I bought a 12 year old Autotrail Cheyenne Motorhome in 2020. It was in great condition, but the electrics would have been regarded as a little dated even in 2008. The following series of posts discussed the various upgrades carried out. Some of the changes mentioned I later changed further in fact, so this is pretty much a Journel of Adaption
Part Six. Added the Solar Array
Panel Installation
Now the weather is improved, been working on the solar setup for the motorhome.
Bought the panels ages ago, carefully selected to maximize the use of the space across the roof and between two vents.
The panels are 90W Mono ones from Victron, as mentioned chosen due to their dimensions. Got a total of 3 panels which nicely cover the space. These will be fitted to the roof rack – using mechanical fittings as I am more more comfortable with a physical mounting than adhesive and as the rack is there may as well make use of it
I was originally intending to make the array tiltable but when I started building the frame I though long and hard on this matter and decided that in reality I really would be unlikely to get up on the roof to do the tilting, plus the way I would have set up the tilt direction in order to have access to do it would not suit how I would want to position the van anyway. So tilting is out.
Cut two strips of angle to the length of the three panels and mounted the panels front and rear to them
Used industrial style self-tappers to secure the panel to the angle section.
The underneath….
To secure the angle to the rack, I used 38mm (1.5″) exhaust-type clamps. This is the frame secured (there are two connecting sections to help with the positioning)
And the panels secured
Also drilled the roof to get the cables outside and routed to the array.
Slightly annoyingly, the cables were around 2″ shorter than I would have liked for the neatest job, so that will be dealt with on Tues or Weds when a new combiner kit arrives which will effectively lengthten the cables by around 3″. Once that is done, I will put the black solar cables in a length of conduit against the side.
I am having the 3 panels connected in Parallel as a precaution against shading as there is an opening roof vent directly in front of AND behind the middle panel and so it is possible I could be shading that panel.
The new Combiners arrived today and are just the ticket to allow the extra cable reach and which will mean I can get some conduit in place once it stops snowing! Have to say it is so nice to have solar harvesting again – makes such a difference to get free charging again
Now I have the new Combiners, time to fit the conduit …
Before:
After:
Pleased with how that has worked out.
[SPOILER ALERT: I added more panels to the roof array at a later date and will document that. I am leaving this section showing the initial installation as it is all part of the ‘journey’ I went on modifying and updating the Motorhome]
Harvesting Data
Just did a quick look at what the array is doing …. (note that these screenshots are from different dates so the values may appear to jump around a bit)
For the time of day and I also have a large pine that blocks “prime time” harvesting as well as other parts of the day, 53W is looking quite nice. be interesting to see tomorrow when the panels are connected throughout the day.
This shows the information from the VictronConnect app and also the ‘advanced’ view from VRM – It shows how the same data is shown in the different systems and you can chose which you prefer and suits you.
The numbers for Solar Watts, Solar V&C and Battery V&C may often not match precisely as VE.Connect is real-time and the detailed VRM info is sampled data once a minute at the very fastest. Battery Temp usually moves a lot slower so likely would always be a match.
Just got back from a trip into town and found a very surprising result!
Today is a pretty yucky day – cold, miserable and rainy -so I don’t expect much from the solar.
But ….. a very surprising peak and harvesting from the PV array
I would not expect to see 261W from a 270W array until the summertime. There must have been a clear bit of sky just as the sun was overhead.
Just checking what is going on today and ….
268W yield from my 270W array is really good I think. These are Victron Panels I have fitted and I am wondering if, like other Victron kit, they are “under-declared” in terms of their true capacity?
And with 253W into the battery – so a 94.5% efficiency – that is a pretty decent conversion rate as well by the controller.
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