Grid Tied Solar PV - will a back up generator cause problems?

[jimk280]

Hi guys, I am interested in installing a grid tied PV system. The property is rural and there are occasional power cuts for which a back-up generator is installed that powers up on a cut.

Anybody had any experience of this and will it affect the inverter? Or can the system be installed without problems?
thanks Jim

 

[Markc]

Hi Jim

We have only come across this one once and when we asked the supplier of the inverter we were told that an automatic interlock is required to prevent the PV inverter energising while on standby generator. The reason being the stand by gen set will have erratic sin wave due to increases and decreases in load. The inverter constantly senses the sin wave to synchronise to it. We fitted a contactor controlled by the mains voltage to the coil so when power was lost the contactor dropped out and so disconnected the inverter from the supply. Once mains voltage was restored the PV would start automatically once the owners swapped back to it on their selector switch.

It also depends on type of generator. If its a domestic cheaper one that can only supply some power but not all then the above should be considered. If however it a all singing all dancing bugger then there may be a self regulating unit to prevent sudden and erratic wave.

Not many manufactures of inverters will swallow on their guarantee damage caused by a on site stand by gen set.

Our situation is in a dairy unit as well so the gen set is run by a PTO off a tractor, Lots of pumps and motors as well. The more revs on the tractor the higher the voltage! As the herdsman didn't look like the sharpest tool we thought this best as well!

 

[Dan]

Don't mind me while I bump some threads in the solar PV forum. If they're not current or applicable topics, just ignore the threads; they'll drop off the page. If they are, feel free to chip in and chat solar stuff in the solar panels forum.

 

[Berniethebolt]

Hi guys, I am interested in installing a grid tied PV system. The property is rural and there are occasional power cuts for which a back-up generator is installed that powers up on a cut.

Anybody had any experience of this and will it affect the inverter? Or can the system be installed without problems?
thanks Jim

Hi Jim, not sure what you need to keep running while there is an outage, But for TV / Sat internet etc, have you thought about an UPS.
For a long outage, (which has happened to me only once in 10 years) I use a generator to keep the batteries topped up on my UPS. But it is large. 3kW with 4 x 12v batts. so the generator feeds a 50v power supply to the batteries. If power is not back on in about 10mins, I go and fire up the generator, power here is never off for long. I have only ever filled the petrol tank once.
Yes it's a bit oldball, but so am I..........