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UK Energy Saving Trust Reviewes Benefits of Micro-inverters

Micro-inverters get around the need for all panels to have the same characteristics and be operating under the same conditions by having an inverter installed to the back of each panel. This means when the performance of a panel is affected, for example by natural shading or from obstructions from leaves or debris, it will not affect the overall performance of the system, as would a string invertor – particularly one without MPPT.

Micro-inverters also include MPPT which micro-inverter manufacturers claim works more effectively than it does in string inverters where something as small as an antenna could reduce the performance of the whole system.

Benefits of micro-inverters

Benefits claimed for micro-inverters include:

• performance of the solar PV array is optimised and reports claim the system could have improved energy harvest of between 5 per cent and 20 per cent over the lifetime of the system
• improved energy harvest should result in increased income the potential for enhanced monitoring as the performance of each individual panel can be monitored separately
• greater reliability - if one micro-inverter fails, it will not affect the whole system
• installation of micro-inverters is cheaper and easier as wiring is simpler and no high voltage DC equipment is required, which also makes them safer to install.
• it may be easier to increase system size by adding new panels.
• Increased lifetime – the single most common cause of failure in a solar PV system is the string invertor, which normally requires replacement at least once over the lifetime of the array. The latest micro-inverters have fewer life-limited components, and manufacturers claim a lifetime of 25 years to match the panels
• the cost per watt is more for micro-inverters but is offset by a simpler installation and increased energy harvested.

(Source at  http://www.energysavingtrust.org.uk)