At SolarTherm UK, we are often asked to design solar PV systems where roof space is limited but the client wants to maximise energy generation. These projects require careful planning, accurate system design and the experience to overcome challenges that less experienced installers may overlook.
This recent 25kW commercial solar installation is a perfect example of how the right design approach can dramatically increase system performance and panel capacity.
The Challenge: Limited Roof Space and Shading
The building featured a south facing flat roof, which is typically ideal for solar PV. However, the presence of a parapet wall around the roof perimeter created a significant design challenge.
Several other solar companies had already assessed the site and proposed systems that:
- Installed modules laid flat to maximise the number of panels
- Used a standard string inverter
- Designed only two string for the entire array
- Installed around half the number of modules we ultimately achieved
While laying modules flat can sometimes increase panel count, in this case it would have caused a serious performance issue.
During winter months, the parapet wall would have cast shadows across the first two rows of modules, significantly reducing solar irradiance and therefore energy generation. With a standard string inverter, shading on even a small section of the array can impact the performance of the entire string. In short, the proposed designs would have looked good on paper but underperformed in real world conditions.
The SolarTherm UK Solution
Our design team approached the project differently. Rather than simply maximising module count, we focused on optimising both space and performance. The system was designed using:
- Ballast mounted A-frame mounting systems
- South facing module orientation
- Optimised spacing to reduce winter shading
- Module level optimisation technology
The final installation delivered a 25kW solar PV system, significantly larger than other companies had proposed.
Advanced Solar Optimisation with SolarEdge
To ensure the system performed efficiently even in partially shaded conditions, we specified technology from SolarEdge Technologies. SolarEdge systems use module level power optimisers, allowing each solar module to operate independently. This means that if one module experiences shading, it does not reduce the performance of the rest of the array.
This approach is particularly effective on rooftops where parapet walls create partial shading, plant equipment casts intermittent shadows and roof layouts limit ideal panel spacing. By combining SolarEdge optimisation technology with intelligent array design, we were able to significantly increase the number of modules installed while maintaining excellent system efficiency.
High Efficiency Modules: Aiko 460-465W
The system uses high performance solar modules from Aiko Solar, rated between 460-465 watts. These modules offer several advantages for commercial solar installations, especially where space is limited. The higher efficiency gives more power generation per square meter with excellent performance in partial shading conditions, resulting in improved long term energy yield.
Using higher output modules also helps maximise system size where roof space is constrained.
Rapid Installation: From Empty Roof to Power in 48 Hours
Another key success factor for this project was the installation speed. All system equipment was craned directly onto the roof, allowing our team to begin work immediately without delays caused by manual material handling.
From the moment work started to final commissioning, the system was:
Installed, connected and switched on in under 48 hours.
This rapid turnaround minimised disruption to the building occupants and allowed the client to begin generating renewable energy almost immediately.
Why Experience Matters in Solar Design
Solar PV installations are not simply about placing as many modules as possible onto a roof. Proper system design must consider:
- Roof orientation and pitch
- Shading from surrounding structures
- Parapet walls and rooftop plant equipment
- Inverter configuration and string design
- Long term energy yield, not just installation capacity
At SolarTherm UK, we regularly deliver solar projects where other installers have either overpriced the solution or walked away from the challenge entirely.
Our design led approach ensures every installation delivers maximum performance, reliability and return on investment.
Thinking About Maximising Your Roof Space?
If your building has limited roof space, shading challenges or complex layouts, SolarTherm UK can help design a system that delivers the best possible performance. Whether it’s commercial solar PV, complex rooftop installations or large scale arrays, our experienced team will ensure your system is designed and installed correctly from the start.
Contact SolarTherm UK today for a free, no obligation quote and design, tailored for your building, energy usage profile and future energy goals. No hard sell, just honest, expert advice – and the time you need to make an informed decision.
Your business. Your energy. Your future.
