Will the solar class please come to order

[Domeguy]

1. Overview
OK class settle down, and you BWRR, stop pulling LADYHK's hair and take a seat. Now, I am Professor Domeguy and I will be your instructor for the remainder of this class. Now lets get started. Who can tell me what a bypass diode is? Any one, no, how about a polycrystalline wafer, still no one. OK, one last one, who can tell me what a maximum power point tracking charge controller does, we'll guess what, it doesn't mater. In this little class we will show you the basics of solar electric and solar thermal hot water, as to how they are custom designed, manufactured, installed, and used in each individual setting. What works for your neighbor may not work for you. We will cover subjects such as how to do a site survey to find out where or if a solar system can be used at a certain site. You may find the perfect site to put the system is the worst place it could possibly be. Did you know shading on the panels, even on just one, reduces performance by an amount proportional to the level of shading. A 10% shading effect reduces the energy gain by 10%. And in a worst case scenario, a 10% shading can reduce the energy output by 90%. So what does all this mean, sun good, shade bad.
So after we find the best place to put the array, then what? Well I'll tell ya, we will get into that in more detail later.
Together we will find out how many panels are needed and do we put them in parallel or in series. We will do a load analysis to see how much electricity is used in a day, a week, a month, and a year.
After we determine the size of the array, we will then choose the inverter. Will we use 1 large inverter for the whole system, or choose to have a small inverter on each panel.
We will cover what size wiring is needed as to cover any voltage drop, where to put the ac and dc cut off switches, and the rest of all the goodies that make a safe and happy solar powered home.
Now somewhere along this happy little project, some one will come along and say they want to be off the grid. So what do we do then? Now we have to consider how we are going to watch the reruns of Matlock on channel 14 at 7:00pm. So now we have to figure out a battery system to power the tv to tune into Matlock, while we heat up out microwave dinner.
Hopefully when we are done with out site survey, selecting the right system for our needs, and installing it, we will do the system checkout and inspection. This is where it gets serious. Until now we have been playing with a giant puzzle. There has been no electricity flowing through the wires. You should NOT...I repeat NOT make any final hook ups. I would strongly suggest you call in an electrician or your local code office, and see who they need to send over and to certify everything is hooked up correctly and SAFE. Then a certified person will come over and charge you about a thousand shackles just to throw a switch. But just think about that for a minute or two. Even if just one wire is hooked up wrong, and you are tempted to try it out yourself, your next of kin could be going through your will to see if they get the house.
I don't want to seem like I am over simplifying everything. I have been doing small plumbing and electrical projects in each home I lived in. My first real project was installing a shower in a bathroom that only had a bathtub in the early 80's. I installed ceiling fans here and there, replaced wall switches that would go bad and such. I always seemed to have a "green thumb" when it came to for home repairs. I watched This Old House for over 30 years and others like the DIY channel. I learned by watching and by doing, but always small projects. Fast forward to 2005. Somehow I convinced a bank to loan me a lot of money to build a house when I had no experience, and no blueprints. I had always dreamed of building my own home, with as little outside contractors as possible. But I also new my limitations. I knew I couldn't lay my own foundation and concrete block...some times I just didn't have the right tools, and others, the right knowledge.
I subbed out the foundation, siding, HVAC, and at the last minute, my wife told me she would not be able to lift and hold the drywall, so I subbed that too. I also subbed out the roofing, although I did help out a lot on the roof. We did everything else ourselves, the floor joists, subfloor, framing, windows, doors, tile floors, fixtures, sinks and toilets and electrical and plumbing. I even cut my own granite countertop. This scarred the crap out of me, because if I made one wrong cut, it could crack, and I would have wasted 4 slabs of granite. I had no room for error.
I say all of this, not to brag, but to show I knew my limitations. I knew what I could do, and what I could not do.
Take a good long look at yourself before you try to do any of this. You should not be working with any live electricity, but there are plenty ways to get hurt, or even die.
KNOW YOUR LIMITATIONS AND DON'T GET HURT

[Katrina]

present. Is the wafer the little black things on the solar panel?

[ElevenBravo]

Here sir, please... continue with the lessons.

EB

[Domeguy]

present. Is the wafer the little black things on the solar panel?

That would be correct, and with that answer the teachers pet gets a gold star on her wall chart..

[bacpacker]

I'm here DG. Let the learnin begin. BTW, please don't grade me on my spellin.

[Domeguy]

I'm here DG. Let the learnin begin. BTW, please don't grade me on my spellin.

It's a deal, as long as you don't grade me for my writing.

[Domeguy]

2. Site survey
Well, has anyone dropped out yet? I hope not, I'm sorry, who did...well we didn't need them anyway, he smelled like cheese...I don't like cheese. So in this session, we will have a little math involved in it. Math is not one of my best subjects, but since I have a book in front of me with all the answers underlined, it's good to be me.
Now lets discuss that big hot yellow thing in the sky. No, not the Jiffy Donut sign, the other big yellow hot thing. But that was a good guess. I remember my first time I ever went to the
Jiffy Donut store. I had just bought my first car, a used 76 Honda Civic. I was just cruising and enjoying life...that's when I saw her. She was the most beautiful woman I had ever see. She was over 6ft. tall, had long blond hair down to her waist, and she had the biggest set of.........sorry, I got lost there for a minute. So where we're we, yes, thank you ...big yellow hot thing, THE SUN. The sun pumps out energy all day and all night. Yes, the sun is still working at night, just on the other side of the world. It just keeps on going 24/7, 365 days a yr. I guess it must have a lousy union. The energy reaches us as solar radiation. The term for the solar radiation striking a surface at a particular time and place is called insolation. When insolation is discussed as power, it is expressed as anumber of watts per sq. meter,and is usually presented as average daily valuefor each month. On a clear sunny day, the total insolation hitting the earth is usually determined to be about 1000 watts per sq. meter. But other factors can take a good easy number to do some figgurin with and screw it up, there by having less insolation to work with. Assorted atmospheric conditions such as rain, snow, sleet, flying green monkeys and clouds nor dark of night will keep us from our appointed rounds....no, no, no, sorry, that's the Post Office, but I think you know what I mean. Also you need to factor in the earths position in relation to the sun, ie. summer=more, winter=less. Also factor in obstructions at the site. Peak sun hours are the numbers of hours per day when the solar insolation equals 1000 w\ m2. For example, 5 peak sun hours (peak hrs. are between 9 am-3pm) equals 5kWh / m2. OK class, now if everyone would get out your calculators and lets get ready to do some math. What I need you to figure out how happy I am someone has already done all the math for us (remember, I don't like math.). The website to the National Renewable Energy Labratory Resource is http://rede.nrel.gov/solar. The site will have all kinds of information that will keep you up at night with excitement, no BWRR, not that kind. The have already run the numbers for us, and it will look a bit like this.
Http://img580.imageshack.us/img580/3741/a9s0.jpg
I will use the location closest to my home, which is Huntsville, AL.http://img194.imageshack.us/img194/1348/vegz.jpgo
So we will leave the numbers for a while and go outside for recess, no, it's a hypothetical recess.
While we are outside, we can use this time to hop and skip on down to your local utility company, and find out what kind of paperwork you need to be filled and any permit fees paid. I would also check in with my local townhall/courthouse and ask around there who you might need to talk to for paperwork and permits. You don't want a cease and desist order shutting you down. And for the biggest piece of BS, you will need to check with your Home Owners Association. They may be the worst to deal with and be more restrictive than the permit people. This may be a good time to take up smoking and drinking again, and if you never started, the is no time like the present.
So, lets take a close look at this roof of yours, or if you know the array won't fit, or just want to have it on poles in the back, We can look there also. If you don't know by now, I live in a geodesic dome my wife and I built ourselves, and putting an array on my roof would be impossible. You will want to know how long has this roof been on this structure. Are the shingles cracking, splitting, curling up on the edges, or the granular material on top of the shingles is missing, than it may be time to replace your roof before you start putting up things that will soon need to come down if you put up new shingles. Older homes may still have the original shingles on them, and while you are checking the roof, now is a good time to checkout the attic for leaks, sagging roof structures, and also check the trusses, as they may need to be added on to for a stronger roof that will stand up to most everything. BANG, I thought you were falling asleep there on me...so to recap for the night school, what do we have. We have checked out the local and state electrical codes and paperwork, and we have determined the roof is still in good shape. So, where do we go from here?
Yes, you I the back with your arms waving madly. You must know the answer by seeing you jump around...oh, yes, you can go to the restroom,and speaking of restrooms, Guys, never while you are standing at the urinal, turn to the stranger standing beside you, look him straight in the eyes and ask him "hey buddy, does this look infected to you". Trust me, it won't end well.
More to follow about the site survey tomorrow. So tune in tomorrow, same bat time, same bat channel.

[4suchatimeasthis]

Thanks! Great stuff so far!

[Brownwater Riverrat 13]

BY the way............I like smell of cheese. Now....that was great training Master "sun" I would much like to learn more. Preach on....

[Domeguy]

Well, it looks like one of you little rugrats has somehow gotten into my %#^*%#%= computer and erased tonight's %#*{%#+% lesson. If you think you will get that easy, you are so *^%#^*£ mistaken. I can write the ¥€*% thing again. HA HA HA HA HA...see you tonight.
Sniff...sniff...it still smells like cheese in here!

[ElevenBravo]

the teachers pet gets a gold star on her wall chart..

That right there is straight up BS, a gold star on the second day of class. I think your flirting!

[Brownwater Riverrat 13]

I'll pay to watch Domegal whoop his ass for that! I believe that would be considered a "solar flare"

[Katrina]

Thank you professor. Guess something I read stuck.

[Domeguy]

Spring break. Somehow with my 4yr old grandson running and acting like a fool, tonight's lesson has been eaten by the neighbors dog..we will pick it up again tomorrow. But in the mean time, for homework, I will need a 3500 word theme, single spaced, front page only, about how you have the most wonderful instructor in the world. Feel free to mention all the other accomplishments I have had on this big blue rock, such as being an ace fighter pilot, world class animal trainer,(mostly hungry tigers), solar installer to the British Royal Family,
General Chin, the first emperor of China, Fred Taylor, my neighbor down the street, and Marilyn Monroe.

[Domeguy]

Thank you professor. Guess something I read stuck.

http://img41.imageshack.us/img41/2047/35sh.jpg
Congratulations Katrina

[Gunfixr]

Actually, I already knew I needed a new roof.

And to cut down many of the neighbors trees.....................

[bacpacker]

Aw crap, we done went and sceered the teacher off!

:rolleyes:

[Domeguy]

SILENCE.....................class is now in session. If everyone would please pass forward your homework essays........quickly......quickly please.....I haven't got all day....well, actually I do, but I'm mot going to tell you that....Hahahahahahahah...oh, you heard that..........
Well, we have covered checking the roof for damage prayer to installing our solar array, Because???...yes Katrina,........very good, because we don't want to take it all down again just to fix the roof. You get another gold star.
We discussed solar insulation which as you recall is the solar radiation striking the earth at the site. Also important to know is the sites latitude. Latitude (the distance north or south of the equator) determines whether the sun appears to travel in the northern or the southern sky. The earths distance from the sun, and the earths tilt also effects the amount of insulation available. The earths latitudes are tilted towards the sun from June to August, which is what we call our summer. We experience the longer summer days with the more favorable tilt of the earth, and we get to welcome the long,hot and muggy days and sultry, steamy nights...settle down BWRR. http://img547.imageshack.us/img547/9572/qx63.jpg http://img600.imageshack.us/img600/4254/y3fa.jpg http://img841.imageshack.us/img841/8782/l9hv.jpg
Once a day the sun rotates on its axis, which is tilted approx. 23.5 deg. from the vertical. The suns apparent location east or west of true south is called azimuth. At Possum Hollow Dome, we are 2-3 deg. east of true south, places in Maine are 18-22 deg. East of TS, and California is from 13-19 deg. West of TS. Sense there are 361 deg. In a circle, and give or take, 24 hrs. The sun appears to move 15 deg. In azimuth each hour. Magnetic south (on a compass) and true south are not the same thing. A compass aligns with the earths magnetic field. The deviation of mag. South from true south is called declination. The daily performance of an array will be greatly enhanced if the array is facing true south. The suns height above the horizon
Is called altitude, which is measured in degrees above the horizon.

[Domeguy]

Seasonal changes of the suns altitude must be considered to optimize a systems performance, the following outlines the optimum tilt angle of a PV array for different seasonal loads.
For a year round average load ------tilt angle equals the latitude at instillation.
For winter month loads---------------tilt angle equals the latitude plus 15 deg.
For summer month loads-------------tilt angle equals the latitude minus 15 deg.
So with that being said, don't worry to much about it. Why. Because I said so.
The reason being the roof angle. I didn't discuss this during the roof inspection because I didn't want to have a spoil alert. This is the coolest part ever...it's gunna be like your having a mind trip...like to Bora Bora, like to Tahiti, or even like Boise, Idaho....so are you ready for this...cuss it's some heavy shit man....OK, here it is......the roof angle can be used instead..WHOA.....BOOM......Blown away.....see....I told ya. Unless you live in some ridiculous kind of a building like a geodesic dome.....You can usually let it slide, I mean tighten it down first, then let it slide, not like slide, but like sliiiiiiiiiide. Also, I have to take this time to tell you it is also a lie you must have the array facing
100% true south. What are you gonna do, move the entire house. The part about shading is true...remember those immortal words, shade bad, sun good. You don't want the array shaded if at all possible, but the rest isn't rocket science, well I guess the panels on the space station might be considered rocket science. You can fudge 5-10 deg. here and there, and not loose too much efficiency, because double redundancy is built in later, it's not rocket sc.... What ever. This would be a good place for a picture. And maybe a cheese sandwich.http://img13.imageshack.us/img13/8913/yjg7.jpg http://img801.imageshack.us/img801/2854/qm9w.jpg http://img833.imageshack.us/img833/8689/3ymk.jpg
The closer you can get everything to perfect all the better, but, and this is a really big butt.....haha..I said big butt. You would have to be outside all the time moving each panel to be perfect all the time. That is why a lot of people set it up for 2 changes a year, summer/winter, or install it once and never move it again, average for the year. See...it's all starting to make sense now isn't it!...or is it?

[Katrina]

The area I am planning on putting the panels/shingles is in the sun all day long ( southside of garage roof and house roof) and the angle of the roof would be okay with possible adjustment of panels for the weaker winter sun, correct?
The back of my house faces south all day long, am considering solar shingles so it won't be too obvious that we will have alternative power source but that's for another lesson thanks

[bacpacker]

I have a question, but you haven't gotten to that point in class yet. I will post it so you can plan it into the class.

My roof line is totally wrong to mount panels to. When we get to the point of moving toward solar, I plan to mount an array on a post and rack system. My question is, How far can I have the panels from the house without suffering too much line loss? I expect to use a very large gauge wire to try and improve my odds.

Great class so far!

[Gunfixr]

Ahhh, Katrina.
The shed.
Why didn't I think of that?
The house is shaded by the neighbors' trees, but the shed, well, it's open to the sun year 'round. Not as much space, but open.
I already have power routed to it, so there's already a line running between the shed and house.

[Alas Babylon]

I second bacpackers question. My roof is full of solar pool panels, so the electric will need to be somewhere else. I have some (800watts) on the barn roof at perfect angle for year round in Fl, but they get shade in the AM from the neighbors huge pine trees. youd think on 6 acres you would not have "neighbor trees problems" but you still do (at least at the barn)

[Domeguy]

No class for the next day or two, due to Mother Nature taking a huge crap in my backyard.

[Gunfixr]

That's ok, not a serious hurry.

Get your personal stuff straightened out first.

[cwconnertx]

Line loss will be a function of distance, wire size, and voltage (or current, higher voltage = lower current at a given power level)

The fact is that with MPPT charge controllers or modern inverters you can run pretty high voltages on your panels and not worry too much about line loss even with normal household sized conductors. You can also have an inverter at the pole if you wish, they make inverters which can take the weather, and you can run 220 volt AC back to the house (or wherever you like)

With proper design anything is possible, however with average components, and assuming you don't want to mount an inverter at the pole, the closer the better. I would try to keep my wiring such that I could use common 10 gauge wiring and not resort to anything exotic. At 100 feet, with a 15 amp load, you lose about 3%. If you wire your panels at 100 volts, 15 amps or less (<1500 W strings) you can use 10 gauge at 100 feet without too much concern. I would use smaller strings, and even consider higher voltage and lower current myself. Of course all the time we have to comply with electrical code as well, so even if the loss is acceptable, the design will have to comply with electrical code.

Without knowing the exact intentions for size of the system, purpose, and such its hard to give a hard and fast rule, how far is too far? They transmit AC electricity 100s and 1000s of miles, but I assume you don't want to have transformers on both ends of the transmission line.

I don't want to take over class here, but I had a little time, and have experience with solar systems, prior work as an electrician, and an electrical engineering degree that I don't get to use too often anymore.

[Domeguy]

That's ok, not a serious hurry.

Get your personal stuff straightened out first.

Not really personal, I had a large dead tree come down from the ridge directly behind the dome. It missed hitting everything( dome, 2 heat pumps, ladder) and missed the eave of the roofline by 1 inch.

[Domeguy]

No trouble at all, and in fact you should be running this. You are more qualified than I am, and i am going on information that is several years old. When I got to inverters, and voltage drop, I was going to do some research on them, especially with the micro inverters and the same with the pole mounted racks, as I to don't have any roof space with my dome triangle roof

[Domeguy]

Teacher comes back tomorrow, and he will be so glad to see all the good little students

[cwconnertx]

Teacher comes back tomorrow, and he will be so glad to see all the good little students

Sorry to hear about nature crapping in your yard, I had a tree fall last summer in a storm and spent a day in 114 degree heat cutting it up.

Even a 12 pack of beer couldn't keep me hydrated :) (and 15 liters of water and 6 quarts of gatorade, still didn't urinate all day)

[Domeguy]

That's just too damn hot to be working outside in the sun. Where was this tree growing.....on Mercury?

[cwconnertx]

That's just too damn hot to be working outside in the sun. Where was this tree growing.....on Mercury?

Close... we just call it Texas.

Though the official temp at the airport was only 109 that day at DFW. The thermometer on my porch (in the shade, as required) read 114.

It takes a 12 pack of beer to make it bearable.

[Domeguy]

So, lets get this party started. But first, I would like to apologize for my tardiness from the classroom. I went to a second neurologist who gave me new medication that interfered with other meds. already, and have made me feel up was down, right was left, Eleanor Roosevelt was really an attractive woman, black was white, etc. I didn't feel right enough to have you playing around with electricity on my watch, but besides the chronic insomnia, (notice the time) I'm good to go.
Who can tell me where we left off. No BWRR, that will be covered next semester in sex ed. class.
But first I would like to answer a few questions. Katrina, you are correct. As long as the roof is facing southish, with the correct roof racks can be adjusted to give the optimum angle. And Bacpacker, you and I are both in the same boat. I have an excellent place for my solar hot water, but the solar photos. not so much. I am going to have to put them quite a distance away, of ask my neighbor if I can buy or lease a small piece of his dairy land. My other option would be to place them on a pole mounted system. If CWC didn't answer your questions, you can pm me, and I can give you my number, and that goes to all my beautiful students in the beautiful world of Weblandia
Now, it's back to work. Today, I hope everyone has their thinking cap with them, for today, we will be working with my arch enemy, the thorn in my side, the Kryptonite to my soul, yes, I'm talking about MATH! May the good (insert name of god, lord, favorite deity or sacred animal here) take pity on us.
It will be easier for me to just copy a few pages rather than type them.
http://img842.imageshack.us/img842/2137/48fq.jpg
http://img35.imageshack.us/img35/2489/b8du.jpg

[Domeguy]

Now a little teaser about volts, amps, watts, watt hours, series circuits " and parallel circuits.

A volt- is the unit of force that causes the electrons to flow through a circuit.

An amp-is the unit of electrical current flowing through a wire.

A watt- is a unit of electrical power equal to a current of one amp under a pressure of one volt.

Watts- indicate the rate at which electrical energy is used or produced.

Watt hours- to calculate watt hours, there are two things you need to know, the appliance, light bulb, ac unit, etc. and the estimated time the appliances all added together.

Series circuits- loads wired in series, result in a voltage drop that is additive. The total voltage drop is equal to the sum of all the loads in the circuit.

Parallel circuits- as loads are added in parallel, the voltage drop for each remains equal to the source voltage.
Now is a good time for a few pictures.
http://img822.imageshack.us/img822/8931/ph1y.jpghttp://img850.imageshack.us/img850/6664/2b8s.jpg
http://img834.imageshack.us/img834/6949/iwkr.jpg

[Domeguy]

Series vs parallel
Series wiring connections are made at the positive end of one module to the negative end of another module. When loads or power sources are connected in series the voltage increases. Series wiring does not increase the amperage produced.

Parallel wiring connections are made from the positive to positive and from negative to negative between modules. When loads or sources ade wired in parallel, currents are additive and voltage is equal through all parts of the circuit. To increase the amperage of the system, the voltage sources must be wired in parallel.

Systems may use a mix of series and parallel wiring to obtain the required voltages and amperages. It's picture time.
http://img443.imageshack.us/img443/4586/fobw.jpg
http://img405.imageshack.us/img405/9676/ehd6.jpghttp://img853.imageshack.us/img853/3778/21t3.jpg

[bacpacker]

Good breakdown DG!. You sound like an electronics instructor.

[Domeguy]

While rereading my posts from several days ago, I realized I forgot to include how to find shading problems, but more importantly how to find that perfect spot. One was is with that demon script, those who practice that dark art call it math. But who wants to use that.
There a few devices on the market. But what I believe to be the most popular and cheapest is the Solar Pathfinder. Here are a few pictures of mine.http://img560.imageshack.us/img560/383/vym3.jpg
You set up, get it pointing north, and get it level. Then you take the white wax pencil and trace the outlines of anything
Showing in the reflection of the top globe. The black sheet has a grid pattern that showers each month and the time of day while the sun is up. You then count the numbers that are NOT in the shaded numbers in the month you are wanting info on. They can add up to 100 in a perfect world. You can understand it better if you look up solar pathfinder on youtube for a demo. You can buy them on amazon and eBay...I bought mine an eBay a few yrs. ago.
A picture of mine set up on north side of property.
http://img545.imageshack.us/img545/3892/hbxi.jpg
The light area with the sun in it is the area you will count
http://img706.imageshack.us/img706/3999/iu7k.jpgthis one is from the west side of my garage
And one from the north east side of property
http://img547.imageshack.us/img547/4535/ezlg.jpg

- - - Updated - - -

If you wanted to borrow mine, I'm sure we can come to some kind of an arrangement.

[ElevenBravo]

DG, seams as though you have some level of education in Electronics, so we have something in common there! Im an electronics hobbyist, have been for over 20 years... but Im self taught.

Ill want to see what details you have on charge controllers, Id like to build one based on a Pic microchip to make it smart but dont know enough about them at this point to build one.... Solar is not the same as mains so Im sure there are some differences in HOW the smart charge controller is going to work.

EB

[Katrina]

Now here's where I get lost. What do I add up? The wattage,volts,hours on each thing I want to use?

[Domeguy]

I had a long posting to answer just that question, but lost it to a computer problem. I am helping my son move back to this area, as he is trying to get full custody of his son. I will be busy with that tonight and tomorrow. I haven't slept in close to 40 hrs, so now would not be the best time to reply, but I can promise you I will in the next day or two.......ps, does anyone know how or where is a good site or program to write with, and when done, copy an paste, for the ipad
Domey.

[Katrina]

No problem do what you need to do. We're in similar situation with son 1 Prayers for you and son.

[Domeguy]

That's a great question Katrina. You get another gold star. And just in case anyone has lost count, Katrina - 3, everyone else ... O
So I hope you have all your pencils sharpened, because today, we meet up again with my grand nemesis, MATH.
Now here is where it gets a little tricky. There are many formulas dealing with electricity. It seems some people tend to get a little pissed off when their home burns down, just because I forgot to carry a 2. The main formula we need to be concerned with is a seldom used piece of math genius called :
"OHMS LAW"...(insert the sound of overhead thunder). Here is a pictorial rendition sticker they gave us in electrical school. http://img5.imageshack.us/img5/3010/gabk.jpgAbout 3-4 years ago, I enrolled into night school (industrial electricity.)
And while I am posting pictures, ill just put up a few more we will use in a little bit.
http://img546.imageshack.us/img546/4558/62vs.jpg
.
http://img545.imageshack.us/img545/5055/ap2u.jpg
.
http://img196.imageshack.us/img196/4031/kz1j.jpg

[Domeguy]

Another is called the PIRE wheel, which added one more element to the equation, resistance which is expressed as R.
http://img600.imageshack.us/img600/5563/3uml.jpg
But to answer the question, ummmm, I forgot the question. Did it have something to do with cheese? ummmmmm. Oh yeah, what do you need to figure out your watt usage. You will be using this chart, which is easy to use, and if you get the info. from the manufactures tag, you won't need to use any of that stupid old math.


Now, please remember these numbers are only estimates. The actual numbers needed should come from your appliances. But I understand you can't always get to the manuf. label, such as on a ceiling fan hanging down from the center of a 50' dome. And remember, anything such as a dish washer, a refrigerator, a ceiling, anything with a motor, the minimum surge requirements may be calculated by multiplying the required watts of a load by a factor of 3.

[Domeguy]

I've been standing here for more than 5 minutes, waiting with my hand up, with all 4 fingers pointed up. Who can tell me what I was doing with them up in the air? Yes BWRR, I'm sorry, could you speak up a little louder.....No, I hadn't put then there, and we will have to wait until next year for anatomy class to see if that is even possible. Yes Katrina, I was waiting for the class to get quiet. You have just earned another gold star.
Now as I recall you had asked about what is needed to make a load analysis. Lets take a look at these two manufactures labels. I believe by law, every electrical appliance must have one on it
http://img14.imageshack.us/img14/6742/8ftp.jpg
.
http://img197.imageshack.us/img197/9981/7a3w.jpg
We can now see all of the information we need.

[Domeguy]

The one on the top is from my toaster, and the second is from the food dehydrator. From the top label, they give us 2 of the 3 we need.
We know it has 120 volts, and 3.2 amps, and we don't know the watts. And to answer your question Katrina, we need the.........? Right again, we want the watts. And to get them, we...............any one?...............no? We go over to the power triangle. If you have 2 of the
3, you can cover up the one you need, and then do what the magic triangle of Tibet tells us. If you need to know the the voltage, and the current and power is known, just cover up the E, for voltage,and you have the formula of P/I, or P over I. If you need to know the current,
You would cover the I, which leaves P over I, or P/I. And if you needed to know the watts (P), cover the P, and you are left with I times E equals P, and this is what we are looking for WATTS. Great, big, ol stinking watts. So back to the label with our new found knowledge of the mystical circle of cheddar cheese, I mean triangle of power. So throwing all logic out the window, we just look MATH in the eye, and stare him down. Never before have we seen a more pathetic looser, and leave him bleeding, (or oozing something )in the gutter. But, we are better than that, aren't we, I saw he'll no, and go back to kick him in the ribs, while yelling at him, with a rage I have never felt before.
It felt good to have defeated math, and I spent the rest of my life touring the circuit with the circus, at every stop, recalling my life story, culminating (with great terror in the children's eyes) in the death of math. And they all lived happily ever after. THE END
And if we multiply(P) 3.2 amps times (E) 120 volts, we get 384 watts. And we couldn't have done it with out the magical blue orb of enlightenment, I mean the magic thingy.
And for the vaccum sealer, looks like again we have only volts and amps but want the watts. So, what do we do? Cover the P and multiply the other two, to let us know how many watts or being reduced.
Now we need to know the watt usage of your home. I prefer to get an average for a week or two.
Another way is to look at your electric bill, which you saved right...right... RIGHT? OK, we can also just call up your local neighborhood power company and request a copy for the last year.

[Domeguy]

So here is the formula you will need to do the load analysis you start in one room, and write down on the chart, (I included a blank one above) every piece of machinery you have in the room that uses electric power. Don't forget if the appliance is on a dimmer switch or a timer, but the main thing to remember is if you have a moter in the appliance, triple the endings arts as an overprotection. And lastly, plan ahead for what may be your last days. You need to plan ahead to figure whomever may own the house someday. You may have all boys, and the next owner may have all girls. Throw in a live-in maid and you have your lover the Brady Bunch.
Well , good night, or looking at the clock, good morning. Damn this insomnia. Ill see you later...what do you mean..........I still didn't give out the formula. OK, here it is...mix 3 parts pig blood with two parts,......no, that's Domegals' Halloween punch.
On the top of the sheet, it has room for the most important info. on every individual load, anything using electricity. This chart only shows my bedroom. I would suggest starting with the largest item in the room' and then work in a circle of the room. Then do all the rooms, each one at a time. I wish you would focus, your jumping around like a mad man. The formula is Qty x volts x amps = Watts x use hours per day x use days per wk DIVIDED BY 7 day wk.


On my load analysis of my bedroom, the treadmill, box fan, ceiling fan, and the vacuum have their single watt use, and tripled for surge requirements.

[Domeguy]

Here is your first quarter test. No cheating
http://img703.imageshack.us/img703/7791/br2k.jpg
http://img841.imageshack.us/img841/9453/wvsb.jpg

[Domeguy]

SPOILER ALLERT*********SPOILER ALLERT***********SPOILER ALLERT
Answers for the quarter test. NO CHEATING
http://img585.imageshack.us/img585/9126/xbsm.jpg

[bacpacker]

Dang I got them both right. Must be a good teacher we have here.

[Domeguy]

Wow...I've got to pay more attention to the auto speller. Sorry guys if a lot of it doesn't make any sense. If anyone has any questions, please let me know on the forum page or pm me. Thanks.

[Domeguy]

Today we are going to discuss SOLAR THERMAL. Solar thermal, (ST) uses the suns rays to heat a fluid, and then the fluid is used to heat a heat exchanger, and the bleed off from the heat exchanger is what we are looking to harness for our needs. The heat can be used to heat the water, baseboard heating, in floor heating, a greenhouse, etc.
I hope everyone did the exercise to find out how much electricity they are currently using, and are looking for a way to decrease their electric bill. Lets pretend you calculated all your electrical wants, you will want about a 5000 kw system just to take care of your current needs. It's possible, with a few lifestyle changes, ie. turning off the lights when you leave a room, that kind of a thing, you will find a fair decrease in your electrical consumption, and possibly only needing a 3000 kW system if you took the electric water heater, and switched it over to solar.
I guess here would be a good place to put some boring statistics about ST. Did you know, if you are building a new private residence in Hawaii, you must, by law, install a solar water heating system!
So we are going to supplement our electrical needs by installing a solar thermal hot water system. A solar thermal system (sts) not only heats the hot water in your home, but can (if you want to) also be used to heat the home in the winter, your green house, or even to heat your pool.
There are two main types of sts installed these days. There is the evacuated tube system and the flat plate system...both have their good points, and both have bad points. It's kind of like being a Ford or a Chevy guy...except for the fact that anyone who drives a Chevy is a poopie head. So, flat plate, good and bad you say, well do tell. A flat plate system is usually a box of some kind, usually aluminum with a clear glass or plastic top. It will have a tube or tubes, usually made from copper, and painted black along with the inside of the box, snaking its way through the box (approx. 75-100 feet with a 1/2 - 3/4 inch diameter ) absorbing heat through conduction. The heated water can either rise to the top of the collector or collectors through convection heating, whereby the hot water will rise to the top of the system, thereby pushing the cold water to the bottom, causing a kind of rotation through the system. But 99% of the time a pump is used, along with a few extra gadgets, but, I will get into that later. There is nothing wrong with flat plate hot water systems. They are very simple, easy to build and operate, low in cost to make, but just are not that efficient.
In the case of evacuated tube water heaters, first they start with a double walled glass tube which is about 6ft long, with a vacuum in the middle, just like the older glass thermoses. Inside the glass tube is a special coating that absorbs the suns rays and transfers that heat very efficiently to the fluid inside the copper pipe. http://img27.imageshack.us/img27/4311/5hz8.jpgAs the heated fluid gets hotter, it turn into a gas and rises to the top of the tube and the heat is transferred to the manifold, along with all the other tubes, and heats the fluid traveling through the manifold.http://img801.imageshack.us/img801/4635/h6wl.jpg
Another feather in its cap, is the efficiency of the tube itself. Since the tube is, well a tube, it can absorb the maximum amount of the suns rays at any angle, unlike the flat collector, is at its maximum efficiency only when the sun is at a 90 deg. angle to the sun. The glass tube system is much lighter than a flat plate system, so installation is much easier. A flat plate panel has no insulation to keep the water hot, whereas the glass tubes have a double glass wall with a vacuum in between the glass. What is the down side, well the glass can break. Most companies will send a couple extra tubes along when shipped, in case of breakage while in shipping, installing, or for the general use. If a tube does break, (I have handled mine a little rough, and have never broken one) at least you don't need to worry about losing any fluid, as all fluids are inside the copper tubing. These systems are very efficient, but do cost more than flat plates.
So what else do we need to install a sts. Besides the collectors on the roof, you will need insulated pipe to run from the panel to the water tank, and back again. And while we are talking about the water tank, you will need a heat exchanger of some kind to collect the heat, and transfer it to the cold water. This is a heat exchanger.
http://img38.imageshack.us/img38/3764/f7u9.jpg
I would recommend instead to have a water tank that has the heat exchanger already built inside it. The water tank will have 1 or 2 (in the case of a duel tube heat exchanger), and a food grade antifreeze mixed with water is circulated by a pump, pushing the af/water through the panels and bringing back the warmed fluid to release the heat into the cold water. Sometimes this system is used as a preheater along with the regular water heater, so the regular water heater will always have hot water to be fed into it, so the heating mechanism doesn't come on as much. This is a heat exchanger inside the water tank.
http://img196.imageshack.us/img196/2899/7l4j.jpg
http://img32.imageshack.us/img32/5458/22n9.jpg
In the case of a duel heat exchanger, one line is used to circulate the af/ water, just as above, and the other line can be used for radiant baseboard heaters., under the floor heating, ran outside to heat the green house, hot tub, etc. A pump, either powered by home electricity, or by a small solar panel, is generally accepted as the standard. A control system of some kind is needed to tell the system to turn on and off the pump to keep the fluid at the correct chosen temperature. Besides all the fittings, shut-off valves, gages, etc. you will also need a small pressure tank to hold excess overflow due to heat expansion.
With the newer types of evacuated tube collectors, the system is often all together with the tubes mounted on a metal rack with the water tank mounted horizontally on top of the rack with the tubes underneith. This type is mounted on a FLAT roof, and use gravity as the source or pressure, and are very popular in southern Europe and Asia, and warmer climates. In North America, Canada, and Northern Europe, especially where slopped roofs are used, the panels are clipped onto a special rack, and bolted to the sloped roof, and the tubing is run to where the tank is located. This system is also a pressurized system, so you will have good pressure for that long relaxing shower. The closer the tank and the panels are the less heat loss will occur. Well, you have just wasted about 1/2 hour of your life reading this, and I hope this tiny bit of knowledge is useful.

[Domeguy]

Here are a few pictures I took last week to show you how hot the water will get. The tube is 2 ft long, and is empty inside the core. I poured water in the tube from the kitchen sink.i started at 12:08, with the outside temp at 79, and a water temp of 68 deg. The tube is in full sunlight for the entire test on a plastic chair, as is the clock with the thermometer, in full sun. The thermo overloads after about 1/2 hr in direct sunlight. Inside the tube is a metal thermo with a 6 inch stem, which is emersed 5 inches into the water. I have placed a piece of foam rubber into the opened tube to serve as a holder for the thermometer and to create a little bit of insulation. The pictures speak for themselves.
http://img191.imageshack.us/img191/5328/lkn3.jpg.12:08---water temp. 68 deg


http://img841.imageshack.us/img841/153/cu26.jpg. 12:10---water temp 96 deg


http://img21.imageshack.us/img21/9830/ocvm.jpg. 12:15-- water temp 110 deg


http://img14.imageshack.us/img14/2876/bvj8.jpg. 12:21---water temp 127 deg



12:23--water temp 135 deg
http://img826.imageshack.us/img826/6585/ylyh.jpg
End of part one, so far, water temp has risen 67 deg in only 15 minutes.

[bacpacker]

DG, This last post showing temp gain is amazing. I would have never guess you would get so much so fast. That is a effcient system to get gains like that.

BTW, good description of the ST system differences and pros and cons. Solar water is certainly as high on my list of wants as charging systems are. More research is in order for me here.

Thanks

[Domeguy]

Depending on the price of instillation, of which you can still get 30% back from "the man." Most installations are going to be around 3-5K. Still a bit heavy, but depending on the size of the family, and the family's usage, a ST hot water, should pay for itself in 2-5 years.
As far as efficiency goes, you ain't seen nuthin yet.

[Domeguy]

I'm sorry these took so long to post.
12:37---160 degrees
http://img843.imageshack.us/img843/6629/wy31.jpg
12:39---165 degrees
http://img51.imageshack.us/img51/8519/i1h7.jpg
1:00----185 degrees
http://img818.imageshack.us/img818/7616/b8an.jpg
1:22----200 degrees
http://img196.imageshack.us/img196/3328/ki4f.jpg
1:27----205+ degrees
http://img844.imageshack.us/img844/6813/0t0d.jpg

I have had this tube filled with water and gotten the water to boil (212 deg), only to have any styrofoam insulation melt. It starts to melt at 212 degrees.
Remember this tube is only 2 feet long while the real ones would be 6 feet long. This tube had only water, and only slightly insulated at the top. The real heating unit would have 20-40 tubes (depending on size of family) filled with a gas that when hot, will rise in temperature and release its heat at the manifold. If a tube gets broken, it's not a big deal. I think all companies will ship an extra 2-3 tubes just in case any have broken during shipment. There also will be no leak, as all fluids are kept inside the copper tubing, not the insulated glass.

THAT IS A TEMPERATURE CHANGE FROM 68 DEG TO OVER 200+ DEG IN A LITTLE OVER 90 MINUTES
FROM JUST THE ***SUN***

WHAT'S NOT TO LOVE

[Domeguy]

Lets talk inverters.
When Thomas Edison was doing his experiments with DC electricity, an unknown man by the name of Nikola Tesla was doing some of his own experimenting with something he called alternating current, or as it would later be known, AC.
The trouble with DC power is that too much current is lost in transmission of the power along a wire line. For DC current to work, Mr. Edison would have had to build a DC transmission plant every 3 miles. AC current can be carried by wires for hundreds of miles before any voltage drop is significant.
Solar panels generate only DC power, and batteries only store DC power, so it's a win/win situation all around right...wrong, because here in the US, and many other countries, only AC power is generated and used as the standard.
So what do we do now...I'd say its time to look into an inverter. So you tell yourself, self, lets go get an inverter. But what kind of inverter...a big one, a small one, a blue one, or a green one.
There are 3 categories of inverters, grid-tied, grid tied with battery backup, and stand-alone. Another classification for inverters is the type of waveform they produce, which are square wave, modified square wave, and sine wave.
The square, and modified square inverters I won't go into as they are not used in the modern solar installations we use in the home systems.
Sine wave inverters are used to operate sensitive electrics that require a high quality waveform. They are the most common inverters today in the residential application and have many advantages over modified square wave inverters. They are specially designed to produce output with little harmonic distortion, and therefore being able to operate the most sensitive electronic equipment. They have high surge capabilities and can start many types of mothers, handling the power surge quite easily. For grid-tied applications you must use a sine wave inverter. When installing a inverter, if the output of the inverter is 120V, the installer needs to verify that there is at least one spare single pole breaker in the service panel to back-feed, and if the output is 240V, you will need a double pole breaker to feed back into the circuit box.
If you are buying an inverter off of the Internet, be sure to check and make sure it is IEEE and more importantly UL listed as approved, as an inspector may refuse to let you turn on the system, or worse, make you disassemble the entire system. Here is a good spot to reinforce the fact you must follow all local and federal laws and codes to be able to pass your electrical inspection. Plus you will be able to sleep at night knowing the house won't burn down in the middle of the night.
A grid-tied inverter will push all of the electricity being produced into the electric panel, unless it is producing more electricity than is needed, then it converts the excess power into the grid, and selling it back to the utility district, usually at a higher price than they would charge you. This is called "net metering". I have heard of some places like CA where the power is charged to the user at different prices during a 24 hr. period. The panel owners will program the inverters to power the home when the price is low, and to feed back to the grid when prices are higher, there by making a profit by doing nothing.
A grid-tied system with a battery back up will be more complex because excess power will want to be sold back to the power company, while at the same time need to charge the batteries, and feed power to the home, all at the same time.
A stand alone system produces power from the array straight to the motor being used, such as pumping water from a well to a pond. The pump will only work when the sun is out, and it slows down during a cloudy day, no harm, no foul...unlike your home.
Now for a little test to see if you we're sleeping during this exciting lecture.
http://img853.imageshack.us/img853/8625/wvhq.jpg
Good luck...the next post has the answer...no cheating.

[Domeguy]

Here is the answer...easy right? I hope so





Wait for it...




http://img594.imageshack.us/img594/6797/y7z4.jpg

Did you get it right, I hope so...see this stuff is easy.

[Domeguy]

And now, for a quick electrical cartoon!

http://img203.imageshack.us/img203/4154/wwx0.jpg

HAHAHAHAHAHAHA

[bacpacker]

Now your starting to sound like one of my teachers from school. :)

That does male you think about calculations in a design.

[Domeguy]

Ok guys, school is back in session after a few minor medical issues, nothing too serious.
So where to begin..I guess I will discuss batteries and charge controller. So what is a battery, it is an electrochemical cell which has the ability through dark magic to store energy in chemical bonds, and is released through white magic as electrical energy when a battery is connected to a load such as a flashlight, an electric motor, a microwave oven, etc. Solar panels are often paired with batterys to store the energy produced by the PV array and supply it to electrical loads as needed. They will also supply power to electrical loads at a steady and predictable voltages, and help to supply surge currents to electrical loads or appliances.
There are two basic classifications of battery's, Primary and Secondary. A Primary battery can store and deliver energy, but CAN NOT be recharged and as I'm sure you can see why, this type of battery is NOT to be used with a PVC system. Secondary batterys CAN store and deliver predictable electric energy, and can be recharged. So what have we learned so far...primary non rechargeable BAD, secondary rechargeable GOOD.
SLI battery's (starting, lighting and ignition) are secondary batterys are designed for shallow cycle service, and can be severely damaged by meme rouse deep discharges. They are designed for mostly automotive us. They contain a large number of thin plates per cell, and provide high current discharge for short period but lack the mechanical strength to sustain many deep discharge. More later