The two main inverter types used in the UK; traditional string inverters and optimised inverters. String inverters offer the most economical solution and are most commonly installed when initial expenditure is the most important factor. If lifetime costs and energy production are higher on the priority requirements, an optimised solution is the best option.
A string inverter requires the panels to be installed in series, consequently restricting each string to the worst performing panel. For example, if one panel is in shade, all panels on that string are limited to the output of the shaded panel.
An optimised solution allows each panel (or pair of panels) to be connected in parallel, allowing all panels to perform to their maximum output.
Most warranties are extendable, however, as standard the optimised solutions have better cover. A traditional string inverter has a 5 year warranty, the optimised solution has 12 years on the inverter and 25 years on the optimisers.
In addition, panel level monitoring is available using the optimised solution; allowing efficient identification of an issue, reducing lost production and time on site fault finding. Equally, any issue is limited to the problem panel, whereas a string inverter would lose the entire string of panels.