Most solar guides tell you to face your panels south and leave it at that. But a significant number of Edinburgh properties do not have a usable south-facing roof. 

This article is about making the right decision for your actual roof, not an ideal one.

What Is the Difference?

Two distinct installation approaches, each with different generation profiles.

• South-facing: All panels on a single south-facing slope, angled to maximise annual energy capture
• East-west: Panels split across two slopes, one facing east and one facing west, at a shallower angle

Both work. They just work differently.

Annual Output: How Much Does It Actually Matter?

A south-facing system at 35 to 40 degrees produces the maximum annual output for a UK location.

An east-west system typically produces around 10 to 15% less total annual generation. For a 4 kW south-facing system generating 3,400 kWh, an east-west configuration generates roughly 2,900 to 3,060 kWh annually.

That difference sounds significant, but annual output is not the whole story. Best angle for solar panels in the UK covers output percentages across all orientations in detail.

The Self-Consumption Advantage of East-West

This is where east-west genuinely competes, and it is the argument most installers do not explain clearly enough.

A south-facing system generates the vast majority of its daily output between 11am and 3pm, when most households are at work. Surplus exports at low SEG rates.

An east-west system spreads generation across a longer window:

• East-facing panels generate strongly in the morning
• West-facing panels generate strongly in the afternoon and early evening

For a household without battery storage, east-west self-consumption can be meaningfully higher than south-facing despite producing less total energy.

How Battery Storage Changes the Calculation

Battery storage largely removes the self-consumption advantage of east-west.

With a battery, midday surplus from a south-facing system is stored and used in the evening rather than exported at low rates. Home battery storage covers how storage affects self-consumption in practice.

• With battery storage: South-facing higher annual output wins
• Without battery storage: East-west self-consumption advantage is significant

When East-West Is the Only Realistic Option

Many Edinburgh properties simply do not have a usable south-facing roof.

Edinburgh Tenements

Edinburgh’s tenements run along east-west streets, leaving individual flats with limited access to the south-facing slope.

East-west across the available roof aspects is frequently the only viable configuration. Do tenement roofs in Edinburgh suit solar panels and cover the specific challenges of tenement installations in detail.

Terraced Properties With East or West Aspects

Some Edinburgh terraces have usable east or west-facing slopes but a north-facing main roof.

Splitting panels across east and west gable ends or extensions gives a workable configuration where south-facing is not possible.

Flat Roofs

East-west is the standard configuration for flat roof installations, not a compromise.

Panels are mounted at a low angle in alternating east and west rows. This reduces gaps between rows, cuts ballast requirements, and produces a better daily spread of output.

When South-Facing Is the Right Choice

• You have a clear south-facing slope with minimal shading
• You have or plan to add battery storage
• You have high electricity consumption from an EV or heat pump
• You want the simplest system with a single inverter string

When East-West Is the Right Choice

• Your roof has no usable south-facing slope
• You have no battery storage and high morning and evening consumption
• You are installing on a flat roof
• You want to maximise total panel count across multiple aspects

Does East-West Affect Inverter Choice?

Yes, and it is worth understanding before specifying equipment.

A standard string inverter can struggle with the mismatch between morning and afternoon output from east and west strings. Micro inverters vs DC optimisers covers which approach suits east-west layouts better.

Some string inverters support dual MPPT inputs, allowing east and west strings to be managed independently within a single unit. Always confirm this with your installer before proceeding.

What About Southeast or Southwest Facing?

Southeast and southwest are strong orientations that are often overlooked.

• Southeast loses only around 5% of annual output vs due south and generates earlier in the morning
• Southwest performs similarly and extends afternoon generation into early evening

For many Edinburgh properties, southeast or southwest is the realistic best option. Both are significantly better than east or west alone.

Conclusion

South-facing delivers more annual energy. East-west delivers better daily spread and higher self-consumption without battery storage. For most homeowners with a genuine south-facing option and a battery, south wins. For those without a usable south slope, east-west is not a compromise. It is the right answer for their property.

Frequently Asked Questions

Does east-west solar produce enough to be worth installing?

Yes. A 10 to 15% reduction in total annual output still delivers significant bill savings and strong returns, particularly for households with high morning and evening consumption.

Can I have panels on three roof aspects?

Yes. Panels on south, east, and west maximise total roof coverage and produce the widest daily generation spread. Each aspect typically requires its own inverter string or panel-level electronics.

Is east-west more expensive to install?

Slightly more complex due to separate strings or dual MPPT inputs, but the cost difference is modest. It is often offset by higher self-consumption and the ability to install more panels.

Will shading on one side affect the other in an east-west system?

On a standard string inverter, yes. On a system with micro inverters or power optimisers, no. Panel-level electronics are recommended for east-west configurations where shading is a concern on either aspect.

What if my installer says only south-facing is worth doing?

Ask them to model self-consumption figures for both options against your actual usage profile. An installer who dismisses east-west without modelling it is not giving you a complete picture.