Solar and stability issues

[sbman]

Along the lines of Diver Dave thoughts on staying with 12V, consider using multiple smaller inverters to do individual jobs and not have to deal with having a massive inverter system to run everything all at once. My fridge has a dedicated 12V 1200VA Victron inverter that runs 24x7 with VERY low idle current (1.3 amps). It's mounted right behind the fridge with dedicated DC cabling. If I add a freezer, I'm just going to add a second small dedicated inverter, even the 600VA model would do the job just fine. They are cheap enough (even the victron) that you can carry a spare or two to swap out if there is any issue with it during your boating season.

 

[Mambo42]

Mambo; thanks for the summary and the benefit of getting what is important for you.

It is a totally reasonable thought to get more free, silent energy. You are at that decision point where a lot of widely different designs are at play.

1) I would definitely cool down your ER. Not just batteries will be happier, but also alternators, rubber hoses, your a/c load and more. Ventilate! I just improved my ERs fans (I have 2 ER's).
2) Go with Li house and don't look back. NO reason to do AGM for house!
3) Give Ampere, Watt, and Voltaire their credit. Its ("Ah", W, kV, etc). I don't know this Wp??
4) I would not assume that the use of a 24 or 48 house bank precludes 12V also, without DC to DC conversion. Certainly entertain separately derived house systems, but only if necessary.
5) I haven't seen the A of each high load device (reefer, freezer, etc). This is needed for the inversion calcs, along with desired redundancy.
6) 24 or 48 will require different engine charging capabilities. You do have 12V engine(s), correct? There are some 48V alternators with diesel mounts at some 70 + Amps. Lots of W there.
7) solar and weight aloft. No real input from me on this one. Solar allows some amount of independent growth as you work out the stability issues. Per the previous post, maybe look at flexible. Glass and copper are heavy. Glass goes away with flex, copper gets smaller as you series panels.

Thanks for all the input, appreciate the effort.


I do have ER ventilation, but still, underway in high summer the temperature does go up a lot. Have not measured it, but I do start sweating almost instantly when I enter the ER and the engines are on. That basically tells me the temperature is well above 40 Celsius or say 85 F. And that is even with the fans on.


I am with you with regard to lithiums. Just got of the phone with a battery specialist and he basically told me that discharging AGM's on a daily basis to below 50 % would serious degrade the life time of the batteries. In good conditions I could expect 6 years out of AGM's, but if I discharge them with high loads each day to below 50 % i could end up with 3 years.



Wp means Watt produced for solar panels. 310 Wp would be 310 Watts per hour at maximum for that panel. But since there are clouds, angle to the sun not optimal etc you regularly get only 50 % of that 310. I am hoping to get to an average of 2000 Wp per hour. During the summer months there should be between 8 and 10 hours of usable sunlight which means I should get a minimum of 16 - 20 Kwh each day out of the solar panels (on average). On better days I perhaps could get to 25 kwh



On board I currently have 12 V, 24 V and 220 V systems. So if I step up to 24 V I would need to have a converter to change the 24 V again in 12 V. The alternators on the engines also need to be changed again (the current ones are perhaps 2 years old), since lithiums would destroy normal alternators in a heart beat.



As for the stability, Mr Lin of Defever warns me not to place a hard top up that high (on top of the fly bridge) and then also put batteries in the pilothouse while removing batteries in the ER. Plus there was this accident in Tennessee where a Defever capsized due to a combination of beam wave and flood wave. At the moment it happened there were 4 persons on the fly bridge. So I take that warning of Mr Lin serious.

 

[diver dave]

...
On board I currently have 12 V, 24 V and 220 V systems. So if I step up to 24 V I would need to have a converter to change the 24 V again in 12 V. The alternators on the engines also need to be changed again (the current ones are perhaps 2 years old), since lithiums would destroy normal alternators in a heart beat.


.

Taking me a while to decode the above...
1. engines, so you have twins
2. you have a 24v system. Engines are forcing this with 24v starters ?
3. when I see (220V ac), I think of a euro boat, like mine, wired for 220 50Hz, with no 120v. But, I think you mean 240/120 50A shore power? Your 6kW genset is 240/120V?
4. alternators need to be changed again? what are they?

back to ER vents (i'm stubborn that way). You have fans, got it. Are they drawing from the top or bottom? I would draw the hottest air from the top.
Additionally, you could have make up air enter battery boxes directly, thereby exposing them to very close to OAT.

 

[Mambo42]

Along the lines of Diver Dave thoughts on staying with 12V, consider using multiple smaller inverters to do individual jobs and not have to deal with having a massive inverter system to run everything all at once. My fridge has a dedicated 12V 1200VA Victron inverter that runs 24x7 with VERY low idle current (1.3 amps). It's mounted right behind the fridge with dedicated DC cabling. If I add a freezer, I'm just going to add a second small dedicated inverter, even the 600VA model would do the job just fine. They are cheap enough (even the victron) that you can carry a spare or two to swap out if there is any issue with it during your boating season.

Thanks, it is a consideration I did not think of as of yet, but worth while. At the moment I already have several inverters on the boat, but the result is that the ER and pilothouse are almost completely clogged with cables and equipment. It is now such a spaghetti of equipment all over the place that it has become impossible to organize it.

One of the things the electrician will do this winter is clean up the cables, bundle them, connect them to switching panels and reorganize the location of a lot of equipment.

I am not the first owner of this boat and I know that the former owner has added a lot of equipment himself. But he was placing it anywhere he could find space. Now that I am about to start changing from 12 to 24 V I need to do a lot of work anyway, may as well clean up all that mess.

In any case there are at least 3 inverters, but if they are 12 V inverters they will become useless if I change to 24 V. I have one inverter for 3000 W, but that is not sufficient for what I have on board. Basically at this moment I have to switch one item off before I can switch something else on, otherwise I trip the circuit breakers. Only on the generator I don't have that problem. So increasing the capacity of at least one inverter to 8000 W will solve that problem for me.

I know you can work with switching something on and off all the time, but problem is when we have guests on board. They don't know all of this, so they can switch something on by accident and the next thing that happens is a circuit breaker tripping. Not a problem if they notice it, but if they don't they won't tell me neither, which means I will be spending a lot of time trying to find out what happened.

 

[sbman]

Thanks for all the input, appreciate the effort.
Wp means Watt produced for solar panels. 310 Wp would be 310 Watts per hour at maximum for that panel. But since there are clouds, angle to the sun not optimal etc you regularly get only 50 % of that 310. I am hoping to get to an average of 2000 Wp per hour. During the summer months there should be between 8 and 10 hours of usable sunlight which means I should get a minimum of 16 - 20 Kwh each day out of the solar panels (on average). On better days I perhaps could get to 25 kwh

On board I currently have 12 V, 24 V and 220 V systems. So if I step up to 24 V I would need to have a converter to change the 24 V again in 12 V. The alternators on the engines also need to be changed again (the current ones are perhaps 2 years old), since lithiums would destroy normal alternators in a heart beat.

I think you are overestimating how much solar production you'll get. Here is a chart from my system, 1150W of hard panels (3 X 385W).

This was from the most ideal day I could find in the last couple of weeks, no fog, very little shading aside from the bay bridge for a bit. My panels are currently mounted low on the boat and get shaded by the railings part of the time or the house depending on which way the boat is facing, but on this day conditions were pretty close to ideal. I also have a problem with seagulls landing and hanging out on them and pooping on them. I'm at 32 degrees latitude and have 8-10 hours of sunlight available, the best I get is about 3 x my rated output Wp for the day, about 3300-3800W on an ideal day, total production.

The dropouts you see there from various shading situations.

With good regulators your alternators should charge lithiums just fine, something like the wakespeed WS500 that monitors current output and throttle it properly based on your settings.

 

[Mambo42]

Taking me a while to decode the above...
1. engines, so you have twins
2. you have a 24v system. Engines are forcing this with 24v starters ?
3. when I see (220V ac), I think of a euro boat, like mine, wired for 220 50Hz, with no 120v. But, I think you mean 240/120 50A shore power? Your 6kW genset is 240/120V?
4. alternators need to be changed again? what are they?

back to ER vents (i'm stubborn that way). You have fans, got it. Are they drawing from the top or bottom? I would draw the hottest air from the top.
Additionally, you could have make up air enter battery boxes directly, thereby exposing them to very close to OAT.

Diver Dave,


I indeed have twin Ford Lehmans, but they are 12 V, with each engine having its own battery pack.



At the moment all the batteries are still 12 V, so the 24 V and 220 V is created via inverters. The genset delivers both 12 and 220 V/50 Hz and via a switching board I can chose to power in the boat via shore power, genset power or via batteries. But this is a manual switching board, not automatic and not digital, plus there is no auto-start of the genset when the house batteries are empty.

There are also 4 solar panels of 150 Wp each, installed on the safety railing on the sun deck, they are connected via a inverter / charger to the batteries.

The boat is lying in Greece, so shore power is also 220 V / 50 Hz. There are no 120 V systems on board.

Alternators are, at the moment 12 V, but if I change to lithium batteries they will need to be changed as well. And if I switch to 24 V it would make sense to change them as well to 24 V.



Whether the ER vents draw from the top or bottom I would need to check. They were installed by an owner well before me, they function, but in the heat of the summer with OAT of well over 40 C they are having trouble keeping the ER cool.





The boat has a lot of heavy drawing equipment on board. Water maker, washing machine, dish washer, 3 fridges/freezers (1 x 12 V and 2 x 220 V), stove, microwave, water heater, 3 x air conditioning (inverter airco 1200 W each), windlass, dinghy lift, passerelle, dive compressor, plus all the electronics for navigation, laptops, printer, tv, trac vision, surround system etc.

What basically happened is that the former owners just kept adding and adding and adding, which is very nice, since the boat is more than luxurious, but the end result was that you basically have to run the generator 24 hours per day when you are on anchor.
In itself that is not too much of a problem, but I find it a pity to lie in a beautiful quiet bay................only to hear the humming of the generator all the time and, when the wind is wrong, smell the exhaust fumes.

Since there is an abundance of sun in Greece and Croatia (hardly any clouds during the summer time) it would be a pity not to use the sun as source of energy while on anchor.


Now that the house batteries are finished I see this as a good opportunity to overhaul the whole electrical system on board, reorganize, change and get more solar on board. The end result should be that I can run most of the time on solar and only a couple of hours per day on the genset.

That would create peace and quiet time while on anchor plus would greatly extend my range, since at this moment the genset is using about 0.5 to 1 liter per hour, but at almost 24 hours, 30 days per month for 5 months we are talking a very nice amount of fuel. Fuel in Europe is very expensive, but luckily I can get tax free fuel in Albania, which is about 60 % cheaper than in Greece and Croatia. However I do need to take into consideration that I need to be able to make it back to Albania for fueling (difference is about 4200 euro for a full tank). In other words, if I can reduce the use of the generator it will offer me huge fuel savings while at the same time increase my range and create peace and quiet time while on anchor. The fuel savings will basically recoup the cost of the conversion in 4 to 5 years. I call that a win-win-win situation.



So that is the thought process behind it all. The electrician came up with the idea to change to 24 V and lithiums. I came up with the idea to increase solar to 3000 Wp (minimum), so now need to figure out what is possible (stability wise), space wise (where to put everything) and cost wise.

Had some great inputs from everybody here so far, makes me think about AGM's again, but the stability has become an issue.

 

[rslifkin]

I'm at 32 degrees latitude and have 8-10 hours of sunlight available, the best I get is about 3 x my rated output Wp for the day, about 3300-3800W on an ideal day, total production.

Depending on panel placement, location, and time of year, that may be a pretty low output. On a good, sunny day in mid summer I've seen 3.7 kwh from my 820 Wp system and that was with the batteries topped off and not enough demand to meet the full panel output after about 2 PM (until the panel output dropped off enough in the evening). Even on imperfect (but still sunny) days I've seen 3.2 - 3.5 kwh.

 

[sbman]

Depending on panel placement, location, and time of year, that may be a pretty low output. On a good, sunny day in mid summer I've seen 3.7 kwh from my 820 Wp system and that was with the batteries topped off and not enough demand to meet the full panel output after about 2 PM (until the panel output dropped off enough in the evening). Even on imperfect (but still sunny) days I've seen 3.2 - 3.5 kwh.

You are getting 4x your Wp per day in the summer and I'm getting 3x my Wp in winter, I think we are on the same page basically.

The OP is talking about getting 6X - 8x his Wp per day and I don't think that's going to happen.

 

[rslifkin]

You are getting 4x your Wp per day in the summer and I'm getting 3x my Wp in winter, I think we are on the same page basically.

The OP is talking about getting 6X - 8x his Wp per day and I don't think that's going to happen.

Yeah, more than 4x would be unrealistic in my mind. 4.5 or even 5x can happen at the peak of summer if everything else lines up perfectly, but I wouldn't count on it.

 

[diver dave]

So, currently you are locked into 12V by the engines. You don't currently have any users of 24V, but that could change. All electric galley. El dive compressor +++....

I'm going to submit you are in the area of a required 48V house bank. Lots of inverters in that league. I will also envision the engines will add to the current, smallish 12V alternators with 48's. Balmar has a 100A/48V unit now. Yeah, 4.8kW, at least for awhile.
It will be up to you to figure your nightly Wh demand, and then pick about 3x that for panels. If that is crazy big, then its back to making your genset quieter.
OR, a significan downsize on consumption as a function of headcount. ie. don't fill all the reefers and turn on all the a/c zones just because you can.

 

[Mambo42]

I think you are overestimating how much solar production you'll get. Here is a chart from my system, 1150W of hard panels (3 X 385W).

This was from the most ideal day I could find in the last couple of weeks, no fog, very little shading aside from the bay bridge for a bit. My panels are currently mounted low on the boat and get shaded by the railings part of the time or the house depending on which way the boat is facing, but on this day conditions were pretty close to ideal. I also have a problem with seagulls landing and hanging out on them and pooping on them. I'm at 32 degrees latitude and have 8-10 hours of sunlight available, the best I get is about 3 x my rated output Wp for the day, about 3300-3800W on an ideal day, total production.

The dropouts you see there from various shading situations.

With good regulators your alternators should charge lithiums just fine, something like the wakespeed WS500 that monitors current output and throttle it properly based on your settings.

Thanks for the info, I will google the wakespeed WS500. Is that what you have installed as well ?





Great insight in what you have in solar. For November you still have good numbers.
We however are not on the boat in November, we only use it from April until end of September. Good part is that Greece and southern Croatia in summer time do have a lot of blue skies. Of course it rains sometimes and sometimes even for a couple of days, but when it doesn't rain there is usually not a lot of clouds to be seen. Official night time hours are around 6 to 7, with usable sunlight time between 8 and 10 hours per day.



My estimates are based on what the current panels are delivering during the summer season. On average, I came to between 3.5 and 4 KWp on a normal sunny day in the peak summer months.

That translates to an average of 2/3 of max capacity for a period of almost 8 to 10 hours per day. There would be a couple of peak hours (4 to 5) at almost full capacity (90%), then some hours at a lower capacity and early morning plus evening it could be 1/4 to 1/5.

My panels are lying free on the sun deck, nothing blocking the sun and get cleaned every single day in the morning.



So I hope that the additional panels, which will also be lying without any obstruction to the sun will be able to give me also 2/3 Max Wp for 8 to 10 hours per day. With 3000 Wp that makes 2000 Wp on average, which is between 16 and 20 KWp per day during the summer season.

A lot however will depend on the quality of the panels itself, so probably will have to spend a bit more to get a good quality panel, but I think that will be worth it.



Of course the beginning and end of the season will give me less, but luckily I don't need the airco at that time. Then I only have the fridges /freezers plus some other small equipment (lights, laptop, TV perhaps, music), which means I would get to about 400 - 500 Amps at night absolute max. I should be able to recover that during the daytime hours with the solars.

And since the fridges and freezers don't have the compressors running all the time it should actually be much less Amp usage.

 

[sbman]

Thanks for the info, I will google the wakespeed WS500. Is that what you have installed as well ?

And since the fridges and freezers don't have the compressors running all the time it should actually be much less Amp usage.

No I don't have the wakespeed installed. My alternator system is an older system that I haven't updated. I am primarily on Solar and not too concerned about engine based charging.

My household sized top freezer, front opening 120V AC U.S. spec fridge uses between 700-1000W of power each day depending on ambient temps and how often it's opened, including inverter and charging losses. About 70 amps of battery power each day on my 12V system. It draws 84 watts when running and runs intermittently. It is 'energy star' rated at 360KWhr per year and is performing quite close to that rating in real world use.

 

[BruceK]

I think Koliver, and maybe Flywright, did drop down/lift up hinged panels. You could PM them for info.
Being conservative, I usually assume panel output at 50% of the predicted max. Panel output can be overrated, and there are clouds etc to consider. Check for shadowing, even a shroud supporting a mast can have negative effect.

It looks like you are getting a plan to revamp your electricity supply with less genset operation. Hope it goes well.

 

[Mambo42]

A fws quick thoughts. If your batteries are as shot as you say, suggest getting those squared away before digging in to additionalsolar panels. Fresh bank might make all the difference.

Second, as you consider moving your battery bank, don't neglect proximity to inverter. There's a practical limit on low voltage side driven by cable size vs amperage.

Finally, I don't recall age of your battery charger, but not all are capable of correctly charging lithium. Something to check

Good luck.

Peter

Good point about checking the quality / age of the charger, have not done that yet.

With regard to getting new batteries first, it is indeed the reason for the whole overhaul. It does not make a lot of sense of just buying new batteries and end up with a system again which is not sufficient for my needs.
So before i buy anything new I want to have the new electrical system completely clear, every component identified and of course cost calculated.



However, now that I am running into problems with finding a good place for the batteries and then stability issues with the panels.

 

[Mambo42]

No I don't have the wakespeed installed. My alternator system is an older system that I haven't updated. I am primarily on Solar and not too concerned about engine based charging.

My household sized top freezer, front opening 120V AC U.S. spec fridge uses between 700-1000W of power each day depending on ambient temps and how often it's opened, including inverter and charging losses. About 70 amps of battery power each day on my 12V system. It draws 84 watts when running and runs intermittently. It is 'energy star' rated at 360KWhr per year and is performing quite close to that rating in real world use.

My fridges / freezers are slightly bigger. One is a standard 2 door home fridge / freezer, takes about 300 Wt per hour when the compressor is working. Then I have one 'table model' fridge, which takes about 100 Wt per hour and the last one is a 12 V fridge, small one, which is on the fly bridge.

And I am thinking of adding a small (table model) freezer with 4 drawers (appr 70 Wt/hr) so that we don't need to come into port every other day to get new supplies.



I have never measured the exact Kw that each fridge/freezer uses during a 24 hr period, but for calculating purposes I just assume the compressors run 24 hr per day. Then I will always be safe.

I could of course change all the fridges and freezers to official marine models, but perhaps I will do that once they need replacing. For now they are working fine.

 

[Mambo42]

I think Koliver, and maybe Flywright, did drop down/lift up hinged panels. You could PM them for info.
Being conservative, I usually assume panel output at 50% of the predicted max. Panel output can be overrated, and there are clouds etc to consider. Check for shadowing, even a shroud supporting a mast can have negative effect.

It looks like you are getting a plan to revamp your electricity supply with less genset operation. Hope it goes well.

Thanks for the tip, will try to find their posts about the drop down panels.



It is indeed a revamp or better: 'overhaul' of the electricity supply. It is a fundamental change of bringing power to the boat without sacrificing too much comfort.

We will need to adapt our way of life a bit, e.g. do laundry and run the water maker or even dishwasher while underway instead of 'whenever you want'. But those are small changes.

Perhaps in a later stage I will take the stove out and change it for an induction plate. The current stove can turn an electricity meter in a ventilator , does not make any sense. I have seen some good options on Amazon, but unfortunately they are out of stock due to supply problems.



I hope that in the end it will be possible to leave the generator off for most of the day, for that after all is the goal.

 

[Mambo42]

I think Koliver, and maybe Flywright, did drop down/lift up hinged panels. You could PM them for info.
Being conservative, I usually assume panel output at 50% of the predicted max. Panel output can be overrated, and there are clouds etc to consider. Check for shadowing, even a shroud supporting a mast can have negative effect.

It looks like you are getting a plan to revamp your electricity supply with less genset operation. Hope it goes well.

After a lot of searching I have found the topic about the solar panels of Koliver. Thanks for the tip Brucek


I even found some of the pictures and it is exactly what I was thinking of. Will suggest this now to Wilson in Taiwan, hopefully he can shed some light on it. It should not be a problem once the dinghy is off the boat. The total amount of solar panels is roughly the same weight as the dinghy plus outboard engine.