Newbie with lots of questions

Mr. Prep

Hi everyone! I'm new to the idea of solar power and I'm creating a retreat location remote in the mountains. I know I can get a large amount of sun exposure and considering a grid tied/ stand alone system with a battery farm attached. I've done quite a bit of research and just have a few questions that would help me more understand. I plan on making the panels myself and have found a number of solar cell providers on the web. I am under the impression that like most things bigger is better, is this the case? I found 3x6 and 6x6 cells and the 6x6 seem to produce more amps and volts. Also which brand names are best?

Next is there a formula that will help me to determine how big, or how many, panels I would need?

Next in regards to batteries how many would I need? Which batteries would be best deep cell/standard, wet/dry?

Would it be best that the panels be fixed or movable?

When it comes to wiring, do I want thick wire, ie 8g, or do I want something thinner like 16g or 20g?


PLEASE, help me. Thank you.

Cariboocoot

Re: Newbie with lots of questions

Welcome to the forum.

Step #1: STOP! Do not spend a dime on anything. Plan first, buy later.

Some things about your post that indicate you have some more studying to do:

considering a grid tied/ stand alone system with a battery farm attached

If you've got grid, use it. Off-grid power is very expensive.
Terminology: you can have grid-tie (no batteries), off-grid (must have batteries), or hybrid grid-tie (includes battery back-up).

I plan on making the panels myself

Change the plan. You can not possibly build panels as good a quality or as inexpensively as you can buy them for. You can build some as a learning experience, but what you will learn is that you have better things to do with your time and money.

Next is there a formula that will help me to determine how big, or how many, panels I would need?

Next in regards to batteries how many would I need? Which batteries would be best deep cell/standard, wet/dry?

What you start with for an off-grid system is: How much power do you need to supply? Loads, loads, loads. It's all based on loads. Once you know that number you can size the inverter (if applicable), battery bank, and array to recharge that bank. Doing it otherwise is extremely frustrating and yields disappointing results.

When it comes to wiring, do I want thick wire, ie 8g, or do I want something thinner like 16g or 20g?

Wire size depends on two things: the amount of current going through it and the length. It is unlikely you will see either 16 or 20 gauge anywhere in a solar electric power system except for monitoring/communication. Think 10 AWG and larger. Think 0000 AWG battery wires. And also think "fuses".

PLEASE, help me. Thank you.

That is exactly what we're here for.

Mr. Prep

Re: Newbie with lots of questions

Cariboocoot wrote: »

Welcome to the forum.

Step #1: STOP! Do not spend a dime on anything. Plan first, buy later.

Some things about your post that indicate you have some more studying to do:

Lol that's what I'm doing and that's why I'm here. I haven't bought anything yet and don't plan to until I have EVERYTHING planned and designed.

If you've got grid, use it. Off-grid power is very expensive.
Terminology: you can have grid-tie (no batteries), off-grid (must have batteries), or hybrid grid-tie (includes battery back-up).

I had planned on using the grid and offsetting my utility cost, though if the grid goes down I have a solar back up. Wasn't sure if I needed the batteries or not. Thanks

Change the plan. You can not possibly build panels as good a quality or as inexpensively as you can buy them for. You can build some as a learning experience, but what you will learn is that you have better things to do with your time and money.

Well this part I'm not sure about quite yet. From what I've seen on the web I can have my columes set in an afternoon and everything wired and sealed in a weekend. As for cost I can get 100 6x6 cells for $80 or so, and as for glass, wood and solder I have, another $20-$40 in wire and I can build 2 panels. Are you sure I can buy panels that cheap?

What you start with for an off-grid system is: How much power do you need to supply? Loads, loads, loads. It's all based on loads. Once you know that number you can size the inverter (if applicable), battery bank, and array to recharge that bank. Doing it otherwise is extremely frustrating and yields disappointing results.

Could you be a little more specific on this, loads? What do you mean by loads and what is a load?

Wire size depends on two things: the amount of current going through it and the length. It is unlikely you will see either 16 or 20 gauge anywhere in a solar electric power system except for monitoring/communication. Think 10 AWG and larger. Think 0000 AWG battery wires. And also think "fuses".

Thanks that clears that up.

Cariboocoot

Re: Newbie with lots of questions

Panels: http://www.solar-electric.com/hiposopa.html
Look at that: as low as $1.13 per Watt. With a warranty, guaranteed to work. No mis-matched cells rejected by the manufacturer, no trouble soldering tabs, no incorrect glass cover, no poor-quality encapsulation that fails. Plus, they are legal for grid-tie use; homemade are not. No worries about an insurance company getting out of paying on a claim either.

Does your homemade cost include everything? Bypass diodes, aluminium frame, connecting wires, et cetera? And by the way "wood" does not enter in to building a solar panel.

Loads. Quite simply, what do you want to run? For off-grid this is the be-all and end-all for system design. For grid-tie it's a matter of how much energy demand you want to offset. For back-up power it's back to what you need to keep running when the power goes off.

For instance a refrigerator may consume 1 to 2 kW hours per day. If you want to keep that going when the grid is down you need enough battery capacity to supply that, and enough panel to recharge the battery.

Mr. Prep

Re: Newbie with lots of questions

Ok new question what kind of diode would you recommend? I find then ranging in $.10-$5 each, all various sizes and designs.

Cariboocoot

Re: Newbie with lots of questions

Typical bypass diode: http://www.solar-electric.com/8ampbypdiod.html
How many and where they are placed (electrically) depends on the particular panel design.

Mr. Prep

Re: Newbie with lots of questions

Ok 8 amps, but what's it's peak reverse voltage, the description doesn't say.

Cariboocoot

Re: Newbie with lots of questions

You just have to poke about a bit.
Full specs: http://lib.store.yahoo.net/lib/wind-sun/MUR-DataSheet.pdf
For the MUR1560 it's 600 Volts.

niel

Re: Newbie with lots of questions

Mr. Prep wrote: »

Ok 8 amps, but what's it's peak reverse voltage, the description doesn't say.

now that i hit the right button go to the details section and follow the link to the pdf spec sheet and you'll find what you want to know there.

Cariboocoot

Re: Newbie with lots of questions

If you're going the "build your own" route, try one first and see how you like doing it. Then when you have your system design finalized see how many panels you'd have to build to accommodate it.

Skippy

Re: Newbie with lots of questions

Cariboocoot wrote: »

If you're going the "build your own" route, try one first and see how you like doing it. Then when you have your system design finalized see how many panels you'd have to build to accommodate it.

Then put it up, and spray it with the garden hose for the final test . .

I know a guy who is going that route as well, will have to ask and see how it's going for him. . .

BB.

Re: Newbie with lots of questions

The difficult issue with DIY solar panels is thermal cycling... 100-185 degrees during the day, and sub freezing at night (for many locations). Add water and freezing, even worse.

The "typical" DIY panels seem to last a few months. If there are folks with DYI panels that last over several years--My hat off to them.

-Bill

conntaxman

Re: Newbie with lots of questions

Bill Im on my 3rd year with my diy panels 65 and 80 watt. made them the same as a thermopan window.

BB.

Re: Newbie with lots of questions

Conntaxman,

My hat's off to you!... Do you have a set of instructions that folks can follow to build reliable panels?

-Bill

Mr. Prep

Re: Newbie with lots of questions

My next question, what are the best cells? Mono, poly, or multi crystalline? Any opinion or reasons why?

Volvo Farmer

Re: Newbie with lots of questions

My DIY panels have been up for six years and they still make power. I also made them like a thermopane window. They all get moisture in them from time to time but I vented them and it eventually dries out in there. I would NOT do it again, nor would I recommend my construction technique. If you want to do DIY panels, there were some folks over at Fieldlines that wrote up very detailed instructions. They were doing it right, encapsulating the cells in EVA and baking the panels in a low temp oven.

Cariboocoot

Re: Newbie with lots of questions

Mr. Prep wrote: »

My next question, what are the best cells? Mono, poly, or multi crystalline? Any opinion or reasons why?

There are three panel types: amorphous (cheapest but also least efficient by far), polycrystaline (more expensive, but better than 2X the Watts per area over amorphous), and monocrystaline (most expensive per Watt, most efficient per square inch). Other terms used like "multicrystaline" are just terms for one of these three (in this case polycrystaline).

Which is the best? Pretty much a matter of $ per Watt weighed against area available for panels. RV applications, for instance, often have limited "roof real estate" and so you'd select the more expensive monocrystaline panels to get the most Watts in the space available. Polycrystaline panels are often the best over-all value, putting fairly decent efficiency in a reasonable amount of space for a reasonable price. Amorphous panels can be really cheap per Watt, but you tend to need twice (or more) as much area for those Watts. In terms of efficiency, amorphous panels are about 7% efficient, polycrystaline around 14 to 16, and monocrystaline about 18 to as much as 21 (Sanyo HIT).

There are some other slight differences in functionality, but such rarely has any bearing on the application.

BB.

Re: Newbie with lots of questions

I am not sure that amorphos panels with plastic (instead of glass) construction have more than a 10 year life... However, they are probably a bit more resistant to rocks and hard knocks (crystalline panels are 1/8" tempered glass--fairly strong until they get a sharp whack--then they shatter into a thousand pieces).

-Bill

Mr. Prep

Re: Newbie with lots of questions

Well I need the most efficient cells. This is a project that I'm working on here in Ohio but a learning tool to perfect it in another location that I'm custom building. I was told that I needed to know my loads to figure out how many watts and how many panels I would need. My household consumes 825-850 kWh/month that works out to be roughly 29 kWh/day. However, if I could get that number down to say half, maybe better, what do you think. 1) is that do-able? If so 2) how many panels at what watts would I need for both rates? 3) how many batteries would I need to go off grid? 4) what size inverter/charger would I need?

Cariboocoot

Re: Newbie with lots of questions

Half of 29 kW hours per day is 15. To get that off-grid with all the inherent losses of battery-based systems you are looking at about 7 to 8 kW of array. That is based on 4 hours of equivalent good sun (it isn't always good and it isn't always that long) and the usual 52% end-to-end efficiency.

A ballpark figure of what you'd need minimally: 1250 Amp hours of 48 Volt battery (for 25% daily DOD), two 3896 Watt arrays on two 60 Amp MPPT charge controllers. How big an inverter would depend on your maximum Watts and any given time. That is not 100% solar either, as you still need a back-up charge source if the sun doesn't shine on day 3 (25% DOD on day one, 25% more on day two, day three start the generator).

So it can be done. But it won't be cheap.

inetdog

Re: Newbie with lots of questions

Mr. Prep wrote: »

Well I need the most efficient cells. This is a project that I'm working on here in Ohio but a learning tool to perfect it in another location that I'm custom building. I was told that I needed to know my loads to figure out how many watts and how many panels I would need. My household consumes 825-850 kWh/month that works out to be roughly 29 kWh/day. However, if I could get that number down to say half, maybe better, what do you think. 1) is that do-able? If so 2) how many panels at what watts would I need for both rates? 3) how many batteries would I need to go off grid? 4) what size inverter/charger would I need?

Half of that, call it 15Kwh per day is still very big for off-grid. You would need a battery bank of at least 1000 AmpHours at 48 volts to support that properly, along with 4Kw or more of solar panels. Much more panel wattage if you will be using it as your primary power source during the winter.


But be sure to take any electric cooking, heating, water heating and clothes drier usage out of the 29Kwh right at the start, before "conserving", because you will end up using something other than electric for those loads when you are off grid.

PS: If you will be able to get grid power at your new location, even if it costs tens of thousands of dollars up front, do it, as solar will cost you far more in the long run.

PPS: What Coot said....

Mr. Prep

Re: Newbie with lots of questions

Ok, so....... I need to figure out OTHER alternative power sources. Anybody have any knowledge on other alternative renewable resources?

Gas/coal, water, wind, methane, ethanol?

conntaxman

Re: Newbie with lots of questions

Mr. Prep wrote: »

Ok 8 amps, but what's it's peak reverse voltage, the description doesn't say.

.
Have fun doing what you want to. Let me TELL YOU, that you wont find many that will give you credit for building your own panels. Most will PUT YOU DOWN.
Myself I give you credit,I have made so far about 1200 watts of panels, and their working for 3 to 4 years,.
Let me say this, don't use wood,wood will rot or let in air, and moist, I use glass on both sides,.Just keep asking questions and reading and surffing the net. Oh another thing, if you mention that you SEEN or was thinking of buying ANYTHING from over seas, you will get Jumped on, telling you that you are stupid,the product is no good, it will catch on Fire, not Ul approved, it's Junk, it won't work, it is not a MPPT controller , don't buy junk, and Don't SAVE ANY MONEY. I guess its kind of like " I have a cadillac " and that is the best car.
Also no one ever add's in the Shipping cost for the panels or other things.
I just wanted to tell you what to look for on some of the replies that you will be getting. I guess it's kind of like " well I spent 4 thousand dollars on MY controller, so it's THE BEST, and your's is junk/ [well maybe it will do the same, but I spent more then you.
You will have a lot of fun reading your answers for some.
I got to a point will only reply to some.
Have fun,,,good luck,,,, and I hope you save money...............oh I forgot one
your insurance wont cover it !

Photowhit

Re: Newbie with lots of questions

Somewhat worried your thinking you can still 'save money' going solar...

If you can make solar panels at $1 a watt or less, and there have been cheapers solar panels available with UL ratings, I had 4Kw delivered for about 85 cents a watt. That isn't the major part of your system;

You still will need an inverter likely $1500+, yes you can get a cheap modified sine wave inverter, but it's likely to shorten the life of things with motors like a fridge, microwave and use more current doing it.

Combiner box,Fusing(see E-Panel), wiring, your mounting system for the array, Charge controllers (figure $500+ and you'll need 2 likely), battery, those forklift batteries (alone will cost $4000 and up). Inverter, batteries, charge controllers, all these things need to be replaced from time to time....

conntaxman

Re: Newbie with lots of questions

Have gotten prices for / solar panels $0.51 per watt - -3000 watt pure sine wave with built in 40amp battery charger also built in transfer switch $420.00, 60amp MPPT controller $260.00
this yr prices

Mr. Prep

Re: Newbie with lots of questions

Conntaxman,

Thanks for the heads up, I appreciate it. I've always been a DIY kind of guy and I find that by DIY you actually do tent to save money. And as for the bashing I've already kind of figure that and may have experienced it already. I have NEVER spent more money on something then I have to, nor am I a person that has to have a measuring contest by spending money. As for insurance covering it I'm not worried about that. Thanks for the info and vote of confidence.

Cariboocoot

Re: Newbie with lots of questions

I hope that's good equipment you got those prices on. Otherwise you buy it twice. :roll:

(Oscar Wilde was right; I'm not young enough to know everything. )

Mr. Prep

Re: Newbie with lots of questions

Photowhit wrote: »

Somewhat worried your thinking you can still 'save money' going solar...

My biggest concern is NOT about saving money. It's about being independent. I don't care to spend money, so long as I know I'm getting what I'm paying for.

If you can make solar panels at $1 a watt or less, and there have been cheapers solar panels available with UL ratings, I had 4Kw delivered for about 85 cents a watt. That isn't the major part of your system;

You still will need an inverter likely $1500+, yes you can get a cheap modified sine wave inverter, but it's likely to shorten the life of things with motors like a fridge, microwave and use more current doing it.

Combiner box,Fusing(see E-Panel), wiring, your mounting system for the array, Charge controllers (figure $500+ and you'll need 2 likely), battery, those forklift batteries (alone will cost $4000 and up). Inverter, batteries, charge controllers, all these things need to be replaced from time to time....

Trust me I'm under NO illusion that I can build this system without spending money. As for "replacing" things like cables, batteries, controllers and what not. It's no different then having to do ANY kind of maintenance on any other household.

mike95490

Re: Newbie with lots of questions

Mr. Prep wrote: »

Ok, so....... I need to figure out OTHER alternative power sources. Anybody have any knowledge on other alternative renewable resources?

Gas/coal, water, wind, methane, ethanol?

Hydro (water) if you have a lot of water flowing, and elevation drop.

Wind, if you have to tie your hat on when you go outside.

Ethanol is not renewable, if you have to buy diesel for your tractor and cooker.

Bio-Diesel or peanut oil diesel could be used, but the crankcase oils are fossil based.

Photowhit

Re: Newbie with lots of questions

Mr. Prep wrote: »

Ok, so....... I need to figure out OTHER alternative power sources. Anybody have any knowledge on other alternative renewable resources?

Gas/coal(not renewable in the short term), water, wind, methane, ethanol(not much better than energy neutral on a large scale other than sugar cane...yet)?

If you have falling water, that makes a good source of energy, I don't do or understand wind, and it's intermitent everywhere I've lived, though 50+MPH gusts today testing my new array. (no problem)

You could 'go native', the way much of the world lives, heat and cook with wood(or brush, peat, dung), dry, smoke or can your extra food... You can get down to a very minimal solar system to provid lighting.

Conntaxman - I'm impressed with anyone making their own panels, just don't think you can do it cheaper than buying panels. I would also question if they would last as long, though a double glass design is likely to seal them well, but glass at what cost, picture framing glass is more than a $1 a square now, and it's not tempered..., 100 watts of solar cells @$40, aluminum framing material $??, junction box with wires $12-15, tabbing wire, solder, neutral medium. I just can see more cost than what you can find premade panels. If you find it fun, premade panels will not give you that, if you can do it cheaper with recycled glass, that's actually really cool! Maybe you'll just find this one of your fun replies...

Mr. Prep

Re: Newbie with lots of questions

Photowhit wrote: »

If you have falling water, that makes a good source of energy, I don't do or understand wind, and it's intermitent everywhere I've lived, though 50+MPH gusts today testing my new array. (no problem)

You could 'go native', the way much of the world lives, heat and cook with wood(or brush, peat, dung), dry, smoke or can your extra food... You can get down to a very minimal solar system to provid lighting.

Conntaxman - I'm impressed with anyone making their own panels, just don't think you can do it cheaper than buying panels. I would also question if they would last as long, though a double glass design is likely to seal them well, but glass at what cost, picture framing glass is more than a $1 a square now, and it's not tempered..., 100 watts of solar cells @$40, aluminum framing material $??, junction box with wires $12-15, tabbing wire, solder, neutral medium. I just can see more cost than what you can find premade panels. If you find it fun, premade panels will not give you that, if you can do it cheaper with recycled glass, that's actually really cool! Maybe you'll just find this one of your fun replies...

I find it one of the fun little replies, but that's just me. Lol