College Farm Solar PV Installation

Overview 

• Location: Bedfordshire 

• Date of Installation: April 2025 

• Type: Commercial 

• Mounting Type: Renusol Roof-mounted, 15-degree pitch 

• Panel Count: 150 × Longi Hi-MO X6 530W Mono Panels 

• System Size: 79.5 kWp 

• Battery: 6 x Growatt APX HV 5.0P-B1 Batteries 

• Inverter: 2 x Growatt KTL3-XH 25kW Hybrid Inverter 

• EV Chargers: 5 x MyEnergi Zappi 2 7kW Untethered  

• EV Charger: 1 x MyEnergi Zappi 2 22kW Untethered 

System Overview 

The installation includes 150 Longi Hi-MO X6 530W Black-White Mono solar panels, each rated at 530 watts. These are paired with a cutting-edge, three-phase Growatt MID 25kW Hybrid Inverters, specifically designed for commercial and industrial solar energy systems. The panels are mounted on a Renusol pitched roof system. An advanced 30 kWh (6 x Growatt APX HV 5.0P-B1) battery storage system allows excess energy generated during the day to be stored for use at night. The installation also features a suite of six MyEnergi Zappi v2 EV chargers—five 7kW untethered units and one 22kW untethered unit—designed to provide flexible, future-ready vehicle charging. The project includes complete electrical works, battery storage integration, commissioning, certification, and all necessary notifications.  

Roof South West 
Orientation: 66° 
Pitch: 15° 

Roof North East 
Orientation: -114° 
Pitch: 15° 

 The solar PV system is expected to generate approximately 63,690 kWh of electrical energy per year. 

Performance Estimates 

Annual Energy Generation 

The annual energy generation for this system is approximately: 63,690 kWh 

Consumption & Grid Export 

An energy consumption analysis was conducted based on an approximate electricity usage of 30,000 kWh per year.

The expected distribution of generated electricity was approximately: 

• Self-consumed directly from solar: 11,814 kWh 

• Stored and used via battery: 7,912 kWh 

• Exported to the grid: 42,409 kWh 

• Losses: 854 kWh  
  
  

  
  

Smart Export Guarantee (SEG) Eligibility 

The installation qualified for SEG payments, allowing excess electricity exported to the grid to be sold back to an electricity supplier. More information on SEG eligibility and applications can be found at Ofgem.

Disclaimer: The performance of solar PV systems is impossible to predict with certainty due to the variability in the amount of sunlight from location to location and from year to year. This estimate is based upon a model that takes account of meteorological data at your location and makes an allowance for losses due to shading of the panels. This is a complex calculation, however, and no model can be 100% accurate. It should not be considered a guarantee of performance.  

Environmental Impact 

The system contributes significantly to reducing the property's carbon footprint: 

Annual CO₂ savings: 13.2 tonnes 
Equivalent to: Approximately 47,000 miles driven by a diesel car (400g CO₂ per mile) CO₂ absorption of approximately 600 mature trees annually (22kg CO₂ per tree per year)  

Disclaimer: These calculations are based on estimated system output and standard carbon emission factors from the UK Government’s Greenhouse Gas Reporting: Conversion Factors 2024. Actual results may vary due to energy usage, weather conditions, and grid carbon intensity.  

Performance and Financial Projections 

The total cost of the installed system was £82,645.88 (Including VAT). Based on current electricity prices and the system’s projected performance, the estimated first-year displacement savings of approximately £6,904 plus export income of £6,361.34. 

The estimated payback period for the system is just over 6 years, after which it will continue to provide significant energy cost savings throughout its operational lifespan. 

Disclaimer: Payback periods are estimated based on current electricity prices and SEG rates. Future price changes and usage patterns may affect the payback timeline.  

Live Monitoring and Updates 

The installed system is monitored by Chiltern Solar via the Growatt Shine WiFi-X platform, which provides: Graphical display of power flow Battery and inverter monitoring System alarms and performance alerts .

Frequently Asked Questions 

Expected system performance over its lifetime follows industry-standard degradation rates. With an estimated solar radiation value of 864 kWh/kWp and a shading factor of 0.99, long-term output remains efficient.  

Installation 

The system was designed and installed by Chiltern Solar Ltd, an MCS-accredited (NAP 28870) company and a Renewable Energy Assurance Scheme (RECC) member (No. 44711).

The project included: Scaffolding Mechanical Install Electrical Install.

Travel & Subsistence G99 <50kWp Application and Confirmation Installation of Bird Prevention . 

Warranty

Panels: 25 Year 
Inverter: 5 Years (extendable to 10 years) 
Battery: 10 Years 
Chiltern Solar Installation: 5-year workmanship warranty 
EV Chargers: 3 Year Warranty