In researching stage...

[Atokatim]

Well, after finding that wind power in my area is not reliable, I am moving on to solar energy.  I have read alot of things on SunElec.com but I would like to know a few good resources instead of just one.  Where are some good places to purchase solar cells or just panels.  I am looking to produce a minimum of 500 watts.  I know solar cells are being sold per watt, but enough research, I can find reliable and accurate solar cells.  From what I have read, I will need enough cells to produce 1000 watts just to produce a true 500 watts.  The battery bank more than likely will either be 24v or 36v.  Not 100% sure why some use 48v systems.  Still reading that.  As you can tell, I am a true newbie on this, so any help is greatly appreciated.  I am currently looking for the best "bang" per buck.  I don't want something cheap, but I want something that will last.  Ebay solar cells worry me.

[ghurd]

Better find some honest stuff about making panels from cells, that work very well for very long.
Books on CD advertisements are BS.

36V?  No, don't do that.
Find a 36V inverter.

http://www.solar-electric.com/

G-

[TomW]

First thing I will say is:

Good Luck finding a modern 36 volt inverter.

Unless you are just using DC you want to be sensible and go at least 24v volt and preferably 48 volt.

It is plain silly to start with an arbitrary system voltage with no reason behind it.

I don't have time to explain it all as it took me decades to understand the details of system design.

Just don't get locked in to any system voltage without some research. There are very good and valid reasons to stick with 24 and 48 volt systems. 12 volts is a toy and not very suitable for a system of any capacity. Some research should yield some reasons.

Good Luck

Tom

[Atokatim]

Thanks for the replies!  As far as the 24v vs the 48v system, I am a little confused on what are the advantages between the two.  Not all solar cells produce the same voltage for what I have read.  Running them 1 row in parallel, and each row in series will yield higher voltages and more amperage.  The question is, what solar cells are reliable so I don't have to replace cells all the time?  I want to first buy the cells and build my own panel or if price is better, buy pre-made panels.  After it is together, I can move to the controller, batteries, and inverter.

[ghurd]

The problem is not the cells, it is the housing.  Not very DIY-able.
'Homemade PV" and "something that will last" do not go together.

http://fieldlines.com/board/index.php/topic,135682.0.html

[Atokatim]

oh ok.  I see now.  The panels are the problem for durability....not the cells.  I have a friend down the road from me who has a large plastic vacuum mold machine that I thought could work wonders on this kind of project.  Apparently, moisture is a large problem in solar panels.  The problem is, if 1 or 2 cells go bad, I don't want to have to replace the entire panel.  Just sounds like a waist to me.

[DanG]

If you really want to get into it just for its own sake perfect the 3V module and stack them.

[ghurd]

The problem is also the cost.
Low lead glass. Frames. etc.
Can buy factory-made name-brand panels for $2.50/W.

If you want to do it for fun, I like the 3V panel idea.
Myself, I can think of things that are more fun, cheaper, and have a much higher probability of success.
That much soldering is tedious.

[birdhouse]

to help you out with your system voltage question-
you want 500 watt.  500 watts is roughly 42 amps at 12 volt.  you would need some pretty hefty wire runs to connect everything.  if you go to 24 volts, then you only have to manage 21 amps worth of current, and 48 volt system would only be pushing 11.5 amps.  as your system grows, the amperage for a 12 volt system gets pretty rediculous. 

watts = volts x amps.  you'll get really familiar with this formula as time goes on. 

hope this helps!

adam

[Atokatim]

Thanks for the clarification on the watts!

As for building my own.... I am not looking to build solar cells, I am just looking to build my own panels to hold the cells.  I am not that advanced to build the cells :p  I prefer to buy the cells from a respectable source and solder / wire them in together to form my panels.  I have 30 feet of roof to mount as many panels as needed.  With the high price of solar cells, I wonder if it is worth buying any off ebay or just shop around till I find some at a decent price.  I don't know where the best place to purchase solar cells is.

[Volvo farmer]

As for building my own.... I am not looking to build solar cells, I am just looking to build my own panels to hold the cells.  I am not that advanced to build the cells :p  I prefer to buy the cells from a respectable source and solder / wire them in together to form my panels.  I have 30 feet of roof to mount as many panels as needed.  With the high price of solar cells, I wonder if it is worth buying any off ebay or just shop around till I find some at a decent price.  I don't know where the best place to purchase solar cells is.

Why do you want to build your own panels, as opposed to purchasing factory panels?  Why do you want 500 watts of solar panels? What are you planning on doing with the energy that you produce? The answers to these questions might help people here understand your motivations and guide your research more accurately.

[B529]

With the price of solar panels dropping everyday, I would have a tough time justifying building my own frames... I would try to steer you towards complete panels with a long warranty.

I live offgrid, we are miles away from utilities. So obviously I have batteries. From my experience of baby sitting battery and their cost, I would suggest skipping the batteries and get a grid-tied inverter. You'll get more bang for the buck due to the inefficiency of the batteries/DC-AC conversion, especially with your usage of 90KW hrs a day.

I've installed a few grid-tied systems here in sunny Colorado, one of the systems is 3200 watts, it has averaged 500KW hrs a month in production for the last 3 yrs. Based on my own 2200 watts of battery charging solar array and what I net, I would give a rough guess of  60-65% of that 450KW hrs net if it was a battery based system.

What is your daily sun hrs?

[Atokatim]

well, I have 2 motives.  One is, I just got a $240 electric bill and I know I have the brains to get this bill lower.  
I have an all electric house and I would love to either,
A: supply enough power to help reduce my electric bill at least $100 or more
B: connect the panels to a controller which is connected to the power grid. The electric company pays for what I can produce. Minimum wattage is 500 watts.
C: Supply power to my house and dump any excess to the power grid.  (I doubt I could get to this point)

Purchasing pre-made panels have a few good and bad factors about them.
1 : It is tough to replace just 1 cell if it goes
2 : They are extremely expensive. Shipping them to my house is expensive as well.
3 : They are already built and that is less time I have to spend on them.
4 : They may last longer than home made panels depending on the quality.

If I built my own, I could save a little money and, if done correctly, I could build a durable unit that can last as long as a pre-made one.  This is what I am battling with.  
Should I even attempt to build my own panels with purchased solar cells?
It is more worth it to purchase pre-made panels and hope they are not broken or damaged in shipping?
What are some good affordable panels to get and where can I get them?
Is building my own controller ok to do, or should I stick with buying one?

I know I have alot of questions, but for now, I am just in the research stage.

[Atokatim]

With the price of solar panels dropping everyday, I would have a tough time justifying building my own frames... I would try to steer you towards complete panels with a long warranty.

I live offgrid, we are miles away from utilities. So obviously I have batteries. From my experience of baby sitting battery and their cost, I would suggest skipping the batteries and get a grid-tied inverter. You'll get more bang for the buck due to the inefficiency of the batteries/DC-AC conversion, especially with your usage of 90KW hrs a day.

I've installed a few grid-tied systems here in sunny Colorado, one of the systems is 3200 watts, it has averaged 500KW hrs a month in production for the last 3 yrs. Based on my own 2200 watts of battery charging solar array and what I net, I would give a rough guess of  60-65% of that 450KW hrs net if it was a battery based system.

What is your daily sun hrs?

I would love to live off grid, but coming up with the money to get to that point would be extremely hard to do for me.  What do you mean by skip the batteries and get a grid-tied inverter?  Does this mean to just have the solar panels directly connected to the inverter which is connected directly to the power grid bypassing my house?

The current daylight hours is roughly 8am to 7pm. This is when you can begin to see your shadow. Actual light is visible from around 6am to 9pm.  I live in a wide open area and the sun comes up on the left side of my house and goes down at the right side of my house.  The back side of my house is a solid roof with no angles so it sees daylight all day long.  I believe it is an ideal place to mount the panels.

[B529]

What do you mean by skip the batteries and get a grid-tied inverter? Yes Does this mean to just have the solar panels directly connected to the inverter which is connected directly to the power grid bypassing my house? Kind of, the inverter would back feed into your breaker panel. The AC output of the inverter will be connected to a breaker(s) in your breaker panel.http://www.sma-america.com/en_US.html Excellent grid-tied inverters. Look around on their site, check out their stringing calculator.

The current daylight hours is roughly 8am to 7pm. This is when you can begin to see your shadow. Actual light is visible from around 6am to 9pm.  I live in a wide open area and the sun comes up on the left side of my house and goes down at the right side of my house.  The back side of my house is a solid roof with no angles so it sees daylight all day long.  I believe it is an ideal place to mount the panels.
[/quote]

Sounds like you have a very good "solar window". Is your roof south facing? Do you have a compass to check precisely? Where do you live?

I have installed Sharp and Sanyo panels. Have Sharp panels on my system. A few of my offgrid neighbors have panels that are 15yrs old or older without a problem, I'm not too concerned about panel failure. I took down some panels a couple yrs ago that were over 20 yrs old, BP or Seimens I believe, still working. Scott from this forum or his neighbors are using them now. Have had several panels shipped to me going up our very rough long mountain road, not one panel has arrived damaged.

To build a controller/inverter? The SMA inverters have been around for a long time. Tough to beat. Excellent customer service.

Glad to read your comment about you doubt you can get to the point of dumping power to the grid. So many people I talked to about installing a solar/wind system on their home have unrealistic expectations, they have it in their head they will be making money by selling power back to the grid. It can be done, but it is very expensive and a poor return on your investment. The goal should simply be to reduce or eliminate your utility bill. That reduction should start with lowering your usage, you have control over that.

 

[Volvo farmer]

Let me help you in your research.

Average US electricity price is $.12/KWhr

Let's guess on 5 average sun-hours/day since we don't know your location.
http://www.wholesalesolar.com/Information-SolarFolder/SunHoursUSMap.html

The cheapest (Kaneka) factory panels are approaching $2/watt You CAN NOT build your own solar panel for $2 a watt. Trust me. BTDT.

I don't think you can get a 1KW capable grid tie inverter for less than $1600. a 1KW array would run at least $2000.

a 1KW array at 5 sun hours makes 5KW/day or $.60/day. You have now invested $3600 to save $18/month on your electric bill.  To save $100/month, you would need to invest over $12,000.

Costs I have not included:
Panel mounts
Wiring
Junction boxes and breakers
Labor for installation

There may be federal and other incentives to help lower your cost but I'm not going to research that for you.

If you really want to save money on your electric bill, you're going to have to break out your pocketbook!

[wooferhound]

I's almost impossible to make your own power for less money than you can buy it off the grid.

You talk very little about conservation. are you using all fluorescent lights, do you have proper insulation, are you cooking using mostly a microwave oven, are you adjusting the thermostat properly to limit cooling & heating, do you turn things off when you leave a room. without conservation first, you will be throwing your solar power away.

[TomW]

What Woofer Said.

Conservation first, then conserve some more. repeat.

Much easier to save a KWH than make one!

You might be amazed how much you can save with a few switched power strips, flipping off some lights and doing even a basic energy audit of your home. Some power companies will do it for you, too.

Just one immutable fact in RE: CONSERVE, CONSERVE, CONSERVE, REPEAT.

Good luck on the project. It is not rocket science but it is important.

Tom

[Bruce S]

What Woofer Said.

Conservation first, then conserve some more. repeat.

Much easier to save a KWH than make one!

You might be amazed how much you can save with a few switched power strips, flipping off some lights and doing even a basic energy audit of your home. Some power companies will do it for you, too.

Just one immutable fact in RE: CONSERVE, CONSERVE, CONSERVE, REPEAT.

Good luck on the project. It is not rocket science but it is important.

Tom

What TomW and Woofer both said to then nth degree.
I am on grid, and I can say I could not currently have a system installed and save $$$.
 I did just what TomW said, I grabbed a few power strips, and plugged "stuff" into those.
You can actually watch the little wheel on the meter slow down by using the power switches on the strips to turn off whole sets of "stuff".

Cheers
Bruce S

[Atokatim]

What do you mean by skip the batteries and get a grid-tied inverter? Yes Does this mean to just have the solar panels directly connected to the inverter which is connected directly to the power grid bypassing my house? Kind of, the inverter would back feed into your breaker panel. The AC output of the inverter will be connected to a breaker(s) in your breaker panel.http://www.sma-america.com/en_US.html Excellent grid-tied inverters. Look around on their site, check out their stringing calculator.

The current daylight hours is roughly 8am to 7pm. This is when you can begin to see your shadow. Actual light is visible from around 6am to 9pm.  I live in a wide open area and the sun comes up on the left side of my house and goes down at the right side of my house.  The back side of my house is a solid roof with no angles so it sees daylight all day long.  I believe it is an ideal place to mount the panels.

Sounds like you have a very good "solar window". Is your roof south facing? Do you have a compass to check precisely? Where do you live?

I have installed Sharp and Sanyo panels. Have Sharp panels on my system. A few of my offgrid neighbors have panels that are 15yrs old or older without a problem, I'm not too concerned about panel failure. I took down some panels a couple yrs ago that were over 20 yrs old, BP or Seimens I believe, still working. Scott from this forum or his neighbors are using them now. Have had several panels shipped to me going up our very rough long mountain road, not one panel has arrived damaged.

To build a controller/inverter? The SMA inverters have been around for a long time. Tough to beat. Excellent customer service.

Glad to read your comment about you doubt you can get to the point of dumping power to the grid. So many people I talked to about installing a solar/wind system on their home have unrealistic expectations, they have it in their head they will be making money by selling power back to the grid. It can be done, but it is very expensive and a poor return on your investment. The goal should simply be to reduce or eliminate your utility bill. That reduction should start with lowering your usage, you have control over that.

Yes, the back of my house is facing south.  Upon further investigation of my power bill, my average KWH per month is around 2,000.  I think 90% of that is my AC unit.  Now that I have that figured out, I need help on finding a solar panel set up that can reduce my bill by at least $100 or 1,000 KWH a month.  What I am not sure about is if a panel system is rated at 3000 watts, is this per minute, per hour, per day?  I know there has to be a formula to calculate what exactly I will need.

[ghurd]

Scroll down to "What is a Watt?"
http://www.econvergence.net/electrofaqs.htm

[Volvo farmer]

Now that I have that figured out, I need help on finding a solar panel set up that can reduce my bill by at least $100 or 1,000 KWH a month. 

Here's the formula:  Multiply how much you want to save per month by 200. Now withdraw that much money from your checking account and buy solar panels and inverters with it.  When you have spent all that money, go withdraw a few more thousand to get it installed.  

[Atokatim]

Now that I have that figured out, I need help on finding a solar panel set up that can reduce my bill by at least $100 or 1,000 KWH a month. 

Here's the formula:  Multiply how much you want to save per month by 200. Now withdraw that much money from your checking account and buy solar panels and inverters with it.  When you have spent all that money, go withdraw a few more thousand to get it installed.  

Lol... that is funny.  I know what I am looking for and what I know don't quite make sense, but it does to me at the moment.  By trying to make some sense of it, if I use 2,000KHW a month and I buy and install a 3000 watt system,  am I really helping the electric bill at all?

This is the math in my head :
2,000 kwh / 0.001 = 2,000,000 watts used a month
2,000,000 watts per month / 31 days = 64,516.13 watts per day (This is apparently 64 KW per day)
64516.13 watts per day / 24 hours = 2688.17 watts per hour

So if I only have, lets say, 8 hours of sunlight per day.  This would mean that if I installed at 3,000 watt system and it produces 1500 watts average, I could produce eliminate 1188.17 watts per hour for 8 hours which would eliminate 9505.36 watts per day.

I know my math is probably WAY off, but please feel free to correct me if I am wrong.  I need to know what I am working with before I jump into it!

[TomW]

Just to add a bit more spin to all this:

Most Panels will only actually make about 80% of the rated output in a direct charging system. More with MPPT but not sure if they get the full rating then or not.

You still have a few issues regarding KW AND KWH but you will eventually work it out.

Its that darned algebra they said I would need to survive. The H is a factor and must be preserved in all calculations of power over time.

Tom

[Volvo farmer]

Additionally, you need to research average sun-hours or solar insolation charts for your location. 8 hours is too large a number in most of North America, your number will be closer to 4 or 5.

You may have been amused by my comment, but once you work the math out for yourself, I bet you'll  find I am right in the ballpark on the money required to meet your goals.

[defed]

heck, i use 8KwH/day and can't even fathom getting off grid!  i got a kill-a-watt meter and most of my standby loads are minimal, tho i did find one that was 30w just being plugged in.  so it got unplugged real fast (720Wh/day).  my fridge uses about 3KwH/day, so i'm going to investigate how much more efficient one i can get at a reasonable cost.  have to check into LCD monitors to replace the CRT of my desktop which uses about 70w-100w while powered up (at least 450Wh/day for the time it's on per day).  was browsing fridges, and the few i checked specs on use less than 1KwH/day, so if i got one of those and an LCD that uses 30W (180Wh/day)...i could get my overall usage to about 5KwH/day (8KwH - 720wh - 180wh - 2KwH = 5KwH).  granted, to save 3Kwh/day would cost at least $600 (5 yr payback).

i'm messing around w/ turbines and solar now, but never expect to get off the grid...because grid power is so darn cheap.

you NEED to conserve!

[SteveCH]

Yes, unless you simply want the fun of making some of your own power from the sun, while remaining connected to the grid, or unless you want to spend $60K or whatever to get off the grid while living the same as you have been on the grid, it won't work.

However, if you are willing to change your stuff-that-requires-electricity to more efficient stuff-that-uses-less-electricity and shed a bunch of the same stuff that all grid families have, solar electricity is way, way cost prohibitive to anyone but the wealthy.

It can easily be done. We have a freezer, a 'fridge [both Sunfrost and 12 volt], a greenhouse with a swamp cooler and fans, lights, kitchen stuff such as a Kitchen Aid and etc., TV, stereo, several computers, washing machine, well pump, and so on and we don't feel like we are doing without. We are not grid-connected and we do this with about 2 Kw worth of panels [or, they make, in the method you were using to calculate, '2000 watts' if you are talking about peak production.]

If you are going to a) continue to use the appliances, etc., that you almost certainly have right now and b) are not willing or able to cut back on electrical usage in any case, the solar electric will be fun but not a solution.

However, I would not want to discourage you and would certainly welcome you to the pv life. The people I've seen fail in attempting to transition were either unwilling to change their usage or they had family members who were unwilling. One person I know is still doing it, living off-grid with PV, but she is constantly complaining about the ongoing battle with her three teens who, though they have grown up since day 1 off-grid, simply will not adhere to a conservative style when it comes to electricity use. [Things such as, they will stand in front of the open refrigerator for ten minutes, thinking about what they might want to eat. Or, using a hair dryer after sundown.]

[defed]

geez Steve....you use alot more stuff than i do!  and i don't feel as if i'm doing w/o.  i can't imagine what Atokatim is doing to use THAT much power!

my brother uses alot of power (power tools, laundry, HUGE fridge/freezer) and he still uses 'only' 13KwH/day.

[kurt]

we ran the air conditioner most every day last billing period and we averaged 18.5 kWh per day and that is way up from this month last year but it is allot hotter this year. but we are in northern IL. and we always turn the air conditioning  off around 10 pm and do not turn it on again until 10am to 12pm the next day when we start seeing heat gain in the house and it gets uncomfortable. we can do that because here in our area even on the hottest days once it has been dark for a few hours the outside temperature will normally drop lower than the inside temperature of our home so therefor all heat gain to the interior of the home stops and reverses and the home actually sheds a little heat through the night keeping the house at an even temperature allowing us to sleep comfortably with only a fan.

[defed]

ah yea, i think the OP said he uses the AC.  that is definitely a power hog.

[B529]

Where do you live?

If a potential customer here in Colorado was wanting to generate 1000KW hrs a month with a PV system. Based on the sun hours here and data from several systems I've installed, I would size that system with 6500 to 7500 watts of PV. depending on the panel selected.

[Atokatim]

Thanks for all the replies so far!

Yeah, the AC is crucial at this point because my wife is a 76 degree woman :p  The temp is always set at 76 day and night.  We do have a touch screen thermostat which can be programmed, but my wife fusses at me when I bump up the temp....especially when she was pregnant.  I really think the AC is the biggest part of our bill.  During the summer, our bill is around $180 to $210.  In the winter, since we have gas heat, our bill is about $60 to $80.

Currently what I use electricity wise in the house is:
2.5 ton 220v air conditioner.
A brand new refrigerator which is roughly 1.5 years old. Not sure how big it is, but when we put it in, I had to rip out a side wall.
All "10 watt" light saver bulbs everywhere in the house.
3 computers.  Not all are on at all times.  One is my main computer I use for programming and electronics (Stays on all the time).  One is only when we watch netflix movies online (Connected to TV). The last one is in the guest room.  My wife uses it occasionally.  It stays off most of the time recently because of the last electric bill.
Laser printer.  It is in "sleep" almost all of the time.
52" projection screen TV.  This is a newer one.  Got it for free...could not pass it up.
Home theater : 12" sub towers, 200watt.  This stays off most of the time unless we watch a movie.
A saltwater fish tank (75 gal) running 3 powerheads, heater, sump pump, protein skimmer, and a nice lighting system.  If needed, I could sell it to save....they are just nice to look at
A freshwater tank (10 gal) running clip on filter and heater.  No lights.  I could probably chunk that one out back.

I know alot of these could be cut out to save.  Not much stays on in the house since all I do is work on the computer in one room.  Here soon, just about everything will be off since I will be starting a new job next week and me and my wife will be gone most of the day.

And to answer a previous question, I live about 1 hour from Memphis TN but out in the country where it is quiet...for now.

[B529]

Don't know if any of these programs will help you, check them out.http://www.dsireusa.org/incentives/index.cfm?re=1&ee=1&spv=0&st=0&srp=1&state=TN

With your sun hrs, would probably bump up my estimate 10% for producing 1000KW hrs a month.

Do you unplug your stereo/tv when not using it? They are a huge ghost load.