Input please .. Question about a quote for a 8000w grid-tie system. Micro inverters

[Derka181]

Got the quote from a company. They’re using micro inverters, the company choose Aps ds3-l which are rated from approximately 750w, this micro inverter allows 2 solar panels to be connected to it. He is attached 2- 500w panels (total- 1000w solar panels) to the Microinverter. Those micro inverters are rated for approximately 750w. I asked him why he would put 1000w of panels on 750w micro inverters? He is his response…..

“ From an install perspective 2 channel inverters are much easier to work with. As it stands you will need at least 1 jumper mc4 for each set of 2 modules because not all the modules leads are long enough to reach the inverter. With a 4 input inverter it could be 3-4 leads per 4 modules which becomes harder to wire manage - also harder to access if there’s ever problems.

In terms of product selection both of your houses are east/west orientation. Meaning you’ll never get the full production out of each module, so you’ll never be in a position where your system clips energy production. If you were south facing you could use the 880w version but in this case it wouldn’t be worth it. Bearing in mind 500w modules are 85-90% efficient in the best conditions. 768 watt is a good AC to DC ratio for that wattage of panel.”

What are you thoughts on this?

 

[Q-Dog]

Plausible. I would like to see real data from a similar install they have done in your area. Will they offer a performance guarantee?

 

[Ampster]

1000 Watt panels on a 750 Watt inverter is a DC to AC ratio of 1.33 to 1 which is fairly common..the panels do not reach full capacity except under rare conditions. The occasional clipping is offset by the extra production from having a larger panel in winter and cloudy days. Annual production is the important metric to optimize.

 

[740GLE]

What have other quotes provided you for set up and installs?

 

[Derka181]

What have other quotes provided you for set up and installs?

No other quote I’m getting cost plug 5% with a buddy’s company

 

[SeaGal]

In terms of product selection both of your houses are east/west orientation. Meaning you’ll never get the full production out of each module, so you’ll never be in a position where your system clips energy production

Never say never... BUT, the ratios sound plausible.

I have E-W config ground mounts in UK; they are only at 15 degrees tilt and in high summer can produce about 5.5kW from 6.6kWp theoretical max.

Assuming yours are at a greater tilt angle, being on the roof AND being more northerly in Canada I suspect the ratio is about right. It is common to overpanel anyway, as others mentioned.

If you want to check out your expected output, with your location and tilt you could one of the online tools for calculating solar yield.

 

[wpns]

My main issue with micro inverters is that they work fine (plus or minus RFI as in the other recent thread) when your system is grid tied, net metered but when things change (and believe me, your power company is trying to change that deal) it’s really difficult to pivot to adding batteries or swapping your inverter for other operating modes. Monolithic string inverters are much easier to convert/replace for whatever next year’s requirements are.

 

[Ampster]

Monolithic string inverters are much easier to convert/replace for whatever next year’s requirements are

That is a good point but AC coupling is a reasonable workaround for adding a hybrid inverter later. . In retrospect, had I known that I was going to install a SolArk, I probably would have started with the SolArk and incrementally added AC coupled capacity later.

 

[wpns]

That is a good point but AC coupling is a reasonable workaround for adding a hybrid inverter later.

Indeed, until the AC coupled power is more than your load and battery charge requirements. Lots of threads here about AC coupled systems both on (when zero export required) or off-grid having issues. Really glad I’m decomissioning my grid-tie inverters, though two of them are less than a year old.