going Solar?<\/h2>\n

As can be seen above a lagging reactive power factor of 0.9 potentially means 500W from a 5kVA inverter at peak power production provides you with no meaningful benefit. Obviously we would all prefer to have losses kept to a bare minimum and a potential 10% loss due to a 0.9 reactive power setting seems huge, but is it actually as bad as all that?<\/p>\n

Lets have a look:<\/p>\n