East-west vs south-facing solar in the UK: yield, self-use, and the real trade-offs
Should you put panels on an east-west roof or keep everything south-facing? A UK-specific, numbers-first guide to yield, self-consumption, export, and when east-west can actually win on savings.
East-west vs south-facing solar in the UK: yield, self-use, and the real trade-offs
If you have a south-facing roof, solar is straightforward.
If you have a typical UK roof with two slopes, the real question is often:
Do I split panels across east and west, or concentrate them on the “best” side?
If you want to ground this in your local baseline (not generic internet advice), Find your postcode and compare layouts against your region and tariffs.
This guide explains the trade-off in the way that actually matters in the UK: not just annual kWh (kilowatt-hours, your energy total, see Glossary), but when that kWh arrives, and how much of it you use at home.
We will anchor examples across the country, from the higher-output South Coast to colder, darker northern latitudes.
Postcode examples used in this guide:
- CT1 (Canterbury)
- GU1 (Guildford)
- BH1 (Bournemouth, Christchurch and Poole)
- B29 (Birmingham)
- YO1 (York)
- M20 (Manchester)
- SA1 (Swansea)
- AB15 (Aberdeen City)
You will also see a few spot references to:
- LE1 (Leicester)
- G12 (Glasgow City)
- BT9 (Belfast)
Quick answer: is east-west solar better than south-facing in the UK?
- South-facing usually produces more annual kWh per installed kWp (your system size rating, see Glossary).
- East-west often produces less annual kWh, but spreads generation across the day, which can increase self-consumption.
- If your home uses electricity in the morning and late afternoon (common in the UK), east-west can reduce midday export and raise the share you use at home.
- The “better” option is usually the one that produces the most valuable kWh for your household, not the most kWh on paper.
- If you are deciding between layouts, do not guess. Use your local baseline and tariffs.
If you want a grounded baseline for your roof and region:
Check your postcode: SolarByPostcode
Assumptions and variability
- We assume your roof is broadly usable for solar (no severe shading for most of the day, no structural constraints that force a single layout).
- We assume you are comparing like-for-like periods (season and weather swings can dwarf small layout differences).
- Results vary most with roof pitch, shading, and how your household uses electricity (quiet midday vs busy mornings/evenings).
- Export value depends on your tariff, so “more kWh” is not always “more savings”.
- For how SolarByPostcode estimates local output and savings, see Data sources and methodology.
The mistake people make: judging layouts by annual kWh alone
A south-facing array tends to produce a bigger midday peak.
An east-west array tends to produce a flatter, wider curve.
That shape difference is the entire story, because it determines how much solar lands during the hours you are actually using electricity.
If you live in a higher-yield part of the country like BH1 (Bournemouth, Christchurch and Poole) or GU1 (Guildford), the midday peak can be big enough that export becomes the default, unless you actively shift usage.
In darker winter months further north, like AB15 (Aberdeen City) or G12 (Glasgow City), the peak is smaller, but the “timing” argument still matters because winter generation is already limited.
The core concept: valuable kWh, not total kWh
A kWh is not equally valuable in all situations.
For most UK homes:
- Self-used kWh replaces imported electricity at your unit rate.
- Exported kWh is paid at your export rate (often lower).
So even if east-west produces fewer kWh overall, it can still deliver similar or better savings if it increases the share you use at home.
Here is the simplified trade-off:
This is why a blanket statement like “south is best” is only half true.
South is usually best for raw yield.
But for savings, east-west can be surprisingly strong, especially if your daytime demand is not perfectly aligned with a midday spike.
Why UK households often benefit from east-west timing
Many UK households have a demand pattern like this:
- small daytime base load
- morning spike (kettle, showers, breakfast, school run chaos)
- midday dip (house empty or quiet)
- late afternoon and evening spike (cooking, lights, screens, laundry)
That pattern shows up whether you live in CT1 (Canterbury) or M20 (Manchester). The difference is that the South East often has a higher generation ceiling than the North West, so export waste can become more visible.
If you want a regional intuition anchor:
East-west does not magically create more energy. It often creates more usable energy.
How much yield do you lose with east-west in the UK?
There is no single percentage that is always correct, because roof pitch, shading, and local weather matter.
But in practice, compared with an equivalent south-facing layout at a good tilt:
- East-west often produces somewhat less annual kWh.
- The trade is that it produces more earlier and later in the day.
The simplest way to use that in decision-making is:
1) Check your local baseline yield (postcode).
2) Check whether your likely self-use fraction improves enough to offset the kWh reduction.
If you are doing solar maths, do it with your actual household assumptions. This sizing guide pairs well with the decision:
When south-facing is clearly the better choice
South-facing tends to win when at least one of these is true:
1) You have high daytime demand (or you can create it)
If someone is at home all day, or you can reliably run loads at midday, a south-facing peak is easier to exploit.
Think home office usage in GU1 (Guildford) or a household with daytime appliances, hot water scheduling, and an EV that can charge mid-day.
2) You have a strong export rate
If your export rate is unusually good, export becomes less “wasteful”.
In that case, maximising kWh can be closer to maximising value.
3) You are constrained by roof space
If you can only fit a small number of panels, then squeezing maximum kWh out of each panel matters more.
A compact south-facing array on a smaller roof in CT1 (Canterbury) can outperform an east-west split simply because every panel is doing the most it can.
4) Shading is asymmetric
If one side is shaded heavily for meaningful parts of the year, you do not “average” your way out of it.
In many UK streets, one slope can be much cleaner than the other.
In that case, a concentrated layout on the clearer aspect can beat a balanced split.
If your underperformance confusion is driven by graphs and peaks, these two guides will save you time:
- Cloud cover vs solar output: what actually happens on overcast UK days
- Why your solar panels will never hit their rated output (and why that’s completely normal)
When east-west is the smarter choice
East-west tends to be attractive when at least one of these is true:
1) Your home is empty or low-demand at midday
This is extremely common.
If your midday peak is mostly exported, a bigger peak does not help your bill much.
A flatter profile can reduce export and raise self-use.
This tends to show up quickly in urban areas like B29 (Birmingham) and YO1 (York) where household schedules are not “solar aligned”.
2) You have two good roof slopes and want more panels
Many UK roofs are effectively built for an east-west split.
If your only “good” roof is small, going east-west can allow a larger total system size without dumping everything into a midday peak.
That can be especially helpful when you live in regions with a strong summer ceiling like Southern.
3) You want better morning and late afternoon generation
This is the underrated part.
East-facing panels can help cover the morning spike.
West-facing panels can help cover late afternoon and early evening.
That is a good match for typical household use patterns, whether you are in SA1 (Swansea) or M20 (Manchester).
4) You are worried about inverter clipping on bright days
A very peaky south-facing system can hit inverter limits during bright midday periods.
Spreading generation across the day reduces peak power and can reduce clipping.
This is not always a major factor in the UK, but it can show up in higher-yield areas like BH1 (Bournemouth, Christchurch and Poole), where clear bright spells can create sharp peaks.
Regions: why “best aspect” advice changes across the UK
UK latitude and cloudiness shape the baseline.
A south-facing system in the South East will often have a different “headroom” than a system further north.
Use these region hubs as your macro baseline before you compare screenshots from different parts of the country:
- South East England
- Southern
- West Midlands
- East Midlands
- North West England
- North Wales + Merseyside
- South Wales
- North Scotland
A practical intuition check:
- If you are in the South East (for example CT1 (Canterbury)), you often have more total generation available, so the question becomes “how do I use it?”.
- If you are further north (for example AB15 (Aberdeen City) or G12 (Glasgow City)), winter generation is limited anyway, so over-optimising for peak power can be the wrong instinct.
A simple decision framework that works in real homes
Use this as a practical chooser.
Choose south-facing (or mostly south) if:
- you have one clearly best roof and you cannot fit many panels elsewhere
- you will regularly use electricity at midday (or can schedule it)
- your export rate is strong and export is not “wasted”
- you want maximum annual kWh from limited space
Consider east-west (or a split) if:
- your midday demand is low and export would dominate
- you want generation earlier and later in the day
- you have two good roof slopes and want a larger total system size
- you want a flatter profile to support self-use and reduce midday saturation
If you are unsure which bucket you are in, your postcode baseline will often make it obvious.
Check your postcode: SolarByPostcode
How this interacts with batteries and tariffs
A battery changes the story, but it does not remove the trade-off.
- A battery can capture some midday excess from a south-facing system.
- East-west still helps because it reduces the burden on the battery by providing power in shoulder hours.
If you are pairing solar with storage, aspect choice matters, but your sizing and economics matter even more.
This guide is the right companion if you have not done the sizing logic yet:
Reality check: if your “south-facing” roof is not really south
UK homes rarely have a perfect textbook roof.
A roof can be “south-ish”, but actually closer to south-east or south-west.
That often behaves more like a partial east-west shift than people expect.
If you are already slightly off-south, the incremental benefit of forcing everything onto “south” can be smaller than the benefit of spreading across two slopes for better timing.
Common misunderstandings that derail the decision
“South-facing means my panels will hit rated output”
Not in the UK.
If you want the mental model for why rated power and real output do not match, start here:
“East-west is bad because it produces less”
It can produce less.
The real question is whether it produces less valuable energy for your household.
“My friend’s south-facing system is better, so south must be best”
A system in BH1 (Bournemouth, Christchurch and Poole) and one in M20 (Manchester) are not comparable without controlling for weather, latitude, and household usage.
Benchmark locally first.
FAQs
Is east-west solar worth it in the UK?
Often yes, especially when your midday demand is low and your evening demand is high. East-west can raise self-consumption by shifting more generation into usable hours.
How much less does east-west generate compared with south?
It varies by roof pitch, shading, and location. The important point is that east-west tends to reduce the midday peak and widen the generation curve. That can offset a lower annual total by increasing the share you use at home.
Does east-west work better in the north?
The timing benefits exist everywhere, but total winter generation is lower in northern regions, so you should be especially careful not to over-optimise for a single “perfect day” idea of solar.
If you want a macro baseline, compare your region hub first:
North Scotland
Should I do east-west if I am getting a battery?
A battery makes midday surplus more useful, but east-west can still help by reducing how concentrated your generation is. The best result is usually a mix of good roof coverage plus realistic sizing.
Next reads
- Roof pitch for solar in the UK: what changes, what barely matters, and what to do with a “bad” roof
- Shading and solar panels: when a single tree really does matter
- Aspect penalty map: how roof direction changes UK solar yield
- Solar system sizing in the UK: choosing the right kWp without wasting money
- Self-consumption vs export in UK solar: how the Smart Export Guarantee changes the maths
Bottom line
- South-facing usually wins on total annual kWh.
- East-west often wins on timing and can raise self-consumption.
- In the UK, savings are driven by valuable kWh, not just total kWh.
- The best choice depends on your postcode baseline, your tariff, and when your home uses electricity.