600 Watts of solar power
It has been a while since we posted anything here. Much work has been done since. It will be another month or so before I can get caught up. I am posting one particular improvement now though as there has been interest in the project on the Bayliner Owners Club forum I participate in. So here goes.
How much current might one get at about 46 degrees latitude in the Pacific Northwest on a clear summer day? I took readings from the solar controller the first chance I got. The batteries had been carrying the house load for about 20 hours. These are the readings I took from the time I awoke to the time we headed home:
I installed two 300 watt rigid solar panels made by Canadian Solar off of the web. I won't mention the web site because I recommend against that option for large panels such as these. I installed the panels on two very sturdy rails designed for spans up to 12 feet purchased from ironridge.com. In order to get a quote from ironridge.com I had to specify the layout of my system in their Design assistant. It asked for the number of rows and columns of panels I was installing. I entered 1 row, 2 columns. I was given the chose of some local electrical supply stores from which to get a quote. I chose one nearest to me named Platt Electric.
The quote from Platt included the rails, mounting hardware, end caps and 2 panels. By the time I received this quote I had already received my Canadian solar panels which I paid $150 to ship and $250 each for the panels. They arrived on a pallet! The panels in Platt's quote were made by Silfab which have just as good of a warranty as Canadian solar but cost only $186 each and would not require me to pay shipping. Lesson learned.
The controller I purchased is a EPEVER 40A MPPT Solar Charge Controller 100V Input Tracer 4210AN.
To determine the wire size needed I used an android app named Electro Mission. It's a great app. I used its Cable Size Calculator. There were two runs of cables to calculate. One is the run from the solar panels to the controller and the other from the controller to the house batteries.
I chose to wire the two 30 volt solar panels in series raising the output to 60 volts. With a higher voltage the wire size needed is reduced. Running wire from the cockpit lazarete up to the panels was a bit of a challenge so I wanted to keep the wire size down. The calculator requires the current in amps. The calculation of amps is WATTS/VOLTs so 600/60 = 5 amps. I'll probably never see 600 watts from the panels because they are not angled with the surface perpendicular to the sun so this give me an automatic safety factor. I wanted voltage drop of less than 3 percent. Another important input is the wire run length which is the total of both wires. It's 35 feet from the controller to the panels so that's 70 feet of wire. The calculated wire size is 4.0 square millimeters. The app has a cross section to AWG conversion table which I used to arrive at 12 AWG. Had I chose to run the panels in parallel the wire size needed calculates to 8 AWG. I think I did the calculation too many times and didn't trust my answers so I opted for 6 AWG wires. Go figure.
The schematic lays out like this. Two solar panels wired in series connected to two wires that run to the controller. There are two other wires running from the controller to the house batteries. That's it! The only other complication is to fuse protect the wires near to the power source. I installed one breaker up under the upper helm in the solar panel wiring and another near the controller in the cockpit lazarete.
I already mentioned the Ironridge rails. I needed some way to attach them over my half top (Bimini). The half top is constructed like a tuna tower using 1-1/2 inch anodized aluminum tubing. I created my own mounting system using 3/4 inch starboard, see pictures.
How much current might one get at about 46 degrees latitude in the Pacific Northwest on a clear summer day? I took readings from the solar controller the first chance I got. The batteries had been carrying the house load for about 20 hours. These are the readings I took from the time I awoke to the time we headed home:
8 amps, 12.4 volts
at 8:00
18.5 amps 13.2 volts
at 9:30
27 amps, 13.5 volts
11:30
27 amps 14 volts
13:00
20 amps, 14.3 volts
at 14:00
20 amps, 14 volts at
15:00
Not too shabby!
Update: definitely keeps up with our loads, even when the morning is cloudy.
Update: definitely keeps up with our loads, even when the morning is cloudy.
 |
| Custom home made rail mounts |
 |
| Looking down about 10 feet of rail |
 |
| My initial plan for mounting. I opted for something more substantial. |
 |
| Looking up at the panels on the rails. |
I installed two 300 watt rigid solar panels made by Canadian Solar off of the web. I won't mention the web site because I recommend against that option for large panels such as these. I installed the panels on two very sturdy rails designed for spans up to 12 feet purchased from ironridge.com. In order to get a quote from ironridge.com I had to specify the layout of my system in their Design assistant. It asked for the number of rows and columns of panels I was installing. I entered 1 row, 2 columns. I was given the chose of some local electrical supply stores from which to get a quote. I chose one nearest to me named Platt Electric.
The quote from Platt included the rails, mounting hardware, end caps and 2 panels. By the time I received this quote I had already received my Canadian solar panels which I paid $150 to ship and $250 each for the panels. They arrived on a pallet! The panels in Platt's quote were made by Silfab which have just as good of a warranty as Canadian solar but cost only $186 each and would not require me to pay shipping. Lesson learned.
The controller I purchased is a EPEVER 40A MPPT Solar Charge Controller 100V Input Tracer 4210AN.
To determine the wire size needed I used an android app named Electro Mission. It's a great app. I used its Cable Size Calculator. There were two runs of cables to calculate. One is the run from the solar panels to the controller and the other from the controller to the house batteries.
I chose to wire the two 30 volt solar panels in series raising the output to 60 volts. With a higher voltage the wire size needed is reduced. Running wire from the cockpit lazarete up to the panels was a bit of a challenge so I wanted to keep the wire size down. The calculator requires the current in amps. The calculation of amps is WATTS/VOLTs so 600/60 = 5 amps. I'll probably never see 600 watts from the panels because they are not angled with the surface perpendicular to the sun so this give me an automatic safety factor. I wanted voltage drop of less than 3 percent. Another important input is the wire run length which is the total of both wires. It's 35 feet from the controller to the panels so that's 70 feet of wire. The calculated wire size is 4.0 square millimeters. The app has a cross section to AWG conversion table which I used to arrive at 12 AWG. Had I chose to run the panels in parallel the wire size needed calculates to 8 AWG. I think I did the calculation too many times and didn't trust my answers so I opted for 6 AWG wires. Go figure.
The schematic lays out like this. Two solar panels wired in series connected to two wires that run to the controller. There are two other wires running from the controller to the house batteries. That's it! The only other complication is to fuse protect the wires near to the power source. I installed one breaker up under the upper helm in the solar panel wiring and another near the controller in the cockpit lazarete.
I already mentioned the Ironridge rails. I needed some way to attach them over my half top (Bimini). The half top is constructed like a tuna tower using 1-1/2 inch anodized aluminum tubing. I created my own mounting system using 3/4 inch starboard, see pictures.
Comments
Post a Comment