Design
Does an east-west roof work for home solar in South Africa?
Yes — many SA homes run east-west arrays successfully when stringing, inverter sizing and winter shade are designed honestly. You trade a sharp northern midday peak for broader morning and afternoon production that often matches home and EV loads better. It is not “second-best by default.”
Updated 27 October 2026 · Illustrative ranges — not a formal quote, credit decision or legal advice.
Answer first: Judge east-west on self-use and Stage-season evenings, not only on brochure kWh/kWp versus a perfect north roof — orientation & tilt · roof suitability.
What changes on the production curve
East arrays wake earlier; west arrays carry afternoon loads (pool pumps, geysers delayed to solar, home-office peaks). Midday may look flatter than a north array. Monitoring apps that only show a single “ideal” curve confuse homeowners — monitoring.
Design rules that keep quotes honest
- Separate MPPTs for east vs west pitches where possible.
- Winter shade study (Jacarandas, double-storey neighbours, geysers).
- DC:AC ratio stated per MPPT, not one vague “oversizing” line — hybrid vs string.
- Roof load and penetration notes for both pitches — roof warranty.
When microinverters or optimisers help
Complex multi-pitch east-west roofs with chimneys and dormers often justify module-level electronics — price monitoring and spares — shade / MLPE.
Tariff and self-use fit
On Cape Town TOU or Eskom Homeflex-style schedules, afternoon west production can displace expensive blocks. Export-heavy north peaks help less if export cents trail import — Cape Town TOU · Homeflex · self-use.
Battery pairing
East-west + battery often charges earlier and later, leaving less midday surplus. Size usable kWh for evening Stage windows — Stage 4 · DoD.
Common east-west quote failures
- One MPPT shared across mismatched pitches.
- Summer-only shade screenshots.
- Payback modelled as if the roof were true north.
- No winter kWh table.
Ground-mount alternative
If both pitches are hopelessly shaded, a north ground-mount may beat a compromised east-west roof — price structure, theft and SSEG honestly — ground-mount · theft.
Installer brief sentence
“Show east vs west stringing, MPPT assignment, winter kWh, and self-use vs export on my tariff — not only north-equivalent kWh/kWp.” — read a quote.
Worked comparison sketch (illustrative)
A 6 kWp north array might edge annual yield, while a 3+3 kWp east-west split displaces more late-afternoon import on a home with after-school and EV loads. Run both against your 12-month bill — monthly savings · payback.
Closing checklist
- Pitch angles measured, not guessed.
- Winter shade documented.
- MPPT plan on the single-line diagram.
- Tariff self-use story on one page.
Confirm structural and municipal rules before deposit — get quotes · check a quote · roof space.
Cleaning and access on dual pitches
East and west pitches may need different ladder plans and fall-arrest anchors. Budget cleaning access if pollen or coastal salt is heavy — roof suitability.
Inverter placement noise
Dual MPPT hybrids near bedrooms need a noise conversation — inverter noise.
Expanding later
Leave MPPT headroom or a documented expansion path if you might add a west carport later — expand later · carport solar.
Theft visibility
Street-facing west arrays on single-storey roofs need locks and insurer notification — theft · claims.
Stringing mistakes that waste an east-west roof
Series-stringing east modules with west modules on one MPPT forces the pair to the weaker irradiance. Separate MPPTs or module-level power electronics exist for this reason. Ask to see the string map on the single-line diagram before deposit — hybrid vs string · shade / MLPE · NRS inverters.
Tilt and Highveld vs coastal climates
Existing roof tilt usually wins over building custom frames. Highveld hail and coastal wind uplift still need engineer sign-off for add-on tilt frames — orientation & tilt · penetrations · hail.
Load matching examples
- Work-from-home mornings favour east arrays.
- After-school geysers and ovens favour west arrays.
- EV daytime parking favours whichever pitch sees the driveway sun.
Map your weekday vs weekend profile before insisting on north-only — solar + EV · geyser · pool pump.
Export-limited homes
On zero-export or low credit metros, a flatter east-west curve that tracks loads can beat a tall north peak that clips against export limits — zero-export · self-use · fixed charges.
Monitoring what “good” looks like
Expect two humps, not one. A west string that dies at 14:00 in winter is a shade or fault story, not “normal east-west.” Set alerts per MPPT — fault codes · winter production.
Body corporate and aesthetic rules
Some estates reject west street-facing arrays on appearance grounds. Get written aesthetic approval before ordering modules — sectional title · estate / HOA.
Desk closing note
East-west is a design choice with maths, not a consolation prize. Demand winter tables, MPPT maps and tariff-coloured self-use on the quote — read a quote · get quotes · check a quote · choose installer.
DC cable runs on dual pitches
East and west arrays often mean longer DC runs to a single plant room. Voltage drop, earthing continuity and SPD placement must be designed, not improvised with extra MC4 barrels in the ceiling — surge · CoC.
Inverter kW vs dual-pitch kWp
A 5 kW hybrid with 6 kWp split 3/3 east-west is a different clipping story to 6 kWp all on north at midday. Ask for expected clipping hours in summer and winter on the quote appendix — hybrid vs string · UPS vs hybrid.
Scaffold and safety costs
Two pitches can mean two scaffold setups or more rope-access time. If the quote is oddly cheap versus a single north roof, ask what access method was assumed — install timeline · read a quote.
Fire-fighter and labelling notes
Dual arrays still need clear isolation labelling for emergency responders. Put label photos in the handover pack — labels · fire myths.
When to walk away from east-west
Heavy winter shade on both pitches, estate bans on street-facing modules, or a rotten roof structure can make a north ground-mount or a wait-for-reroof plan wiser — ground-mount · roof suitability · roof space.
Confirm structural letters and live tariff cents before deposit — get quotes · check a quote · payback · monthly savings.
Quote appendix lines to insist on
- East kWp / west kWp separately.
- MPPT assignment and expected summer clipping hours.
- Winter kWh table for your metro latitude band.
- Self-use vs export split on your tariff code.
- Scaffold / access method and roof penetration warranty notes.
If any line is missing, the east-west brief is incomplete — read a quote · red flags · orientation · winter.
Quick questions
Is north always better than east-west in SA?
North often wins annual kWh on a clear pitch, but east-west can win self-use timing. Compare both on your bill profile.
Do I need two MPPTs?
Usually yes — separate east and west strings on different MPPTs or use module-level electronics when pitches differ.
What about winter?
Lower sun angles and neighbour shade matter more — demand a winter table on the quote.
Sources & related
When East–West beats a crowded South face
Split East–West arrays often flatten the mid-day peak, cut inverter clipping, and serve morning kettles plus evening cooking better on TOU homes. Yield per kWp can trail a perfect North roof, yet bill savings can win if self-use rises — orientation & tilt · Cape Town TOU · DC:AC.
Shade and two-MPPT planning
Put chimneys and geezers on the string plan before you buy modules. Different azimuths usually want separate MPPTs or optimisers — shade / optimisers · MPPT.
Quote language for East–West
Ask for separate yield tables per azimuth, clipping hours, and a self-use percentage versus an all-North alternative on the same kWp budget. Without that, you are buying aesthetics — read a quote · DC:AC.