East-West Solar Panels: The Split-Array Truth
Told your east-west roof is wrong for solar? It isn’t. A split array makes ~80–88% of a south roof’s output — and often beats it on the savings that actually reach your bank account.
The short answer
East-west solar works, and the “you need south-facing” line is a myth. A split array — panels divided across the east and west slopes of a pitched roof — generates around 80–88% of a south-facing system’s annual output. That modest shortfall comes with a real advantage: instead of one sharp midday peak, you get two gentler peaks (morning east, evening west) — a flatter curve that matches when people are actually home using power.
And that’s why the headline percentage misleads. Savings are driven by self-consumption, not total generation: a self-used unit saves ~26p, an exported one earns just 4–15p. South-facing homes without a battery self-consume only ~35–40%; east-west hits 45–52% — often enough to beat south on actual bill savings for out-all-day households. On a flat roof, east-west can out-yield south outright (denser packing). South still wins if you have a battery. The full picture — east vs west, the flat-roof bonus, and when south wins — below.
What this guide covers
“My roof faces east-west, so solar’s not worth it” is one of the most persistent and costly myths in UK solar — costly because it stops people saving money they easily could. The truth is more interesting: east-west is not a compromise you settle for, but a configuration that, for a large share of households, is genuinely the better choice. Here’s the honest, numbers-first case.
The south-facing myth — and why it persists
South-facing does produce the most total electricity in the UK — that part is true, and it’s why the myth has legs. But it’s been quietly overtaken by how the modern energy market actually works. When electricity was cheap and export payments generous, maximising total generation made sense, and south won. Today, with grid electricity around 26p a unit and export paying only 4–15p, what matters is using your own power rather than selling it — and that reshuffles the deck entirely. As installers increasingly report, the biggest mistake homeowners make is assuming their roof is the wrong direction without checking: countless properties dismissed as “north-facing” turn out to have perfectly good east or west slopes, and east-west splits are now a deliberate design choice recommended for households with typical working patterns, not a fallback. The genuine underperformer is north — east and west are firmly in the “works well” camp.
How much less than south? The honest numbers
| Configuration | Annual output vs south |
|---|---|
| South-facing (benchmark) | 100% |
| East-west split (pitched roof) | 80–88% |
| Single west-facing array | ~75–80% |
| Single east-facing array | ~75–80% |
| East-west split (flat roof) | Can exceed 100%* |
| North-facing | ~50–60% |
*Flat-roof east-west fits more panels per m² — see below.
The consensus across UK installers in 2026: a pitched east-west split produces about 12–20% less total electricity a year than south — so 80–88% of south’s output, most commonly landing 80–85%. A single east or west array (not split) sits a little lower at roughly 75–80%. In real figures: where a south-facing 4kW system makes ~4,400kWh a year, an east-west split of the same size makes roughly 3,500–3,800kWh. That looks like a clear south win — until you remember that your savings depend on how much you use, not how much you make. Which is the whole point of the next two sections.
The twin-peak curve: east-west’s secret weapon
A south-facing array produces a single sharp peak around midday — a tall, narrow spike of generation concentrated in the middle of the day. An east-west split produces something quite different: the east panels peak mid-morning, generation dips gently through the middle of the day (when neither face catches the sun head-on), then the west panels build to a second peak in the late afternoon and early evening. The result is a flatter, wider curve spread across far more daylight hours. Picture the two shapes side by side: south gives you a lot of power in a short window; east-west gives you steady power across the morning and evening. For most households that shape is simply more useful — because it delivers electricity when people are home to use it (breakfast and the morning rush, then the evening return) rather than at lunchtime when the house is often empty. That timing difference is worth real money, as the next section explains.
Why self-consumption changes everything
Timing beats volume: the 5:1 rule that makes east-west win
Self-consumption — the share of your solar you use directly rather than exporting — is the single biggest driver of solar savings, because a unit you use yourself saves you ~26p (grid electricity avoided) while a unit you export earns just 4–15p. That’s a value gap of up to 5 to 1 in favour of using your own power — which means when you generate matters more than how much. Here’s where east-west’s curve pays off. A south-facing array dumps most of its output in a midday spike, when a typical household is out or barely using power — so without a battery, south-facing homes self-consume only about 35–40% and export the cheap rest. An east-west split, generating morning and evening, self-consumes 45–52% because it produces when people are home. That higher self-consumption can more than cancel out east-west’s slightly lower total output — meaning for an out-all-day household without a battery, east-west often saves more money than south despite generating less. It’s the clearest case in home solar of timing beating volume, and the reason the south-facing obsession misses what actually fills your bank account. (Want to lift self-consumption further? Our battery and tariff guide shows how.)
East vs west: if you must pick one
Given the choice, split across both — it beats committing to either, capturing morning and evening alike. But if your roof genuinely forces a single direction, west edges it for most households. West-facing panels generate through the afternoon into the early evening, aligning with peak home occupancy (the after-work return), the evening cooking-and-appliances demand spike, and — if you have one — the ideal window to fill a battery for evening use. East-facing panels generate in the morning, which suits early risers, households with a heavy breakfast-time routine, or anyone home and active before lunch. Neither is wrong, and both trounce the “south or nothing” myth — even a single east or west array reaches ~80% of south’s output, so there’s no bad choice here, only a best-fit one. Match it to your daily rhythm: evening-heavy usage leans west, morning-heavy leans east. (Where slopes face genuinely different directions, panel optimisers stop one orientation dragging the other down — worth asking your installer about.)
The flat-roof bonus: when east-west out-yields south outright
On a flat roof, east-west can beat south on total generation too — the one situation where it wins on raw output, not just savings. The reason is geometry. On a flat roof, south-facing panels must be tilted up on frames and spaced in rows so each row doesn’t shade the next, wasting much of the roof on gaps. An east-west layout mounts panels back-to-back in a low “A-frame” at a shallow 10–15° tilt, facing opposite ways with no shading gaps needed between them — so the roof packs far more densely. The upshot: an east-west flat-roof system fits around 25–30% more panels than a south-facing layout on the same roof, and that extra capacity typically more than makes up for each panel’s lower efficiency, producing more total electricity from the space. Stack on the usual east-west perks — flatter curve, higher self-consumption, cooler-running panels that clip less at the inverter — and for flat roofs the east-west A-frame is frequently the outright best design. It’s why it’s the default on commercial flat roofs and increasingly on domestic ones, and the low tilt handles wind loading with less ballast too.
When south still wins — the honest exceptions
This guide isn’t anti-south; south genuinely wins in clear cases, and naming them is only fair. The big one: if you have (or will add) a battery, south’s advantage returns. A battery does the same job east-west does naturally — shifting energy from generation-time to use-time — so with storage you can capture south’s higher midday output and spend it in the evening anyway, making south’s greater annual yield the deciding factor. Second, if your goal is maximum total generation or export income (a generous export tariff, or simply wanting the most kWh), south’s higher output wins. Third, if you already have one good south slope with room for all your panels, there’s no reason to complicate it. The clean summary: south is best for battery homes and maximum-generation goals; east-west is best for no-battery, self-consumption-focused, daytime-absent households — which is a very large share of UK homes. Neither is universally right, which is exactly why a good installer models both against your actual roof and usage rather than reciting “south is always best.”
Frequently asked questions
Do east-west solar panels work in the UK?
Yes — well. A split array makes ~80–88% of a south roof’s annual output, with a flatter twin-peak curve (morning and evening) that often matches household usage better. The “you need south” line is a myth; east-west is installed across Britain every day with good returns.
How much less than south do they produce?
A pitched east-west split makes ~80–88% of south (12–20% less); a single east or west array ~75–80%. But savings depend on self-consumption, not total output — so east-west often saves more despite generating less. On a flat roof it can out-yield south.
Should panels face east or west?
Split across both if you can — it beats either alone. Forced to pick one, west edges it for most (afternoon/evening generation matches home occupancy and evening demand). East suits morning-heavy households. Both reach ~80% of south, so there’s no bad choice.
Why is self-consumption so important?
A self-used unit saves ~26p; an exported one earns 4–15p — a 5:1 gap, so timing beats volume. South-facing homes self-consume ~35–40% without a battery; east-west hits 45–52% by generating when you’re home — often enough to beat south on real savings.
Is east-west better on a flat roof?
Often yes — outright. A low back-to-back A-frame needs no anti-shading row gaps, fitting ~25–30% more panels than tilted south rows, which usually out-generates south in total. Plus flatter curve, higher self-consumption and less ballast. The flat-roof default.
When is south still better?
If you have a battery (it time-shifts south’s midday output, so higher total yield wins), if you want maximum generation or export income, or if you already have one good south slope. South for battery/max-output homes; east-west for no-battery, daytime-out homes.
Not a compromise — often the better roof
The bottom line: An east-west split makes ~80–88% of a south roof’s output, but its morning-and-evening curve lifts self-consumption to 45–52% (vs south’s ~37% without a battery) — so for out-all-day, no-battery households it often beats south on actual savings. On a flat roof it can out-generate south outright thanks to denser packing. South reclaims the edge if you have a battery or want maximum output. Don’t let anyone tell you a non-south roof rules out solar — get both modelled for your usage.
Get my free quotes →The verdict
East-west solar is the clearest example of how the old rules of thumb have quietly stopped being true. South maximises generation; east-west maximises usefulness — and in a world where using your own power is worth roughly five times more than selling it, usefulness is what fills your bank account. For the very common household that’s out during the day, has no battery, and uses most of its power at breakfast and dinner, an east-west split isn’t the consolation prize for lacking a south roof — it’s frequently the better system, and on a flat roof it can win on sheer output too.
So if your roof runs east-west, the honest message is: relax, and check the actual numbers rather than the myth. The only way to know whether east-west or south suits your home is to have both modelled against your real usage, roof and battery plans — which is exactly what a good installer does. A couple of free, no-obligation quotes from MCS-certified installers will show you your roof’s genuine potential, no south-facing dogma attached — and very possibly reveal that the roof you were told was “wrong” is quietly one of the right ones.
Important
Going Solar UK is an introduction service, not an installer. This guide is general 2026 information: solar yield, self-consumption and savings vary with your roof, pitch, location, shading, usage pattern, tariff and whether you have battery storage – the figures here are typical estimates, not guarantees. Always have your specific roof and usage modelled by a qualified installer before making decisions. Rates and tariffs change; confirm current figures at the time.
We may receive a commission when we introduce you to an installer, at no cost to you. Any contract for work is directly between you and the installer.