40kw install

[BruceB]

The extra performance is great, but to decide whether it is the right answer then you need to know the relative price and what the limiting factors are in the installation. In the installations I have done, high performance panels were the right answer only where space is at a premium and a particular level of output was required.

 

[Outspoken]

The extra performance is great, but to decide whether it is the right answer then you need to know the relative price and what the limiting factors are in the installation. In the installations I have done, high performance panels were the right answer only where space is at a premium and a particular level of output was required.

Bruce, I totally agree, in many situations HP panels may not be the most efficient solution overall, especially where installation costs are restrained, and I am certainly not advocating they should be used regardless. If you have a wide open roof space that can accommodate 20+ panels then I do not see the need for the HP panels for a domestic customer because the over-riding factor is always going to be price in the here and now, it is likely only corporate customers who are likely to see the benefits of the HP panels over the 15-25 year life of the installation, and the manner they intend to use them will always be a factor. If they are used to charge batteries for emergency use only then the HP panels do not make economic sense, but if you going to use the panels daily for energy generation to power internal lighting and to feed back to the grid then the HP panels likely will make sense, this is why we have just installed almost 150kW of panels on a Job as they will be providing all the power necessary for the ancillary and office area lighting, in the plant rooms and to feed back to the grid (~60kW). This is why we chose the SunPower E20 series, it makes economic sense.

 

[jason121]

What are the figures for NOCT of the sunpower

 

[Outspoken]

what are the figures for noct of the sunpower

45°c +/-2°c

Just dug out a link for you

Data Sheet is HERE

 

[SolarCity]

150kWp of SunPower panels made commercial sense?

I'm very surprised at that.

 

[Outspoken]

150kWp of SunPower panels made commercial sense?

I'm very surprised at that.

You can argue that with the money men, they made the final decision between the data for the SunPower panels and panels made by Samsung and BP Solar. Their calculations told them that the SunPower units, for our location mind, will provide between 15% and 20% more electricity and thus revenue over the expected 15 year lifespan they have given the building. I'll accept that some of the cost/benefits could be connected to the discount received for the bulk buy as I know there were significant differences between the final three on that, but I do not deal with the money aspect of the Jobs...I leave that to the Guys who have no life.

 

[Gavin A]

point of order here, sunpower panels aren't hybrid panels, they're just very high efficiency N-Type mono-crystalline panels.

As such, while they are more efficient than other N-Type mono-crtystaline modules, there will be minimal difference in low light, high temperature or lifetime performance per Wp than other high quality N-Type modules such as those from Yingli Panda, LG Neon, Romag, etc.

And high quality polycrystaline panels will have better medium to low light performance than any of them on a per Wp basis, though the high temperature performance of the N-Type mono's will be better.

So IMO the money men have been misled as they don't understand the technologies involved and just went on the sales blurb, plus they were only given options of 2 x old style panels or latest generation sunpower, rather than equivalent but cheaper panels.

Panasonics HIT panels on the other hand are hybrid panels, and have a -0.29% per deg temp coefficient vs -0.38% for the sunpower, as well as I'd expect, higher low light outputs, though as someone on here pointed out, in the UK that's actually offset by the temp coefficient working against them in cold UK weather.

 

[Earthstore]

You can argue that with the money men, they made the final decision between the data for the SunPower panels and panels made by Samsung and BP Solar. Their calculations told them that the SunPower units, for our location mind, will provide between 15% and 20% more electricity and thus revenue over the expected 15 year lifespan they have given the building. I'll accept that some of the cost/benefits could be connected to the discount received for the bulk buy as I know there were significant differences between the final three on that, but I do not deal with the money aspect of the Jobs...I leave that to the Guys who have no life.

When did you install the BP solar panels?

 

[Gavin A]

When did you install the BP solar panels?

BP - AKA entirely chinese panels with the BP branding, but nowt to do with BP?

 

[Outspoken]

When did you install the BP solar panels?

Read my posts again, we did not install BP branded panels, I have no idea who makes them, we used SunPower as I clearly indicate in the post

 

[Earthstore]

Thanks, I was just remembering that BP pulled out of solar about 18 months ago, that was all.

 

[Outspoken]

point of order here, sunpower panels aren't hybrid panels, they're just very high efficiency N-Type mono-crystalline panels.

As such, while they are more efficient than other N-Type mono-crtystaline modules, there will be minimal difference in low light, high temperature or lifetime performance per Wp than other high quality N-Type modules such as those from Yingli Panda, LG Neon, Romag, etc.

And high quality polycrystaline panels will have better medium to low light performance than any of them on a per Wp basis, though the high temperature performance of the N-Type mono's will be better.

So IMO the money men have been misled as they don't understand the technologies involved and just went on the sales blurb, plus they were only given options of 2 x old style panels or latest generation sunpower, rather than equivalent but cheaper panels.

Panasonics HIT panels on the other hand are hybrid panels, and have a -0.29% per deg temp coefficient vs -0.38% for the sunpower, as well as I'd expect, higher low light outputs, though as someone on here pointed out, in the UK that's actually offset by the temp coefficient working against them in cold UK weather.

You can argue with the manufacturers and the scientists who provide the data that we used to calculate the most efficient then, because we have to go by what information they give us as we do not manufacture them. Incidentally I did not say the SunPower where Hybrid panels, I said they were HP (high performance) panels. If that gave the incorrect impression I apologise as that was not the intent.

 

[Gavin A]

You can argue with the manufacturers and the scientists who provide the data that we used to calculate the most efficient then, because we have to go by what information they give us as we do not manufacture them. Incidentally I did not say the SunPower where Hybrid panels, I said they were HP (high performance) panels. If that gave the incorrect impression I apologise as that was not the intent.

ok you didn't, but you did start off by talking about hybrid panels, then effectively gave the sunpower system as your example having switched mid discussion from talking about hybrid to HP panels.

I've no need to argue with the scientists, as I've already stated I've had this discussion with panasonic's main technical guy and he agreed with me, I'm arguing with you because you're the one who made the statement. You can track everything I've said back to the manufacturers own data if you wanted to.

What you appear to be doing is regurgitating the marketing spiel coming from sunpower without critically analysing it to see in what circumstances and to what extent it actually applies.

Not that I'm saying Sunpower panels aren't very high performing panels, as they obviously are, I'm just questioning the economic rationale you're using to justify recommending them on a big installation such as this... though obviously that rationale may be different if you have been given a significant volume discount for the panels.

 

[Outspoken]

Gavin, I'm in work now doing some night cover, looked up a lot of our costings etc...the price we paid for the SunPower panels, due to volume and using the same supplier for the Inverters etc meant that we paid the same price as we would have for the BP Solar branded and I found in the quote that originally they did a spec using REC panels, but they were rejected as the original spec called for a minimum of 16% efficiency from the panels.

I have looked through the proposals and the data and found that the savings are partly down to the way we are using the panels and the fact that the amount being fed back into the grid will be a minimum of 60kW, in fact looking at the BMS, in the last week we have averaged some 10,801.2 kW/hr back into the grid..

Now I appreciate that a domestic user is never going to be able to compete with that level of generation unless they have a substantial home to mount the number of panels on we have, and it would need to be something like a small stately home too...and clearly a domestic user is not going to be able to negotiate the kind of discount our client's buyers did. Apparently we paid (well our client) £278.34+vat for each of the SunPower panels

With regards my comments about the Sunpower and hybrid panels giving the incorrect impression, please accept my apologies, not the intention at all.

 

[SolarCity]

I found in the quote that originally they did a spec using REC panels, but they were rejected as the original spec called for a minimum of 16% efficiency from the panels.

We get that kind of nonsense spec'd all the time. I doubt very much that the guy doing the spec had any idea what that actually means.