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How much is too much Solar Power and how much is just enough?


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On 09/02/2021 at 23:31, DaveP said:

if you're prepared for the expense and nerdiness of  LiFePO4, then again 800-1000Ah of batteries

I haven't found this to be the case at all - I researched what I needed, compiled a shopping list, assembled and wired it all up. Now I have forgotten about it - I have an app on my phone that tells me the level of charge and I base my generator time on this. I have 24 volt 100A/h LiFePO4 - I use around 40A/h per day - fridge on... My generator charges at 24 V 25A so if I need to move from 25% of my battery to 50% I charge for 1 hour...No huge battery required - I have purposely invested as little as possible in batteries because the rapid development of batteries doesn't warrant huge capital outlay that you are stuck with while better batteries come along. 

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On 10/02/2021 at 09:02, Col_T said:

 

Is this true? If the two battery banks are linked then you may only need the one monitor.

It's a mystery, of course I have three banks (two domestic, one starter), and I can tell from the ammeter reading that each one is connected and drawing independantly from the alternator. Other than that ,I observe what they are showing, and determine how things are progressing. I know what the readings are when batteries are full (err very nearly max capacity).

On 10/02/2021 at 09:22, markeymark said:

My only advice is that a fridge (high energy consumer) is superfluous when its cold. I have a rat-proof metal box on the foredeck with cheese, milk etc. in so cut the fridge out for 4-5 months of the year. In the summer when there is often too much solar then I use the fridge.

I don't know if I mentioned it, but Cravendsle Filtered Milk lasts weeks if unopened and reasonably cool.

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  • 5 months later...
On 10/02/2021 at 11:36, doratheexplorer said:

I've 525w of solar.  From mid-Feb to Beginning of November, I can get enough power to get by on, if it's a good day. From April to September I don't need to run my engine for electric at all.  During those shoulder seasons the weather makes a lot of difference, heavy cloud and mooring under trees or tall buildings is a problem, I'll get some but I'll likely need to top up.

 

It's possible to tilt my panels but it's a faff, but that's something to consider.

 

I reckon if I put another 200w of solar on my boat, I'd probably get another 10-20 days a year where I currently run my genny/engine, but wouldn't need to.  Is that worth it?  For me, probably not.  If I run my engine 3 hours a day, I'm probably using less than £2 of petrol from my genny, over 15 days, that's £30 at the most.  If I put another 200w solar panel on my roof, I'd need to replace my charge controller, buying cheap, the panel might be £50, the charge controller £200, plus about £20 for extra cables, connectors etc.  So £270 to save £30.  So it would pay for itself in 9 years.  But in that time, I would have less space to store things on the roof (important for liveaboards).  At the moment, my 3 x 175w panels, plus chimney, plus pole, hook & plank, leaves me enough space to squeeze 15-20 bags of coal on the roof, so I'd need a much better reason to add to my solar.  In other words, there's a sweet spot where the law of diminishing returns makes it unreasonable to add more panels.  This will vary from boat to boat, but for me, it's about 500w.

 

 

Apologies for resurrecting an old thread, but I'm currently pondering whether it would be worth doubling my solar from 650-ish watts to maybe 1200 watts, so this is very relevant for me- and this was a very thought-provoking post that I think captures the key considerations, at least for me anyway. 

So I wanted to add my personal maths/issues that are involved in making this decision.

Although I totally agree with your approach and rationale here, I wanted to add in the cost of engine servicing, for those not using a petrol generator. 

My canaline 38 needs a service every 200 hours, and (setting aside the cruising hours) running it for 3 hours each day just to recharge would mean about 90 hours per month of engine running, which very roughly means a service every 2 months in the winter. If I do the service myself the parts and oil cost under £50, but I do have to find somewhere (legal) to get rid of the waste oil.

But cost-wise, that's about £25 per month to add into the overall budget when running the engine just to recharge in the winter months (and maybe half that figure in spring and autumn?).  

Plus there are some summer days when you cant find a mooring spot that isn't overlooked by trees etc, so your solar intake gets reduced.

E.g. A few days ago I was moored in the cutting just north of the chirk tunnel, and whilst everyone else was sweltering (and collecting lots of solar power), I stayed cool and comfortable, but got almost no solar power, and had to run my engine to recharge. 

 

I also agree with you about leaving some space on the roof for coal, although in my case it would be maybe 4 bags on the roof, with another 8 or so in the bow and stern. 

The other thing I'm thinking of doing is removing the roof mountings for the plank and pole, and finding somewhere inboard to put them. I haven't used either of them in my first 8 months of cruising, so I'm starting to get a bit blase about how critical they really are. If I store those two items indoors, that would free up about 3 metres of roof for panels. 

It is still early days for me as a newbie boater, but so far I have come across a few locks where I had to use the roof to get to the lock ladder, so my thinking is that my panels cant be more than a metre wide, in order to allow me space to walk the roof.

Also, if I mount some extra panels flat on the rear half of the roof, using those rounded-edge mouldings, then the panels wont foul the centre line when I need to throw it around the roof a bit. 

 

The other part of the plan would be to re-mount the existing forward panels on steeply-tilting brackets so that even in winter, I can get at least a few amps for say 7 or 8 hours. The ability to tilt I think might be quite important when the sun is so low, and I have heard a few people say how much it helped them. But your point is correct that it needs to be an easy/fast tilting system, otherwise I wont be inclined to use it every day. 

 

I see the boat as a 8-10 year lifestyle (it does depend how much I take to it long term, but so far its been very good).

So as long as a new solar setup breaks even over 10 years, it's worth doing (provided the other factors are ok).  

 

So in summary, these are my parameters- a ten year ownership period; about 100Ah of power used per day; and a rather poor B2B recharge system that charges my lithium batteries at about 45 amps (meaning about 2 hours engine running per day if there is zero solar).  

 

Given those parameters, the real question from me seems to be this: will 600 watts of non-tilting panels add enough power during the marginal months of Oct, Nov, Feb and March, that I can greatly reduce or stop running the engine to recharge? 

 

 

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11 minutes ago, Tony1 said:

Given those parameters, the real question from me seems to be this: will 600 watts of non-tilting panels add enough power during the marginal months of Oct, Nov, Feb and March, that I can greatly reduce or stop running the engine to recharge? 

 

Just wondered how you intended to get power in December and January ?

 

You are unlikely to be able to fit sufficient solar panels onto the roof of a narrowboat (are you narrow or a fatty ?) to be self sufficinet and your existing 600w will not do anything much to recharge your batteries during the Winter 4 months. Doubling to 1200w will make an impression but (guesstimate) it would probably only provide 50% of your daily requirements so you'd be running your engine at least an hour per day. A week of overcast, rain or snow and you'll be back to running your engine 2+ hours per day.

 

I consider Solar to be a Summer option only with a small contribution in Spring and Autumn. You will need to find alternatves for the 3 or 4 Winter months - either take a mooring in a Marina, run a small generator, or run your engine. ANYTHING you do get from the solar is an unplanned bonus.

 

Running your engine not only charges the batteries but provided hot water 'free' - what method of water heating and central heating do you have as an alternative to running the engine.

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19 minutes ago, Alan de Enfield said:

 

Just wondered how you intended to get power in December and January ?

 

You are unlikely to be able to fit sufficient solar panels onto the roof of a narrowboat (are you narrow or a fatty ?) to be self sufficinet and your existing 600w will not do anything much to recharge your batteries during the Winter 4 months. Doubling to 1200w will make an impression but (guesstimate) it would probably only provide 50% of your daily requirements so you'd be running your engine at least an hour per day. A week of overcast, rain or snow and you'll be back to running your engine 2+ hours per day.

 

I consider Solar to be a Summer option only with a small contribution in Spring and Autumn. You will need to find alternatves for the 3 or 4 Winter months - either take a mooring in a Marina, run a small generator, or run your engine. ANYTHING you do get from the solar is an unplanned bonus.

 

Running your engine not only charges the batteries but provided hot water 'free' - what method of water heating and central heating do you have as an alternative to running the engine.

 

When there's not enough solar even from 1.2kw (which as you say will be the case for Dec and Jan), then it will have to be more engine running to get power.

I don't envisage getting a genny, or at least not yet.

I do recall a few clear days last Winter where a few amps were coming in, but with 650 watts of panels it was not enough to make a real difference.

I guess my question is: is this a matter of degree, or is is it really a binary thing?

I.e. would an extra 600 watts of solar ever collect enough additional power that I could  reduce my engine running by say half? 

Or is it really a waste of time going above 650 watts, because the gains would be so marginal? Spending a few hundred quid to get 2 amps instead of 1 amp on overcast winter days, for example, seems like a poor investment. 

I was in a marina last winter so I wasnt paying much attention to my solar input, and so I dont have a reliable feel for how much power is collected on average by the current panels. 

I did get the impression, however, that lithium batteries seem to complement solar quite well, in that whatever energy the panels pass to them, they seem to keep, and you can then use. 

With my old (and admittedly rather knackered) lead acids, they could collect solar charge (and indeed engine charge) all day during say August or Sept, but still be down to 50% by 10pm. 

 

ETA- hot water is via running the engine (which is great if you need hot water after you've run the engine), or else the diesel CH (which is much less effective at getting the water hot)

 

 

 

Edited by Tony1
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I'm in a very similar position.  I do double up to 1200w in winter, but also switch off my fridgefreezer - this cuts my daily consumption down to 40-50Ah, which the panels can generally keep up with even in Dec/Jan.  But it is marginal, a couple of days of very poor weather will tip the balance (I'm still not totally trusting of letting my Lithiums get lower than 30%)....

 

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1 hour ago, DaveP said:

I'm in a very similar position.  I do double up to 1200w in winter, but also switch off my fridgefreezer - this cuts my daily consumption down to 40-50Ah, which the panels can generally keep up with even in Dec/Jan.  But it is marginal, a couple of days of very poor weather will tip the balance (I'm still not totally trusting of letting my Lithiums get lower than 30%)....

 

 

Thanks a lot Dave, its really useful hearing from someone with long term hands on experience with the sort of setup I've been considering. 

 

I need to find a way of using the cratch for cold storage, and turning off the fridge in Dec and Jan- last winter (my first as a liveaboard) my cratch was a dusty mess full of coal, tools, spare ironmongery, often a couple of bags of rubbish- you name it.

It didnt seem like a great place to store food, even sealed, and because it has windows, even in winter it can warm up a fair bit if there's any sun.

 

But regardless, I'll have to figure something out, because running the fridge probably requires 40-50Ah per day, which is an hour's engine running to recharge- and that's before you add in things like lights, recharging the ebike, laptop charging, etc etc.  

 

Once I'm able to switch off the fridge in the coldest 3-4 months, I should only need about 40Ah per day to run everything else, and from your experience it sounds as if that will be achievable maybe half the time. 

So is it worth the cost and hassle of doubling my solar, to collect 40Ah per day in those coldest few months, instead of my current 20Ah? That's the real question. 

It would mean not having to run the engine on almost every day, so that's a plus. 

I have about 400Ah of lithiums, which I mostly try to keep between 25% and 85% SoC (with a 100% charge every month or so, to synchronise the battery monitor). So if I cruise twice a week for say 4 or 5 hours in winter, I'm putting in 200Ah of charge, which will take the batteries from 25% to 75%, and in theory gives me 4 or 5 days of power, during which time I wont need to run the engine. 

 

The other place the extra solar would be useful is on those overcast autumn/spring days, or moorings with high bushes/trees, where my existing solar sometimes struggles to collect the 100Ah or so that I need each day. On those sorts of days, the extra solar should in theory gather the extra power needed, so its not only about the coldest months. 

 

My other option would be to spend the solar money on beefing up my charging setup, so that an hour's engine running gets me maybe 80-100Ah, instead of the crappy 40-50Ah that its delivering at the moment.  But that would need an alternator upgrade, as my current one overheats as soon as it starts putting out more than 60 amps of charge.   

 

There's a lot to think about, and I need to do a lot more homework on the costs and energy gains, but it is very encouraging to hear that on at least half of the worst days, with 1.2kw of panels you can still pull in just enough solar to run the boat. 

 

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5 minutes ago, Tony1 said:

My other option would be to spend the solar money on beefing up my charging setup, so that an hour's engine running gets me maybe 80-100Ah, instead of the crappy 40-50Ah that its delivering at the moment.  But that would need an alternator upgrade, as my current one overheats as soon as it starts putting out more than 60 amps of charge.   

 

 

1. Alternators are designed to get hot, they should be happy running so hot you won't hold your hand on them. The inside is forced air cooled, but the outside relies on radiation and convection, so will get hot.

 

2. Unless you change to lithium batteries, and that will really cost, any hope of fully charging lead acids in an hour or so is not going to work. With lead acids the largest alternator you can imagine is likely to spend most of the charge time delivering only a few amps. It's batteries that control the charging amps after a short while, not the alternator, and that way lead acids work makes them refuse high charging currents for most of the charging time.

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42 minutes ago, Tony Brooks said:

 

1. Alternators are designed to get hot, they should be happy running so hot you won't hold your hand on them. The inside is forced air cooled, but the outside relies on radiation and convection, so will get hot.

 

2. Unless you change to lithium batteries, and that will really cost, any hope of fully charging lead acids in an hour or so is not going to work. With lead acids the largest alternator you can imagine is likely to spend most of the charge time delivering only a few amps. It's batteries that control the charging amps after a short while, not the alternator, and that way lead acids work makes them refuse high charging currents for most of the charging time.

 

Thanks for this info Tony- I have lithium batteries already, and when I first got them-  because I had heard about lithiums absorbing more charge from alternators than leads acids absorb, and the alternator overheating as a result, I took the precaution of buying a directional-type thermometer.

When charging the lead acids, neither alternator rose above 50 degrees, but when I started charging the lithiums (via my Sterling A2B charger), the temp on one alternator went up to 140 degrees within about 5-10 mins.  

I dont know the first thing about alternators and almost nothing about electrics in general, in fact I was only able to set things up with a hell of a lot of advice from the incredible helpful Nick Norman, Peter, and others.

But the alternator going up so quickly to almost three times its normal temperature worried me, and I did some more testing and fiddling around to try to find how hard I could push the alternator without it getting above 100 degrees. 

It seems as if 60 amps is as much as it can put out without overheating 

I think the difference with lithiums is that they have much less resistance to charging, and will absorb all the charge an alternator can throw at them, so the alternator has to work harder than it does with lead acids, and I think there are some alternators that have problems delivering the charge that they are rated at to lithiums, but that is guesswork to be fair.  

 

I should probably have gone for an upgraded alternator (but I'm not sure how much I could upgrade with a canaline 38), and maybe a regulator, but instead I went for the simpler solution of using a B2B charger, which will not allow more than 60amps charge to the lithiums- but in practice it is usually less than 50 amps, and often 40, so its far from ideal, and I might look at upgrading that in the future. 

 

Edited by Tony1
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26 minutes ago, Tony1 said:

I should probably have gone for an upgraded alternator (but I'm not sure how much I could upgrade with a canaline 38), and maybe a regulator, but instead I went for the simpler solution of using a B2B charger, which will not allow more than 60amps charge to the lithiums- but in practice it is usually less than 50 amps, and often 40, so its far from ideal, and I might look at upgrading that in the future. 

 

 

Like you, I fitted a Victron B2B charger with a max of 30A to charge the lithiums, due to the alternator direct to lithium issue. I couldn't see another relatively straightforward way round it.

 

In my case, I have 500W of solar to charge them, and use a Honda EU10i generator via a Sterling Pro Charge Ultra, (60A), charger, and don't do much cruising. The B2B is therefore rarely used, and was actually fitted as a back up after the Pro Charge Ultra failed, (blown fuse and dirty fuse holder was the problem - diagnosed with no thanks to Sterling, and lots of thanks here!).

 

The B2B does what it was fitted to do and I see between about 20A and 27A when it's charging. In reality, my I have never seen my alternator put out more than about 34A, so fitting a B2B bigger than 30A would achieve little/nothing as far as I can tell - I think it's a 55A model.

 

At 60A my guess is that your B2B is a Sterling. I understand that you could buy another and get 120A, (or 80A to 100A :) ), as long as your alternator can supply it.

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23 minutes ago, Tony1 said:

 

Thanks for this info Tony- I have lithium batteries already, and when I first got them-  because I had heard about lithiums absorbing more charge from alternators than leads acids absorb, and the alternator overheating as a result, I took the precaution of buying a directional-type thermometer.

When charging the lead acids, neither alternator rose above 50 degrees, but when I started charging the lithiums (via my Sterling A2B charger), the temp on one alternator went up to 140 degrees within about 5-10 mins.  

I dont know the first thing about alternators and almost nothing about electrics in general, in fact I was only able to set things up with a hell of a lot of advice from the incredible helpful Nick Norman, Peter, and others.

But the alternator going up so quickly to almost three times its normal temperature worried me, and I did some more testing and fiddling around to try to find how hard I could push the alternator without it getting above 100 degrees. 

It seems as if 60 amps is as much as it can put out without overheating 

I think the difference with lithiums is that they have much less resistance to charging, and will absorb all the charge an alternator can throw at them, so the alternator has to work harder than it does with lead acids, and I think there are some alternators that have problems delivering the charge that they are rated at to lithiums, but that is guesswork to be fair.  

 

I should probably have gone for an upgraded alternator (but I'm not sure how much I could upgrade with a canaline 38), and maybe a regulator, but instead I went for the simpler solution of using a B2B charger, which will not allow more than 60amps charge to the lithiums- but in practice it is usually less than 50 amps, and often 40, so its far from ideal, and I might look at upgrading that in the future. 

 

 

The lithiums forces the alternator to run at maximum output all the time it's no wonder it gets very hot almost straight away. On lead acids within maybe 10 minutes in most situations the output would have dropped from maximum so it's also no wonder it ran cooler. The question is, is that 140 degrees too hot and will it get any hotter. Personally, I doubt it would get hotter.

 

Having trawled the internet a bit it seems that nowadays 130C is accepted as a typical running temperature but various sources quote much higher temperatures. I suspect that 140C would be within the design range of a modern alternator. Don't forget they are basically automotive units where under bonnet temperatures can get to well above 200C and higher for alternators located behind a transverse engine block close to the exhaust. Some claim to run them at 300C on test.

 

I think that you can up the charging current to a higher figure with safety, as long as you shut down the charge when the batteries need it.

 

Basically, the "normal" temperature is way above 100C. I think you are limiting the charge for a not very sound reason.

 

Pinging @Sir Nibble for his take on alternator running temperature.

 

 

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24 minutes ago, Richard10002 said:

 

Like you, I fitted a Victron B2B charger with a max of 30A to charge the lithiums, due to the alternator direct to lithium issue. I couldn't see another relatively straightforward way round it.

 

In my case, I have 500W of solar to charge them, and use a Honda EU10i generator via a Sterling Pro Charge Ultra, (60A), charger, and don't do much cruising. The B2B is therefore rarely used, and was actually fitted as a back up after the Pro Charge Ultra failed, (blown fuse and dirty fuse holder was the problem - diagnosed with no thanks to Sterling, and lots of thanks here!).

 

The B2B does what it was fitted to do and I see between about 20A and 27A when it's charging. In reality, my I have never seen my alternator put out more than about 34A, so fitting a B2B bigger than 30A would achieve little/nothing as far as I can tell - I think it's a 55A model.

 

At 60A my guess is that your B2B is a Sterling. I understand that you could buy another and get 120A, (or 80A to 100A :) ), as long as your alternator can supply it.

 

Thanks Richard- and apologies to the OP if this is sidetracking the thread a bit, but it is an important related issue. 

I was desperate to get my charging setup running asap so that I could leave the marina and go cruising, so I went for a quick fix with the B2B (yes, its a Sterling!)- but in truth the alternator is always going to be a significant limitation. I think its rated at 100amps, but there are two of them and it could be the 70amp one, I cant be 100% sure. 

 

I think the reason I'm seeing less than 50amps into the lithiums might be because some charge is going into the 'source' battery, which is a knackered lead acid (which I'll be replacing soon).

If I go for the next model, say the 80 amp version, its possible my alternator will get really hot pushing out that much current, so I'm hanging fire on a charging fix until a professional (who has good knowledge of lithiums) has taken a look at things.

I suspect there's not much more I can safely get from my current alternator, so I'm hoping that replacing the source battery will improve things for now. 

 

 

Edited by Tony1
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7 minutes ago, Tony Brooks said:

 

The lithiums forces the alternator to run at maximum output all the time it's no wonder it gets very hot almost straight away. On lead acids within maybe 10 minutes in most situations the output would have dropped from maximum so it's also no wonder it ran cooler. The question is, is that 140 degrees too hot and will it get any hotter. Personally, I doubt it would get hotter.

 

Having trawled the internet a bit it seems that nowadays 130C is accepted as a typical running temperature but various sources quote much higher temperatures. I suspect that 140C would be within the design range of a modern alternator. Don't forget they are basically automotive units where under bonnet temperatures can get to well above 200C and higher for alternators located behind a transverse engine block close to the exhaust. Some claim to run them at 300C on test.

 

I think that you can up the charging current to a higher figure with safety, as long as you shut down the charge when the batteries need it.

 

Basically, the "normal" temperature is way above 100C. I think you are limiting the charge for a not very sound reason.

 

Pinging @Sir Nibble for his take on alternator running temperature.

 

 

 

Thanks Tony- having seen reports about overheating alternators and lithiums like this sort of thing below, I was probably a bit over cautious.

 

It is worth making an upgrade if I can.

A the moment, when using engine charging, I'm paying 70-80p to burn a litre of diesel and I'm only getting about 40Ah of charge in return - it seems a bit wasteful, and it would be great to up the charging rate if I can do that safely.  It seems like the sort of upgrade that would eventually pay for itself in saved fuel.

 

 

 

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12 hours ago, Tony1 said:

 

When there's not enough solar even from 1.2kw (which as you say will be the case for Dec and Jan), then it will have to be more engine running to get power.

I don't envisage getting a genny, or at least not yet.

I do recall a few clear days last Winter where a few amps were coming in, but with 650 watts of panels it was not enough to make a real difference.

I guess my question is: is this a matter of degree, or is is it really a binary thing?

I.e. would an extra 600 watts of solar ever collect enough additional power that I could  reduce my engine running by say half? 

Or is it really a waste of time going above 650 watts, because the gains would be so marginal? Spending a few hundred quid to get 2 amps instead of 1 amp on overcast winter days, for example, seems like a poor investment. 

I was in a marina last winter so I wasnt paying much attention to my solar input, and so I dont have a reliable feel for how much power is collected on average by the current panels. 

I did get the impression, however, that lithium batteries seem to complement solar quite well, in that whatever energy the panels pass to them, they seem to keep, and you can then use. 

With my old (and admittedly rather knackered) lead acids, they could collect solar charge (and indeed engine charge) all day during say August or Sept, but still be down to 50% by 10pm. 

 

ETA- hot water is via running the engine (which is great if you need hot water after you've run the engine), or else the diesel CH (which is much less effective at getting the water hot)

 

 

 

Tony I have a lot of solar as you know but even 4.6kws isnt enough sometimes! 1200 watts is a good compromise and is what I have normally on domestic batteries, it covers most of my usage winter I switch drive solar to domestic as well, if my panels lilted it would be better in winter is all I can say

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30 minutes ago, peterboat said:

Tony I have a lot of solar as you know but even 4.6kws isnt enough sometimes! 1200 watts is a good compromise and is what I have normally on domestic batteries, it covers most of my usage winter I switch drive solar to domestic as well, if my panels lilted it would be better in winter is all I can say

 

Cheers Peter, I'm thinking I might get more solar AND also upgrade the charging power a bit.

I must say it's great knowing you can moor up for five days at a time and never have to run the engine because the solar's collecting all/most of the power you need. 

But realistically, there will still be plenty of days when an engine charge is needed, and over say ten years, a charge system upgrade will also pay for itself, especially if diesel prices start to creep up. 

Solar first though, I think.....

 

I'm now realising the summer dilemma many boaters face- do I moor in a nice, open and sunny spot and never have to run the engine, but on the downside the inside of the boat gets to 30 degrees and above...

OR do I get into the shade, and have to leave lights on during the daytime (my windows are not very wide), and have to run the engine to recharge? 

On balance, when its as hot as this, I think I prefer the shade, and sod the solar  😀 

 

 

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5 hours ago, Tony1 said:

 

I need to find a way of using the cratch for cold storage, and turning off the fridge in Dec and Jan- last winter (my first as a liveaboard) my cratch was a dusty mess full of coal, tools, spare ironmongery, often a couple of bags of rubbish- you name it.

It didnt seem like a great place to store food, even sealed, and because it has windows, even in winter it can warm up a fair bit if there's any sun.

 

Have you considered installing an under-floor food store somewhere in the cabin, so food can sit on or close to the baseplate and be maintained at canal water temperature?

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1 hour ago, David Mack said:

 

Have you considered installing an under-floor food store somewhere in the cabin, so food can sit on or close to the baseplate and be maintained at canal water temperature?

 

Thanks David, and yes- for anyone with half decent joinery skills thats a good shout, but I fear the mess I could make if I start hacking up the floorboards. 

To be honest, I'm nearly finished laying some vinyl plank flooring, which has been a lot more work, sweat and faff than it should have been- so for the time being I haven't got the motivation to lift that stuff up and create a floorspace, although it would be a great solution. 

 

I think as a first stab, I might buy a largish plastic storage box that fully seals, and then I'll get some smaller boxes/bags to put inside that- maybe one box for beer, one for butter/cold condiments etc, one for meat/fish etc- I'll be able to figure out some sensible stacking/storage system, and keep the food clean, and free of coal dust and creepy crawlies. 

 

There will be some sunny days when the cratch warms up a lot, but on those days I'll get some solar, so maybe I can bring the food back in and stick in into the fridge- or maybe just stick it on the back deck under a cover- there has to be a fairly easy way of managing it, and its worth the effort whilst my charging system remains a bit puny. 

 

My boat was a holidays-only vessel for the previous owner, so its still got less than 1100 hours on the engine after five and a half years, so I'm not concerned about putting lots of engine hours on it- its more the fuel costs and more frequent servicing that would be needed.

 

A very ingenious chap once described a possible solution- he proposed an idea to install a small tube, perhaps an inch diameter, leading from outside the hull and feeding the cold air through into the lower part of the fridge (with various mesh filters to stop insects etc), and with air sucked in using a tiny computer fan.  You would also need some sort of valve or exit for the warmer air near the top of the fridge. 

Between November and Feb, such a device could suck in enough cold air that the fridge compressor would need to switch itself on far less often.

It sounds a bit mental, but my fridge is 5 years old, so I feel I could take a chance on butchering it a bit to create inlet hole for the cold air. 

What I'm far more dubious about is the idea of creating a 1 or 2 inch hole in the hull, just to test out an untried and slightly mad idea. 

 

Edited by Tony1
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While I understand the niceties of reducing everything to cost and budget on the various means of power production, very little arguments here include the aesthetics side of solar, namely the peace and quiet. 

 

Faced with a choice of spending a few hundred on panels and an additional solar controller, or running a genny/engine power plant a few days less per annum; I know what I would choose - the faff of hauling the genny off the boat - getting the petrol - the noise - the possible CO dangers - the immediate environmental impact -  the neighbours peace and quiet and my own, would sway me every time. 

 

Get more panels.

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Oh, another thing I forgot to mention - consider using rigid panels - If you cover much of your roof with these, you effectively create a double  layer roof and you won't need to find shade on sunny days...the panels provide.

Edited by alistair1537
missed a word
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4 hours ago, alistair1537 said:

Oh, another thing I forgot to mention - consider using rigid panels - If you cover much of your roof with these, you effectively create a double  layer roof and you won't need to find shade on sunny days...the panels provide.

Very true my roof is full and my boat is cooler than others

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11 hours ago, alistair1537 said:

Oh, another thing I forgot to mention - consider using rigid panels - If you cover much of your roof with these, you effectively create a double  layer roof and you won't need to find shade on sunny days...the panels provide.

 

I'm definitely getting rigid panels, I've heard quite a few reports of flexible panels not yielding anywhere near as much power as a similar sized rigid panels, and in the winter I'll need all the marginal gains I can get.

I've seen some great-looking mounts that allow you to easily tilt in either direction, and even tilt at the ends as well. 

Only downside is these are great with 80cm wide panels- if you fit much wider, the potential tilt angle is reduced. 

I saw one boater in May, moored pointing roughly east-west, who had a panel semi-permanently attached to the south side of his superstructure. He'd been stuck for 2 months with a broken engine though. 

 

 

 

 

 

 

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5 hours ago, peterboat said:

Very true my roof is full and my boat is cooler than others

 

Can I ask Peter, how do you get to the lock ladder when singlehanding in locks, when the lock ladder is halfway along the lock?

There don't seem to be many like that, but I've come across a few. 

So far I use the roof to get to the ladder, but that will be difficult or impossible if the roof is full of panels

 

I've heard some people use the gunnels to reach the awkward ladders, but there are a few locks (like Hurleston) where I'm not sure they are wide enough for you to walk along the gunnels. 

 

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48 minutes ago, Tony1 said:

 

Can I ask Peter, how do you get to the lock ladder when singlehanding in locks, when the lock ladder is halfway along the lock?

There don't seem to be many like that, but I've come across a few. 

So far I use the roof to get to the ladder, but that will be difficult or impossible if the roof is full of panels

 

I've heard some people use the gunnels to reach the awkward ladders, but there are a few locks (like Hurleston) where I'm not sure they are wide enough for you to walk along the gunnels. 

 

I've had my solar panels occupying the first 3.5m of roof since 2013; the question of ladders did concern me, but it has turned out that very, very, few locks are badly placed.  I now tend to bow-haul the boat (at least partially) in or out as needed.  During the winter months, I have another pair of panels (1.0m x 3.5m) about 2/3 along the boat, again I'll bow-haul the boat to the right place.  These panels are offset to the centreline, so there is a wider shufflepath past them, although it's not the best.

 

Dave

 

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On 20/07/2021 at 18:02, Tony1 said:

 

 

A very ingenious chap once described a possible solution- he proposed an idea to install a small tube, perhaps an inch diameter, leading from outside the hull and feeding the cold air through into the lower part of the fridge (with various mesh filters to stop insects etc), and with air sucked in using a tiny computer fan.  You would also need some sort of valve or exit for the warmer air near the top of the fridge. 

Between November and Feb, such a device could suck in enough cold air that the fridge compressor would need to switch itself on far less often.

It sounds a bit mental, but my fridge is 5 years old, so I feel I could take a chance on butchering it a bit to create inlet hole for the cold air. 

What I'm far more dubious about is the idea of creating a 1 or 2 inch hole in the hull, just to test out an untried and slightly mad idea. 

 

I constructed (well, bodged together with some gaffatape) a box to fit next to my front steps with tubes leading to and from the bilge with a computer fan controlled by a thermostatic relay.  It worked fine for a winter (with about 1/10 of the power used by the fridge), but it turns out that a box in the cratch works just as well for everything except milk, which was fine in a plastic bag in a hessian bag hung over the gunnel outside the kitchen window into the canal (hessian wicks up the water for evaporative cooling, plastic prevents water touching the food containers).

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