Solar design software, EPiSolar, has been updated to support the latest MCS guidelines for solar PV installations.

The latest revision to the software package includes regional variations and estimates of over shading from neighbouring buildings and features – a key aspect in the new updated MCS guide.

Commenting on the news, technical director, Patrick Riley, said: “We’ve had a flood of enquiries from installers who are worried about how they can keep up with the new requirements.  We’ve been quick to address this in EPiSolar so that our users can be sure that they are complying and up to date.”

In view of the statement in the MCS Guide to the Installation of Photovoltaic Systems saying that results from proprietary software packages “must not be given greater prominence than the standard MCS estimate”, great care has been taken to ensure that EPiSolar follows the MCS Standard Estimation Method in both the calculation of system performance and the estimate of shading factors.

The latest MCS guide takes into account the regional variations when estimating the performance of solar PV panels. The old SAP 2009 method was based on an installation in Sheffield representing a national average.

As a comparison, the following table shows an example of a 4kW system, facing south at 45° roof pitch, shading factor 1.  It compares the SAP results with the latest MCS method and shows the effect of regional variation on the same installation.

Annual electricity generated (kW hours)

Location (Region)

SAP 2009

MCS Guideline

Brighton (South East England)



Sheffield (East Pennines)



Inverness (Highland)



From a sales perspective, the variation in payback period resulting from the new guide lines would favour installations in the south of the country over those in the north.

ProFactum has been developing software for direct sales teams since the 1980’s focusing on the need to make software simple to use so EPiSolar can be used in front of the customer as a sales and design aid, producing 3D visualisation of the solar PV installation and while showing the cost benefits of the design. The quick feedback process lets the designer experiment with alternative layouts to produce the optimum configuration.

EpiSolar plans to keep up to date with constantly changing standards through regular downloadable updates.