Photovoltaic reliability, using micro inverter

<div style="text-align: justify;">In my previous article I presented the principle for avoiding production losses  when photovoltaic systems are located in such cases where there is shadow of  trees, dust, chimneys, antenna, other buildings … We speak of photovoltaic shading.<br /> Then I presented a good solution to avoid these which is distributed MPP Tracking: one micro inverter per photovoltaic module to track individual Maximum Power Point. I also detailed 2 design approaches with pro’s & con’s arguments.<br /> In this article, I will give some concerns and questions about photovoltaic reliability.</div><div style="text-align: justify;"><br /> </div><div style="text-align: center;"><img alt="http://engineering.electrical-equipment.org/wp-content/uploads/2010/02/photovoltaic-shading1.jpg" src="http://engineering.electrical-equipment.org/wp-content/uploads/2010/02/photovoltaic-shading1.jpg" /></div><div style="text-align: justify;"><br /> <div style="background-color: orange; color: red; text-align: center;">photovoltaic shading</div><br /> It’s a main point and certainly the success key factor of this disruptive innovation.<br /> A manufacturer writes “no failure point”: that‘s great! But when a micro converter is embedded on the photovoltaic module and fixed on a roof, it’s not acceptable to have failure. This is not thinking to have a field engineer or installer which climb on the roof, uninstall a photovoltaic module and break water tightness (in case of BIPV)  for a US50$ micro-converter part only !<br /> <br /> The design must integrate the unfavourable constraints for the component choice (very low temperature the winter (- 20°C), very high temperature the summer (+70°C)). To be serious, a manufacturer should describe which working profile conditions are using for the design…<br /> <br /> This is the most critical point and a lot of manufacturers are not talkative on this topic.<br /> <br /> One indicates: “specific components are chosen for reliability design (HALT). Also those tests have run for the equivalent of over 50 years”. It’s great, but it’s not serious: the life time indicate nothing about photovoltaic reliability!<br /> (for example : I can keep a car during 20 years (20 Years life time) and every week the car mechanic repair it (7 days MTBF))<br /> <br /> What is the Photovoltaic reliability of distributed system? What is the true MTBF or the true “lambda” ?<br /> <br /> How many chances have a customer to have a failure on his roof? How will customer ROI be impacted if we have to repair it during the life-time. That is the true and one question I have to request myself before suggests it on his roof! <br /> To summarize<br /> <br /> In my point of view this distributed technology applied to photovoltaic sytem is a very interesting new approach of solar energy harvest with a lot of benefices under specific condition. But today this technology is developed by very small companies witch take not enough in count the photovoltaic reliability aspect. It’s a shame because this innovation could be nip in the bud.<br /> <br /> Yves Jeanjean</div>

Photovoltaic reliability, using micro inverter

In my previous article I presented the principle for avoiding production losses  when photovoltaic systems are located in such cases where t...

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