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Try it · Solar · Example report

What comes out the other end.

This is the design report Trident produces for the made-up house in the Solar Try it. Every figure on this page was worked out by Trident's own engine for this example, not typed in.

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Solar PV design report

14 Example Street

Example Solar Ltd · prepared with Trident Solar · example data

System
7 × DMEGC 465 W · 3.25 kWp
Inverter
SolaX X1-BOOST-3.6K-G4
Grid
G98, notify after install
Network operator
National Grid Electricity Distribution (South West)

One thing to sort before install: at the standard 1,200 mm roof-hook spacing the fixings fall short of the wind uplift. At 900 mm they pass. See section 2.

1. Placement

EAVE · SOUTH RIDGE CHIMNEY VENT

400 mm boundary DMEGC 465 W panel

Household use2,700 kWh a year (Ofgem typical, example)
Panels to cover it7
G98 limit7 panels (3.68 kW ÷ 465 W)
What the roof fits9, inside the 400 mm boundary
Designed7 panels, 3.25 kWp: one block from the eave
Face usedSouth, 35° pitch
Not usedNorth face (faces away; chimney), east and west hips (not needed)
ObstructionsSoil vent kept clear
PanelDM465G12RT-G48HBB, 1762 × 1134 mm, 24 kg

2. Wind, snow and fixings

EN 1991-1-4 UK NA + BRE Digest 489 · EN 1991-1-3 UK National Annex · combined to EN 1990 Expression 6.10

Wind
Basic wind speed, map (south west)23.0 m/s
Altitude 40 m, factor1.04
Basic wind speed23.92 m/s
Peak velocity pressure, 7.5 m, open terrain784.4 Pa
Net uplift coefficient (BRE 489, central zone)-1.3
Design uplift (× 1.5)1.530 kN/m²
Less dead load (15 kg/m²)0.147 kN/m²
Net uplift on the fixings1.382 kN/m²
Snow
Snow zone1
Ground snow load, zone base0.30 kN/m²
At 40 m altitude0.336 kN/m²
Shape coefficient at 35°0.667
Roof snow load0.224 kN/m²
Panel front load rating5,400 Pa
CaseUndrifted. Drift not calculated: the report says so.
Fixings (C16 timber, 1.406 kN pull-out per hook)
Hook spacingFixing capacityNet upliftResult
1,200 mm1.172 kN/m²1.382 kN/m²Fails: engineer review
900 mm1.562 kN/m²1.382 kN/m²Pass

Roof structure, rafter positions and hook spacing to be confirmed at survey. Dynamic analysis: not required, h < 15m, natural frequency > 5 Hz per EN 1991-1-4 §6.2.

3. Strings and inverter

IEC 62548 + manufacturer datasheets · coldest day -5 °C (south west), hot cell 70 °C

CheckValueLimitResult
Open-circuit voltage on the coldest day 274.36 V 600.00 V Pass
Short-circuit current per MPPT input 15.88 A 16.00 A Pass
DC to AC ratio 0.89 1.96 Pass
Strings on the inverter inputs 1 string on 2 MPPT inputs 1 input per MPPT Pass

One string of 7 on MPPT 1. Panel Voc on the coldest day 39.19 V; Vmp hot 27.70 V; strings may be 2 to 15 panels on this inverter.

4. Network operator

RouteEREC G98 — Notification (auto-connect, <=3.68kW/phase)
Why16.0 A/phase vs 16 A/phase G98 statutory limit (EREC G98/G99) — 1φ at 230 V nominal
WhenInstall, then notify the DNO within 28 days of commissioning
FormG98 Form B: G98 Notification
MPAN2200001234569 · check digit valid · distributor 22
Network operatorNational Grid Electricity Distribution (South West)
Export3.68 kW, not limited
Interface protection (EREC G98 Issue 1 Amendment 7 (2022))
Under-voltage (Vφ-n −20%)184 V · 2.5 s
Over-voltage stage 1 (Vφ-n +14%)262.2 V · 1 s
Over-voltage stage 2 (Vφ-n +19%)273.7 V · 0.5 s
Under-frequency stage 147.5 Hz · 20 s
Under-frequency stage 247 Hz · 0.5 s
Over-frequency52 Hz · 0.5 s
Loss of mains (RoCoF)1 Hz/s
Labels to fit (5)
  • Main service point: "PHOTOVOLTAIC SYSTEM ON SITE" (BS 7671 §712.537.2.2.1.1)
  • Point of interconnection (G100 scheme or back-feed): "UTILITY INTERCONNECTION — BACKFEED PRESENT" (BS 7671 §712 / ENA G100)
  • DC isolator: "PV ARRAY D.C. ISOLATOR" (BS 7671 §712.537.2)
  • DC junction / combiner box: "DANGER — CONTAINS LIVE PARTS DURING DAYLIGHT" (BS 7671 §712.537 warning)
  • AC isolator + consumer unit: "SOLAR PV AC ISOLATOR — SWITCH OFF BEFORE WORK" (BS 7671 §712.537.2)

5. Single-line diagram

Single-line diagram From the 7-panel array through the DC isolator, inverter, AC isolator, generation meter and breaker to the consumer unit, meter and the network operator's cut-out. DC · ROOF AC · HOUSE NETWORK PV array 7 × DMEGC 465 W · 1 string of 7 in series + / − DC isolator ≥ 600 V DC · BS EN 60947-3 inverter maximum input voltage; current ≥ 1.25 × module Isc per string SPD Surge protection: Type 2 — if required by BS 7671 Section 443 risk assessment = ~ Inverter X1-BOOST-3.6K-G4 · G98 type-tested · 1 phase 16 A inverter maximum AC current (datasheet) AC isolator ≥ 16.0 A · 16 A 2-pole 2-pole (L+N) switch-disconnector, sized to the inverter's maximum AC current kWh Generation meter Generation meter (MID-approved) · Between inverter AC output and consumer unit CONSUMER UNIT (EXISTING) MAIN SPD MCB for the solar circuit MCB, In ≥ 16.0 A (16 A standard size); cable Iz ≥ In BS EN 60898 / BS EN 60947-2 · 16 A inverter maximum AC current (datasheet) Main switch rating to confirm at survey M Supply meter existing · confirm at survey Point of Common Coupling Single Phase · DNO service cut-out (fuse rating: confirm at survey) DNO cutout fuse, inside the property boundary Earthing: TN-C-S, TN-S or TT, confirm at survey · frame bonding per BS 7671 Section 712, confirm at survey
Drawn from the network operator pack for this design. Amber items are site facts Trident can't know from the address, so the surveyor confirms them.

6. To confirm at survey

  • Roof structure, rafter positions and the hook spacing (section 2)
  • Earthing arrangement: TN-C-S, TN-S or TT
  • Cut-out fuse rating and the consumer unit's main switch

The real report also carries the generation estimate (MCS method, with the cautious P90 figure beside it) and shading for each panel. They're left off this example.

See your own roof designed

Bring three addresses you're quoting this month. On a 30-minute Teams call I'll design them in front of you, and you'll get this report for each.

Book a demo with your addresses

Or ring me, Steven Hassall, on 07807 025270. I built Trident and I'll be the one on the call. Email works too: hello@trident-os.com.

If it isn't right for how you work, I'll tell you.

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