PV Flowchart - System option decisions.

Before contacting anyone for a firm quotation on a solar pv system it is really best to have an understanding of what you'll be looking for in order to ensure that your system meets your requirements, not those of the supplier.

Below is a basic decision making flowchart to help identify where a potential pv system can be installed and what to look for in order to start to build a full specification, or someone specifies a system for you. The chart effectively provides an idea of the thought process required to ensure that the installation location will be valid and hopefully helps potential customers understand the reasons behind a decent installer's own decisions within the quotation process.

In order to maximise total generation, the roof to which PV panels are installed should be orientated as close to South as possible, however, this does not necessarily translate to a solution which is best suited to particular households as energy usage patterns vary considerably. Take for example a household which is occupied throughout the day where the energy consumption pattern is evenly spread throughout the day and compare to another where occupancy and energy consumption is low during the day and concentrated in the evenings for cooking and entertainment (TVs etc). Obviously a PV system with an almost due South orientation would be suited to an all day even energy consumption household, whereas a system which is closer to a South Westerly orientation could better match afternoon and evening generation to the usual consumption pattern. Contrary to popular conception, the reduction in total annual generation in the UK due to orientation differences between South and a 90° differential is relatively small. If South represents a generation potential of 100, then South West would likely achieve around 90 and West somewhere around 80. However, the further from South the panels face, the more noticeable the difference in the shorter daylight months.