Quality of chinese Ebay solar panels vs reputable source? - Page 1
Forum section: electronics / general

author: Freesurfer
author_rank: Regular Contributor
timestamp: February 19, 2019, 04:00:36 pm
content: Hello, forum. This is my first post on here. I have been following Dave on youtube for quite some time and it is one of my favourite channels, and thought I'd make an account on here and say hello :-)I have a project going on with renovating an old boat house and need some more permanent (not to mention silent!) solar powered off-grid solution for electricity. Today I have a petrol powered generator sitting there, but it is noisy and a bit overkill for just some light electricity usage.I have been looking in local stores where a 30W panel costs about 100 euro, and a 80W one costs about 200 euro. However comparing these to ones sold by chinese Ebay sellers, I realise that I can get them much cheaper on ebay. For example here's a link to some panels that are like a third of the price from a local store:https://www.ebay.com/itm/30W-12V-Semi-Flexible-Solar-Panel-Battery-Charger-Cable-For-RV-Boat-Motorhome/372493504585?hash=item56ba57d049:g:RJIAAOSw8LBaydBK:rk:11:pf:0These particular ones don't have an aluminium frame, but there are aluminium ones with comparable prices.However as with most things on ebay, I am sceptical about the claimed power and overall quality of the panels. Does anyone have any experience with chinese ebay solar panels and how they compare to similarly rated panels from more reputable local retailers? Do they usually perform up to their claimed performance? Perhaps someone can recommend some cheap panels?My application will be for maintenance charging a 48V battery bank made up of a bunch of 12V/40Ah VRLA batteries (I will have 8 or 12 of them in an array, with groups of 2-3 paralleled, and 4 of these groups in series). I think the easiest option will be to get 4 solar panels as well as 4 cheap solar controllers to charge each individual group of paralleled batteries. To make sure they are properly balanced. They will be used in the boat house for powering a 48VDC - 230VAC inverter for lights, charging hand drill batteries and such. I think 120W should be plenty for maintaining the battery bank as we don't visit the place that often, and the panels will have plenty of time to recharge between each visit. Not sure if I can trust the 4x30 = 120Watts, but at least it should be better than Solar Freakin' Roadways, or what?

author: coppice
author_rank: Super Contributor
timestamp: February 19, 2019, 04:03:46 pm
content: 100 Euros should get you a good quality aluminium framed 300W panel, not a 30W one. Your local supplier sounds like a rip off.

author: Freesurfer
author_rank: Regular Contributor
timestamp: February 19, 2019, 04:15:33 pm
content: Rip-off indeed, as with most things in local shops here. That's why I am looking for alternatives and scouting ebay (but no use buying things there at a third the cost there, if they only perform a third of their claimed performance). I am not sure if I have seen panels as cheap as you suggest though. At least not unless ordered in larger quantities.

author: OwO
author_rank: Super Contributor
timestamp: February 19, 2019, 05:29:36 pm
content: Quote from: coppice on February 19, 2019, 04:03:46 pmLast time I checked $0.3/watt was the bulk pricing of the bare solar cells, and the finished product was more like $1/watt. Where can you get a 300W panel for $100?

author: fourtytwo42
author_rank: Super Contributor
timestamp: February 19, 2019, 05:32:59 pm
content: I don't buy anything electronic from China on EB as in mine and others experience they are frequently fakes or under-spec parts from the grey market, if something is ridiculously cheap there is a reason!The other issue you need to take into account is return's not only are they nire impossible on EB but you get to pay the shipping so it's far better to look in your own country firstPersonally I only buy panels made by manufacturers I have actually heard of and have a website where I can check the specifications.Finally be very wary of "leisure panels" they tend to be very high cost per watt and of unknown parentage.You might be better with some non-leisure high voltage panels and a reputable charge controller IMOP

author: metrologist
author_rank: Super Contributor
timestamp: February 19, 2019, 08:18:54 pm
content: I bought a 100W Chinese panel for $96USD shipped. Something like NuPowa brand. It did everything advertised and I've had it on the roof for a couple years now. No problems. I just use a cheap PWM controller and a SLA batteries typically and I also have an MPPT 42V Li-ion charger connected for the e-bike.I wish I'd bought a setup for at least 4 of them, but would rather have 300W panels. These are poly-crystalline, mono-crystalline are more efficient.

author: george80
author_rank: Regular Contributor
timestamp: February 19, 2019, 09:00:59 pm
content: As said, fleabay panels are notoriously under spec. The 30W panels you are looking at are probably20's. At best.For some reason, Chinese sellers on fleabay the wold over tend to be a bunch of lying, deciptful Ripoff merchants and outright Crooks. They put Ficticious numbers on everything they sell then try and make BS excuses.Before I woke up I bought some LED lights. Nothing like the rating advertised when Measured with a multi meter. When I Complained and send pics of them on the multi meter I was told they have an equivelent output to xxxW Nah, not wearing that you crook. Got my money back after a fight ( Wanted to know If I was an electrictian and qualified to take measurements, I said yes, are you?) but learend my lesson. Measured some lights and things mates Bought with the same sub par results.Given you are wanting to do a proper system, what are you even looking at tinly little 30W Panels?I have bought and set my house up with proper 185-265 Panels I have bought used that have been taken off houses for upgrades. Just bought 4kw worth of 260W panels and an inverter for $400. Even the people charging way too much are only asking $50 for up to 250W panels.Fleabay panels are not cheap from China, they are a rip off too.I usualy buy from Gumtree or Craigslist as they tend to be offered there a lot cheaper than fleabay. There are often odd 1-2 panels listed there as well as completer 2Kw+ sets.I have bought over 120 used panels now and just discovered my first bad one last week. It's got a hot junction burn mark but when I tested it, the thing is still doing good output. I'll probably get up and change it today given it's nice and cool and overcast. I have a bunch of spares so I'll just replace it with a slightly bigger panel I have and all will be good and the array will be back up to full speed. We did have some VERY hot ( 47oC) weather here a few weeks ago so the fact only one panel has shown a problem I think is great considering what I have paid for them all.Domestic panels are all designed for 20+ year service lives and if you buy them 7-8 years old for $25 ea, you are getting a lot of years of power for very little money. Everyone talks about the performance drop off with age but really like so many things in the solar game, I think it's well over blown. I have got fractionaly HIGHER output than rated on occasions like the other day. My 4.8 KW array which usualy doesent do much more than about 4KW was pumping out 5.1 KW. I thought the inverter had gone on the fritz then I flicked on the other meter I have on that array and it said the same thing. Checking other arrays they were all doing screaming outputs as well. In my repeated experience, the weather is a lot more significant than any panel degradation. If it's overcast, new panels will be down and underperforming too. I have in fact found that very light passing cloud gives the best ( short term) outputs due to something called Cloud edge effect. In a nut shell it's basically the water droplets in the clouds acting like little magnifying glasses and concentrating the suns radiation. You might think is a little overcast but then see your arrays are performing outstandingly. Doesen't last long but gives a real boost when it does and even older panels can really crank out the watts.Given yo are running 48V you may need to run 2 panels in series to get the voltage up high enough for the controller. Either way, even if you get 250 Panels I'd get 2 anyway. There is no such thing as too much solar especially in winter when the lower solar radiation would mean that 500W of panels is probably outputting 200W, IF they are in the right orientation and tilt to start with and a whole lot less if they are not. Throw in some overcast weather. You'd be lucky to be getting 5W per 30 W panel.The other BIG benefit of having plenty of panels is you may not need to discharge the batteries at all when using the inverter. If the power coming from the panels equals or exceeds the draw, the batteries are never discharged and that's the best possible thing for battery life.I have a play setup with panels, a Good PWM controller , Some batteries and a UPS as the inverter atm. I hooked in 1 Kilo of panels with the 4 in 1 cable adapters I just bought and was running the UPS ( only 600W) flat out with dummy loads and was charging the batteries from where I discharged them while setting up and was still running the loads. This is what you really want to aim for. The less you dig into the batteries reserve the happier they will be and the longer they will last.Anyway, I'd be looking for used Household type panels of 185W and above. Don't waste your time with garbage fleabay and pissy little 30 and 80W panels. Get some used panels where people have upgraded to larger / newer systems. Much cheaper, infinately better and more practical.And don't be afraid to buy a lot more than you think you need. allows you to expand the system if you want and takes all worry about power away.Maybe you could even charge neighboring boat sheds for power and get a return? :0)

author: Red Squirrel
author_rank: Super Contributor
timestamp: February 20, 2019, 05:23:32 am
content: I find it's very hard to find solar panels at least in Canada but I'd imagine UK too, not a lot of sites seem to sell them to the general public. I ended up buying mine on Amazon at a bit of a markup but shipping was free. Some sites that DID sell them wanted like $300 to ship per module. Avoid local hardware stores as they charge like 5x what you should pay. Nearly identical 100w solar panels I got for $160 per unit were like $600 at Canadian Tire. They went "on sale" for like $300 at one point which was still too expensive. I find the rule of thumb is to try to pay under $1.5 per watt.I'm hoping with growing popularity we start to see more retailers stock them at reasonable market prices.I don't think I would trust Ebay stuff though, but it's really hard to tell. All solar panels are made in China anyway, so you could very well be buying the exact same panel done in the same factory as a name brand one, but for way cheaper. I imagine lot of chinese factories will produce more product than the customer needs, so they can sell units themselves at a cheaper price under a different name. Makes sense to me if you have all the tooling in place.

author: Nauris
author_rank: Regular Contributor
timestamp: February 20, 2019, 06:12:12 pm
content: Quote from: OwO on February 19, 2019, 05:29:36 pmHere the going rate seems to be about 140 euros per 270W panel of decent quality and certainly no lack of sellers to choose from.

author: DougSpindler
author_rank: Super Contributor
timestamp: February 22, 2019, 05:43:05 pm
content: In the US there are a couple of companies selling excess panels from large commercial installations. Meaning a contractor will have a contact to install say 926 panels. But price wise it's more cost effective to by a lot of 1,000. They sell the excess to a broker who then sells the 74 panels for a lot less than what “we” could ever buy them for. What’s being sold are brand new, name brand panels and inverters.

author: metrologist
author_rank: Super Contributor
timestamp: February 22, 2019, 06:57:30 pm
content: Hook us up! I think you are around SF?

author: DougSpindler
author_rank: Super Contributor
timestamp: February 23, 2019, 08:48:55 am
content: There’s a compny in Florida which has a far amount of product in Nothern and Southern California. Sorry cant remember the name, will have to look on my other computer.

author: Freesurfer
author_rank: Regular Contributor
timestamp: February 26, 2019, 12:06:59 am
content: george80:I understand what you mean about "the more the better". But "more" also comes with a higher price tag, so the general rule I'm taught about sizing solar systems appropriately/cheapest for the purpose is "Enough battery storage to last for the entire stay" and "Enough solar power to recharge the batteries between each stay". (and of course margins, worst case conditions, longer stays or more frequent stays than usual have to be added in).With a system powering a home you live at, it's a bit different as you are continously using power and need to replenish that just about every day, and often you can backfeed excess power back to the grid so no solar power is ever wasted.For camping/cabin/cottage purposes, smaller panels may do fine as there may be several weeks between each stay. If the solar array is oversized it may only spent perhaps 10% of the duration recharging, and another 90% sitting idle. Not an ideal investment when you can downscale the array to 1/10 the size.And while I haven't done the exact maths, I don't think 120W worth of solar (assuming the panels are up to their rated spec) is all that outside the ballpark. :-)I still think that ebay panels are going to be the cheapest option, even if they are not up to their rated spec. At least where I live, it's not possible to buy any panels in the price range that will ever repay themselves as there is just not a market for them here. It's not common for people to have roof mounted or grid tied systems installed in their homes, and people only use them in places where electricity is otherwise unavailable.

author: george80
author_rank: Regular Contributor
timestamp: February 26, 2019, 07:37:45 am
content: Quote from: Freesurfer on February 26, 2019, 12:06:59 amI have severe reservations about that low an input to the size battery banks you are proposing. I think this will amount to no more than a trickle charge more suited to floating the batteries than charging them.You comment about weeks between visits is entierly wrong. You NEVER want batteries sitting partially flat for weeks, may as well just use them for target practice and be done with it. the effect will be the same. Spending 10% ( or less) of their time is EXACTLY what you want. If you look up anything about batteries, you will soon learn the faster you can recharge them and having them at float voltage the better.Running them down and then having them still to reach full charge a week later will kill them sure as shooting them will.I guess a lot would depend on which is cheaper for you, replace battery's every 6-12 Months or buy more panels. If you have a free/ cheap supply of battery's, then not to worry. Where I am battery's are expensive and panels are cheap so my situation may not apply to your yours.There is another practical and worthwhile soloution if not one seen as politically correct now days. It's probably a filthy term but seeing some of us are grown up her.... It's called a Diesel generator.Actually a diesel engine driving a car alternator will do just fine. Picked up a new 6 HP diesel the other day for $50 and an alternator wouldn't cost any more. Bit of fabricobbling and you have all the power you want when you want it. Hook it up to your batteries and you can run a big inverter all day and when you are finished the batteries will still be 100% Charged. Solar panels will keep them floating and all is well and long lived with the world.I built one of these setups and it works great. I over geared the alternator with a 6" pulley on the engine and a 2" on the alt and the engine only hast to fast Idle to provide real good power which keeps it quiet and uses minimal power.You could use a petrol engine as well, you'd be lucky to use 2L of fuel a day, so not worth worrying about.

author: Freesurfer
author_rank: Regular Contributor
timestamp: March 03, 2019, 11:51:02 pm
content: Quote from: george80 on February 26, 2019, 07:37:45 amYou have some good points there about batteries being damaged sitting partially discharged for that long. So I will go with more than the suggested 120W.I came across someone selling four used 60W panels locally from what would be our equivalent of "craigslist". So that's 240W in total. I think I will be going with those for now, and if it turns out to be too little I can get more panels later. With some simple PWM charge controllers the panels may do 3-4A on a sunny day and recharge the entire battery bank (from completely empty) in 30-40 hours of perfect sunlight. Chances are the batteries won't be entirely drained either (they really shouldn't).We already have a 2kW Honda petrol generator sitting there which can take some of the bigger loads. The last visit we had while working there for 3 days we consumed about 4-5 litres of petrol. The solar stuff and battery bank is just so the petrol generator doesn't keep us awake at night.

author: DougSpindler
author_rank: Super Contributor
timestamp: May 10, 2020, 04:24:53 pm
content: How does one know which are the cheap brands and which ones are quality? Hard to stay if they or any solar resseler or installer will be in business a few months from now. In the US the government rebate for installing solar greatly decreases end of this year which will make solar more expensive.I live in California where the power company during the summer pays me $0.53 kWhr fold excess energy. I can buy that kWhr back later in the day for just $0.13/kWhr. That’s got to be one of the best deals for solar. But the power company doesn’t offer that rate plan anymore. THe current rate plan the power company is offering solar customers has them buying excess electricity for just $0.15 kWhr and when you need to buy it back later in the day you have to pay $0.47 kWhr.At this time there is just too much solar produced electricity and the power company doesn’t need it. Solar produced electricity just inn’t worth it for California’s anymore. And for all of those people who recently installed solar, as soon as the power company changes their rate plan they will find themselves paying an enormous premium for electricity.Solar just isn’t worth it anymore for Californians.

author: bdunham7
author_rank: Super Contributor
timestamp: May 11, 2020, 02:56:29 pm
content: Quote from: DougSpindler on May 10, 2020, 04:24:53 pmThat's a bit pessimistic. My solar system has more than paid for itself--probably near double in 8 years and AFAIK I'm grandfathered in for a while. My current system might not work out as a new install today, but that doesn't mean total defeat, just that since the utilities aren't going to subsidize solar as much, a more sophisticated system, typically involving some storage, will be required. Those systems are now available and more are coming soon.

author: bdunham7
author_rank: Super Contributor
timestamp: May 11, 2020, 03:01:35 pm
content: The first thing to consider is whether standard 60-cell or 72 cell panels that you would use on a home or commercial roof array will work. If so, those are typically much more cost effective than the smaller RV/hobby panels. I don't know the market in Norway, but in many cases here the local sellers with more expensive small solar panels are ust selling you Chinese imported panels of the same dubious quality but at a steep markup. e-Bay and Aliexpress are hit and miss, but at least you usually don't lose your money if you follow the rules.

author: DougSpindler
author_rank: Super Contributor
timestamp: May 11, 2020, 05:09:33 pm
content: Quote from: bdunham7 on May 11, 2020, 02:56:29 pmWould you share the economics or math calculations for your system?Do you use your power company for energy storage like I do?While you are grandfathered how much are they “paying” you for the excess electricity you sell to them?In my case during the summer it’s $0.53 kWhr. And then later in the day I can buy the electrons back for $0.13 kWhr. How does that compare to the rate plan you are on.New solar customers and at the end of your grandfather term, which is probably in just several years how much will the power company pay you for that excess electricity?In California new solar customers are being paid not $0.53 kWhr like I am, but just $0.15 kWhr. And then later in the day when the need to buy back the electricity they have to pay $0.47 kWhr.Our power company has 13 different rate plans for customers. A Stanford professor created an app which allows you to compare how much you would pay for the 13 different rate plans. For the rate plan I am on right now I have $236.50 in energy credits with the power company. But once the grandfather period is over, (or if I just had solar installed on my house), I would be owing the power company $10.52.If you do the math like I just did you will see people who install solar in California are getting screwed by installing solar. Having a credit of $236.50 vs having to pay $10.52 is why I say Californians are now going to get screwed for installing solar.It would be interesting to hear from others who are grid tied to see if the power company is screwing them for going solar. If so, please show you math.

author: bdunham7
author_rank: Super Contributor
timestamp: May 11, 2020, 05:40:49 pm
content: Quote from: DougSpindler on May 11, 2020, 05:09:33 pmEconomics and math--my bill was/would have been over $300 per month average and that's before buying an electric car. Now my annual bill is pretty close to zero, typically a small check or less than a hundred dollars due. The system cost 8 years ago was about $22K, $15K after tax credits etc. 30 panels with microinverters. It is grid tied with no storage, so yes I use SCE for 'storage'.I'm on SCE plan TOU-D-A and last I knew, the numbers were about the same as what you are quoting. I have no idea when or if the plan expires, but if you have definite information on that, I'd like to see it.The power company isn't screwing anyone. Right now I'm screwing them, to be honest. Whether a particular system works economically depends on all the circumstances and the characteristics of the system. You just have to do the math. At this point, even if the rate changes and I have to pay an electric bill, just the reduction in what that bill would be otherwise would be a significant benefit. Your bill would be $10.52? Try not having solar and see what it is. I don't know what plan you are quoting that requires solar users to 'buy back' the same electricity at $0.47/kWh, but I think the new strategy, as I said, requires storage so that you don't have to buy it back. Are you saying the rate is $0.47 at night? I haven't seen that.

author: DougSpindler
author_rank: Super Contributor
timestamp: May 11, 2020, 06:57:12 pm
content: Quote from: bdunham7 on May 11, 2020, 05:40:49 pmI do a agree with you the power company isn't out there to screw anyone. They provide a product which I have the choice of buying or not. But here's why I think our power company is screwing "us".1 - Can you name one other consumer product sold on the retail market that we you go to buy it is sold for 13 different prices? That's what our power company is doing. That would be like pulling into a gas station and seeing one gallon of gas is being sold for 13 different prices. It's the same gallon of gas, why should the public be charged 13 different prices at the same gas station?2 - The power companies in California are a monopoly. My choices for powering my home are limited to one, the power company or producing my own power. All of the power companies purchase the electricity they sell from the grid and I would assume they all pay the same price. If I recall correctly, there are around 80 power companies in California. So why is in my power company charges me $0.53 kWhr when the power company next city over is charging $0.18. (And we are just 7 miles away.)3 - But here's the way our power company is screwing or penalizing everyone who installs solar today. For people who installed solar last year they could be on a solar rate plan in which the power company "paid" residential customers between $0.12 to $0.53 kWhr for excess electricity. (Depending on the time during the day, weekday vs. weekend, and time of year.) This year if you install solar they are paying a flat $0.16. Follow these three scenarios.With solar panels for the rate plan I am on right now at the end of the year I will have around $100 in energy credits with the power company. Not getting screwed here.But if I were on the "new" rate plan which replaces the one I am right now. With the same electricity usage at the same time and same solar production on the "new" rate plan at the end of the year I will have to pay the power company over $900.Now if I had not installed solar and was on my original rate plan with the same usage I was paying just under $2,000 per year.This is why I'm saying if you install solar now your are getting screwed. Using my actual data.If I did not install solar I would pay $2,000 for electricity for the year.With a new solar system I would pay $900 plus the cost of the solar system.With my existing system on my current rate plan I will have a $100 credit plus the cost of the solar system.You are with SCE so I think you are just trading kWhrs with your power company. Am I correct? So when you have one excess kW you "give" it to the power company. And when you need a kWhr you can get it back.In Northern California it's completely different. The power companies buys and sells the kWhr at the current market rate for the rate plan you are on. What this means is there are times when I can sell a kWhr to the power company for $0.53. Then when I need electricity later in the day instead of getting 1 kWhr back I get over 4.I know our power company is the only one if the country doing this. (It's an experiment in progress.) But you had better believe the other power companies are watching this closely and will implement something sooner just as soon as they can. So while your panels are producing 100% of the electricity you consume right now just as soon as your grandfather period is over you might wind up paying $900 a year like I will have to.That's my definition of the power company screwing people who install solar today.

author: bdunham7
author_rank: Super Contributor
timestamp: May 12, 2020, 12:10:50 am
content: QuoteAirline tickets? Same deal, location and time of day are huge factors in the overall cost of the product.QuotePower companies were set up as regulated monopolies for good reason. Privately owned power companies are just a near proxy for publicly owned utility services like water, sewer, etc. In many places, of course, they actually are publicly owned. I'm not sure whether LADWP or SCE would be a better deal, but that's a complex issue. Besides that, I'm pretty sure you arechoosingto pay $0.53, as I am, and that other rate plans are available with lower maximum rates.QuoteSo then you would have to do the math and see what solar system, if any, makes sense given the available rate plans. The utility company isn't there to make your solar system economical at the expense of themselves and all the other rate payers. $2K/year makes you a marginal candidate for solar in the first place; typically the cutoff for economic viability is about $150/month, with the exception of some very small, cheap systems that just reduce your bill at bit during the day.QuoteNope, I've been on a plan just like you describe pretty much from the beginning. I get paid for generation at the same rate that SCE would charge me at that very instant if I were buying. It's about $0.13 at night, which they describe as 'super off-peak', then twice that for 'off-peak' then 4x for 2-8PM weekday non-holidays. The times used to be different earlier on and corresponded better to my solar output, but they changed the plan in response to the 'duck curve'. Just google that and 'CAISO' for more info.Look, I've been doing this for 8+ years and I've paid SCE less that $1K for the use of their grid for storage, backup and stability, including a fair amount of their electricity--my actual usage in kWh is quite a bit higher than my generation, but the price arbitrage makes up the difference.

author: bdunham7
author_rank: Super Contributor
timestamp: May 12, 2020, 12:28:51 am
content: Quote from: Freesurfer on March 03, 2019, 11:51:02 pmFWIW, I know someone that has a fully electric, solar charged boat that uses older lead-acid deep discharge batteries and it works a bit like your system--he takes it out once in a while then it charges back up over the next few days or weeks. I think he can plug it in if he needs it sooner. Batteries do go bad if you let them sit too long at too low a level, but he has no problems with his and I think that as long as they are receiving at least some charge as time goes by, they'll be OK. Also, IIRC, VRLA cells are the ones that are best able to withstand extended partial charge operation. You said 'boat house'--do you visit and use the place in the winter? The only snag I can see is that you definitely don't want them to get cold while discharged.

author: DougSpindler
author_rank: Super Contributor
timestamp: May 12, 2020, 03:35:11 am
content: @bdunham7You made some good points, but airlines are not monopolies and prices are not set by the PUC.For the rate plan you are on with SCE does SCE buy you excess solar electricity during the day and pay or credit you at the market rate of the electricity at the moment? Or do they credit you on kWhrs?Where I am in California we sell and buy electricity at the current market rate. For the rate plan I am on for every kWhr I sell to the power company during summer peak hours I can get 4 back later in the day during non-peak hours.It is my understanding with SCE you just trade kWhrs and ignore the value of the kWhr. Or is my information not correct?

author: bdunham7
author_rank: Super Contributor
timestamp: May 12, 2020, 03:46:18 am
content: Quote from: DougSpindler on May 12, 2020, 03:35:11 amNo, as I explained at the end of my last answer, I get a credit in dollars for generation. The only limitation is that I won't actually get a check for that full amount if I end up with a surplus at the end of the year. One kWh at 2 PM today will pay for about 4 to charge my car tonight, which sounds similar to your situation.

author: DougSpindler
author_rank: Super Contributor
timestamp: May 12, 2020, 04:06:36 am
content: Quote from: bdunham7 on May 12, 2020, 03:46:18 amGot it. I was told PG&E was the only power company in the US that was crediting at market rate and giving energy credit dollars. All other power companies were just trading kWhrs.Do you know the period of your grandfather clause? Mine ends in about 4.5 years. Last year they were force switching me to a rate plan where the max they would pay/credit for solar was $0.15 kWhr. Peak hours would start at 5:00 at a rate of $0.47. On this rate plan I would have to have a system 3 or 4 times what I have not just to break even. Solar customer would have to sell PG&E 3 kWhrs just to get one back later in the day.Just seems unfair that I can sell 1 kWhr and get 4 back later in the day. And my neighbor has to sell 3 kWhrs just to get 1 back later in the day.

author: MerrySweet94
author_rank: Newbie
timestamp: June 12, 2020, 01:29:52 pm
content: I'm very happy that eco electricity is developing so fast in our world. A company has recently appeared in the UKusave.co.ukwhich has installed its equipment in more than 100,000 houses. What is most surprising is that their services are much cheaper than those provided by the state, we pay 0.23$ per watt per month, this is amazing! I hope that in the future we'll all give up things that are harmful to our planet. We must leave our planet safe for future generations, so that they, too, can breathe fresh air and admire the expanses of the earth.

author: Scrts
author_rank: Frequent Contributor
timestamp: June 15, 2020, 07:12:52 pm
content: Getting back to the topic: did anyone look into reputable manufacturers in China? It seems like China is evolving very fast in renewable energy and electric vehicles, so there should be good manufacturers as well.Other than that, what are considered to be good brands?

author: DougSpindler
author_rank: Super Contributor
timestamp: June 15, 2020, 07:34:00 pm
content: Quote from: Scrts on June 15, 2020, 07:12:52 pmI would buy Chinese. All of our cell phones, computers, ICs, TVs and many appliances are coming from China. Would you even consider buying an American made cell phone, TV, or appliance today? Solar panels have become a commodity. If one stops working you just unplug and replace in a hour or so.It looks like next generation of solar panels are about to flood the market. I don't know much about them so maybe someone else who knows more could offer more info. But current panels are in the 300-350 watt. The next gen solar panels are 500 watt. Looks like they have hit the market and can be purchased.https://www.alibaba.com/countrysearch/CN/500-watt-solar-panel.html

author: Scrts
author_rank: Frequent Contributor
timestamp: June 16, 2020, 02:26:14 am
content: Quote from: DougSpindler on June 15, 2020, 07:34:00 pmIt depends... People buy Tesla cars made in the USQuote from: DougSpindler on June 15, 2020, 07:34:00 pmThe problem is that you scroll down the items in your link and it's like 1000 different sellers...

author: wizard69
author_rank: Super Contributor
timestamp: June 21, 2020, 01:53:44 am
content: Quote from: Scrts on June 16, 2020, 02:26:14 amThis is a huge problem because you really want to deal with the manufacture or an authorized seller. Like buying anything from china that doesn't have a well known reputation, you need somebody that knows their way around manufacturing in China.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 21, 2020, 10:21:34 am
content: Solar panels are a commodity just like computers, TVs and other appliances. If a panel goes bad in 5 or 10 years do you really think you’ll get it replaced under warranty? For just a couple of hundred dollars you just get a new one. And in five or 10 years you will probably get a much better product.

author: coppice
author_rank: Super Contributor
timestamp: June 21, 2020, 11:40:33 am
content: Quote from: DougSpindler on June 21, 2020, 10:21:34 am... and it will be a different shape and size, with different connectors, different mounting arrangements, and a different voltage rating. So, it will be a huge pain to fit into the existing system, and will look at bit of an eye sore.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 21, 2020, 03:55:44 pm
content: Quote from: coppice on June 21, 2020, 11:40:33 amDo you even know what you are talking about? There are only two sizes for sizes for solar panels. The connectors were standardized years ago. The mounting for solar panels has also been standardized. The voltages for solar panels were standardized too.Huge pain to replace? What are you talking about. To replace a panel all one needs to do is unplug it, loosen four bolts, physically remove the panel and replace with the new one. Tighten four bolts, plug it in and you are done. Could not be easier. As for ascetics, aren’t solar panels ugly enough? But do you really think 5 or 10 years from now they will look the same as the ones you have right now? I don’t think so.

author: coppice
author_rank: Super Contributor
timestamp: June 21, 2020, 04:35:21 pm
content: Quote from: DougSpindler on June 21, 2020, 03:55:44 pmPerhaps where you live the main suppliers have largely standardised on a couple of sizes of solar panel. Go to a big supplier in China, and you will find a large range of sizes. You will also find quite a variety of framing and retaining arrangements. Unfortunately, for many people with an awkward shaped roof, they don't make a good range of complementary panels to fill in around slopes, so many people end up with a lot of wasted roof.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 21, 2020, 05:25:45 pm
content: Quote from: coppice on June 21, 2020, 04:35:21 pmWell I live on plant Earth. We defined standards a set of standards for solar panels. There is ISO 9488. For connectors we use MC4. And as for the frame size there are two common sizes.Just think about it for a moment. If the connectors, sizes and voltages were not standardized they could not be mass produced or consumed. Even if your application if for a space station or a Mars rover there standards.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 21, 2020, 05:39:21 pm
content: Quote from: blueskull on June 21, 2020, 05:33:53 pmExactly. No sure why the other guy is saying otherwise especially when there are ISO standards.

author: coppice
author_rank: Super Contributor
timestamp: June 21, 2020, 05:44:38 pm
content: Quote from: blueskull on June 21, 2020, 05:33:53 pmInverters are designed to work with a wide range of inputs. They are designed to handle varying length strings of panels, so they need to handle a wide voltage range, not one fixed value. The also need to handle panels with 150W rating to 350W rating, so they need to be quite flexible about the current too. Do you think those 150W panels are the same size as the 350W ones?

author: bdunham7
author_rank: Super Contributor
timestamp: June 21, 2020, 08:14:04 pm
content: Quote from: DougSpindler on June 21, 2020, 05:25:45 pmAFAIK, ISO 9488 is merely the ISO standard for vocabulary. I'm not sure what it has to do with sizes or connectors, perhaps you could explain--or perhaps I'm misinformed. It is true that solar panels for grid power use generally use MC4 unless they use something else like MC3 or Tyco...or H4 which is sort of like MC4 except sometimes they don't connect well to actual MC4 and catch on fire. As power levels increase, it is certainly possible that panels 15 years from now will use some other connector. Frame sizes? While 60-cell and 72-cell have become the defacto standards, the manufactured panels often have slightly different outside dimensions which might make replacement a bit of a struggle. And there are at least two different popular methods of frame retention. In addition, the 500-watt panel you yourself referenced in an above post is in fact a 96-cell panel...and it is not the same size as either of the current common models in the US. Larger panels will probably become the norm, and 15 years from now a 60-cell replacement panel might not be a common commodity.

author: bdunham7
author_rank: Super Contributor
timestamp: June 21, 2020, 08:19:31 pm
content: Quote from: blueskull on June 21, 2020, 05:33:53 pmThis company's current line of home/small commercial microinverters has 6 distinct products for different panel size, power and voltage levels. And this is just for single-phase US applications. You can pick your inverter after you pick your panels only if you pick the right one!https://enphase.com/en-us/products-and-services/microinverters/family

author: DougSpindler
author_rank: Super Contributor
timestamp: June 22, 2020, 04:38:43 pm
content: Quote from: blueskull on June 22, 2020, 12:59:34 amcoppice who is a Super Contributor for some reason believes the panels a years from now will not be anything like the panels we have today. , "different shape and size, with different connectors, different mounting arrangements, and a different voltage rating. So, it will be a huge pain to fit into the existing system, and will look at bit of an eye sore."Not exactly sure why he thinks things will change when it taken years for the solar industry to standardize the sizes, connectors, voltages, etc.My comment was solar panels have become a commodity like TVs, refrigerators, stoves and many other appliances. Doesn't matter which one you buy as they are all pretty much the same. If a panel goes bad all one has to do is loosen for bolts, unplug the defective panel and plug-in the new one. Certainly much easier than upgrading a computer.

author: Scrts
author_rank: Frequent Contributor
timestamp: June 23, 2020, 05:12:58 pm
content: Quote from: bdunham7 on June 21, 2020, 08:19:31 pmIt seems like inverters are optimized to certain panels, but in general all should work fine with any...

author: coppice
author_rank: Super Contributor
timestamp: June 23, 2020, 05:24:10 pm
content: Quote from: Scrts on June 23, 2020, 05:12:58 pmThat link is for microinverters, which are designed for one small inverter per panel systems. Microinverters are very much optimised for a particular panel type. They are popular in the US, but rare in most countries. Most inverters are designed to work with a flexible chain of panels, so they happy with a wide range of panel configurations that fit within certain power output constraints.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 23, 2020, 05:32:43 pm
content: Quote from: coppice on June 23, 2020, 05:24:10 pmSo isn't that that point? Solar panels are a commodity like a refrigerator, washer, stove, TV. They all come with more or less the same warranty, there are standard sizes and voltages. If one is defective it can be replaced with the same or another manufactures panel without any problems.

author: Bassman59
author_rank: Super Contributor
timestamp: June 23, 2020, 09:36:36 pm
content: Quote from: coppice on June 21, 2020, 04:35:21 pmOK, hmmm. I live in southern Arizona, which has 13 months of sunshine every year. So you can imagine that residential rooftop solar power is quite popular here. There are also a dozen or more different roof styles, based on what was popular when houses were built. Some roofs allow for simple panel-array installation. My house has a "built up" roof, which is basically layers of material sealed with asphalt with a reflective rubberized coating on top, all at a slight angle for rain run-off. Other houses have fancy clay tiles that make panel installation tricky but they're do-able with care. Other homes have standard asphalt shingles. Some roofs have steeper pitches than others (but we don't worry about snow load). And so forth.But here's the thing -- nobody's roof is 100% covered with solar panels. Not even close. Why? Because the panels on even a modest home will generate more than can be consumed. The excess is sold back to the grid. Of course at night, we pull from the grid. Now if we had batteries, the math would be the same -- the excess generated during the day would be stored in the battery for use at night. If you top off the battery, then what? (You might as well use the grid as your battery.)So my point is that I have about 1600 square feet of roof space and the solar array occupies only about a fourth of that. Is that "wasted roof?" There's no need to be clever and use all available space.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 23, 2020, 10:33:44 pm
content: Quote from: Bassman59 on June 23, 2020, 09:36:36 pmI'm in California with similar solar story but things are a bit different with our power company, PG&E. During the day, we get to sell excess power to the power company for $0.52 kWhr. Then later in the day, when the power company is selling power for $0.12 we get to buy that kWhr back for just $0.12 leaving us with a credit of $0.40 to buy electricity at another time. Or to put in another way, for every kWhr we "sell" to the power company during the day we can get back 4.33 kWhrs. This has got to be one of the best deals ever. Where else can you get a 430% return?The sad part is all of the solar "experts" I've talked to in California screw their customers. They tell potential solar customers if they consume say 12,000 kWhrs in a year they need to buy a solar system which produces a little over 12,000 kWhrs in a year. (This allows them to sell customers at least twice as many panels as the actually need.) The way they get away with this screw-job is to have the customer get on one of the highest rate plans the power company offers. Or even worse, see them a battery pack of two for another $10,000 each. The solar companies have the customers change the batteries during the day, when the power company is buying power for $0.52. And then having the batteries discharge at night when power costs $0.12 kWhr. The customer losses $0.40 on every kWhr. Isn't that a wonderful deal?

author: Scrts
author_rank: Frequent Contributor
timestamp: June 24, 2020, 08:28:24 pm
content: Quote from: DougSpindler on June 23, 2020, 10:33:44 pmSo wait, people use powerwall and batteries? I thought the most reasonable solution in such scenario is hook up microinverter under each cell and sell it during the day, especially when everyone is at work and the only electricity user is the fridge.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 24, 2020, 08:41:45 pm
content: Quote from: Scrts on June 24, 2020, 08:28:24 pmThat's what all of the solar companies and Tesla wants you to do. At a cost of $12,000 they want you to buy 2. Then with the tax break your fellow tax payers have to pay 26% of the cost while the solar companies collect 100% of the sales commission.

author: Bassman59
author_rank: Super Contributor
timestamp: June 26, 2020, 05:18:18 am
content: Quote from: DougSpindler on June 23, 2020, 10:33:44 pmArizona's net-metering rate was customers were paid the retail rate by the utility for power they generated, and for power they pulled from the grid they paid that same retail rate to the utility. Of course the utilities weren't having that, and the Arizona Corporation Commission (until very recently) a wholly-own subsidiary of those utilities, changed the rate so that customers pay the retail prices for power they pull but are paid the wholesale rate for the power they send back to the grid. People who had solar installs prior to the rule change are grandfathered in, but still.QuoteThe company we chose was the only one that didnottry to oversell a system. They also refused to do leases. I honestly think that what will kill solar faster than anti-renewables government and the incumbent utilities ratfucking are those ripoff installers. Talk about consumer confidence going down the drain.

author: DougSpindler
author_rank: Super Contributor
timestamp: June 26, 2020, 05:41:54 pm
content: Quote from: Bassman59 on June 26, 2020, 05:18:18 amAre you in California? Do you "sell" and "buy" kWhrs with your power company like I do with PG&E? Or do you trade or bank kWhrs with them?

author: Bassman59
author_rank: Super Contributor
timestamp: June 26, 2020, 09:12:25 pm
content: Quote from: DougSpindler on June 26, 2020, 05:41:54 pmArizona. We do the banking/trading. For the benefit of those who don't know how this all works, follow:We have two meters. One records what we generate, the other records what we pull from the utility and send back to them. The monthly statements show both numbers. If our generation exceeds our use, then the excess is put into our "bank." Our bill for that month is just the connection charges of about $25.If our usage exceeds our generation and we start to pull from the utility, we start taking out of that "bank." As long as we don't deplete the bank to zero, our bill remains zero (plus fees).If, during a month, our usage exceeds our generation and what is in our "bank," we are charged for what we pull from the grid at the retail rate. Last year, this never happened. Two years ago, for one month, it did, and our bill that month was about $70 ($45 usage plus $25 fees). That was, I think, in September, so we had built up sufficient reserves to get us through the heat of the summer with A/C. The October bill was back to usual and by then our generation exceeded our usage.After a year (which for us ends in September), if you still have power left in your reserve bank, the utility puts a credit on the bill for that amount, at the retail rate and the reserve balance is cleared.With everyone being at home this year for obvious reasons, our usage has gone way up, and I expect that the July and August bills will be non-zero.