Solar Array Oversizing - All the Benefits and Considerations

This video looks at a very important topic in solar installation design - solar array oversizing (sometimes called inverter oversizing).

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Chapters:

0:00 Intro
1:47 The benefits of oversizing
4:42 Higher inverter efficiency
5:32 East and West Arrays
6:12 DC coupled batteries
7:15 Quick and easy install
8:40 Less export opportunity
9:29 Lower power output
10:25 How much can you oversize?
11:14 Summary

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(c) 2024 Gary Does Solar. All rights reserved.

DISCLAIMER
Whilst every effort is made to ensure the accuracy of the content in this video, no warranty for that content is provided, nor should it be implied. Viewers acting on the content, do so at their own risk.

#solar #array #oversizing

[GaryDoesSolar]

* NOTES SINCE RELEASE *

I've been informed that some of the most recent inverters have a very flat efficiency curve that only seems to fall away 5% of the inverter rating. I don't yet have any sources to confirm this, but would welcome if you hear of any.

[emildiver]

Shocking value given for free. so well explained. Gary deserves 20X more subscribers.

[Xeldur]

Why is this the first time I hear about the interesting DC and AC battery setup, and of the oversizing of panels? Sounds kinda smart to be honest.

[artisanelectrics]

We recently installed 31kWp of panels for a house which only had a single phase supply and therefore a limit of 17kW could be connected to the grid, but we were able to use 17kW of SolarEdge inverters and oversize, works really well!

[Scarletsby]

WOW I cant beliive this video has come out today, my system has come online today and my installer recommend a 6KW inverter for my 8.1 kw total panels and 10.5 kW battery system and this video has proved him right.

[highflowhighflow]

great easy video! another positive thing with oversize array is reaching faster the minimum input voltage of the invertor so that helps getting more solarhours usefull

[ssoffshore]

Well done! The only thing I think you missed was that oversizing the array also changes the shape of the curve (same orientation) by allowing more production earlier and later in the day, as well as in cloudy conditions. Basically it will produce more earlier and later, adding to total output or area under the curve...

[coalrunner]

Thank you so much Gary. I have only just discovered your channel with this video. I installed a 5kw array with 5kw inverter a few years ago. My needs have changed dramatically since then. I now have an EV and battery and combined with a pool pump and upcoming heat pump install my system can no longer cope. I’ve been trying to find an inexpensive fix and your video has been a God send. I did not know this was a thing. Oversizing!!!! Wow. I’m a man on a mission now. Many thanks again. I’m now an avid fan and subscriber. So many more of your videos need watching.

[TCPUDPATM]

I’m planning my own system, and currently working on sizing based on the system input, and panel configuration.
I had come to the same conclusion to over-provision on the PV side, and this video further confirms this industry standard practice.
I’ve been playing around with a single 100W and 400W panel as a proof of concept, and I’ve personally seen examples of everything you’ve described. Thanks!

[FrankPloegman]

What you described is probably the solution with the highest possible available financial ROI at the moment. We need to supply power in the morning and evening (see duck curve). We do this by placing panels east-west, not toward the equator. It matters little if your setup harvests relatively less power around noon, because power will often be cheap if not free or negatively priced at that moment anyway.

Oversizing works especially well if panels are cheap and inverters are expensive, which seems to be the case. I heard from a source that I consider reliable that panels HALVED in price over the last year. Prices of inverters seem to have changed very little over the same time period.

NB: It’s important to look at your *actual* expected peak power. 25 panels of 400 Wp each placed east-west probably won’t ever actually produce 10 kW, especially if you’re farther from the equator.

If you have a DC-coupled battery you can get even more power out of your inverter.

[vijaygopalmuvva]

THANKS FOR THE WONDERFUL AND SIMPLIFIED EXPRESSION. SO INFORMATIVE AND EDUCATIVE FOR A NON ENGINEER LIKE ME.

[kencotton]

It was interesting hearing the solar energy requirements in the UK. In the US, most inverters for residential use are sized around 15kw with many being twice that size. A 3kw inverter would be something you would choose for a tiny off-grid cabin. My local utility sets a maximum of 17kw for a grid tied solar system.

[litnoregrets]

This is a great video. You explain things so well, and the graphics are excellent. Thank you so much.

[j.sancho]

First time I see one of your videos. Congratulations for such a clear and great video. I subscribed right away!

[gramos]

Very interesting, good for you .More people will take up solar when they see simplistic explanations of the solar power available . I installed 28x 400w panels at latitude angle with 2x 6000ES + inverters and 3x 9.6kw Li batteries . The result is an abundance of power on a daily basis . The system has been running for 20 months now and I am always looking for more appliances too use up the surplus. 1 inverter had a charging failure which meant that the 2nd inverter had to handle all the charging and loads . It coped well with this, thus qualifying your ( and my ) theory on over panelling . Panels have never been cheaper I encourage those looking into a PV system to add more panels than the energy audit suggests .

[obrace]

Good to see someone 'focus' in on the issues

[AlValentyn]

I did this without realising. Managed to get another 3 panels on, y Tony roof in landscape, on top of the rest in portrait. It’s really made a difference. Next looking to get some on the back roof even through it’s north east facing, maybe 4 more, and then add the batteries. While my export rate is great here in Ireland at 29c a unit, it’s dropping more and more. So batteries with extra panels make more sense.

[veronicathecow]

Thanks Gary, I must admit I thought i knew what you were going to say and I got some of it right, but you made many more points than I expected.. Excellent video content and delivery.

[JimNichols]

This is a great video and extremely informative well scripted, videography was great and the information was accurate and well spoken to the targeted audience.

Also it highlights some of the issues I have with solar power being pushed so hard. Firstly I think that solar is a wonderful thing there is no argument there at all, none, however storage is less than optimal and expensive. Then the very folks (read the government) that push the solar alternative charge you exorbitant fees to add solar above some prescribed rating to your home. Then the insult to that injury is that the folks that push the solar (read the government) on you regulate the amount of income you can receive from the power company for excess electricity that you, using the equipment bought, paid for and installed by you, kindly sell back to the grid for your neighbors usage.
If you step back and take a zoomed out view, instead of the myopic view of solar is so great and I am doing something great for the planet, then you can see that something is just not right at all with the "solar plan" the government makes, if it is needed so badly why charge crazy fees for the licensing above a certain size, the licensing for the installation, the taxes on the equipment and taxs and fees for the re-selling back to the grid?
And yes I understand the need for electrical qualified electrical installations that are inspected by those very folks. (read the government) (humor here).
Where I live there are no restrictions for solar you can add as much as your wallet allows, but I used 390 kwh of electricity last month so my 50 dollar electric bill does not make me want to install $10k worth of solar panels, inverter, solar battery managers and batteries to drop the grid.
The perfect solution was fielded by Musk at one time, electrical co-ops, where you and nine other neighbors (10 being an arbitrary number) were the entire 'grid' for yourselves. 10 homes with this oversized solar like in the video, a centralized 10 Powerwall system and 10 inverters, one in each home. No power back the real grid, and everyone shares the benefits and the costs.

[rollo]

Really useful information, thank you! We recently had a 7kW array installed with a 6kW inverter 10kWh SolarEdge battery. I wondered how the battery was able to take 5kW while still exporting 2kW to the grid and this video answered it (the battery is DC coupled). Also watched the video about batteries too. Excellent information really clearly communicated. It's hard to find this level of technical detail without the information being hard to understand.