Are North Facing Solar Panels a Waste of Money? Our February Data Doesn't Lie.

Well, that's totally changed my mind on optimisers and our NE roof - thanks! Also, I think a really interesting piece of analysis would be the amount of storage you could have used each day. i.e. the lessor of the amount you imported or exported. Most people aim to match their daily usage, but I suspect maximum ROI would be for a much smaller battery - just enough to soak up the excess and get you through the night.

Thanks for sharing. Your system output almost exactly what ours did for Feb. We only have 17 panels, but 13 are south facing and 4 are west facing (all 420w panels and we don't have any other usable roof space for more). Being better orientated on balance, we saw better output on sunny days, over 20kWh was repeatedly achieved, but on the cloudy days your system beats ours hollow. Very interesting to compare the 2 on a day by day basis. From this I conclude ours will do better on sunny days until the sun gets high enough for your lovely north facing panels to get excited. Then your overall panel capacity will win out. In the winter, where dispersed light is more prevalent, your system's north panels will be very influential, as you pointed out. During the summer we will both be exporting like mad, so surely it is the winter production that is more influential in our overall self-consumption. You did the right thing putting that north facing array in! We have optimisers on all panels due to shading and a single string. I believe you will see much more influence from your optimisers as the direct sun gets cut out by shading from your roof.

Main takeaway for me is don’t simply write them off as *bad*. Surface area can help a lot to make it a more nuanced decision. And indirect light on dull days can be surprisingly good for covering base load

Good vid. Seems like an incredibly good result for the NW facing panels. It's made me rethink my assumptions on them, never a bad thing! As you say, they must like diffused light conditions. Be interested to see their relative output over the year, to see how they stack up versus the SE panels. Cheers.

Have just got solar quote on our south facing roof (9) and on our south facing garage (8), now you got me thinking of the other side of my roof!

Great video - you may have saved my sanity as I debate what to do in my (Dorset) renovation! My property is also NW/SE but with some tree shading on the SE side. Octopus declined to quote, based on my trees and those on the opposite side of the road, stating the Tigo optimiser wouldn't be sufficient - which made me sceptical about the whole concept, (despite currently seeking permission for extensive tree work - unrelated to PV installation, I should add). I too want to go to ASHP - if I don't do it now, I never will! Well, I've just requested a survey from Dorset Solar Solutions, thanks to your experience/recommendation.

Hi, I have a NNE/SSW split for the reasons you mention in the video - on an overcast day it doesn't really matter what orientation the panels are, and those are the days that you need as much as possible. I find that compared to most people on YouTube, my system has less variation between good days and bad days.

Nice video. I hadn't considered the diffuse light point. I suspect the NW roof will also benefit from direct sunlight later in the day in summer. For anyone on octopus flux, that will be quite lucrative given the higher export rate from 4-7pm. I think it will be very informative to see how the SE to NW generation ratio varies over the year. It might debunk the 'only get solar if you have a south facing roof' view that is heard a lot.

Great video, and your summary was bang on. Defuse light works well with my array, so i expect you will be looking for a bright, cloudy summer. My only concern would be algae that may form on the north facing panels as the sun & heat may not be enough to burn this off. What have you considered for routine maintenance in keeping them clean?

Interesting stuff! We have N facing panels on our new build due to high tree cover to the south of us and was wondering if further investment into PV was worth considering. I think the answer is yes! Thanks

Fantastic. I would love to see an average generation by hour graph. As someone who I not keen on getting battery storage it would help see how easy self utilisation would be ie how big is the mid day peak vs the early morn and late eve. Having said that. The 15p export and agile octopus means it is often better to export than use it!

I would expect the optimisers to be more active on sunny days when the sunlight is directional, rather than on cloudy days when the sunlight is scattered from all directions

I do think optimisers are oversold, they add a failure point per panel to your system too. The safety aspect of them is what might swing me, knowing if something odd happens they can disconnect the current.

Good stats & proves that we should not ignore North facing roofs for solar. I'm just about to have 5 additional 425w panels installed on our NW roof to compliment the existing 10 panels on our SE roof. Optimisers are included for the 5 new panels which will be located inside the loft space & not under the panels on the roof which is std practice. This provides easier access should any need to be replaced in the future i.e. no need for on roof access / scaffolding to effect the repairs. I'm also having an additional 9.5kWh battery installed (19kWh total). This will give us double the storage capacity, more export options & allow us to run longer into the day in winter on battery only power. After this I will be maxed out on solar & I will move on to alternatives for house heating & hot water to replace our gas boiler.

Spot on video!

Not only was this Feb the worst Feb for pv generation in the 9 winters I've had pv but the worst month, period! March is looking much better and then take off until October! It always used to be a no no for North facing panels but 3 things have developed in the last 3 years or do, 1. The efficiency has increased significantly 2. The capacity of each panel and 3. The cost now less than half. So definitely worth doing now I think, if that's your only option. Not sure about optimizers tho, unless you have a shading problem as I do slightly with the chimney. They do seem to delay or reduce the startup threshold, presumably its to do with their start up voltages. Also, ad someone else mentioned they are something else to go wrong.. the only 2 times I've had problems with my system was to do with optimiser failures and they are Solaredge, one of the best supposedly..

Would be great to see the kWh/day numbers alongside the total monthly numbers. Per day generation is perhaps most useful and intuitive, matching up with what we know about daily demand

I'm an idiot! I was interested to see how your NW panels perform, but I've actually got NW panels, but I've always referred to them as east and west, this is on my double garage installation, they are actually NW & SE, so the NW panels are exactly the same orientation as my NW roof, only difference would be 30 degrees pitch instead of 10. I need to get up there and have a measure and see what I can fit, its a large roof, but there is a chimney stack which will cause some shading mid to late afternoon onwards. This February has been the worst February for my original system since it was installed in December 2015, although Feb 2017 was only very slightly better.

Panels going up Monday down hear in Devon a 8 panel East / 10 panel West split of 18 420w with a Givenergy system with 2 x 9.5 Battery's. Adding battery's hear was near a must as they limited my export to 3.68 so holding on to 19kwh hear and using it or dumping it to grid when I want is how I have gone. the North facing you have is a good way to go with the roof space you had to work with but I can see a battery in the crystal ball in your very near future come summer your export is going to fly out and you will wish you had some of it to use later Happy to hit a sub in for you. The off grid solar powered Koi pond down hear in Devon

I installed 6 kw system due north and had two chimneys causing a sundail effect. Used a SMA inverter with Shadfix look it up. Sysytem made 3100 kwh.