Powering On: The Pros and Cons of Leaving Your Inverter On All
Leaving your inverter on all the time can increase your energy bill, but the amount of the increase depends on the inverter''s power consumption and your local energy rates.
Voila, Solar Voltage Rise. In the ideal situation, the voltage rise is not a problem: the inverter increases the grid voltage from 240 volts to 242 volts. The problem arises when the customer's cables between the inverter and the grid are too small for the size of their solar system. Let's get back to basics to understand why.
In marginal cases your inverter may not trip off, but may reduce its power output instead as a way to cope with grid voltages that are a little too high. When your inverter reduces its power due to high grid voltages it is in what's called "Volt-watt response mode".
When your inverter reduces its power due to high grid voltages it is in what's called "Volt-watt response mode". This feature is recommended in the latest version of Australian Standard AS4777.2 - and if your inverter has the feature, the standard mandates that it must be activated. I knocked out this sketch to show what happens.
If your inverter wants to send 20 amps back to the grid, then we should “let it flow”. The only way left to balance the equation is to increase the voltage even more. The higher your cable's resistance is, the higher the voltage must be to force the current to the street. Solar Voltage Rise starts becoming a problem.
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