Illustrated Guide to Solar Installations on Boats

[rgleason]

"Illustrated Guide to Solar Installations on Boats"

Just a reminder again please see Post #1 by Steadman Uhlich

[Randy P]

1977 Trojan 26 went solar this year with
2 170W PVs wired in parallel to hardtop.
Victron smart 100/30 MPPT controller to house bank (formerly 2 FLA 100AH wired in parallel, going to be 2 100AH Battle Born LFPs next year).

In process of correctly wiring to accommodate 1 FLA 100AH deep cycle dedicated to engine,
3 way battery switch,
Victron Orion 12/12-30A charger wired between engine and house banks, and installing
Victron BMV 712 monitor.

I have no idea how to post pictures to this link.

[olivierlc]

Hello,
Do you have a diagram, an electrical plan ?
Thank you

[Randy P]

I hope I did this right. Here are pics of diagram of what I plan to do, but it’s not complete until I get back to the boat. Also pics of the 2 170W mono panels and wire routing, as well as Victron 100-30 Smart MPPT. There is an inline fuse on the panel wiring as well as a 40A breaker before the MPPT. Bluetooth on the MPPT allows for functions via iPhone/iPad.

[olivierlc]

Thank's

[Sailing Ohm]

We have two 330 watt Panasonic HIT panels in series for 660 watts but routinely see higher. They recharge our 60V battery bank.
They are large panels 62x40 and weight like 40lbs each.
We have a midnite solar classic mppt charge controller.

The panels cost us about $450ea including shipping from California to Florida.
We got these panels for their industry leading efficiency @19.7% and their high nominal voltage @69.7

We used our panels as our Bimini top. Since the panels are off the stern we have only the tiniest of shading from the split back stay so we routinely get our full rated power.

They have been working amazing for three years now. We almost never have a want for energy and frequently put in power when it rains. As of writing this at 7:30 am we are putting in 50-65 watts and are usually topped off well before noon.

Oh and we have an electric motor (thus 60V battery bank) and the solar panels can move the boat along at 4-5kt by themselves in a protected waterway.

We had a lightning strike a two summers back in which one of the panels had a blown junction box. Ordered a new one from China and with a little solder that panel was putting out full power in no time (actually that day we finished the repairs we saw 770total watts).

[olivierlc]

beautiful boat and beautiful installation

[Sailing Ohm]

Here’s another solar installation (actually it was a full electrical redo) I’ve done for a neighbor using 300w panels (very similar to my Panasonic HIT Panels) on a Catalina 36. Replaced 3 of his dying/dead Renogy 100w.

I’m in South Florida (West Palm Beach) and have done a few solar and battery installations for neighbors if anyone is interested.

[noelex 77]

Originally Posted by Sailing Ohm

We have two 330 watt Panasonic HIT panels in series for 660 watts but routinely see higher. They recharge our 60V battery bank.
They are large panels 62x40 and weight like 40lbs each.
We have a midnite solar classic mppt charge controller.

The panels cost us about $450ea including shipping from California to Florida.
We got these panels for their industry leading efficiency @19.7% and their high nominal voltage @69.7

Have you wired the panels in series or parallel?

[Sailing Ohm]

They are wired in series which I always prefer to do. Especially with the high quality mppt controllers these days.

[noelex 77]

Originally Posted by Sailing Ohm

They are wired in series which I always prefer to do. Especially with the high quality mppt controllers these days.

Great

Generally parallel connection is better on a boat, but with your high house bank voltage I was worried that the Vmp may be too low for the battery voltage. Series connection fixes this concern.

Watch the safety of the +130v, but with electric drive I suspect you have sorted this better than most 12v boats. Unfortunately, they do not always properly consider the safety aspects of their high voltage panels.

[Sailing Ohm]

Originally Posted by noelex 77

Great



Generally parallel connection is better on a boat, but with your high house bank voltage I was worried that the Vmp may be too low for the battery voltage. Series connection fixes this concern.



Watch the safety of the +130v, but with electric drive I suspect you have sorted this better than most 12v boats. Unfortunately, they do not always properly consider the safety aspects of their high voltage panels.

I agree about the safety aspects but I’ll take it a step further in that many unfortunately don’t consider the issues with electricity in general no matter the voltage.

I do disagree about parallel wiring being better on a boat. Maybe this was the norm when most solar panels found on boats were nominal 12vdc and mppt controllers weren’t as popular/available/cheap. It’s my understanding that these modern mppt solar controllers, and thus your batteries, benefit from the highest voltage possible. (Ideally they want panel voltages 20% min above battery voltage)

While higher voltages are potentially more dangerous (honestly I don’t want to get shocked by a 12vdc battery either) it is really the same design/setup you would have on an appropriately installed 12vdc.

As a comparison I think tasers deliver less than 100watts... the fact that the power is DC inherently means safety should be primary concern.
Some data:
“300-500mA of DC is enough to cause fibrillation.
LOW VOLTAGE DOES NOT IMPLY LOW HAZARD!
100mA for 3 seconds = 900mA for .03 seconds … causing fibrillation Note that a difference of less than 100 milliamperes exists between a current that is barely perceptible and one that can kill.” ( source- https://www.wikilectures.eu/w/ELECTR...AND_HUMAN_BODY)

One safety benefit I see of this is having lower current running through the wiring. Most safety issues I’m aware of are due to improper installed wiring or improper installation of an electrical device (some people just can’t seem to properly crimp and seal a wire terminal)

I think many people are walking a fine line between wiring cost and required wire size. A nice thing about the high voltage panels is that cheap 8 gauge wire will handle 4x the maximum current possible (sized at 3% voltage drop) therefore practically eliminating the risk of inadequate wiring which is where many systems fail.
We’ve also required our windlass with a small 60v electric motor allowing 8gauge wire to be used and still fall within a safe current range at 3% drop. One of the added safety benefits I think of using a higher voltage system...not to mention cost also

[Sailing Ohm]

Definitely went off topic... my bad

[AKA-None]

Originally Posted by bcboomer

Okay, here is my installation. I don't have all the numbers yet as it just went "live" this week.

O'Day 40

588 watts + whatever I get from reflected light.

Panel size is 1510 x 540 mm.

2 faced Gioco FGSE 147. Purchased last year when they were offered here at a discount.

Total cost about $10,000. Mostly for the framework.

Efficiency? Don't know yet.

Haven't seen winds over 30 knots yet but they don't budge at that speed.

I put a curve of about 10% in the mount so they won't flutter. It sems to work.

If I had to do it over I would use different controllers. I bought 4 Blue Sky "Solar Boost" SB1524iX charge controllers and the IPN Pro Remote without enough research. They don't actually boost low voltage panels so I won't get as much output in poor conditions.

However, the system should give us all the power we need while cruising the coast of BC.

That’s a really nice looking installation if I may say so. Maybe a bit of something under the bottom to protect the cells but it looks like it was factory designed

[Randy P]

Finally got around to doing my proposed solar/LFP/FLA system in PowerPoint. I’ll label fuses, wiring awg, etc when I start install after the snow melts.

I may replace the 1-2-All-Off single switch with dedicated ON-OFF switches for Engine and House Banks.

The boat is a 1977 Trojan F26 cruiser with single Chysler Marine 318 and single 70A “dumb” alternator.

Comments & suggestions are welcomed!