Hi Dick You're welcome.
.... So what DO you want to accomplish? a trickle system? a weekender system? an off the grid system? Fair winds, Judy B ________________________________ From: Sonshingle <[email protected]> To: [email protected] Sent: Thu, April 15, 2010 12:37:02 PM Subject: Re: [IC27A] Re: Solar system [was: Inconvenient battery installation on Catalina 27] Judy, Thank you so much for all this valuable information. This will save us having to go through 6 books and 11 websites to find out this much information and it is all relative to what we want to accomplish. I've been wanting to put on a solar panel but was gun shy because I was ignorant on the subject. Thank You, Thank you !! Dick Schmidt --- On Wed, 4/14/10, Judith Blumhorst, DC <drju...@blumhorst. com> wrote: >From: Judith Blumhorst, DC <drju...@blumhorst. com> >Subject: Re: [IC27A] Re: Solar system [was: Inconvenient battery installation >on Catalina 27] >To: ic...@yahoogroups. com >Date: Wednesday, April 14, 2010, 9:07 PM > > > >Rick, > >What is your goal? To keep your batteries trickle charged on a mooring? Or >to go "off the grid"? For a trickle charge panel, less than 10 watts, you. > >1. Trickle charging: > >For a trickle charger, the rule of thumb ishat your panel should provide >about 1 watt or less for every 25 amphours of battery capacity. If your panel >provides more than that, you'll damage your batteries. For a 90aH battery, a >5 watt panel is close enough and you won't hurt the battery. If you have AGM >batteries, which have lower internal resistance and a negligible rate of >self-discharge, you can use a 2 watt panel to keep your batteries topped up. > >For a two battery bank, a nice system would be a Unisolar flexible 11 watt >panel and a dual battery controller. I like the Flexcharge PV7D. It's a >smart-charger, very effieicent, will charge both batteries, and can handle up >to 7 amps from the panels. It's under $100 at West Marine and can take a >beating or a dunking. That's what I have for my trailer sailboat that doesn't >have shorepower available. (And AGM batteries). > >In sunny San francisco, the 11 watt panel recharges the amps we use on a >weekend daysail (for lights, radio and occassional autopilot use,) as well as >maintains the battery. We don't have or need a cranking battery, just enough >for one light inside and the vhf and the stereo. We rarely sail at night, and >we carry battery powered backup lights for longer trips, just in case. > >2. Small solar system for 3 season use "weekender" use, providing moderate >creature comforts: > >The biggest panel manufactured for 12v systems is 135watts. For that you >would need a conroller. A 135w panel is the largest one made for 12 systems, >and they generally can't produce more than approx 7.5 amps per hour under >ideal conditions, no matter what the voltage. So you could use a 7-10 amp >controller with a single 135w panel. You can put together a nice135w system >with controller for under $500. Depending on your weather, that'll give you >up to 50 amphours a day in the summer, 30 in the fall/spring and 15 amphours >in the winter. That's just right for a two bank system of about with two >house batteries of 90-100 aH each. Use one battery for the engine and use the >other two for the house. You'll have one days' reserve capacity in the house >bank if it rains. In the winter, you're not going to get enough juice to use >all your creature comforts, so use shorepower. > >4. Off the grid livaboard system: > >For an "off the grid" 12v system, to provide more creature comforts, costs >jump geometrically. You'd need a lot more panels, wired panels in parallel, >and a controller with the apropriate amperage range. Now we're talking >around $250-300 and up for a controller. $300 per panel. Mounting systems >for the panels. Wiring costs increase as the diameter of wire increases. And >if you really want to go off the grid, then you need to invest in a much >larger battery bank. So now we're adding more weight and more expense. > >5. The moral of the story: > >If you can keep your consumption down to 25-30 amphours per day of usage for >spring/summer/ fall, you can get away with about $500 for the solar system, >(and $500 for two nice AGM batteries that'll last you 7 or 8 years and charge >up really fast) > >6. Or get a Honda 2000i gas generator for $1000.... and run it on the >foredeck. Use your fridge and microwave as much as you'd like.... >~~~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~ ~~~~~~ > >I plan to buy a 135w panel. 135watts/12v = 11.25 amps right? So if I have my >135w panel out for an hour at noon, I should get 11 amphours worth of charge >in my batteries, right? > >Sorry, but that's not how it works. You'll get about 6 amphours back in your >battery bank in one hour at noontime. > >A 135 watt panel can't produce more than about 7.5 amps. Photovoltaic panels >are nominally rated at 17.7 volts... so that they produce enough voltage to >charge a battery even if conditions aren;t perfect and part of the panel is in >shade .So 17.7v * 7.5a = 135 nominal watts. But at 12.3v the equation works >like this: 12.3 * 7.5 = 92 watts. > >To figure the output of a system, you use the 7.5 amps x the number of peak >sun hours. then de-rate that output by 0.80 (average) for system >ineffieicencies. So you get 6 amps per hour in the noon-day sun. > >(You need between 13.5 -14.3 volts, which is the range that's required to >fully charge a battery. And if the day is too hazy, or the sun angle too >low, or more than about 30% of the panel is shaded, the voltage drops too low >to charge the battery.) > >That's all I can tell you in general. Designing a system gets down into the >particulars. But I hope this helps provide some practical guidelines for cost >vs. benefit. > >Fair winds, >Judy B > > > > ________________________________ From: Sonshingle <sonshin...@yahoo. com> >To: ic...@yahoogroups. com >Sent: Wed, April 14, 2010 4:21:03 PM >Subject: Re: [IC27A] Re: Solar system [was: Inconvenient battery installation >on Catalina 27] > > >Judy, > >This is excellent information and thanks for sharing it. What have you learned >about voltage regulation to the batteries? I understand there has to be some >sort of regulator to prevent overcharging and that good regulators carry a >pretty good price tag. > >Dick Schmidt >Greenville, NC >Rush NoMore > >--- On Wed, 4/14/10, Judith Blumhorst, DC <drju...@blumhorst. com> wrote: > > >>From: Judith Blumhorst, DC <drju...@blumhorst. com> >>Subject: [IC27A] Re: Solar system [was: Inconvenient battery installation on >>Catalina 27] >>To: ic...@yahoogroups. com >>Date: Wednesday, April 14, 2010, 5:18 PM >> >> >> >>Hi Tim (And David) >> >>I have completed the first two courses for my solar designer certification >>with NABCEP, the North American Board of Certified Energy Practitioners. >> >>Let's see if I can help a little here.... >> >>Here's a real-world example, based on my homeport -- sunny San francisco, at >>latitude 38 degrees. A high-quality 135w solar panel will replace about 30 >>usable amphours per day to my high-quality batteries per day, if I have a >>high-efficiency solar charge controller. >> >>Where are you located? How much sun you get determines how much power your >>panels generate. The rating on the solar panel doesn't tell you what you're >>going to get in the real world. It's just an output rating in ideal >>conditions. (And the definitions aren't always what you'd expect). >> >>Good panels put out more juice than crummy ones when the sun isn't perfect. >>Efficient chargers constantly adjust the "maximum power point" varying >>varying the resistance to the panel so they put out the most usable amps at >>the right voltage. Good batteries have low internal resistance and can >>absorb a charge faster and with less wasted energy. >> >>With less than excellent components, you might get only half as much usable >>amp-hours out of your system. >> >>And your location makes a huge difference: >>To size a solar system for a given geographical location and climate, we use >>a concept called "peak sun hours" >> >>In san Francisco, we get the equivalent of 7.3 peak hours, hitting a >>horizontally mounted panel. In January, we get the equivalent of 2.2 peak >>hours. For the whole year, we get an average of 4.7 peak hours per day >> >>And then we have to "de-rate" the performance for factors like temperature, >>dust on the collector, electrical resistance, etc. An efficiency factor of >>.80-.85 would be excellent performance in the real world. .75 would be >>average. >> >>Here are some good links to play around with... >> >>For peak sun hour factors by city and state in the US: >>http://rredc. nrel.gov/ solar/old_ data/nsrdb/ redbook/sum2/ state.html >> >>For a solar system sizer (for off-the-grid systems) >>http://www.advancep ower.net/ advcalc.htm >> >>Fair winds, >>Judy B, >> ________________________________ From: Tim Millar <seascoutship76@ verizon.net> >>To: ic...@yahoogroups. com >>Sent: Tue, April 13, 2010 1:20:19 PM >>Subject: Re: [IC27A] Inconvenient battery installation on Catalina 27 >> >> >>David, >> >> >>Got my answer from Coleman/Stearns Consumer Service: >> >> >>The Coleman Solar Charging units are licensed products manufactured and >>distributed by ICP Solar Technologies, 7075 Place Robert Joncas, Suite >>131, Saint Laurent, Quebec H4M 2Z2, Phone: 888-427-7652 or 514-270-5770 Ext. >>133, info-customers@ icpsolar. com, http://www.icpsolar .com. That's one >>possibility - double battery, controller = about $140. >> Just searched eBay for "solar marine battery charger" and don't know what >>I'm looking at. I'd leave it hooked up in the cockpit on the mooring. We >>don't need much house power - just lights, radio, bilge and fresh water pump >>- plus the starter battery for Universal M-18. Suggestions? >>Tim >> >> >> >>Even if the Coleman ones are end-of-life' d, there are a TON of solar panels >>of all shapes, sizes, and wattage on eBay for cheap. >>I had picked up a one-watt panel for about $6 (shipped, no less) to trickle >>charge my car's battery during the week since I take public transit to work. >>One watt is not much juice but I wanted to squeeze more life out of my >>5-year-old battery and that was a cheap way to go about it. Maybe next winter >>will be the death's door for it...David >> >> >
