Can Voltage Optimisers be installed along side Solar PV systems?

My initial reaction to this question was probably no! However, after a bit of Googling I came across a company that seem to be one of the market leaders called Vphase who say that their voltage optimizer can be used in conjunction with a Solar PV system provided the pv system is connected upstream to the optimizer. More details can be seen on the company web site at http://www.vphase.co.uk/how-it-works/solar-pv-and-vphase or contact 0845 033 8222.

Apparently, these devices have a toroidial transformer wound in anti-phase that subtracts a desired value from the supply voltage, generally giving an output of 220 volts. The units can handle up to 2 kW in a domestic installation and will go into bypass mode should the load drawn be in excess of 2kW.

The question has been asked regarding whether or not an earth loop test can be conducted through the V-Phase unit? The technical department at V phase have confirmed that it is possible to conduct the test, but the unit will add about 0.2 ohms to the reading and the Max Zs reference values will need to be adjusted for 220 volts.

Much larger 3 phase voltage optomiser units are now being installed in commercial and industrial buildings (typically 150 -250 kVA) which are thyristor controlled and they act somewhat like a large UPS system that is connected in series with the load to be controlled. Again, the supply voltage is dropped to a Uo of 220 Volts and should the input supply voltage fall below 220 V, these units will increase their output voltage to compensate for the short-fall.