Smoggy Posted April 18, 2021 Share Posted April 18, 2021 I'm looking for any real world experiences of semi flexible solar panels from photonic universe, I'm considering going for a 130w panel (space issues) with dual battery controller (including remote monitor), I know they are rated with pefect sun in mind but what to expect at 52 degrees north in normal uk weather? I do have a 12v compressor fridge but don't use an inverter if that is any use. Quote Link to comment Share on other sites More sharing options...
Cheesey69 Posted April 19, 2021 Share Posted April 19, 2021 I had bad experience from the semi flexible panel at sea. It delaminated after six months but I may have been unlucky. The trick is a really good controller and an extra battery because you feel let down when it tells you batteries full and it’s wasting amps😀 The bigger the panel the more it makes in lesser light. I found a constant 4 amp charge would still top up my bank over time. Next time I’m going for a solid panel Quote Link to comment Share on other sites More sharing options...
annv Posted April 19, 2021 Share Posted April 19, 2021 Hi if you do get a panel suggest you get the next higher controler as you can then add get a fold up panel to give you more power when useing the boat, remember a panel can produce power for 18 hours where as your fridge only works for a fraction of this although it takes more, 5a x18hrs=90amps less fridge 10amps for 4hrs totel =40 40 from 90 =50 amps spare ,i have a panel plus a folding one will run my boat providing i dont use heater. John Quote Link to comment Share on other sites More sharing options...
Oddfellow Posted April 19, 2021 Share Posted April 19, 2021 Flexible ones are rarely any good long term. Framed, solid ones are MUCH more reliable. As it's all about surface area, you really need the largest you can fit and get a good MPPT controller that's got capacity for more amperage input than the panel you initially buy to allow for upgrades. Never skimp on cable. Use the correct cable. Quote Link to comment Share on other sites More sharing options...
OldBerkshireBoy Posted April 19, 2021 Share Posted April 19, 2021 There is an artical on solar power in one of the canal boat forums written by an installer who also sells kits to diy people. Quote Link to comment Share on other sites More sharing options...
Smoggy Posted April 19, 2021 Author Share Posted April 19, 2021 I won't be going framed as I don't want to change the lines of the boat so semi flexible is the only way to go, I don't plan to just moor up and be self sufficient for power but would like to be able to go for several days without having to run engines to top up batteries, I don't have space for more panels either and I don't plan on mooring and putting up extra panels. Quote Link to comment Share on other sites More sharing options...
LondonRascal Posted April 19, 2021 Share Posted April 19, 2021 Well, I thought I would add something to this topic, since I sourced and helped install the panels on Broad Ambition. While it is indeed correct that the glass 'framed' panels will last longer, and are more efficient, newer flexible panels have come along and often offer a good compromise if you want to avoid having the unsightly look of framed panels, and also at times can put stuff on them - or even if you really need to - walk on them without breaking them. On Broad Ambition, we have two 100w panels. These are bonded to the cabin topside with VHB tape from 3M. This is the mother of all adhesive tapes, and has done just fine for a couple of years now - in all weathers, from rain, ice, and fierce sunlight. We wired the panels using specialist 'solar panel cable' this is thick stuff, tinned (so wont corrode) but limits voltage drops along its length to the minimum. This then goes to an MPPT solar controller. Here is what MPPT is all about: Quote "...PV solar systems exist in many different configurations with regard to their relationship to inverter systems, external grids, battery banks, or other electrical loads.[5] Regardless of the ultimate destination of the solar power, the central problem addressed by MPPT is that the efficiency of power transfer from the solar cell depends on the amount of sunlight falling on the solar panels, the temperature of the solar panel and the electrical characteristics of the load. As these conditions vary, the load characteristic that gives the highest power transfer efficiency changes. The efficiency of the system is optimized when the load characteristic changes to keep the power transfer at highest efficiency. This load characteristic is called the maximum power point (MPP). MPPT is the process of finding this point and keeping the load characteristic there. Electrical circuits can be designed to present arbitrary loads to the photovoltaic cells and then convert the voltage, current, or frequency to suit other devices or systems, and MPPT solves the problem of choosing the best load to be presented to the cells in order to get the most usable power out..." This is why paying the extra for an MPPT controller is vital to extract maximum efficiency out of the panels. What annoys me about panels when you see them advertised is their wattage figure - this means very little because we are dealing with DC power and the key is Amps. An average 100w panel, in the most ideal, perfect conditions might be able to provide a maximum output of 5Amps. In real life, you might see 3.5A to 4A though. So you can see, with two of them on a ideal summers day you will have in the real world situation maybe 8Amps coming in. This is a drop in the ocean to what your Alternator will put out, or shore based battery charger. So you need to see them for what they are, they will charge a house battery bank over several days of good weather, or they will cover the power draw, or a good degree of it, from say your fridge running. In our set up, on a summers day where we may have an additional coolbox running alongside the fridge the panels help reduce the amount of battery use these take - so for every hour, they reduce the discharge amps by perhaps 4Amps on average. This is very little in the general scheme of things, but every little helps - as does anything else you can do to reduce power use like changing all lighting to LED. If you consider the cost of the panels, cables, connectors, controller and so on it does cost a few hundred pounds and won't suddenly 'power your boat' but you will find your overall power use is less, other than of course the moment the clouds come over or its a dull day where their output will plummet. 1 Quote Link to comment Share on other sites More sharing options...
Vaughan Posted April 20, 2021 Share Posted April 20, 2021 I agree with Robin and would like to add that solar panels provide a regular charge, which tops the batteries up while you are not using the boat and prevents sulfation of the plates. So you will get more life out of the batteries and less long term expense. 1 Quote Link to comment Share on other sites More sharing options...
Smoggy Posted April 20, 2021 Author Share Posted April 20, 2021 Thanks for the input guys, at 130w max I'm not sure mppt will make a great deal of difference over pwm, it seems to be recommended for bigger arrays. 2 hours ago, Vaughan said: So you will get more life out of the batteries and less long term expense. That is quite a big consideration as my free battery supplier is no longer in the same job and I would have to change my battery box to go back to regular leisure battery size or lose a bit of capacity, the batteries I have at the moment would be several hundred each to replace and I don't have shore power at my mooring, just leaving fully charged each time would be a step forward. 1 Quote Link to comment Share on other sites More sharing options...
Smoggy Posted April 21, 2021 Author Share Posted April 21, 2021 I don't suppose you know which type of vhb tape you used Robin? It seems to range from fairly cheap to eye watering depending on the type. Looks good stuff though. Quote Link to comment Share on other sites More sharing options...
OldBerkshireBoy Posted April 21, 2021 Share Posted April 21, 2021 23 minutes ago, Smoggy said: I don't suppose you know which type of vhb tape you used Robin? It seems to range from fairly cheap to eye watering depending on the type. Looks good stuff though. Are the ones you found all made by 3M? Quote Link to comment Share on other sites More sharing options...
Smoggy Posted April 21, 2021 Author Share Posted April 21, 2021 Yes theres lots of different types. Quote Link to comment Share on other sites More sharing options...
OldBerkshireBoy Posted April 21, 2021 Share Posted April 21, 2021 3 minutes ago, Smoggy said: Yes theres lots of different types. Dont make life easy then do they. Quote Link to comment Share on other sites More sharing options...
annv Posted April 22, 2021 Share Posted April 22, 2021 The smaller the panel the more you need to get out of it, a mppt is much better as it works over a wider range also higher amp cable reduces losses. John Quote Link to comment Share on other sites More sharing options...
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