solar diverter


Thread Starter


I would very much like your help and assistance in trying to design and build a solar diverter. There as a number of products available commercially but the prices! They are shocking. ( ahem!)

I would very much like to build something very similar to the Immersun ( product.

I have a grid tie inverter. A Soladin 600 which produces a nominal of 525w 230v ac at a mximum of 2.25A. I have a small set of solar panels which this will be connected to. There is absolutely no intention of trying to bypass any of the safety devices already built into the Soladin.

The Soladin ONLY works if there is an ac voltage detected from the grid. It isn't smart in that it won't dial down its output if the output is not required. It just dumps everything into the grid.

Now here in Spain I can legally feed the grid however, as expected it is tightly regulated, there is a mountain of paperwork and it is an incredible PITA.

I'm looking to build something that will
1. Monitor the draw from the grid
2. Utilise some trickery that will divert any excess current that isn't used by consumers to a diverter load ( I have a 1000w panel heater which we used prior to me completing the central heating project for this)
3. Ensure that if there is no current from the Soladin then the grid doesn't power the diverter load
4. Ensure that nothing gets sent to the grid

I believe I'm right in saying that there will always be a need for some draw from the grid as without it the Soladin shuts down as it would take no incoming current as a power outage. Which means its islanding protection kicks in.

So I know I could just go and buy the Immersun but its in excess of £300 and I'm sure something could be designed and built for a lot, lot less! And where would the fun in that be?

I'm fairly handy with a soldering iron, I undertook my own rewire in our house ( and got it approved by a local electrician ) so I have a grasp of the fundamentals and the dangers of electricity!

So any suggestions as to how I could go about this?

Thanks for reading this
As you say, not a simple device as by definition, the grid supply and the inverter output are one and the same.
the grid supply and the inverter output are one and the same.
I'd like to be able to switch between grid connected operations and stand-alone operations eventually too. Thats another part of the project I guess.