The sun is shining and your solar cells are supplying all the power you need, and then your grid connection suffers a power cut. You are laughing right? Wrong! In most cases your solar will switch off automatically when the power cut happens.
But there is a way…
Why does my Solar switch off?
Some of the primary applications for energy storage were explained in an earlier blog. When a generator is cut off from the grid, but still supplying a local network, it is called an Island. Most domestic Solar PV systems are installed with anti-Islanding equipment designed to detect when grid power is lost and then immediately disconnect the local generator.
This is for a few reasons:
Safety. If there was a power cut and someone is looking to fix the problem, it is dangerous if a local network is still supplying mains power (although in reality, this is not considered much of an issue as electrical workers are used to coping with unexpectedly energised lines).
Reconnect problems. There are concerns that automated grid systems for reconnecting lines after an outage may be confused or cycle on and off due to anomalous power readings.
Frequency/voltage problems. If a generator is Islanded and then wants to reconnect to the grid, it must be able to synchronise frequency and voltage with the grid.
Is there a way to keep my Solar on?
Yes there is, but perhaps not surprisingly it is a little more complex and costs a bit more. The key problem is the frequency/voltage one.
The Inverter in island mode must maintain the 240v/50Hz of the grid so that household goods can run efficiently. However, it is inevitable that it will diverge from the grid system, so it needs a way to sense the grid frequency and align itself on reconnection.
Practical Home Systems
At Fuel Included we use Victron Inverters when someone has a need for full Islanding. For example the Victron Quattro. A useful overview of Victron Energy Storage Systems (Solar + Battery) can be found here.
Victron Quattro Inverter
As mentioned in this blog, we recently added the BYD B-Box battery to our supported supplier list, and this is a great fit for the Quattro for a high performance Island-capable system.
BYD B-Box Pro 10 kWh Battery
Can Generators Help?
If off-grid power is an important consideration, then your energy storage system can be augmented with a generator. This can be configured to auto start in certain conditions so giving you a balanced off-grid alternative with automatic fail-over.
If you are interested in Islanding or our new battery range, please follow the links below.
