The solar panel racket.

[Tony Norton]

Hi All,

it was about 15 years ago that I fitted a single solar panel to a motorhome we owned. After research I had found that "triple junction" panels were, at the time, the most efficient one could get. Reason was they had 3 layers of sensors that reacted to different wavelengths and levels of light. The panel on our 'van was pumping power into our battery when the light was at a very low level e.g. dusk and dawn. It didn't require bright unclouded sunlight, just light in whatever form was available.
I recently had contact from several solar panel suppliers wanting to quote me for supplying and fitting panels. When I asked the question "Are they triple, or multi-junction?" the answer was, without exception, "Leave that with me, I'll get back to you". Did they? Did they b*****y! They either didn't know what I was talking about, or they didn't want to deal with someone who was not prepared to accept the cheapest rubbish they could get their hands on.
Try it next time you're talking to an alleged expert from a fully qualified and experienced firm. So called!

Tony N

 

[binky]

Hi All,

it was about 15 years ago that I fitted a single solar panel to a motorhome we owned. After research I had found that "triple junction" panels were, at the time, the most efficient one could get. Reason was they had 3 layers of sensors that reacted to different wavelengths and levels of light. The panel on our 'van was pumping power into our battery when the light was at a very low level e.g. dusk and dawn. It didn't require bright unclouded sunlight, just light in whatever form was available.
I recently had contact from several solar panel suppliers wanting to quote me for supplying and fitting panels. When I asked the question "Are they triple, or multi-junction?" the answer was, without exception, "Leave that with me, I'll get back to you". Did they? Did they b*****y! They either didn't know what I was talking about, or they didn't want to deal with someone who was not prepared to accept the cheapest rubbish they could get their hands on.
Try it next time you're talking to an alleged expert from a fully qualified and experienced firm. So called!

Tony N

About 15years ago panel efficiency of 10% would have been exotic, today's panels are 20% efficient and mostly use PERC technology - look it up. My own panels are 10 years old, 13% efficient, and were generating around 300W despite it being overcast and raining all day here in sunny Devon. I'm afraid your knowledge is as out of date as your panel.

 

[Andy1733]

Ouch.

 

[binky]

Ouch.

Just saying it like it is..

 

[Doug910]

Sunpower Maxeon 5 are 22% efficient, which is about the best you can get currently, I read some good reviews of these but they cost double the price of a regular 400W panel, so not sure they are worth the extra. Has anyone tried these, are they better or is it just good PR from Sunpower.

 

[binky]

Sunpower Maxeon 5 are 22% efficient, which is about the best you can get currently, I read some good reviews of these but they cost double the price of a regular 400W panel, so not sure they are worth the extra. Has anyone tried these, are they better or is it just good PR from Sunpower.

Always were very expensive, so I've never fitted a set. If you want expensive, fit Panasonic hybrid panels, if you can still get them. They mix silicone wafer with amorphous thin film silicone, which gives better performance in hot weather, although we don't tend to get that much hot weather. The other nice design point is drainage gaps in the frames, so the panels don't collect dirt on the frame edges. A simple thing that makes a difference.

 

[Tony Norton]

According to my information PERC technology was introduced in 1989. If you do the sums you'll find that is quite a lot more than 15 years ago. At my age I don't think I would even get to the break even point cost-wise.

 

[binky]

According to my information PERC technology was introduced in 1989. If you do the sums you'll find that is quite a lot more than 15 years ago. At my age I don't think I would even get to the break even point cost-wise.

If you check the history of solar panels, they go back to the start of the 'space race'. Mitsubishi, being one of the pioneers, I believe have been making solar cells for over 50 years. Many different technologies have been trialled and tested, but not put into commercial use. You should have seen all the solar blurb that was around 10 years ago when the government introduced the FiT scheme. Solar you could roll out and just stick to the roof, solar glazing, solar slates. In reality none of these were cost effective. It's a bit like Beta Max and VHS. VHS won out in the end on price despite, not being the best tech.

PERC may well have been around since 1989, but has only hit the mass market in the last 5 years. That doesn't change the fact that commercial panels have over doubled their efficiency whilst costs have dropped significantly. We used to talk of £2.30 per watt, now its 30 pence

 

[binky]

Sanyo / Panasonic technology looks to be going mainstream soon.

https://www.solarpowerworldonline.com/2019/11/what-are-heterojunction-technology-hjt-solar-panels/

 

[Andy_1000]

Hi All,

it was about 15 years ago that I fitted a single solar panel to a motorhome we owned. After research I had found that "triple junction" panels were, at the time, the most efficient one could get. Reason was they had 3 layers of sensors that reacted to different wavelengths and levels of light. The panel on our 'van was pumping power into our battery when the light was at a very low level e.g. dusk and dawn. It didn't require bright unclouded sunlight, just light in whatever form was available.
I recently had contact from several solar panel suppliers wanting to quote me for supplying and fitting panels. When I asked the question "Are they triple, or multi-junction?" the answer was, without exception, "Leave that with me, I'll get back to you". Did they? Did they b*****y! They either didn't know what I was talking about, or they didn't want to deal with someone who was not prepared to accept the cheapest rubbish they could get their hands on.
Try it next time you're talking to an alleged expert from a fully qualified and experienced firm. So called!

Tony N

A lot of solar panel companies are just sale companies with little technical knowledge. That said solar panels have moved on with the focus on getting more energy out of the cheaper panel technology. Hence the cost of solar electricity price have fall by 70%.

I would not judge them too harshly as they would have to have a details knowledge of PV panels, inverters and batteries. Some manufactures just don't give the technical information out.

 

[binky]

A lot of solar panel companies are just sale companies with little technical knowledge. That said solar panels have moved on with the focus on getting more energy out of the cheaper panel technology. Hence the cost of solar electricity price have fall by 70%.

I would not judge them too harshly as they would have to have a details knowledge of PV panels, inverters and batteries. Some manufactures just don't give the technical information out.

totally agree, whilst I'm interested in the construction of materials, ultimately I'm far more interested in the Euro efficiency rating than how many wires it has running through the cells. My only proviso on that,to avoid returns for failed materials, I avoid fitting the cheapest gear and have spent a lot of time looking into reliable, but affordable products. I do prefer to fit the expensive stuff, but few clients want to pay the extra.