solar Panels survey

These are the important factors we consider at a solar panels survey:

Your geographical location

In Cornwall we are fortunate enough to have more usable daylight hours than any other part of the country. 

The pitch of your roof

Anything above 5° and below 70° are acceptable roof pitches for solar PV. If your roof has less than a 30° pitch, a roof survey is required to determine its weight load capabilities. Our experienced, expert surveyors always conduct an internal roof survey, but when a pitch is below 30° there are extra calculations that need to be made. These calculations are based on the Trada tables that are used by structural engineers. If our calculations show that there are not sufficient weight load capabilities, then strengthening is needed to the existing rafters. We offer this as part of the installation process.

Orientation of your roof

This is possibly the most important factor when considering where to put your solar PV. Optimal orientation on the compass point is 90° East through to 270° West. Anything outside of this, facing towards North, are not subject to the same solar gains. 

Array design

Once accurate measurements have been taken we then draw it out to on 3D software to scale.  This enables us to try various layout options for the solar panels (landscape or portrait) and we can look at the best size panels to maximise the available space. 

Panel output

The highest available output for domestic properties is 4kW, this is due to export limitations placed on homeowners by the district network operator.  However, we are able to install arrays with far higher outputs. This is achieved by restricting how much is exported. 

Shading

Shading analysis is crucial to determine any losses that shading may have on your generation. Determining this at survey stage highlights how best to avoid them. A sun chart is used to consider both near (within 10 meters) and far objects (horizon lines). An equation is then used to calculate how this will affect the overall system.

Mounting System

When considering the mounting system it is important to specify robust fixings that will resist high wind loads over very long periods of time. 

At Harvest Cornwall we specify roof mounting kits that consider high wind loads. We air on the side of caution by specifying the most robust roof hooks and rail available. The mounting kit can never be over engineered and the difference in costs for upgrading is very little.