u/Accomplished_Quit577

Looking to DIY a solar PV retrofit on a nearly 12-year-old timber pergola facing approximately 230° SW, along with adding whatever additional capacity I can fit onto a slate roof extension. This will be a DIY expansion to a 5kW 8.28kWp north/south solar array installed professionally on the main roof.

Pergola/slate roof dimensions are:

- Width: 487 cm
- Length: 366 cm
- Angle: 5-10º

I plan to remove the existing plastic roof sheets and fully cover the pergola with solar panels.

The panels I am considering are approximately:

- 176.2 cm × 113.4 cm
- ~460-495 W

Based on the available space, I estimate I can fit:

- 8 panels on the pergola in portrait orientation
- 4 panels on the slate roof in portrait orientation
- 2 panels on the steel shed roof in landscape orientation

There is occasional shading from a chimney, mainly during winter and shoulder months. By around noon the shading usually clears from the left-most panels, and during spring/summer/autumn it is generally not an issue.

Pergola structure details:

- 7 horizontal rafters
- Approximately 60 cm spacing between rafters
- First rafter is partially hidden beneath the roof soffit

The usable roof depth is likely closer to ~300 cm rather than the full 366 cm, which would leave approximately 25cm panel overhang on each side of the pergola. Assuming the mounting is structurally secure, is this considered acceptable?

Planned equipment:

- Solis S6 6 kW hybrid inverter
- Inverter mounted inside a steel shed
- Electrical final connections completed by an electrician
- I would DIY the panel mounting and purchasing
- Planned cable runs:
- 6 mm² SWA power cable
- 2 × outdoor-rated CAT6 cables

Questions:

1. What is your assessment of the overall viability of this setup?
2. There are two skylights on the slate roof — what clearance margins should be maintained around them?
3. Which mounting system would best suit:
4. - the timber pergola
5. - the slate roof
6. Would the pergola array and slate roof array typically go on the same string?
7. What is the best way to weatherproof the pergola underneath and prevent rain ingress once the panels replace the plastic sheets?
8. I also have a steel shed with one roof face oriented north and the other south

, both at angle 25-30º—could I fit 2x700w panels on either side on separate strings?

Thanks in advance.

Looking to DIY solar panel retrofit of a nearly 12 year old timber pergola facing 230º SW along with whatever I can get onto slate roof extension. Width is 16ft (488cm) and Length 12ft (366cm). I will be replacing the plastic sheets to be covered with all panels.

Solar PV dimensions are ~1762 × 1134 mm for a 480w 54 cell panel, so given the space I would be able to fit 8 on the pergola in portrait and 4 on the slate roof in portrait. There is occasional shading, particularly in winter and shoulder months from a chimney but by noon it typically clears up on the left most panels and in spring/summer/autumn it usually not an issue.

The pergola has 7 rafters horizontally spaced 60cm between each and the first rafter is hidden under the soffit of the roof.

The usable surface area is 12ft (366cm), most likely ~300cm which would mean panels would have approx 22cm overhang on each side of the pergola, is this acceptable if it’s bolted down well?

I’d go with a 6kW Solis S6 hybrid inverter in that steel shed and wiring will be done by an electrician but the purchasing and mounting I would need to DIY. I will lay 6mm SWA power cable and 2x CAT6 outdoor rated data cables.

What’s your assessment on viability?

There are two skylights and how much margin do I need to keep?

Which mounting system would work best here?

Would pergola and slate roof be on the same string?

How do I keep the rain out underneath?

I’ve a steel shed in the back one facing north other south, I could get 2x700w larger cell panels onto them but not sure how they’d be handled, two separate strings?

Thanks in advance.

Just my luck—after spending a couple hours prying open the locking mechanism on my old uPvc door, only to realise at the very end the lock is way too big for the door. There is no way I can see this being retrofitted without cutting part of the door frame. Not just that, the thumbturn knob itself cannot be pulled down without hitting the nuki lock. No idea how they could design something like this to be retrofitted without taking into consideration clearance issues.

Am I out of luck? Short of replacing the entire door, there’s no way I can see this being installed.