Solar PV Panels

The term ‘efficiency’ is a much misunderstood term, but it relates to how much power the panel produces for a given area of panel. Note that a 430W high efficiency panel will produce the same amount of power as a 250W lower efficiency panel, but the high efficiency panel will be smaller. Hence efficiency only really becomes important for small roofs, where high efficiency panels are used to maximise the amount of power that can be produced from the roof area. For large roofs there is no real benefit in using high efficiency panels if you can install the size of system you want with standard panels.

When the cells that make up a solar panel are manufactured, they are tested for power output and sorted into 3 or 4 groups, so that the highest power cells are all used in one class of panel and the next group all used in another, and so on. This means that each make and type of panel is often available in different ‘power classes’ – typically say 420W, 425W or 430W. The panels from the different power classes will all be the same size and look identical, but will be sold according to their power class.

The yield of a solar panel relates to how much energy it will produce under typical weather and light conditions throughout the year. It is a very important factor and can significantly affect the overall output of your solar PV system. Panels from different manufacturers with the same power rating of say 430W can have different yields because they behave differently under lower light levels. The power rating of a panel is measured under standard test conditions of 1000W of solar irradiation at 25C, which is equivalent to a very bright sunny day. We rarely have these conditions for very long in the UK, so it is important to select panels that have a good output under lower light levels too. Solar Voltaics use proprietary solar software to analyse the panel power output data under differing light levels to ensure that panels giving the highest yield are specified for our customers. This combination of high yield, quality and competitive pricing is one of our key aims.

Solar Voltaics works with a range of solar panel manufacturers that are listed as Tier 1 by Bloomberg New Energy. Bloomberg assess a manufacturer’s financial stability and credibility in the market to provide a list of suppliers that are considered ‘bankable’ by financial lenders and have the standing to honour their warranties. We use the same list to ensure that the panels we supply to our customers are of the best quality and are from reliable suppliers.