Repowering PV Ontario MicroFit

[Jay Bee]

Anyone on here know how the IESO handles repowering of the micro fit installed systems?

I have a system we are removing temporarily to do reroofing, and an installer we are speaking to is quoting a repower of the system. I will admit, it's an attractive option, but it basically entails removing the 52 240 watt panels and microinverters, and replacing them with 66 x 340 watt panels connected to a string inverter that's sized at 10kw. My understanding from him is that as long as the inverter is rated at 10kw, that the quantity of panels is irrelevant where the IESO is concerned. So in this case, the proposal would have the system output (nameplate 10kw) closer to its nameplate capacity for more hours in a day, thus improving the ROI of the project.

Questions, has anyone else here done this? How did it go? Was the Payback there? Did the IESO audit the system and approve of the installation? Did anyone find it jeapordized their contract?

I'm in a bit of a hurry because of the roofing project, but from where I'm standing I can't really see how the additional panels is a problem, as long as the grid connection is choked at 10kw...Anyone?

[Rob Beckers]

Hi Jay,

I've heard of several people doing the same thing. The payback may certainly be there (you can run the numbers), the legality depends on your contract.

So, get out the fineprint and have a look: The very earliest version of the 80.2 ct/kWh contracts allowed for the limit to be set by the lower of the inverter or the panels. In short, a 10kW inverter and 15kW of panels is legal under that version of the MicroFIT contract. Later versions defined the HIGHER of the two to set the limit, and this scheme would not be legal under one of those contracts. On the downside, the earlier contracts required "domestic content" based on a points system, and replacing inverter or panels could well be violating that condition. There are no Ontario-made inverters any more (best I know), and very few PV module options that are still made here...

As to audits, I've only heard of one case where the IESO audited (and terminated) a MicroFIT contract. There may be more, they don't tell me. In general the odds of getting audited seem to be pretty minimal when it comes to MicroFIT. Their focus seems to be on the FIT side (my FIT system has been audited twice, thoroughly, my MicroFIT has never been audited).

My 2 cts....

Cheers,

-RoB-