# Home Solar System Schematic

Hi this is Amy at the altE Store. We sella lot of solar panels for DIY offgrid solar projects. Generally when we design a solarsystem, we start with your loads, what you are trying to power, and from there you figureout what size solar panel you need. We’ve got lots of tutorials walking you through thecalculations . But now we are going to look atit the other way around, what can you power with a 100W solar panel? A solar panel israted by the amount of power it creates at Standard Test Conditions, or STC. These conditionsinclude the intensity of the sun, 1000 watt per square meter, the angle of the light hittingthe panel directly, the temperature, 25â„ƒ

or 77â„‰, and other criteria. So as they say,actual mileage may vary, based on all of these factors in the real world. So we generallyreduce the calculations based on the difference between the lab setting and your actual installation.When a 12V solar panel is rated at 100W, that is an instantaneous rating, if all of thetest conditions are met, when you measure the output, the voltage will be about 18 voltsand the current will be 5.55 amps. Since watts equals volts times amps, 18 volts x 5.55 amps= 100 watts. Watts is like the speed of a car, miles per hour, how fast is it goingat that instant, 50 miles per hour. To figure out how much power is generated over a periodof time, you can to multiply the watts times

the number of hours it is running. So in onehour, 100W x 1 hour = 100 watt hours. Again, with your car, 50 miles per hour x one hourequals 50 miles. Now that we know the math behind it, we need to figure out how manyhours to plug into the equation to determine how much power the solar panel will generatein a day. How many hours of sunlight that is equal to the intensity of standard testconditions, which is basically the sun at noon, will the solar panel be exposed to duringthe day? The number of hours of sunlight equal to noon is called sun hours.As you well know, even though the sun is up at 8 in the morning, it is not as bright asit is at noon. So you can’t just say that

the sun is shining for 10 hours, so I’llmultiple 100W x 10 hours. The hour between 8 and 9 in the morning is probably only halfas strong as the sun from noon to 1 in the afternoon, so the morning hour would probablyonly be equal to Â½ sun hour. But the days are so much shorter in the winter than thesummer, the number of sun hours would be dramatically different throughout the year. Also, the amountof sunlight I’d get in Miami Florida would be different than the amount of sun hoursI’d get in Portland Maine. Ugh, this can get complicated. Luckily, some very smartpeople have taken decades worth of weather data and calculated out the number of sunhours for all over the world, broken out by

month, and even the tilt angle that the panelsare mounted. So I can look at the charts to see if I have a 100W solar panel, in Portland,Maine, installed at about 45 degrees angle, on annual average, I’d get 4.6 sun hoursa day. Likewise, if I took that same solar panel in Miami Florida, installed it at a25 degree tilt, I’d have an annual average of 5.2 sun hours. Just as a little aside,I want to make sure you see that during the months of June and July, I’m going to getmore power out of that solar panel in Maine than I will in Florida. With Miami being closerto the equator and Maine being closer to the north pole, the days are longer in the summerin Maine, and so the sun shines on the solar

panels longer. Kind of cool, huh? OK, backto the question at hand, what can I power with a 100W solar panel? I need to figureout my worst case scenario, what is the worst performing month that I’ll be using thepanel? Since for this example I’m going to be using it in Maine, during ski season,I need to figure on December. So how can I squeeze out as much power as I possibly canin December? By tilting the solar panel steeper so it points right at the low winter sun.So I’m going to mount my 100W solar panel at 60 degrees and figure on 3.2 sun hours.I’ll now take 100W x 3.2 sun hours and get 320 watt hours a day in December. Now, asyou know, nothing in real life is perfect,

## How to Solar Power Your Home House 1 On Grid vs Off Grid

yeah hello everyone and welcome to thisseries we’re going to talk about how to power your home or house from solarpower now first of all i have to say thanksvery much to xodar who are sponsoring this series as you have known if youfollowed any other of my tutorials David of X earlier and his companykindly donated all his time to install solar power of my house and what I likeabout XLR and and the companies that for one that have a great choice and varietyin terms of products and brands

David himself like me enjoys tinkeringand finding solutions to problems so he enjoys very much getting involved in thetechnology and making it work well so I certainly appreciate the inputnow today what I’m going to do this whole series is going to cover off fromdeciding whether you want an onboard system and offgrid system the types ofsolar panels where to have a charge controller or a grid tie inverter ormicro inverters battery bank the solar panels that cost involved isn’t worththat the complications of doing this in south africa vs somewhere like Europe orthe states so they’re going to be quite

a few few tutorials covering that off andwhat I ask you is that as I start these tutorials start posting your comments andquestions as we go along and armor training corporate there’s into thetutorials as they go along by all means if the tutorial series hasbeen completed or something has been cut off and you slap a question post a comment and I’ll do my best toanswer for you and it’s worth posting a tutorial on it I will do what we’re going to starttoday though it is getting understanding

all on grid this is off grid but before I walk youthrough this little picture and and discuss on grid vs off grid and what thegrid is and let me just show you some of the equipment so that you are familiarwith what I’m talking about when I shade this diagram and then we’ll get down and explain itok so let’s start off by looking at these solar panels we are going to talkabout these in detail later on a narwhal might even refer you to some othertutorials that up maybe I talk about the

performance of the different types ofsolar panels under different conditions so the one thing to note that today youcan get cheaper panels from china and what have you but you want to be awarethat if you do want to use your panels with high voltage systems which issomething we’ll talk about you have to consider the quality the build qualityand how they put together and that’s something we’ll talk about in terms ofthe gaps with the connectors we’re also going to talk aboutmonocrystalline this is poly crystalline and amorphous and which seemed toperform better under what conditions

this is an MPPT charge controller soit’s a maximum power point tracking charge controller and this device issomething our point out which is especially useful in offgrid systems asit takes the power from the solar panels it converts it does a dcd to DCconversion service at the right voltage for your battery bank to charge a set ofbatteries this can’t supply power directly to yourhouse and that’s why this particular unit is more unit is more useful inoffgrid systems but we’ll have a look that when we come to the actual diagramitself right so here we have the grid