Off Grid Home Forums Technical Discussion Off-Grid solar panel project NEED HELP!

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    Hi everyone! My name is Jeff and I am about to go into the world of solar technology. OK so here is the low down…

    I have yet to build a panel but I do plan to buy some cells off of Ebay to build one. I am going to start very small for my first couple of tries but after I get the hang of it I want to go full scale. I use ruffly 2kw’s a month and I want to make a 5 kw solar panel system. I want to have plenty of electricity for my house but also have a nice chunk left over to pump back into the grid so I can get a check each month from the electric company.

    I understand the basics of how to put the cells together to make a panel from watching YouTube videos however here in where lies the problem(s). I don’t know what to do from there. Like I watched the videos for the battery farms and stuff like that but still don’t understand how I am going to get it all wired together and what all I would even need. Can anyone help me with the following list of stuff?

    1. If I built a bunch of panels, how do I tie them all together?

    2. After tying them together, what comes next? I read about you’re supposed to have a diode? or a controller? Huh?

    3. OK I got a diode now, how do I connect it to the panels?

    4. OK I got a controller, how do I hook it up or does it come with instructions that make it obvious/easy?

    5. OK I hooked up a diode/controller.. now what? Do I go to the battery farm or to a grid tied inverter?

    6. If I went to the grid tied inverter, should I use the one that plugs directly into the electric panel on my house or are the ones that just plug into a regular receptacle OK?

    7. OK assuming that you say that I am supposed to go to a battery farm first.. how do I connect that to the diode/controller that came prior?

    8. Assuming you say that I am supposed to go to an inverter first.. how do I connect that to the diode/controller that came prior?

    9. Whatever the right choice was between questions 7 and 8, what is the next step?

    10. And in summation.. how do I get the inverter to pump the electricity back into the grid and get me money?

    SO! There it is. There is of course the fact that I may have not mentioned any of the other stuff that I would need and if anyone could help me with a step by step way of connecting all of this stuff (and anything else I didn’t mention) I would very grateful.

    So is there anyone out there that can help us out? Thanks y’all!

    Just thought of another question.. how much area would I need to have a 5kw system? I saw this here and was wondering if I have enough land to mount all of this stuff. I got a house and going to have a shed, got a backyard that’s a nice size. Hoping I wouldn’t have to have acres of land to pull it off.

    :) Jeff :)

    ~Jesus rox~


    hooboy, lots a questions Jeff.

    First thing I see that needs clarification is you state that you use 2kw’s a month.

    Kilowatts are a unit of power, it is an instantaneous measure. Power expressed over time is watts per hour, or kilowatts per hour (kwh).

    I find it very difficult to imagine that you are only using 2kwh’s per month.

    A 5 watt device(maybe a small radio) if left on 24 hours a day, for a month would use 3.6kwh’s, nearly twice what possibly your stated usage is.

    So, please confirm how much power you use monthly. You need to define that before getting in too deep.

    I have built one panel in my life, in college back in 1980. Techniques have improved since then, but unless you are extremely tight on money, or want to say you did it. It is much better to latch on to commercial built units. Homebuilding a panel and making it weather proof to where it will last 30 years will be a major challenge.

    I have stuck to commercial panel since. My current system has a power rating of 2.2killowatts of PV. On a good day I have produced close to 12kwh’s, on a bad day, well that is what the batteries are for :)

    There are poster’s here that can answer some or all of your questions. Just need to take it in small bites.



    OK just looked at my bill and it says that I use ruffly 63 kwh’s a day


    Also I wanted to add that though I am a noob, I know I can make some shallow weather proof enclosures for the cells to lie in. Just waiting to see everyone suggestions on getting me to produce crap loads O energy :)


    I am guessing at 63 kwh’s a day that you are all electric? That is about 10 times my daily average. I have gas cooking, water heater, clothes dryer and have all phantom loads on power strips. Y

    How are your soldering skills. The solar cells are very fragile, expect to break a few.

    Somewhere between building that first test panel and gettnig to your crap load of energy production you may want to analyze where the 63kwh/day are going. Invest in a kill-a-watt meter, google it if you are not familiar with it. It lets you see how much you are using on a given device over time.

    Got to get back to work, will try to follow up more. Keep hoping someone else will chime in though.



    Thanks Bob!

    Yeah I’m mostly electric, however also use natural gas.

    Soldering skills are decent, I just bought me a nice new iron speaking of.

    I witnessed on youtube how breakable these things are and yeah your right.. these things look quite fragile.

    I know what a killOwatt is and am looking forward to getting one.

    Much appreciated Bob :)



    After reading your original post I would suggest doingsome review of basic series and parallel circuits. This will answer may of your questions.

    Many newcomers to solar power assume 12V is the way to go. Be aware that most of the newer systems use higher voltages such as 24V, or 48V this has to do with efficiency and wire losses. If this sounds confusing add this to your list of homework studies. Sorry but there is no way around this. If you do not understand electricity and the fundamental principles behind it you need to learn before commiting to expensive projects.

    Now that grid tie systems are becoming popular you will even find 120V or 247V solar panel arrays being offered. These are intended for direct conversion by special inverters to feed into the grid so you can make a “crap load of money” as you put it. However such installations require some pretty good engineering and workmanship to be accepted by the power utility companies. I saw my first grid tie synchronouse inverter back in 1978. It stood four feet high, weighed in at 250 kbs and had a power capacity was 5 KW. Xantrrex the company I used to work for now makes one that capacity you can fit in a carry all at around 40 lbs. The power levels you intend to work with requires a thorough knowledge of electrical system knowledge and safety practices associated with these systems. For your own sake learn how to do this safely to avoid electrocuting yourself.


    OK sounds great.. now for this 48v system or whatever power for that matter..

    could you shoot me a list of stuff to buy, kinda like a solar power grocery list?


    actually nix that. I have now researched and feel like a complete idiot lol

    But I think you already knew that eh? hehe :P

    I did a bit of learning and have figured that to do what I would want I would have to run more than I was even thinking. So now I am going to go down scale a bit. I want to have a battery farm so we can at least supplement our bill. Thanks bob! :)


    Well! ILMAO! It felt like I was freekin speed reading that original post. And the whole time, thinkin to myself, “is this guy typing that fast too?”


    I hope you decide to nix a few of the power hungry appliances you have using up all that much electricity. Thats a lot! My rental home in town with electric heat doesn’t even match that & our tenants have a big screen plasma TV on every time I go there.

    But I used to dream about selling off exztra electricity too. I think a lot of us, used that line as an “defence phrase” every time somebody else who knew even less than ourselves, would question our judgement about going off-grid!


    A good question was posed here a while back. Given the best available commercial panels figure on you needing 5 square meters to produce one kilowatt of energy from the sun. This is assuming the panel is pointed directly at the sun and the panel os perfectly clean and the skiesn are totally clea.

    If the sun hits the panel at an angle or the sun is low near the horizon or dust has collected on the panel surface you will get less power.

    For what its worth experienced power managers have sucessfully lived on a solar array of around 500 watts capacity. A 1000 amo hour battery bank and a 2500 watt inverter while enjoying a almorst normal lifestyle with electric lights a few kitchen appliances and a fully equipped computer station with a wiFi link. This does assume you cook with propane and heat with wood and do not require full time airconditioning. There will always be someone who can manage with less ( more credit to them) but for the average faminy trying to off-grid on solar the transition cam be difficult enough to cope with. Peak demand loads such as a deep well pump will require more power than the inverter can supply so a generatlor boost is needed. These pumping periods using a generator can be combined with doing laundry. Both appliances have higher water and energy demands. It makes sense to carry these out during periods of abundaant energy and water supply times.


    I live with solar and microhydro power, and teach PV as well, and I would encourage you to take a class in off-grid solar design before really DIY’ing too much.

    Your local community college might offer something useful, or you might check out Solar Energy International at They’re my ‘competition,’ but may have some online courses that are reasonably priced. If you’re on the east coast, I’ll be at Rutgers March 7-11, 2011 teaching PV there and would welcome you. See for details about that class; I contract through them to various educational institutions.

    @elnav has offered some good advice – but if you’re going to make your own power, a safe and reliable system really requires the investment of time needed to understand your power system. NEC Code compliance (2011 code) has changed to require “qualified persons” install any PV system and all 50 states require NEC code compliance.




    Here I go, about to dump more cold water on ya Lampshade, sorry… I have heard about those who want to have a solar farm on their house to sell excess back to the electric company and get checks from them…

    First issue, depending on what state you live in, your electric company might not pay you for the excess, only giving you credit on your bill, AND of those who would do that, they pay/credit you the wholesale price, not the retail price you pay them per kilowatt hour.

    Next issue, to be grid tied, I doubt the electric company would allow anything that wasn’t commercially built, UL certified and installed by a licensed electrician to be connected to their grid. That’s for safety purposes.

    People think they can make their meter spin backwards and get paid, nope. IF you live in a state where you could get a check or credit from the electric company, they require a separate meter to determine how much you are pumping back into the grid, you would be charged for this separate meter.

    Each state is going to have different rules and regulations about these things, it’s up to you to research and learn what you can do in your location.

    Good luck, not trying to stop you from living your dream, if this is what you really want to do, then do what it takes to live your dream, don’t take no for an answer, even if that means moving to another place with fewer regulations about what you want to do, that’s what my hubby and I did. Bill is right too, take some classes if you can, the more you can do for yourself, the better off you will be and the cheaper it will be for you in the long run.



    First, you need to figure out how to reduce your usage. It is cheaper to insulate, weatherize, new windows, new doors, an HRV, energy star appliances, cfl, led, and plasma lighting, and change to conserving habits. Saved kilowatts are always the cheapest option. After this is completed, then one has to analyses the actual needs that are left and all the local regulations, rebates and payback schedules in the local area. Your utilities, local government, state government, and fed if applicable should have that information. A contractor that does this type of work should be able to give you the information as part of a bid. This is where you need to get to before considering what you should do next. You can build panels for about $1 a watt if you scrounge and are resourceful. You can find free old patio doors to use as the glass and frames. You can buy brand new panels starting at about $1.40 a watt. Note that you must consider space requirements, mounting conditions, solar aptitude of the location, type of roof, and other factors before you can determine the type of panels that are appropriate. The rest of system costs can run from 1 to 5 dollars a watt depending on all of the above and a few other considerations. So what is it that you are trying to do?



    Build your own solar modules? Don’t. It took 40 years for the state of the art to reach the point it is at today, where the encapsulation technology, UV resistant laminates, waterproofing, etc., last for decades. You can buy this state of the art for $1.40/Watt. Build your own for $1.00 a Watt and you’ll replace them annually, since you can’t buy the right stuff to package PV cells into a module that will last in a rooftop environment of -40 to +90C wet/dry.

    As for the rest of your questions … a good week-long PV seminar will answer them all. I teach this stuff all over the country but my home-base is a local community college in Colorado where my classes, that sell for $1600 per student elsewhere, cost $98 due to state tuition laws. Look around your area for an intro solar PV design class at a local community college – it will be, by far, the best investment you make – in your own skills and knowledge.

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