Purchasing new panels

[athlonoc]

After reading some of the threads on this forum it seems efficiency isn't as important as a lot of panel makers push at you.

A local installer was not able to use JA Solar panels on my roof as there was a error is measuring roof space.

 

So I've gone from a quote of - JA Solar All black 395kWp to produce an estimated 4,585 kWh to Perlight PLM-295MB-54 DELTA SERIES to produce 4,328kWh.

 

While I'm not fussed about the small drop in estimated output, I'm more concerned about the Perlight panels.

 

The installer found that the JA Solar panels would be about 100mm too tall to get two banks on my roof ( his mis-calculation ) but I'm fine with this. We all make errors. So to get me something similar he's opted for a smaller panel. This way he can get two banks of eight on my roof to produce something similar. The efficiency is 19.57% compared to the JA panels of 20.2%.  

 

Anyone know much about Perlight panels and are the 295w variants any good or are they old spec.

I notice most panels now have 60 or 72 cells whereas these have 54. Does it matter?

 

Thanks

 

Lee

[billt]

No. As long as the voltage and current are compatible with your inverter there will be no problem, the difference in efficiency will be swamped by natural variablilty in insolation.

 

Some of my panels are over 10 years old and they work perfectly. They're probably only 15% efficient but that isn't particularly important unless you have a restricted area.

 

[Dillsue]

If youre concerned about Perlight, what's stopping you using smaller JA panels.

[SimC]

Is that 100 mm too tall per panel, or for the whole height of 2 portrait panels including the required spacing between (usually around 24 mm)?

 

The JA Solar 395W are 1722 mm tall (in portrait), and the Perlight 295W are much less at 1504 mm and significantly lower output.

 

There is a Perlight 400W panel that is 1646 mm tall, that may fit, and will keep the total output up at your original target.

 

[athlonoc]

The installer said it was 100mm in total I believe. It would have either have the panels sitting in the gutter and with a downpour he stated it would come over the guttering, or sit too high at the ridge and said the fixing point would be too low and should there be a day of extremely strong winds it could warp or lift the panel and not worth the risk.

 

Small margins I know. There appears to be a lot of people selling them but hardly a review of the panels other than those selling them.