Any experience with the new high capacity 400W plus solar panels?

[GoingWalkabout]

Im wondering if anyone has experience using the new high capacity 400 W and above solar panels. Much of what I have read on this site deals with the lower powered and older panels. The posts on this forum have been fantastic and it has been a tremendous help in learning all of the inns and outs of configuring an efficient and workable solar solution for boats. I want to thank the solar boating pioneers for the hard work in trail blazing in this field. Being one who likes to learn from those who have already experimented rather than learning the hard way it would be highly instructive to learn about use of the latest hardware in particular the higher powered panels and why we are about it any thoughts and info on the latest controllers and other new interfaces would be appreciated.

I know a lot of people are using older gear with 100W panels. What I want to do is configure the baddest most powerful solar array on the cat as can be humanly possible. And then capture as much of that juice as humanly possible without turning my boat into a flaming inferno.

[Stumble]

Keep in mind I make no claims to being a solar expert. That being said I think the biggest determination is what the actual dimensions are of where they are being installed. Assuming a coach roof, divide it down the middle and treat it as two seperate systems, this way at least one side won't be shaded by the mast and boom. Soy outage two identacle areas that end up mirror images of each other.

Then it's just a game of maximizing wattage per side, with the individual panel size being far less relavent than the total power produced.

[GoingWalkabout]

Originally Posted by Stumble

Keep in mind I make no claims to being a solar expert. That being said I think the biggest determination is what the actual dimensions are of where they are being installed. Assuming a coach roof, divide it down the middle and treat it as two seperate systems, this way at least one side won't be shaded by the mast and boom. Soy outage two identacle areas that end up mirror images of each other.

Then it's just a game of maximizing wattage per side, with the individual panel size being far less relavent than the total power produced.

Thanks for your reply. I think your split panel suggestion would be a good idea if your putting them under the main sail. Since it is for a cat instal they will be at the stern. With respect I don't understand you statement about the individual power size being less relevant than total power output. Are you meaning physical size of the panel?

Im really wanting feedback from those who have installed the newer type panels that put out 400W or more per panel.

thanks,
Chaya

[Stumble]

Chaya,

Think of it this way. You have a given amount of room to fit panels on, and most panels will generate about the same amount of power per square inch. So the goal is to cover as much area with panels as possible, ignoring the individual size of the panels in question.

So let's assume you have an area that is 80" X 90" (7200in^2) in that space you could only fit a single 400w panel (77.8"X51.6" - 4014n^2) for a coverage efficency of just 56%. On the other hand if you could find a panel that is 45"x40" you could fit four of them for a coverage efficency of 100%.

The trick to maximizing output on a boat is coverage area, not size of the individual panels. In some installations it may work out that a few massive panels works out well, but it isn't likely to be the case in most of them.

[GoingWalkabout]

Originally Posted by Stumble

Chaya,

Think of it this way. You have a given amount of room to fit panels on, and most panels will generate about the same amount of power per square inch. So the goal is to cover as much area with panels as possible, ignoring the individual size of the panels in question.

So let's assume you have an area that is 80" X 90" (7200in^2) in that space you could only fit a single 400w panel (77.8"X51.6" - 4014n^2) for a coverage efficency of just 56%. On the other hand if you could find a panel that is 45"x40" you could fit four of them for a coverage efficency of 100%.

The trick to maximizing output on a boat is coverage area, not size of the individual panels. In some installations it may work out that a few massive panels works out well, but it isn't likely to be the case in most of them.

Thanks again Stumble. So correct me if I'm wrong. The larger Wattage panels achieve the larger Watt output over others purely based on the larger area of solar cells. I was wrongly thinking that the newer greater wattage panels achieved the higher wattage from a better and more efficient solar cell itself.

So if it is just a matter of configuring the best size and shape to maximize the area of actual solar cells than you are absolutely correct.

Thanks again.
Chaya

[StuM]

Originally Posted by GoingWalkabout

Thanks again Stumble. So correct me if I'm wrong. The larger Wattage panels achieve the larger Watt output over others purely based on the larger area of solar cells. I was wrongly thinking that the newer greater wattage panels achieved the higher wattage from a better and more efficient solar cell itself.

So if it is just a matter of configuring the best size and shape to maximize the area of actual solar cells than you are absolutely correct.

Thanks again.
Chaya

Just looked at a couple of 400W + panels on Google. They were both around 20% efficiency, similar to the smaller ones, so yep - it's just the larger area that does it.

It really pays to look at the specs of whatever you are considering buying, today's common panels generally fall into the 15 - 22% efficiency range and that spread can make a big difference in daily output. Of course, the higher the efficiency, the higher the price as a rule of thumb.

TANSTAAFL!

[socaldmax]

Originally Posted by GoingWalkabout

Thanks again Stumble. So correct me if I'm wrong. The larger Wattage panels achieve the larger Watt output over others purely based on the larger area of solar cells. I was wrongly thinking that the newer greater wattage panels achieved the higher wattage from a better and more efficient solar cell itself.

So if it is just a matter of configuring the best size and shape to maximize the area of actual solar cells than you are absolutely correct.

Thanks again.
Chaya

No, you were correct.

The newer Sunpower E445 panels produce a lot more power than the average 250 -275 panels, while only using slightly more real estate due to being 20% efficient. Most 250-275 watt panels are 40"x65" and only about 14-15% efficient, the Sunpower are 41"x81" and 20% efficient, so about 16" longer, but nearly 200w more power for the slightly longer panel.

The problem is, Sunpower panels are difficult to find in the US, they don't sell them to the public. The efficiency of the panels is usually very important on a boat due to limited space, but since you're populating an entire arch, you could possibly spare a little room for less efficient panels, unless you want the absolute highest output per square foot, then you'll need to pay attention to the solar panel efficiency numbers.

[socaldmax]

Originally Posted by StuM

Just looked at a couple of 400W + panels on Google. They were both around 20% efficiency, similar to the smaller ones, so yep - it's just the larger area that does it.

It really pays to look at the specs of whatever you are considering buying, today's common panels generally fall into the 15 - 22% efficiency range and that spread can make a big difference in daily output. Of course, the higher the efficiency, the higher the price as a rule of thumb.

TANSTAAFL!

How many different brands did you find that were 20% efficient or greater? I've been looking for some, but so far all I can find is Sunpower, which I can't buy for anything but commercial or residential installation.

[GoingWalkabout]

Originally Posted by socaldmax

No, you were correct.

The newer Sunpower E445 panels produce a lot more power than the average 250 -275 panels, while only using slightly more real estate due to being 20% efficient. Most 250-275 watt panels are 40"x65" and only about 14-15% efficient, the Sunpower are 41"x81" and 20% efficient, so about 16" longer, but nearly 200w more power for the slightly longer panel.

The problem is, Sunpower panels are difficult to find in the US, they don't sell them to the public. The efficiency of the panels is usually very important on a boat due to limited space, but since you're populating an entire arch, you could possibly spare a little room for less efficient panels, unless you want the absolute highest output per square foot, then you'll need to pay attention to the solar panel efficiency numbers.

Thanks a lot Socaldmax. My gut feeling was that there must have been greater efficiency achieved of recent. Being in electronics I always expect Moores Law to come into play. For my thinking to heck with the cost. I want to build for maximum power. I could easily accommodate an extra 16". Looks like I have to track down some Sunflower panels. Thanks a lot.

Regards,
Chaya

[StuM]

Not many brands at all

Sunpower are definitely the leader by far, but there are a few Sanyo and AUO/BenQ panels that come close.

[Stumble]

Originally Posted by socaldmax

No, you were correct.

The newer Sunpower E445 panels produce a lot more power than the average 250 -275 panels, while only using slightly more real estate due to being 20% efficient. Most 250-275 watt panels are 40"x65" and only about 14-15% efficient, the Sunpower are 41"x81" and 20% efficient, so about 16" longer, but nearly 200w more power for the slightly longer panel.

The problem is, Sunpower panels are difficult to find in the US, they don't sell them to the public. The efficiency of the panels is usually very important on a boat due to limited space, but since you're populating an entire arch, you could possibly spare a little room for less efficient panels, unless you want the absolute highest output per square foot, then you'll need to pay attention to the solar panel efficiency numbers.

Figure the Sunpower 400w panels generate 10% more power per sq inch than the competitors, this is a huge increase and can't be ignored. But equally important is the coverage efficiency of the panels, being able to increase the sq inch coverage area by 10% results in the same output.

Best is obviously to maximize both.

[W3GAC]

All the 400w panels I've looked at (for home/ amateur radio use) output at 48 volts. Having higher voltage helps keep conductor size down/ and lowers wiring losses. These panels are often connected into large scale installation with connected voltage at 600v or 1000v. While OK for stand-alone systems going into special inverters to directly connect/ sell back energy to the power grid... I'm personally very hesitant to install 'high' voltage (48v) solar system on my boat. The 'smart' controller has to deal with controlling it to charge/ direct power our 12v systems and usually creates a lot of annoying RFI interference to weak SSB signals. Also a wiring mishap could result in over voltage damage to practically every powered device on the boat. My experience on boats is firmly wrapped around the KISS principle and understand the worse thing that could go wrong, because it might! Also, if 48v to 12v smart controller dies while enroute... you just can't 'direct wire' the panels to the battery and manually manage charging. I'll stick to 12v panels... for now anyway.


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[trifan]

Jbinbi:

Spoke with Affordable Solar in Albuquerque a few mins ago and their best deal is the 305W Q-cell panels @ $0.74/watt, or approx $230. Here's the datasheet:

http://www.affordable-solar.com/site...G2_305-315.pdf

Maybe that will help. If you are dead set on the 400W Sunpowers AND if enough others went in with you on the purchase, I could probably order a pallet of them.

[emcmia]

Installed two (2) SunTech 395W panels about year ago; connected in parallel via dedicated ckt breakers to Morningstar Tristar MPPT controller. Monocrystalene panels are flexible (conforming to curved hard bimini), low profile (i.e. no aluminum frame), walkable and nominally 48"x 92" each. Quite satisfied with performance, so far.

[alansmith]

W6GAC, your logic can't be ignored. The "what if's" can always come back to bite you at the worst time. No one needs a nuclear accident at 3 pm in the afternoon....smile