We are often asked to explain the energy saving associated with ground mounted Solar PV systems. So here’s a summary which we hope you’ll find helpful.
The typical annual solar output from a 1 kWp (kilowatt peak) ground-mounted solar PV system in Northern Ireland is approximately 800 to 950 kWh (kilowatt-hours) – units of electricity.
Here’s a breakdown of the reasoning:
- Solar Irradiance in Northern Ireland: Northern Ireland, while not as sunny as some parts of the world, still receives a significant amount of solar radiation suitable for PV generation. The annual global horizontal irradiance (GHI) typically ranges from around 900 to 1150 kWh/m²/year across different locations in Northern Ireland.
- Ground Mount Advantage: Ground-mounted solar systems offer several advantages over roof-mounted systems, leading to higher efficiency:
- Optimal Orientation and Tilt: The panels can be easily positioned at the ideal south-facing direction and the most effective tilt angle (typically around 30-40 degrees in Northern Ireland) to maximize sunlight capture throughout the year.
- Better Ventilation: Ground-mounted panels benefit from better air circulation, which helps to keep them cooler. Solar panel efficiency decreases as temperature increases, so cooler operating temperatures mean higher output.
- No Roof Constraints: There are no limitations imposed by the roof’s orientation, pitch, or potential shading from other roof structures.
- System Efficiency: A typical well-designed and installed solar PV system will have an overall system efficiency (considering panel efficiency, inverter losses, wiring losses, etc.) in the range of 75% to 85%.
- Calculations:
- Let’s take a mid-range annual GHI of 1000 kWh/m²/year.
- A 1 kWp solar PV system will typically have a surface area of around 5-7 square meters (depending on the efficiency of the panels used). For simplicity, let’s assume 6 m².
- Total annual solar energy incident on the panels: 1000 kWh/m²/year * 6 m² = 6000 kWh.
- Considering a system efficiency of 80%, the estimated annual output would be: 6000 kWh * 0.80 * (1 kWp / Installed Capacity in kWp, which we can approximate to the area scaled to 1kWp, so roughly 1/6) = 800 kWh.
Important Considerations:
- Specific Location: The actual output will vary depending on the specific location within Northern Ireland. Areas with higher solar irradiance will yield more energy.
- System Design and Components: The quality and efficiency of the solar panels, inverter, and other components will impact the overall system performance.
- Shading: Even for ground-mounted systems, it’s crucial to avoid any potential shading from trees, buildings, or other obstacles, as this can significantly reduce output.
- Maintenance: Regular cleaning of the panels to remove dust and debris will help maintain optimal performance.
- Tracking Systems (Optional): While not typical for small domestic systems, installing a solar tracking system that follows the sun’s movement throughout the day can increase energy yield by another 20-35%, but it also increases the system’s cost and complexity.
Therefore, while the range is between 800 to 950 kWh, a well-sited and maintained ground-mounted solar PV system in Northern Ireland should realistically produce around 850 kWh of electricity annually per kilowatt peak of the Solar Panels installed.
If you’d like to see calculations for energy savings that include cost of financing, please use our Advanced Solar Quote to model your system parameters.
For more information, or wish to discuss our financing options, please contact us using hello@galgormfinancial.com