Fixing the weak link in PV generation - EPRI report focuses on solar inverters


By: SGN Staff

The deployment of solar photovoltaic systems has grown significantly around the world in a variety of markets, from residential to commercial and industrial. But a report from the Electric Power Research Institute (EPRI) says PV inverters cause a majority of the downtime events in those installations, and that clear and complete specifications are necessary to improve performance in a number of areas.


EPRI's report cites a study conducted by a major PV fleet operator with 500 PV plants found PV inverters are directly responsible for 69% of the plants' downtime.


The report makes several recommendations and observations, among them:

·         The PV inverter is the most critical component for determining plant availability and downtime, which underscores the need for clear and complete inverter specifications that are easily accessed and widely supported.

·         There are a number of avenues available to additionally develop PV inverter performance and acceptance criteria. Specifically, inverter energy conversion performance, grid support functionality and long-term durability are all areas that could use more detailed specification in utility purchases. And, inverters should be specified in detail equivalent to specifications for revenue meters or transformers.

·         The primary measures of energy conversion performance, including testing procedures, have been identified - and EPRI recommends that a sample specification be developed for large-scale, utility grade inverters that will become part of a utility's fleet.


EPRI explains that there are now no comprehensive performance criteria for grid-connected inverters.


The report also addresses exist electric grid interconnection, communication, and safety standards and certifications for PV inverters.

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