Samson Motor Engineers is an independent motor engineering and servicing workshop on Ferndown Industrial Estate in Wimborne, Dorset. With ramps, compressors and diagnostic equipment drawing power throughout the working day, the garage partnered with DES Renewables to install a 15 kWp rooftop solar PV system that offsets that demand at source.
Project overview
DES Renewables designed and installed a 15 kWp rooftop solar PV system at Samson Motor Engineers, connected into the workshop’s existing three-phase commercial supply. The project ran over roughly three months, covering design, the DNO application, planning and commissioning. The Electrical Installation Certificate was issued on 2 April 2024.
Project details
- Company: Samson Motor Engineers
- Location: 1a Cobham Road, Ferndown Industrial Estate, Wimborne, Dorset BH21 7PE
- System: 15 kWp rooftop solar PV
- Installation type: Rooftop solar PV connected to a three-phase commercial supply
- Project timeline: Around three months from design through to commissioning, certified 2 April 2024
The objectives
- Offset the workshop’s heavy daytime electrical demand with power generated on site
- Reduce running costs for ramps, compressors and diagnostic equipment
- Integrate cleanly with the garage’s existing three-phase commercial supply
- Cut reliance on grid electricity and lower the business’s carbon footprint
The solution: bespoke assessment and design
A working garage is close to an ideal solar site. The heaviest electrical loads — ramps, compressors, lighting and diagnostic equipment — run during daylight hours, which is exactly when a rooftop array is generating. That means a high proportion of the power produced is used on site rather than exported.
DES surveyed the workshop roof and sized the system at 15 kWp. The array was connected into the workshop’s three-phase commercial supply, which uses TN-C-S earthing, via a 25 mm supply taken from an 80 A switched fused isolator at the incoming position. The PV circuit itself was wired in 6 mm five-core H07 cable on cable tray and protected by a C32A three-phase MCB.
Installation and completion
Mounting rails were fixed to the workshop roof and the panels installed and connected, with the work carried out around the garage’s day-to-day operations. The PV circuit was run on cable tray back to the incoming position and terminated into the existing three-phase board.
Full testing and verification followed. A Ze of 0.180 ohms was measured at the origin, with a prospective fault current of 1.107 kA, and the PV circuit recorded a Zs of 0.25 ohms. The Electrical Installation Certificate was issued on 2 April 2024.
The results
- A 15 kWp rooftop solar PV system generating clean electricity on site
- Generation that coincides with the workshop’s busiest hours, offsetting demand as it occurs
- A clean integration into the existing three-phase commercial supply
- Verified test results and an Electrical Installation Certificate issued on completion
At a glance
- 15 kWp rooftop solar PV system
- Independent motor engineering and servicing workshop, Wimborne, Dorset
- Connected into the workshop’s three-phase commercial supply (TN-C-S earthing)
- 25 mm supply from an 80 A switched fused isolator at the incoming position
- PV circuit in 6 mm five-core H07 cable on cable tray, protected by a C32A three-phase MCB
- Measured Ze 0.180 ohms, prospective fault current 1.107 kA, PV circuit Zs 0.25 ohms
- Around three months from design to commissioning
- Electrical Installation Certificate issued 2 April 2024
Our accreditations
We are MCS certified, which guarantees that our installations have been designed, installed and commissioned to the highest standard using only MCS certified products.
We are also NAPIT certified, which confirms that we are certified to install and self-certify all of our electrical installations. We also comply with the Renewable Energy Consumer Code (RECC).
Runs a business, club or community facility? See what solar could save you
If your premises draw most of their power during the working day — a workshop, unit, warehouse or office — solar is usually worth a look. get your free bill check and we will review your usage and tell you honestly what a system could offset.
You can also explore commercial solar to see the full range of work we deliver for businesses across Dorset and Hampshire.
Download the full Samson Motor Engineers case study (PDF).
More recent commercial & community installations by DES
Browse all of our commercial solar case studies, or read about the 29.57 kWp community system at Carvers Clubhouse in Ringwood and the electrical infrastructure works we carried out at the Sammy Miller Motor Museum in New Milton.