Current PV panel prices

zeupater

pmpm wrote: »

I understand what you mean. And it's really interesting to know that. But what about this efficiency. The salesman for solarworld was quoting that it has 18-19% (can't remember the exact figure) and sharp panels have 15% efficiency. Now will that make any difference over 25years period?

Hi

When anyone talks about efficiency on solar pv they are really comparing the output in W/sqm. If you have the space to put 4kWp at 12% efficiency or 20% efficiency you will get the same power output in standard (test) conditions, it's just that the 20% efficient array will cover less roof space.

There is a difference between some panels in low light and/or high temperature conditions which is contained in the specifications, but this has nothing to do with the rated efficiency. There is also a difference in how some manufacturers guarantee their panel performance deterioration, mainly whether it's stepped or straight line, but the end result is probably the same as it seems that someone has calculated the difference as if a step change actually happens and compares it with straight line, whereas, in the real world, the step change panels degrade the same way.

Regarding Sharp being 'mid range' ... I'd actually compare how long the manufacturers have been producing panels, what their global market share is, where they are used and who by. It's also possible that supporting British industry is relevant to some, in which case it might be appropriate to know that the Sharp european factory is in Wrexham.

If you want to understand the difference between the generating performance on panels download the free 'SunnyDesign' software from the SMA site and check the performance of various panels with their inverters, the results may be more interesting than your salesmen would like you to believe

HTH
Z

pmpm

zeupater wrote: »

Hi

When anyone talks about efficiency on solar pv they are really comparing the output in W/sqm. If you have the space to put 4kWp at 12% efficiency or 20% efficiency you will get the same power output in standard (test) conditions, it's just that the 20% efficient array will cover less roof space.

There is a difference between some panels in low light and/or high temperature conditions which is contained in the specifications, but this has nothing to do with the rated efficiency. There is also a difference in how some manufacturers guarantee their panel performance deterioration, mainly whether it's stepped or straight line, but the end result is probably the same as it seems that someone has calculated the difference as if a step change actually happens and compares it with straight line, whereas, in the real world, the step change panels degrade the same way.

Regarding Sharp being 'mid range' ... I'd actually compare how long the manufacturers have been producing panels, what their global market share is, where they are used and who by. It's also possible that supporting British industry is relevant to some, in which case it might be appropriate to know that the Sharp european factory is in Wrexham.

If you want to understand the difference between the generating performance on panels download the free 'SunnyDesign' software from the SMA site and check the performance of various panels with their inverters, the results may be more interesting than your salesmen would like you to believe

HTH
Z

Thanks a lot for that. I'll have a look at that software tonight when i get back home.

So in a nutshell do you mean to say it really doesn't make much difference with whichever panels I go with?

pioneer

Depends on who you talk to see moulenfrites comments

http://www.thegreenlivingforum.net/forum/viewtopic.php?f=22&t=103871

zeupater

pioneer wrote: »

Depends on who you talk to see moulenfrites comments

http://www.thegreenlivingforum.net/forum/viewtopic.php?f=22&t=103871

Hi

Note of caution there, the referenced poster mentions 'customers'.

Some Sanyo panels are definately panels worth consideration, but whether it's possible to generate an extra 1000kWh/year on a standard sized system would be questionable, that would be a claimed 30% increase in generation on a 4kWp system. I'm pretty sure that when I looked at the Sanyo panel option with the SMA software the estimate showed that they could produce an extra 100kWh or so per year over some makes, so in the region of £50 extra FiTs income annually. At the time the Sanyo panels were prohibitively expensive, their prices have dropped faster than the competition, but I'll leave the relative payback calculations to anyone who wants to compare their own output differentials on the SMA software.

HTH
Z

pioneer

I just plugged the Top Sanyo HIT 235 (19% efficient) into the SMA Software and compared it against the Top 245 (14%) Sharp Panel. The Sharps annual output was considerably more.

Cardew

pmpm wrote: »

I understand what you mean. And it's really interesting to know that. But what about this efficiency. The salesman for solarworld was quoting that it has 18-19% (can't remember the exact figure) and sharp panels have 15% efficiency. Now will that make any difference over 25years period?

If you had a 225wp panel that was 100% efficient it would be the size of a book. If you had a 225wp panel that was 1% efficient, you might just get one on your roof.

However both would produce the same power in the same conditions.

pmpm

Cardew wrote: »

If you had a 225wp panel that was 100% efficient it would be the size of a book. If you had a 225wp panel that was 1% efficient, you might just get one on your roof.

However both would produce the same power in the same conditions.

So why there's a big difference in prices of panels?

Cardew

pmpm wrote: »

So why there's a big difference in prices of panels?

Because the technolgy is more expensive! on the smaller more efficient panel.

Profit margins may be different.

Some exported from Euroland, some from the Far East, some assembled in UK.

Construction of panels different.

You can buy a washing machine, Fridge oven etc from a well known brand and pay far more than an identical machine from the same manufaturer marketed with a less well known name.

Manufacturers the world over will charge what the market will stsnd.

zeupater

pmpm wrote: »

So why there's a big difference in prices of panels?

Hi

All of what Cardew said, but on top of that you have a market price perception. The majority of roofs which can take solar pv installations would have a size constraint, but the majority of consumers would like to benefit from the maximum generation possible ...... this obviously creates a market demand for a higher efficiency panel and an associated supply-side expectation of enhanced profits.

It seems that Sanyo in particular miscalculated the price differential which consumers would pay for their higher efficiency panels. According to some feedback on this forum, they seem to have made a recent substantial price move to rectify this.

HTH
Z

Strapped

keith_r59 wrote: »

£8,526 for a 1.35kWp system is way too high. Tescos do a 1.32 kWp system for £7,499 and I'm sure you will find other suppliers offering cheaper alternatives below the £7k mark.

If you want to get the Solatricity off your back just tell them that you have gone with Tescos.

Sorry if O/T but what sort of roof size does one need for say the Tesco system?