Solar Oyster Barge

[Sunking]

In my corner, 4 x NSB210FT, 10ft3, 528 lbs, 210 Ah, 800 cycles at 50% DoD, $1550

Are you referring to Northstar Red or Blue?

I use quite a few of the Blue models at remote telemetry sites on pipelines, and even a few remote micro-cell sites. Those are Telecom-Data Center batteries and not well suited for cycle applications. From the sounds of your application, there are better alternatives. For example say a Concorde Sun Extender AGM batteries are best in class. Look up Concorde PVX-2120L battery and see what you think. Concorde invented the AGM battery for military aircraft. They also make Chairman (mobile) and Lifeline (marine), Sun Xtender (solar and RE), and of course Concorde (military aircraft). So give both Sun-Xtender, and Lifeline product lines a close look and see what you think.

[Mike90250]

Wind power on a barge. I think the moving parts and the marine environment are just too incompatible. There was an old marine version of the air-x but it was still plagued with problems .

[Sunking]

Wind power on a barge. I think the moving parts and the marine environment are just too incompatible. There was an old marine version of the air-x but it was still plagued with problems.

Well Mike I am certainly no fan of Wind Turds on the consumer level products as you already know. Just no way to get them high enough to clear tree and building obstructions to get them into linear flow without turbulence, and they require gale force winds. Nor am I a boat or ship guy despite serving in the Navy. No wind or sun on a Dolphin as we had unlimited fuel.

But me thinks wind turds do have applications in marine environments especially on a barge or patroon boat where you have no mask, sails, or rigging above deck level. Makes more sense than solar as you know there is no good way to mount solar panels on a boat that pitches, rolls, and yaws around. Every time I am in a harbor I see several wind turds on boats, and when out on open waters when I see boats or ships with wind turds are humming along at a good clip. What I do not know if any of them are quality made.

[Sunking]

Jangr I know you said you did not want to use or rely on shore power, but you might want to reconsider if minimum conditions can be met. What i mean is if you are not on the water than more than two full days without returning to shore, you really do not have any need for solar and would be just added expense and weight you need not expend. Same goes for RV applications if you drive at least every other day. If you are back in port every night, you really should not use solar at all.

Here is where I am coming from. If you properly size the battery, it does not need charged while out on the water. Example if you are out early before sun rise and back after sunset, you size the battery for 2-day capacity, and you can use FLA to save a huge chunk of cash. Use shore power and battery charger when you return each night and be ready for the next day. If you are out for 2 days, and use AGM battery, you size the battery for 3-day reserve, and again recharge on shore power and be ready for the next day.

Before you pull the trigger I think I would use Wind Turds before solar on a boat or barge. Solar just does not work great on a boat/ship where it pitches, rolls, and yaws around. For solar panels to be effective require a fixed mount, oriented due solar south, at optimum tilt angles, with no shade issues from sun rise to sun set. Cannot do that on a boat or any moving vehicle like an RV. Wind Turds do not have that problem.

Something to think about.

[SunEagle]

Well Mike I am certainly no fan of Wind Turds on the consumer level products as you already know. Just no way to get them high enough to clear tree and building obstructions to get them into linear flow without turbulence, and they require gale force winds. Nor am I a boat or ship guy despite serving in the Navy. No wind or sun on a Dolphin as we had unlimited fuel.

But me thinks wind turds do have applications in marine environments especially on a barge or patroon boat where you have no mask, sails, or rigging above deck level. Makes more sense than solar as you know there is no good way to mount solar panels on a boat that pitches, rolls, and yaws around. Every time I am in a harbor I see several wind turds on boats, and when out on open waters when I see boats or ships with wind turds are humming along at a good clip. What I do not know if any of them are quality made.

From what I have heard from boat people with small wind turbines is that they do provide a limited amount of energy to keep their electronics going or battery charged. As long as they are positioned where they get a lot of on shore or off shore wind while docked.

I guess it all depends on how much you pay for the turbine and what their true watt hour output is under normal conditions.

[jangr]

Wind turds...you guys are funny

There are 3-blade, marine-rated turbines in the 48" wingspan range. While they don't come close to their rated output until it's blowing >25mph, the published power curves at average wind speed in my area (12 mph) are 100 watts, which is something. Doesn't sound like much juice to replace a 5 Kw draw, or to replace a 1.2 Kw solar array. But I've thought about this a little and it's not so wimpy as it might appear.

Assuming that a controller could actually make productive use of such a small trickle, the turbine does work 24x7. On an average day you'd harvest 2.4Kw, double that if it's blowing good. On the other hand, using the 5 hour rule of thumb, you COULD harvest 6Kw of solar on GREAT day, but probably average no more than 3Kw per day Apr - Nov.

Looking at it another way, 2 x 300W of panel @ 1.5Kw and 1 wind turd @ 2.4Kw gets you a daily 3.9Kw average. I'm thinking that;s a more reliable 3.9 Kw than the 3 Kw daily solar I can count on docked plus whatever I scrape up on station with the panels stowed flat and randomly oriented.

Re; batteries, I was looking at the Northstar Red 210, they are pretty common in marine applications because of their form factor and discharge capacity. While the lithium would solve some weight issues, what I'm finding is 2x-2x-2x cost for FLA-AGM-Li. When I started this project I had 4 x 8D FLA in mind ($800). Then I realized I needed 105A c/2 and started looking at the Northstar 210Red AGM ($1500). The best $/watt Chinese Li is a 16-pack of 100Ah at about $2500. But they don't seem stout enough to handle a 100A continuous load, and the next step up is 150Ah ($3500). Still pondering.

[ButchDeal]

Wind turds...you guys are funny

There are 3-blade, marine-rated turbines in the 48" wingspan range. While they don't come close to their rated output until it's blowing >25mph, the published power curves at average wind speed in my area (12 mph) are 100 watts, which is something. Doesn't sound like much juice to replace a 5 Kw draw, or to replace a 1.2 Kw solar array. But I've thought about this a little and it's not so wimpy as it might appear.

You can't use AVERAGE wind speed as it gets affected by big guests which generally are outside the operating range for the small turbines.

[Sunking]

The best $/watt Chinese Li is a 16-pack of 100Ah at about $2500. But they don't seem stout enough to handle a 100A continuous load, and the next step up is 150Ah ($3500). Still pondering.

Stay away from Chi-Com lithium batteries (CALB, Winston, GBS, Sinopoly). They can easily handle a 1C discharrge, or C/10 for about 1 maybe 2 years at best. Custom EV and DIY EV builders learned that lesson a long time ago.

Have you looked at Rolls Batteries? They cater to the Marine and Rail Road industries. As for wind turds go not my thing on land or sea. Commercially they only work on a large scale using 2MW turbines mounted on 250-foot and higher towers and they dominate the RE generation in the country. Hydro comes in second, and solar is a distant 3rd. Keep in mind on a Barge perhaps a Spiral Type wind turd would be a better choice and safer from what I understand. What I do know is the power they generate is a cube of wind speed. So if a 10 mph wind generates 100 watts, at 20 mph generates 800 watts. Texas leads the USA in RE production and all comes from Wind Farms.

[Sunking]

OK back to charge controllers and Voc. You need to match the Controllers, Panels, and Battery voltage. Where are you located? Do you live where it gets cold north of I-40? Controllers Voc input varies from 40 to 600 volts. With a high voltage controller of 600 volts, you can run 10 to 15 panels in series. At 150 Voc input is going to depend on the panels Voc an dhow cold it gets. Th elimit is going to be 3 to 5 panels max in series. If you live south of I-40 corridor total the panel Voc, as long as it is under 120 volts total, you are good to go. So if the panels Voc = 30 volts, you can run 4 in series. With a 48 volt battery, minimum you want to run Vmp is 72 volts which would put Voc around.

Your challenge is you are asking for 48 volts. 1200 watt of panels is really territory of 24 volts. One work around is using higher voltage controllers of 200 to 600 volts made by Midnite Solar and Morningstar. Keep asking good questions and we wil get you to where you want to go. For right now WHY 48 VOLTS? At 48 volts you want to run Voc between 90 to 120 volts on a 150 Voc controller. Higher is better. Ideally around 90 Volts Vmp which is about 115 to 120 volt Voc. It is a puzzle you have to find the pieces to fit.

So you can do quick math in your head, here is two easy formulas to get you in the ball park:

1 volt Vmp = 1.25 volt Voc.
16 volts vmp per 12 volt battery.

With that you know right away for a 48 volt battery requires a minimum is 72 volts Vmp @ 90 Voc.

[jangr]

Stay away from Chi-Com lithium batteries (CALB, Winston, GBS, Sinopoly). They can easily handle a 1C discharrge, or C/10 for about 1 maybe 2 years at best. Custom EV and DIY EV builders learned that lesson a long time ago.

Have you looked at Rolls Batteries? They cater to the Marine and Rail Road industries. As for wind turds go not my thing on land or sea. Commercially they only work on a large scale using 2MW turbines mounted on 250-foot and higher towers and they dominate the RE generation in the country. Hydro comes in second, and solar is a distant 3rd. Keep in mind on a Barge perhaps a Spiral Type wind turd would be a better choice and safer from what I understand. What I do know is the power they generate is a cube of wind speed. So if a 10 mph wind generates 100 watts, at 20 mph generates 800 watts. Texas leads the USA in RE production and all comes from Wind Farms.

So batteries...I know as much about batteries as I know about solar, which is not much. But I've spent hours (literally) trawling through charge/discharge curve, internal resistance, C/X tables, etc until my eyes are crossed and I have to close the laptop. So far this is what (I think) I know.

At high discharge rates of 100A for 30-60 mins per duty cycle, you have to size a conventional FLA or AGM battery pack @ energy budget x 2 (50% DoD) then add 20-30% more. For instance, the Rolls 210Ah AGM is arguably a very nice battery, but only carries a C1 of only 116Ah, not much wiggle room there. A thin plate, pure lead Northstar 210 Red has a C1 of 148A, way better. Coincidently, the Northstar is still marginally better at C10, 204Ah vs 189Ah. Both batteries weigh in at 132-ish pounds.

To get a comparable C1 in a Rolls battery, you have to step up to 260Ah, at a whopping 171 lbs, with a C1 of (identically) 148A. And pull out your wallet. The Rolls 260 AGM is $732 on eBay today, the Northstar 210 is less than $400 on multiple sites.

I'm sure some battery geek can explain this, or tell me what I've missed.

[jangr]

OK back to charge controllers and Voc. You need to match the Controllers, Panels, and Battery voltage. Where are you located? Do you live where it gets cold north of I-40? Controllers Voc input varies from 40 to 600 volts. With a high voltage controller of 600 volts, you can run 10 to 15 panels in series. At 150 Voc input is going to depend on the panels Voc an dhow cold it gets. Th elimit is going to be 3 to 5 panels max in series. If you live south of I-40 corridor total the panel Voc, as long as it is under 120 volts total, you are good to go. So if the panels Voc = 30 volts, you can run 4 in series. With a 48 volt battery, minimum you want to run Vmp is 72 volts which would put Voc around.

Your challenge is you are asking for 48 volts. 1200 watt of panels is really territory of 24 volts. One work around is using higher voltage controllers of 200 to 600 volts made by Midnite Solar and Morningstar. Keep asking good questions and we wil get you to where you want to go. For right now WHY 48 VOLTS? At 48 volts you want to run Voc between 90 to 120 volts on a 150 Voc controller. Higher is better. Ideally around 90 Volts Vmp which is about 115 to 120 volt Voc. It is a puzzle you have to find the pieces to fit.

So you can do quick math in your head, here is two easy formulas to get you in the ball park:

1 volt Vmp = 1.25 volt Voc.
16 volts vmp per 12 volt battery.

With that you know right away for a 48 volt battery requires a minimum is 72 volts Vmp @ 90 Voc.

I've read several of your posts on this topic and I conclude that the advantage of a fully/mostly serial, max Vmp array is highly dependent on site and array size. The tradeoff is controller cost vs wiring and combiner cost. Relative to size, as you scale from a small array <2Kw to a much larger array >5Kw, the economics favor a series array with a larger Voc controller and fewer combiners. Relative to site, longer wire runs also favor a larger Voc controller.

However, for a small array <2Kw, where the panels, controller and battery pack are virtually co-located, a smaller controller will always be a better option. 2S2P with 300W-ish panels meet the Vmp requirement at 72V, using a modest 150Voc controller. Wiring and combiner costs are negligible. On the other hand, a 4S configuration would require a more expensive controller in the 250 Voc range. Without any material costs to offset the more expensive controller, the 4S configuration seems to be a loser.

As for why I'd want to run a 48V system off a 1.2Kw array? There's a 5kW gorilla in the room, an intermittent duty PMAC and controller. And there's a limited footprint for panels, 100 ft2. It is what it is.

[Sunking]

I'm sure some battery geek can explain this, or tell me what I've missed.

What you are missing is Peukert Law which states: As the rate of discharge increases, the battery's available capacity decreases.

Manufactures play games with the numbers. Manufactures like Rolls, Concorde, Trojan that make quality batteries will specify discharge curves at various discharge rates that take into account Peukert Law. Example Rolls S-290 is rated @ 230 AH at the 20 hour discharge rate or 230 AH / 20 Hours = 11.5 amps.

Amp Hours = Amps x Hours
Amps = Amp Hours / Hours
Hours = Amp Hours / Amps.

If you look at the Cur Sheet that same battery is listed as 294 AH at the 100-Hour rate (2.94 amps), 230 AH @ the 20 hour rate, and 92 AH @ the 1 hour rate. That is Peukert Law in action. Consumer grade batteries are rated at the C/20 rate, Commercial and Industrial batteries are specified at 4, 6, and 8 hour rates. Your application really exceeds reasonable battery application. While a Pb battery can supply 1C, there is a nasty surprise waiting for you. Look at the S-290 Marine Cranking Amps. In that spec hidden in math is the Internal Resistance = 3.6 volts / 781 amps = .004 Ohms corrected to room temp. So lets say you want to make a 48 volt battery out of that battery would take 8 of them in series for a total resistance of .032 Ohms. So with no load you see 50 volts, and with a 1C load of 92 amps your battery voltage drops to 47 volts when fully charged, and @ 50% DOD drops to 45 volts. That is at the battery terminals. Now add cable loses of another 3% and you are down to 43 volts.

AGM has lower resistance and does not suffer as bad as FLA. Lithium batteries do not have as severe Peukert Effect and they are generally rated a 1C. So you are really getting yourself into a situation where you can justify the expense of Lithium. But if the temps are freezing or less, Lithium becomes way too dangerous to charge, and extremely sluggish at discharge because internal resistance spikes. Either way is a fire danger, not something you can tolerate on a boat or plane. At least on an EV or your house, you can bail out.

[Sunking]

As for why I'd want to run a 48V system off a 1.2Kw array? There's a 5kW gorilla in the room, an intermittent duty PMAC and controller. And there's a limited footprint for panels, 100 ft2. It is what it is.

OK but that 5 Kw motor rating is peak??? Do they only make it in 48 volts? You are talking a 5 hp motor.

I do not know why it has to be electric, but wouldn't say a 10 HP ICE and 5 gallon fuel tank be a much better solution? A lot cheaper, lighter, smaller, more power, that can last for many hours, not minutes. What am I missing?

[jangr]

What you are missing is Peukert Law which states: As the rate of discharge increases, the battery's available capacity decreases.

Manufactures play games with the numbers. Manufactures like Rolls, Concorde, Trojan that make quality batteries will specify discharge curves at various discharge rates that take into account Peukert Law. Example Rolls S-290 is rated @ 230 AH at the 20 hour discharge rate or 230 AH / 20 Hours = 11.5 amps.

Amp Hours = Amps x Hours
Amps = Amp Hours / Hours
Hours = Amp Hours / Amps.

If you look at the Cur Sheet that same battery is listed as 294 AH at the 100-Hour rate (2.94 amps), 230 AH @ the 20 hour rate, and 92 AH @ the 1 hour rate. That is Peukert Law in action. Consumer grade batteries are rated at the C/20 rate, Commercial and Industrial batteries are specified at 4, 6, and 8 hour rates. Your application really exceeds reasonable battery application. While a Pb battery can supply 1C, there is a nasty surprise waiting for you. Look at the S-290 Marine Cranking Amps. In that spec hidden in math is the Internal Resistance = 3.6 volts / 781 amps = .004 Ohms corrected to room temp. So lets say you want to make a 48 volt battery out of that battery would take 8 of them in series for a total resistance of .032 Ohms. So with no load you see 50 volts, and with a 1C load of 92 amps your battery voltage drops to 47 volts when fully charged, and @ 50% DOD drops to 45 volts. That is at the battery terminals. Now add cable loses of another 3% and you are down to 43 volts.

AGM has lower resistance and does not suffer as bad as FLA. Lithium batteries do not have as severe Peukert Effect and they are generally rated a 1C. So you are really getting yourself into a situation where you can justify the expense of Lithium. But if the temps are freezing or less, Lithium becomes way too dangerous to charge, and extremely sluggish at discharge because internal resistance spikes. Either way is a fire danger, not something you can tolerate on a boat or plane. At least on an EV or your house, you can bail out.

I might not understand the underlying physics of Peukert's Law, but I know the design and sizing limitations that come with it. All batteries lose capacity as discharge rates increase, AGM holds up better than FLA, and Lithium better than AGM. Price point approximately doubles with each step up this food chain.

That still doesn't explain why the thin plate pure lead AGM outperforms the the rest of the AGM pack. As you say, the Concorde 210 seems the best of the traditional AGMs with a 1C rating 136A, though still less than the Northstar Red at 148A. Similar to the Rolls comparison above, the Concorde comes with a price premium of around $550, compared with the Northstar, a shade less than $400. All these batteries have a similar internal resistance between .032 and .034 Ohms.

I'm guessing that it's a matter of geometry rather than chemistry. All the most popular AGMs at the 210Ah level are 4D or 8D formats with traditional plate designs. The Northstar Red combines thin plate pure lead in a telecom-like format, which is to say more plates, thinner plates, and (mostly) longer plates. I don't actually need to understand why this seeming advantage exists. I just want to make sure I'm not getting fooled into a conclusion based on misleading specs. If the spec is accurate, then there's a reason - beyond format - that marine guys like the Northstar Red.

[jangr]

OK but that 5 Kw motor rating is peak??? Do they only make it in 48 volts? You are talking a 5 hp motor.

I do not know why it has to be electric, but wouldn't say a 10 HP ICE and 5 gallon fuel tank be a much better solution? A lot cheaper, lighter, smaller, more power, that can last for many hours, not minutes. What am I missing?

Yes, that's peak, 5Kw / 48V= 104A. There's also an emergency boost function built into the controller to operate at almost ~6.5Kw for up to 30 seconds. But if I ever I get into that kind of trouble I'll probably just jump overboard

Actually it's almost 7 hp, with a flat torque curve from 1Kw and up. More torque, bigger prop, more thrust. Gas engines don't hit their hp or torque ratings until >75% rated RPMs, and would stall out with the bigger prop. Which is why they (generally) run at much higher RPMs with smaller props to achieve equivalent thrust. Diesel is similar but use gear reduction to boost torque at lower shaft RPMs to drive bigger props. Go-fast boats use gas engines and low-speed displacement boats (like a barge) use diesel.

Virtually every big freighter, container, or cruise ship in the world is actually a hybrid. Diesel generators powering electric motors, with massive props. Swap the generator for PV array + battery pack, you just replaced hundreds of moving parts with pure electronics. In my case, limit range to a nominal 3 nm, getting 6 kts @ 3.7 Kw, and you never pay $$$ for gas or ICE maintenance again. The only maintenance on a PMAC is brushes, every 2,000 hours, which for me is basically never at 135 cycles per year at 1 hr per cycle. And batteries obviously, but that's still a question.

To your point, I'm pretty sure a lot of off-grid solar $$ would be better spent on small, quiet, efficient Honda generators. If someone is driving up to their hunting cabin with supplies, might as well bring 5 gals of gas for the ol' generator. Or if driving an RV 300 miles, use the alternator to charge an appropriately sized battery pack and inverter.

For me, no fumes, zero maintenance, quiet, and sustainable are attractive. Likewise the trade-off of higher capital expense vs lower operating expense is attractive. And if I can get this concept to add up on the nuts and bolts side, which is why I'm here, it will just feel like the right thing to do. I'm sure this last argument motivates many on this forum, which it damn well should.