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let's talk about a little bit about uh you mentioned this briefly about sizing a solar array what's sort of your philosophy and you mentioned generally at the beginning you said get as big as you want and i by the way i have to echo that i mean generally the limitation is really where can you mount them it's not most very few of us almost none of us ever have more space than we need but do you want to talk a little about about how you go about sizing a solar array nigel well um unless you've got a catamaran with a huge amount of deck space and um relatively light electrical loads i.e no air conditioning uh you're not going to be able to put enough solar on to keep up with the boat loads i mean that's just the reality that we've got so put as much on as you as you can um and i have a very crude calculation for the output of it how much i expect to get out of it i take the rated output in watts so it's 100 watt panel i assume i'm going to get the equivalent of that output for three hours a day okay so that's 300 watts yeah now 300 watt house actually so um if it's a 12 volt system then we divide by 12 into 300 uh what else that'll give us amp hours if it's a 24 volt system we'll divide by 24 and that'll give us amp hours at 24 volts and then i just factored that into the energy your budget for the boat uh and it's never enough but yeah and you know on a we've got a fridge and a freezer and um you know lights and all the normal sort of stuff microwave um a decent solar away can keep up in the daytime with the boat loads but it's never going to keep up 24 7. yeah it's uh it's a good point you know you do what you can with solar is another expression i use with people you do what you can what you can afford right i mean that's a factor all of us have a budget you do what you can afford and if you start you know assume that you might want to go for more you know i tell owners i'm like don't spread them to don't be so put your solar panels as tight as you can because you'll be surprised maybe now you're not willing financially to do more because you don't really believe or understand what sort of tangible benefit you're going to get on your solar rate i tell people okay well if you've got room for four and you're only going to do two then put the two really close together you know in a place where obviously you minimize shading always start with minimize shading first but don't assume that you won't do another two and we did our just recently a 56 sea ray you know i mean sedan bridge you're thinking why would that boat ever have solar well you know we started with three panels and now the owner said you know what actually i'm gonna go for another i think it's another one or two and sure enough we when we laid it out we didn't take all the space that we had assuming that they wouldn't do more and now they went now they've got five 171 panels on top or 161 so yeah it's you you always want more than you'll probably have and if you go there go there slowly but assume that you might want more jeff assuming that you're gonna have to top up the batteries by running a generator or battery charging an anchor or whatever or when you're underway um the best time to do that is in the morning and uh so that when the solar kicks in it keeps up with the daytime loads and ideally if you have enough solar it'll give you that slow trickle charge at the end of the charge cycle if you've got lead acid batteries to top them off so the batteries don't suffer from sulfation but in one way and another it'll keep that i got the dog here it'll keep the the batteries in a higher average state of charge and that will substantially extend the life of the batteries if they let acid batteries yeah big difference big time big time and by the way for the listeners out there um you know you got to remember if you're curious there's we've got tons of articles on this on this concept of three-stage charging right bulk absorption float um it's a little bit like our appetite you know you start a big meal you know maybe at mom and dad's you know you start with a lot of gusto you're gonna be bulk and eventually you're like oh i can't do more but you keep going that's absorption and when you can't do any more and you're just basically eating a little bit or barely you're afloat it's sort of the analogy i use because i love food and you know the great thing about solar is of course it's able to do the absorption which is the top off in a way that really you're not running that generator and getting so little like what nigel was saying it's so frustrating to run an engine and get so little out of it at the end of the charge you know it's that's the hard part to justify like the first hour you were getting maybe 100 or 200 f you know depending on what you're getting now the your fourth hour or fifth hour you're getting only 20 amps or 10 amps out of that engine that's where solar it's divide and conquer have the alternator or your generator run your high alpha chargers at the beginning and when those chargers are out of bulk then on the absorption or partially in the absorption have the solar keep going and then your it's a win-win you know um the solar doesn't care if it takes ten hours or eight hours because there's no real cost of running that and it's in the background and silent nobody hears it nobody's bothered and so that's really good advice nigel um thank you there's another cost issue that nobody ever thinks about um if you take the cost of a battery bank let's say for argument's sake it's a thousand dollars and let's say uh over the life of that battery what if we if we take the the number of cycles we're going to get out of it say 500 and uh we get 100 amp hours out of it at each cycle but we can do the math and we can figure out how much energy went in and out of that battery before it died so this is not generating the energy this is just storing it in the battery and then delivering it back to the boat and then at some point the battery dies so if we look at how many kilowatt hours of energy went in and out of that battery over its life and we divide that into the cost of the battery we come up with a kilowatt hour throughput cost but this isn't making the energy this is simply the privilege of storing it and delivering it back to the boat yeah calculation with lead acid batteries you discover that the kilowatt hour throughput cost is somewhere between 30 cents and a dollar a kilowatt hour just for the storage realize so for every kilowatt hour of energy that the solar panel delivers directly to the loads yeah you've just saved yourselves another 30 cents to a dollar every time because you didn't have to put it in the battery and take it back out again yeah there's no it goes in goes out on some of our boats you know with big battery banks so two three four thousand dollar battery banks that kilowatt hour throughput savings on the battery bank can end up being really substantial over a year or two big time yeah it's it's just it's all in all honesty to all the listeners out there uh solar is not a gimmick i mean that's what angel i try to tell you it's you know it's it's not a feel-good purchase it's not only that it's it's if you've got space on your boat and you're committed to your boat and you're not going to sell your voting like nigel said if you just use it for one or two weekends a year maybe it doesn't make sense but if you're taking your boat off for a couple weeks even just a couple of weeks every year and you're facing this constant state of discharge because you're an anchor and you're worrying about your fridge you know stopping in the middle of the night or beeping or inverted beeping because it's got a low voltage solar is a great way uh for a lot of us to offset all the loads that we're running on our boats to give us all the creature comforts that we have on our boats it's uh it's a really good way to do that um throw in another thought here on through foot cost if you do the same calculation with lithium-ion batteries even if you're paying a thousand dollars a kilowatt hour up front you know five times what you would for some lead acid batteries if you do that same calculation because the lithium ion batteries have such an amazing cycle life you know now the with the iron phosphate they'll talk they used to say two thousand cycles and now they'll say three on four and five thousand so if you do that calculation um it looks like the lithium-ion batteries firstly cheaper over the long run than the lead acid because the kilowatt-hours throughput cost goes down well below 20 cents a kilowatt hour and you can never get it that low with lead acid so on that basis you'll see a lot of lithium ion uh manufacturers claiming that in the long run their batteries are actually cheaper than lead acid there's a fallacy here unfortunately i mean i wish it was it was this easy the reality is none of us will ever get that cycle life out of the batteries that we're not gonna live long enough to put three thousand or four thousand or five thousand cycles on the patrick yeah that's for commercial applications yeah like a ferry that's being used every day recycling that many times then the throughput cost goes up directly proportional to the reduction in the number of cycles we put on the battery and all of a sudden they get to look fairly expensive again of course they have lots of other reasons for for using them but that particular argument which i see used quite a bit um doesn't pay attention to the fact that none of us are ever going to get that cycle light out of the batteries we're just not going to live long enough to do it exactly and we don't use our vote i mean exactly i mean how many people a cycle by the way for the listeners out there is you start at one point whatever the voltage is and you go down and that and then you go back so a cycle is almost like sometimes that cycle might be over two days right you might not even recharge your batteries some boats you know that before solar sailors would stay at anchor you know two three four days let the batteries discharge discharge discharge without charging that's just a cycle so now four days on the hook was one cycle so you know to extrapolate that and say i'm going to get 3 000 cycles or 2 000 cycles and a cycle is not a day here sometimes a cycle is two days three days four days i mean if you're blessed enough to be able to use your about 3 000 cycles and every cycle is a couple days 6 000 days on the water congratulations i honestly i applaud your ability to be dedicated to voting for that level most of us will never get that it's just it's just not gonna happen it just won't happen yeah that's a good point nigel really good point do you want to talk a little bit about uh rigid versus flexible give us a little bit of your input on the choices there that voters have well actually i think i'd rather start with cells because all right let's do it let's start with this house why not let's start it's one of my next talking points let's do it because there's been a lot happening over the last um decade and even the last year or so in the uh cell world which is the which is the fundamental building block of any panel regionals yeah um for for a number of years by far the the best cells on the market the most efficient have come from a company called sunpower and they call them their maxion cells and um they're also known as ibc cells interdigitated i have trouble with that word back contact and actually i have a little demo board here but do you see that that matte black cell yeah that's a that's one of those sun power ivc cells and what's different about those to all other cells every other cell has to have a grid on the front of it to collect the electrons with the sun power cells they're collecting both the negative and the positive um on the back of the cell so there's no grid structure on the front every other panel the front is negative and the back is positive or vice versa but they're they're doing it all on the back so there's no grid structure and that gets rid of all of the grid and that actually means the entire surface area is producing electricity whereas every time you put a grid on there the grid's obstructing some of the surface area right so people are being super efficient cells uh about 24 efficient at converting sunlight into electrical energy that's high well i know and they held that pole position for probably a decade and we've we see those in the boat world on high-end panels and then um we got another technology just in the last few years which comes from panasonic and it's called a hit h.i.t head throw something rather again i forget what the acronym stands for but um that's a that's an interesting technology because it's a combination of a of a solid crystal cell with a with a um thin film cell and that's even more efficient than the sun power cells so those are now the most efficient cells on the market but only like half a percent to a percent more efficient but we're seeing those coming onto the market we're seeing those in panels and then there's another technology that's been around for about a decade but it's only now really getting really widespread usage it's called perk p-e-r-c and again i can't remember what the acronym stands for but it's another coating that you can put on the back of any cell other than the sun power cells and it effectively reflects some light back through the cell and it reduces the heating because heating always reduces the output and it also improves the efficiency slightly you get another three or five percent improvement in efficiency in the panels so we've got those three technologies that the ibc the hit and the perc put all of them in our world at the moment on different panels and all of them having a significant beneficial impact on the efficiency of the panels so then um we can put those different cells into rigid or semi-flexible it's the same cells going into the panels uh the the difference being obviously with the semi-flexible you can bend them to a certain extent and then you can conform them to a deck [Music] or a flexible canvas or something like that yeah in order to make them flexible they've also they've got to have you know a plastic backing as opposed to rigid aluminum frame to them and so on um so and they're considerably more expensive and the rigid panels but you've got to consider the insulation costs for the rigid panels you know you've got to build a whole structure for them and whereas and you can't just bend them to a deck put them on a deck and you can't walk on them a lot of these semi-flexibles now they have a non-skid surface walk on them uh so they've got a lot more adaptability than the rigid panels and the other thing with the richer panels is they're not built for the boat market the minute you take a rigid panel which has a 25-year warranty in the home power market and stick it on a boat you have no warranty of course it's gone yeah whereas the semi-flexible that are built for the boat world uh they all come with a warranty of some sort and we will talk about warranties in a bit i think but yeah we will there's a big difference yeah that's a good point um yeah i think the last one i heard i think the only one that ever did that you might know is kira sierra i'm not sure for the japanese manufacturer that had panels about and they're off the market now um they are on our boat they're 12 years old yeah kyocera panels because we've have a we have a solid uh bimini the structure on top of the bimini and mounted them on there um there's 340 watts of kyocera panels up there and they're still working great but that's because they were really good a very secure mound and they're a good panel but those panels were top of the line when i bought them um 12 years ago and their efficiency then was 16 to 18 percent wow you know you know i mean flexibles were running at twenty three and twenty four percent some of them so it doesn't sound like a huge difference but it's fifty percent more output for the same surface area yeah yeah that's all about proportionality yeah um i i wanna for the listeners out there i mean and i can't that's one of the biggest challenges with ridgid is rigid is not gonna bend so you know some of us that care about aesthetics more than others and all of us are different of course uh that's the one advantage with flexible especially with a lot of the power builders that we deal with you can actually have the flexible match the curve of the boat so if you have a hard top that is curved like a c ray that actually has a curve where you're looking to profile your boat and you don't want to have a single line the whole boat has no straight lines on the boat you know other than a mass and a boom very few boats have straight lines everything are just variations of curves which obviously to some of us myself included makes the boats beautiful um that's one of the advantages of flexible is that you can have the profile of your boat not be altered by a solar panel and you're right i mean the challenge is where are you going to mount the ridgid and so sail boaters in the past would have to create these arches they would hang them off the lifelines which we still do again sometimes we have to do that but now with the flexible you can have them either you know follow the curve of the hard dimmi like you have us we've done you know hans christensen that are having hard dodgers hard even bimini's you know we're mounting uh flexible solar panels on that and the advantage is some of them even you can have them ordered like sodium for example you can have a flexible solar panel with a peel and stick backing so you don't have to do any deck penetrations for the mounting and then you can even have the junction be actually underneath so literally the solar panel is just this flat thing no junction box and the wires come from underneath so when you're ordering solar panels depending if you're willing to go for the high-end stuff uh you'll be able to order the panels and nigel talked about this before you can actually even have it with an anti-skid so there you can actually have the surface actually not be so perfectly smooth that if you walk on there with wet shoes or a slight inclination you're gonna slip off it's almost like an ice rink um you can actually have it with an anti-skid and so now if it's properly obviously bedded and there's no voids you can on some solar panels walk on them so that's another advantage of the flexible ridgid now that being said for the listeners out there because i can see some of the comments if if price is king it's going to be rich rigid will give you the most and i get this at mojos should i do flexible origin in my cottage i'm like you have a cottage i i can't see an argument for flexible maybe there is one but you're going to go rigid from a cost perspective rigid is going to really keep your costs ready but as a voter there's an argument to say maybe you'll spend more for flexible but you don't have to worry about the mounting you don't have to create a structure there's another issue there jeff you know on your cottage uh there's not going to be a lot of vibration and motion right those rigid panels you get a little bit of a movement and the cells are going to crack the minute the cells crack you get a significant loss of output output and you can actually end up actually with hot spots that can cause other problems and we'll come back to that in a moment but right now uh i'd like to take a little break and bring in devin because he's going to want to go home soon okay let's do it you can talk about where we're headed in terms of cell sizes and where the whole panel manufacture process is headed in the next all right let's do it surrounded by pros look at my smile it's like christmas right yeah i know it's just awesome honestly there's there is no replacement i mean you could be smart in life but there is no replacement for experience let me tell you knowledge is something that you have to learn the hard way and it takes time it takes time and so thanks for being here to share your knowledge with us today so tell me what's devon what do you want to share with the listeners out there uh regarding um the the manufacturing and also the specifications of uh solar panels yeah so i was listening to your combo a little bit with nigel and i think um some of it's probably already been said but it's worth repeating what were i had a really good conversation with a solar company recently and they were talking about how blessed we were in the last five years with really stable cell sizes and as nigel said the technology the efficiency has gotten closer and closer to that ibc that sun power 24 obviously with hjt cells getting up to 24 but what we're starting to see now is the cell size change so we've historically had um you know the four inch cells from the ibc sun powers the the sr plus hjt cells are about five inches and this year we had this funny little inversion go on where the cells looked almost the exact same size but what they did is instead of having lopped off corners they had a full cell size and they gained a couple millimeters on each side they also upgraded into perk which is around 22 so all of a sudden we had these you know quote unquote lower efficiency cells producing a higher output on a total panel which is totally bizarre but what you know that just kind of illustrates what i think is going to uh be in the pipeline for the next few years we're going to have cell size changes um the efficiencies are getting closer and closer as nigel said so you're going to start to see different outputs jumping from year to year i think still you know well i guess if we if we look into the future a little bit the cell sizes i won't get into the actual details they're called like m1 m2 g1 g2 no one's going to remember that but um what's going to happen is they're going to start to get larger there's going to be a 7-inch cell that comes online and then an 8-inch cell it sounds like eight inch is going to become the standard cell size um so then you're going to start to hear the terminology of half cells in quarter cells so i know if you guys covered already that the voltage the voltage per cell is is sort of fixed by the photovoltaic properties so it's around 0.6 volts per cell they wire them in series and that's how you get your voltage and then the size of the cell typically dictates the amperage coming out of it so as the cells get larger theoretically you get higher amperage but then you're going to have a really low voltage panel unless you get half sales or quarter cells so we're going to see we're going to see the the um we're going to see lots of changes in sizes um it doesn't necessarily i think what they're doing now is they're filling the panel a little bit better as efficiencies get higher yeah that's true yep so there you'll see yep there's a diamond shape in a lot of these solar panels it's going to go away in the future so and as far as uh other notes i have about the future i think that hj i know nigel talked about hjt cells or they're also called hit cells basically panasonic had a patent on those that ran out they're notoriously hard to produce a high efficiency hjt cell so there's other companies they're going to start to produce these and they're they're going to be the sell of the future they're going to they can get right now they're at 24 they're going to hopefully inch up to 25 um maybe a little bit higher but um silicone has a limit of around 28 or 30 efficiency uh conversion yeah then you've got to get into a different type of uh cell technology um i had uh yeah do you want to talk about or maybe nigel or yourself i'm not sure one of the topics we want to talk about cells is what does actually efficiency mean you know you you hear that term and it's it's thrown out there but you know uh when you're thinking about obviously that's the out but there's also the efficiency of the whole panel as a whole not only in the cells how they're interconnecting you want to talk a little bit about efficiency of the panel and what it what it actually translates to yeah an everyday border i think there's probably a lot of confusion around what efficiency of the panel actually means and i think a really good analogy is the thermal combustion efficiency of uh gasoline engines you know so it's about 20 percent but no one's running around there saying i don't want to use a uh you know gasoline engine because it's only 20 efficient it just means that out of the potential power that the sunlight or the gasoline is um the potential energy in that source only 20 is being used so that's what you get into with the solar cells like nigel said his old his boat um a lower lower efficiency 16 um whatever the rating of that panel is say it's a 100 watt panel and it's a 16 efficient panel it's still going to have a 100 watt output just like a 24 efficient 100 watt panel would be it's just the 24 efficient panel can do more with the energy of the sun and thus it's going to be a smaller panel yeah that's that's worth it's a way to have more out of less right in terms of space right yeah exactly and if you had an unlimited field to put these in who cares about efficiency we're going to go with cost but on a rooftop or a boat we know we don't have a limited amount of space yeah a hundred percent i tell that all the time you know some power voters have huge feminists like i'm talking it's it's almost like you know you could have a party and you could be 20 people under that bimini uh but for the sail boaters that have these small biminis i tell them well at this point you know it's like down it's like building downtown you know you gotta at this point you gotta make every single square foot or square meter of real estate you have is important if you're living in the vast somewhere deep you know you build a rancher you got lots of land doesn't matter you're not gonna build stories you're not gonna be a high-rise building but yeah efficiency certainly matters for us as borders where we have limited space and we realize that we need we want as much solar power and that's what i did on my boat you know when i did it came on my boat i have an older boat from the 1990s especially 1990 you know the vietnamese not that big and i wanted to maximize my solar array and that's exactly right i mean i chose solar panels that had the highest efficiency at sun power sales from soviet the sb align and um you know i went like okay well i gotta do it because that's how i'm gonna be able to maximize the output given the limited space that i have on my sailboat and that's how you when you go about that that's a good point um do you want to talk a little bit about how cells are actually interconnected can you talk a little bit about that yeah and i think nigel might be able to expand on this um but i i think that uh in general for the for that voters understanding of how these cells work um the the voltage that you're going to see if you guys got into voc and vmp not yet now we're going to get there yeah um so so in general the the the cells are interconnected they're wired in series it's just like the way i learned it is you think of a like a triple a battery or something that's 1.5 volts your wire doesn't it's 2000 series you have three volts so every little cell is worth is about 0.6 volts so they're all wired in series um and then so you get your tonal voltage 100 watts is typically around 16 volts um but they also have uh they have in case uh shading happens you've got bypass diodes inside the panels and those are alternate routes for electricity in case they're shading on some of the cells and the shading turns the cell off it can't get through there the power can't get through the cell and like i mentioned earlier that amperage is actually dictated by the size of the cell so that's how you get your total you get volts times amps and that's your wattage of the pin that's cool yeah it's amazing how you know as all of us as voters you look at 100 why you think oh it's there's there's a lot of technology in the panel there is it's it's not it's not just you know like a nail or a hammer you know it's not this there is what you see is you got to look deep to understand the quality that you're buying and know that certain panels are built differently of course than others some panels are built for cost and that's what matters the most to the builder the manufacturer that's what they're going for and other builders uh like solera or sylvia you know to name a few um are gonna go and they're gonna say you know what we're going for quality you know we're gonna try to build you know not the best panel there is but we're going to try to build a really good panel at our of course it's going to be more than the cheap panel um but you got to make that decision as a voter as if you you know if you find that you know it's worth it for your budget and what you want to get out of the panel yeah is there anything else you want to add devon on your side that you want to talk about that i haven't asked well man i could go on forever but um i think you and nigel probably uh probably nailed the major points and i think most people want to hear from you guys anyway so thanks for letting me join hey nice thanks for sharing thank you guys thank you hey nigel welcome back all right so we talked a little bit about cell sizes well we didn't talk about jeff tell me it's um monocrystalline polycrystalline thin film please let's weigh in on that because that's a big question that we get all the time yep all the time when uh to make the cells for the monocrystalline they take a a crystal of of um silicon and they put in a fat molten silicon and they withdraw it slowly and it creates a big crystal it's a single crystal okay and it comes out as a cylinder typically well if if it's a five inch cell it'll be about that big around and you know six and so on and then and then they square off the edges but if you think about it if you want to make it totally square you've got to take a fair amount of material off so they just trim a bit off and that's why on a lot of these panels you see the little corner because if they wanted to make it totally square they'd have to cut all that extra material off which becomes weights and then as uh devin was saying now they're actually getting to where they're making monocrystalline cells and they are actually own them off all the way um because that little bit here costs us a tiny bit of efficiency because you know we can't get any electricity off it so that's the the monocrystalline the polycrystalline they have a seed again a silicon seed and a fat of molten silicon but they just let the whole thing harden around the seed in a square container so then when they slice it they don't have that issue with the round corners that they got to square off so it's quite a lot cheaper to make them but but the grain structure on the polycrystalline is all over the place with the monocrystalline it's all in one direction and with it in one direction they can get greater efficiency in terms of converting sunlight into energy so in theory the monocrystalline are more efficient than the polycrystalline but that's only in theory because after they've made this anger and they slice it up they take the individual slices and they test them for efficiency and they put them in different bins so the highest efficiency ones go in one bin and then the next level in another bin and so on and so forth and you can get pretty low efficiency monocrystalline cells from the ends of the anger and so there's a big variation in efficiency and you can get polycrystalline cells that are more efficient than lower efficiency monocrystalline so the key issue is not whether it's monocrystalline or polycrystalline that's what the actual efficiency of the cell is in other words which bin it came out of yeah and they don't tell you that no so then you get a manufacturer like sunpower that's making these super efficient cells the best on the market for years but they have the same binning arrangement and solar panel manufacturers can go and buy the lower grade cells at a much price often a quarter or six of the price and put them in a panel and they can legitimately claim it's a sun power cell in that panel and people assume because of that that it's a high quality high efficiency cell but unless they actually tell you and underwrite it and say this is a 24 efficient cell you don't know whether it's 24 or 15 and there have been manufacturers in the boat world that have been buying these these um lower grade sun power cells and putting them into panels and advertising them with some power panels which they are um but uh nowhere near as good as the high-end manufacturers it's all in the details always so then the other technology we have is basically to spray a film of silicon onto a sheet and this is what nails are just a complete black sheet of silicon what we call a thin film or amorphous silicon well up until a decade ago we could get 10 or 12 percent efficiency out of those for a given surface area and for for an equivalent uh monocrystalline or polycrystalline cell the top was 16 to 18 so there was a significant difference between them but but not really radical but then over the last decade the efficiency of the thin film was barely grown at all i mean that the graph is very very level the efficiency of the monocrystalline and polychristine has gone up quite dramatically so now your thin film might be at 12 and your monocrystalline might be 24 so there's less and less reason to use the uh the thin film technology on a boat because we want the most efficient we can get because of our lack of surface area yeah technology in the boat world anymore and i certainly wouldn't recommend it to anybody yeah we don't see that i mean we're always you're right i mean the choice right now is really mono or poly yeah and that's between rigid and semi-flexible that's right and uh you want a panel that's basically um well then let's talk efficiency because then we've got the individual cells uh but then we've got to put a grid structure on them unless it's a sun power cell and then that grid structure reduces the efficiency a little bit and then we've got to connect them in series in the panel so the efficiency of the panel is driven by the weakest cell not the best one so if we've got one 20 percent it's going to drag down the efficiency of the whole panel and then we've got to include all the white space or the black space or whatever it is we're using for the backing material uh the edges so on um so the uh the actual panel efficiency uh is going to be substantially less than the cell efficiency and so the best of the manufacturers will actually have on the label they'll give you the panel efficiency and uh i think if we can get uh 20 panel efficiency we're doing pretty well yeah and you generally have to pay for that i mean it's really good yeah and it's to echo you know at the beginning nigel started uh his formula for calculating what are you going to get out of the solar panel you know our method is slightly different but we come up to the same number we we look at wattage of the panel be it 100 watt or 200 water the array could be a 500 water rate and generally in the summer months you know when it's not the end of the world and it's not raining super hard like we have here in the pacific northwest because we do live in a rainforest that rainforest is generally more in the winter than the summer we're looking at you know generally a rule of four on average it can be better than that and so if you've got a 500 watt array you're gonna generally divide that by four and you're gonna get at 12 volts 125 amp hours now of course if the solar if your batteries are 24 you're gonna have that um but yeah efficiency does matter because we're all trying to get as much power as we can out of that solar array and we all have most of us unless you have a massive catamaran and we've done catamarans 50 55 feet and even those silver arrays like nigel talked about are not sufficient to do everything i've done a solar array of over 22 2200 watts on a about a 55-foot cap and it it does a big difference but you know they still need to be considerate of what they're trying to do with that boat uh 55-foot catamaran is a house it's it's not like you put a 16 000 btu air conditioner on there and actually there's going to be two or three air conditioners because there'll be uh four cabins in the saloon um and uh the running load on that air conditioner is going to be uh at least a kilowatt right there so you have two or three cabins you're trying to cool and the solar might conceivably if you've got enough deck space and enough so i might conceivably keep up over the course of the day but in a minute you get to be nighttime of course it's not going to do anything you're going to run the batteries down exactly exactly all right so we talked a little bit about what the efficiency did with devin and also with you that's really good to tell people what's going on there well i'd like to talk about the grid structure a bit yeah that's exactly great because i was saying how they're interconnected that's really important um because as i mentioned you know with the vibrational movement particularly with the rigid panels you get cracking onto silicon the silicon is very brittle if you you you get a cell and you just bend it the slightest little bit fractures it shatters actually um so it's pretty brittle and um and then the minute it cracks like that uh we've got discontinuity so we've got no electrical conductivity so the way we we get the energy out of these bells can you see that green fine grid structure on there yeah yeah we can see it oh yeah other than the uh the sun power you know which where they do everything on the back of the cell but everybody else they uh that's actually um silver they screen print it on there and then you put it in an oven and bake it and they cook it into the into the silicone and that's what we use for collecting the electrons from the silicon and then we go ahead and on an old-fashioned style solar panel and most of the uh the rigid ones that we still see you'll see two or three metal strips on the top of the the grid and those are the bus bars that are collecting the energy from the grid that we call these little pieces the fingers and then the energy from the fingers and then because we're putting the the cells in series we take the bust bars from the top of one cell and they go down to the underside of the next one because that's from positive to negative right exhale we do the same thing the top to the bottom um and so we've got these three to five fingers that are going under onto the next one well we get a little bit of motion and they're copper and the copper work hardens and then it fractures yeah i mean the thinness of a human hair or something like that that's what i've heard so the common failure modes on these panels are cracking of the silicon itself or cracking of the fracturing of the grid structures and then of course we've got no conductivity through the panel and we lose the panel or we've got reduced conductivity because we fractured one out of three or one out of five of the the links between the cells um so the the one of the substantial benefits of the sun power stuff is that they've got a continuous edge-to-edge connection from one cell to the next so it gets rid of many of those failure points that we have with traditional grid structures and then just this last year we had coming into the market this um structure here you know again if you can see it the yeah i can see it mtat and if you look in between all the little uh we've got the the fingers underneath which you can hardly see but then we've got on the top all of these little bus bars like three or five metal strips that are like this wide we've got all these narrow copper strips and actually if you look at them you'll see they're tapered from one end to the other because as they collect more electrons they get wider and the other thing if you look at them closely you'll see there's lots of little waves in them yeah i saw that yeah what is those they're like springs so that as the panel flexes they don't crack and there's over 2 000 connection points on every cell between the grid structure on these mtac grids and the silicon so they've actually driven pickup trucks over these in testing and still got i don't know eighty percent of the output of the panel out of them because there's so many individual connection points and because the the grid itself is flexible it's got those little springs in it effectively yeah and then when we go from one cell to the next which we can't see on here oh right here i don't know if you can see there's hundreds of little wavy spring connections wow so we're gonna by the way we're also gonna include uh an image of that on the side as well we'll do that oh yeah i've got some photos i can send you because i actually went to the factory to see how they made these things and took a bunch of photos so i'll send those to you yeah that grid structure is way more robust than anything we've had it in the past and that's only been brought into our market last summer i think no well let me no it must have been 2019 because i actually went to visit them i wouldn't have been allowed to do that last summer so we've had that technology for like 18 months to two years um so so anybody looking for the top-of-the-line solar panels today i would say uh that mtap mtat grid structure is really important now that who's providing those panels these days well they uh it's proprietary technology for a california company merlin yeah oh i've had those panels on yeah i've we've used those licensed it to solving yeah you know the italian panel manufacturer but the panels actually are made in canada um they're not in canada and california at the moment they're absolutely the top of line panels in the marketplace so with that m-tap grid structure with either the the perk cells high-end perk cells or the uh hit hjt cells i think they they're labeled uh from sylvia and i think they're called the sr plus is that right the um the hit the hjt cells and the saw panels have got the uh the perk cells but uh the sr plus i mean if i was putting solar on my boat today i'd go for the set sr plus panels yeah the terrific panels the uh for all the listeners out there sometimes uh you know we just did a boat recently sometimes you know the panels you can fit are not necessarily the panels you want you know we you know the panels don't come in all sizes and both do as soon as the bimini so sometimes i tried on the boat recently to do the sr plus and i could you know i couldn't do the geometry so i ended up doing uh sunpower uh panels so just remember don't get too fixated on doing perfect it's a vote it's a compromise uh there is no such thing as a perfect boat regardless of money you could have a billion dollars and you wouldn't have a perfect boat you'd be bringing a billion decisions and all of them would be pros and cons so sometimes you know as voters we you you strive for doing the best you can but sometimes you know there's a geometry right it's a little bit like tetris you know you you can only fit when you can fit on the space you have available so you know in in the past um we always had to get the voltage of the panel significantly above the battery voltage the open circuit voltage of the panel if you disconnect it from the battery in bright sunlight on a 12 volt system we'd want to see that voltage up around 20 volts and the reason for that is so that we can deal with shading and other issues which are not the voltage down and still have a voltage higher than battery voltage because you can't charge your battery unless your voltage is above the battery voltage right you have to have a battery a voltage above the battery voltage so when we wanted smaller panels we had to cut the cells up and here i bought this one to show you these are all half cents because in order to get the voltage up we've got to have at least 36 cells in the panel and we don't want to have a huge panel because there's no room so we cut the cells in half and then we put them all in series and that gives us the number of cells that we need to get the voltage up without having a huge panel and as much as cells get bigger we may find people choking them into thirds and into quarters to get enough cells in a panel to get the voltage out that yeah this happened in the last year or two back in the second is voltage is high enough to charge the battery so here i got a panel with 16 cells in it so this panel puts out an open circuit voltage like 11 volts so it's nowhere near high enough to charge a battery and much of the time if there's any shading or whatever the voltage might be down around 10 9 volts so the other big development had in the last uh two or three years is some boost regulators where we can a panel like this but by the single cells not chopping them up we get a more efficient use of the space because then we don't have the spaces between the pieces so we get a more efficient use of the space and then what we can do we can use one of these um these boost controllers and we can take this panel it actually its most efficient point of operation is at 9.6 volts we can take this panel at 9.6 volts and we can boost the voltage up whatever we want 12 volts 24 volts 36 volts so that way we can use larger more efficient cells in smaller numbers and still have an effective mechanism to charge a battery which we never could do like even uh three years ago yeah yeah but those boost the combination of the the uh the hit cells the mtac grids to boost regulators it's a different world that we're living in in terms of solar to what it was uh three to five years ago yeah and that's good for us as borders it's really good it does make it more complicated you know we've got we got way more choices than we ever had and as we know you know you go in a restaurant and they ask you what dressing you want on your salad and they give you a choice of like 15 dressings and you don't know which one you want well it's a bit like that with solar in a minute we got way more choices than we ever had but the the net real result is that we can optimize our systems in a way that we couldn't do in the past yeah that's a good thing i mean it's a blessing it occurs but the flip side is i mean this is what we're doing with education here on this youtube right i mean that ultimately it's part of the journey is trying to do the best you can with what you have and as voters you know we've limited space we all have budgets and you're trying to figure out what's going to be the most bang for your buck but yeah i mean the good news is because otherwise you know running a generator all the time or running an alternator at idle you know on an anchorage to recharge your batteries as we all know there are a lot of reasons why you don't want to do that there's a lot of reasons why you don't want to do that well the other thing with this um you know complexity it does give us a lot of potential benefits but it does mean that um if you're a little unsure of what you're doing it's a mistake to just go and buy the cheapest thing you can find on amazon uh it really pays to go to somebody like yourself uh or like the folks here at ope notion planet energy it pays to go to somebody that knows what they're doing um because they can make sure that you've got the right pieces to optimize the system for your boat 100 there's no replacement for experience you know i mean i was definitely smarter when i was in school my math skills were way better people do calculus i was able to do everything you know but you know i look at me now i'm the same person and experience that's making me i stop repeating the same mistakes over and over again and uh yeah leverage i mean that's a good point i don't you know first is always you know learn right so that you make sure that when you're doing it yourself if you choose to do it i spoke to some voters yesterday uh down i think they were in oregon that exactly they did the whole thing themselves but they followed a plan right they first started planning figuring out what they're going to do and then they did it and when they did it they did it really well and bravado with boats is maybe exciting but it's probably misplaced in the long run you're going gonna regret it if you do that by the way i know because i've tried it that way there's another way that you can also um check the quality of a panel and i don't think many of the listeners will will know about this um if you take a solar panel and you back feed it with uh energy and you get a special camera called an electroluminescence camera if there's any defects in that panel they show up as a black spot in the image that the camera has if there's any cracks you'll see them as a hairline black line if there's any areas that are under performing they'll be grayed out uh so you can see all kinds of failures in the panel that have not visible to the naked eye and probably not even under a microscope so and it's a fairly simple technology i don't know how many panel manufacturers use it to check their panels before they ship them out but i do know because i went to the factory and i saw it that the uh the merlin folks in california um that are making these uh sr plus panels they electroluminescence test every single cell before it goes in a panel and they they toss any that have got flaws in them and then the electroluminescent test the entire panel when it's manufactured before they should um so that's another question i would ask from a panel supplier is whether they do electroluminescence testing because i've got images of panels bought off the shelf brand new undamaged packaging and so on uh you've put them in front of one of these cameras and there's all kinds of flaws that show up and they might be rated at 75 watts and they're putting out you know 55 um because of all these hidden floors that you can't see with the yeah yeah um nigel i will have to call it a day today because um we've we've you know what i i didn't think we could do it i think we're close but i think we might have to do another one on solar again is there anything in closing on your side that you want to add to the conversation yes hoping that many of the listeners are still tuning in will be critical when they put the solar insulation on the boat wherever they connected into the uh electrical system there has to be a fuse 100 i've seen boats burn to the water line because people thought oh my solar panel only puts out 30 watts uh it can't do any harm it's not the solar panel you're worried about it's the battery at the other end of the wire and uh if you don't put an over current device in there where you connect up to the boat system it doesn't have to be at the solar panel end it's at the other end and you get a short circuit in the wiring you're effectively putting a dead shot across your batteries and the wiring is going to melt down and set the boat on fire so yeah absolutely got to have the right overcome protection in in the system where you connect to 100 100 every every single circuit on a boat not every single one there are some exceptions but pretty much 99.99 temperature sensors are the only one i can think of where you don't need overcome protection yeah um and uh yeah don't take shortcuts and having something work is not sufficient it might work but it doesn't mean it's safe it's like driving a car without a seat belt you can certainly bring yourself everywhere without a seatbelt in a car but the moment that you're going to need a seat belt if you don't have it buckled in or you don't have one period it will be a life altering event life altering event and uh a fuse is a pretty inexpensive piece of hardware to be missing it's it's it's pennywise or pound foolish or whatever the expression is but you do not want to say we're skimp on abuse and you're right nigel you've got to put that at the start of the circuit and in specifically related to solar it has to be at the battery you have the very least you have to have one a lot of slower controllers come with fuses now built in and you know we talked about uh some solar controllers the fuse is a little bit more hidden than others and they'll have a fuse between the controller and the panel but you have to have a fuse at the start of the circuit from the batteries to the controller and uh you got it you just have to it's not an option it's supposed to be within seven inches of the point of connection to the rest of the boat's electrical system yeah that's a generic little thumb yeah you try it's close as humanly possible you just don't want to have you don't want to have it and that's the same thing with you in homes right it's uh it's i mean it's a sad sad sad thing to happen on about to lose a vote for something like that that's just nobody needs that nigel thank you thank you thank you thank you thank you thank you thank you this is this is this is great for all of us and for all the voters out there this is absolute magic well thank you for what you do i mean this is there's not many people putting out reliable information into the boat yeah and that's and we're gonna change that you know one video at a time yes sure