Solar panels and Radar

[ksceviour]

We purchased a solar system at the boat show this year with the intention of placing them on the top of our fly-bridge enclosure. These are the light weight flexible kind that are increasingly showing up on bimini tops these days.

My wife recently raised the question of radar interference from solar panels installed in front of and slightly below the radar antenna. I've got 30 years experience in using radar but I've never had an array with highly reflective solar panels in front of them.

My own thoughts are any interference would be negligible considering the beams narrow splay that close to the boat and the panels being on the same plane.

Thoughts? Experience?

 

[psneeld]

Look up the beam width of your radar, and make a small to scale drawing and see if it is within that beam angle.

I am not sure but suspect unless you have a broadband radar, the panels would be in the main bang radius and wouldn't interfere.

But then again, the panels would be blocking targets...expand the drawing and see just how far out.

 

[FlyWright]

I'd be more concerned about shadowing on the panels reducing their efficiency than the attenuation of radar signal from the panels. If the frame supporting your FB canvas doesn't interfere, I wouldn't think the panels on top of the frame would have an effect.

Be aware of the need for solar panel cooling air.

 

[ksceviour]

Good points both. Typical beams are 25 degrees vertically on a Raymarine digital system which gives 12.5 degrees down from the arrays center. At 7 feet the manufacturer says this equates to about 20 degrees above and below the element. That would probably catch the pulpit 20 feet out. With the forward panel edge less than 6 feet in front of the arch I don't see it catching much, if any of the panels.

As for blocked returns, the reflector would have to be under the bow.

Personally I can't see an issue with this but it never hurts to toss it out for discussion.

 

[twistedtree]

I agree that as long as they are not in the radar beam, you should be fine. We have not had any problem with ours, and they are in front of the radar scanner, but not in the beam.

 

[ksceviour]

Ahh, so that's what I need to hear. You have a solar array in front of the radar with no issues.

 

[twistedtree]

Yes, see picture. I have a different radar now, but in the same location.

You can also see where shading from the radar can be a problem. I still haven't figured out a good solution other than climbing up there and re-positioning the scanner.

 

[Bob Cofer]

That shading is going to be a problem.

 

[twistedtree]

That shading is going to be a problem.

It is, and I really need to figure out an easy way to park the radar out of the way. Simrad advertises that the radar can be parked in a programmable position, which is one of the reasons I originally selected it. But it doesn't work, and after questioning Simrad about it they confessed that it was impossible to make it work since there was no brake or other way to control where the scanner stops. So they advertise a feature that not only isn't present, but is impossible to ever add. Just one of the many reasons why that radar isn't on my boat any more.

If anyone has any clever ideas, I'd welcome them. Once moved athwart ships, there is no shadow on the panels. The best I've come up with is to use a boat hook so I don't have to climb completely up on the hardtop. But them I'm hanging onto the outside of the railings with one hand instead of two while 20' off the water. So I'm really not sure it's better than climbing all the way up.

 

[O C Diver]

It is, and I really need to figure out an easy way to park the radar out of the way. Simrad advertises that the radar can be parked in a programmable position, which is one of the reasons I originally selected it. But it doesn't work, and after questioning Simrad about it they confessed that it was impossible to make it work since there was no brake or other way to control where the scanner stops. So they advertise a feature that not only isn't present, but is impossible to ever add. Just one of the many reasons why that radar isn't on my boat any more.

If anyone has any clever ideas, I'd welcome them. Once moved athwart ships, there is no shadow on the panels. The best I've come up with is to use a boat hook so I don't have to climb completely up on the hardtop. But them I'm hanging onto the outside of the railings with one hand instead of two while 20' off the water. So I'm really not sure it's better than climbing all the way up.

My new Garmin stops and rotates into the athwart position. It looks nice that way, but there isn't a mechanical brake to hold it from rotating. So the wind rotates it to perpendicular to the wind direction with moderate wind gusts.

Ted

 

[ksceviour]

A closed array with a lower profile? You lose the advantages of an open system but then everything tends to be a trade off in boats.