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solar panel

Discussion in 'Renewable Energy' started by waj1d5, Feb 12, 2012.

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  1. electroyas

    electroyas New Member

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    i also have a small solar panel system which i use for lighting only , about 80W panel produce only 60W max in my place without mppt charger. Anyway its more than enough to light about 9hours Led lights about total load 40W. I use 35Ah battery for backup. We have lots of power cuts so grid tie inverters are useless. And electrcity rate is going exponentially here i dont know why. Thats why i use a solar system.
     
  2. remon7

    remon7 Active Member

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    I could see that my electricity bill was rising after year, since the recent day appliances can’t be turned off any more and before I noticed I had many appliances in the house which are on standby day in day out. Electronic devices increasing day by day, it makes our life comfortable. This all not only harm the environment but also my bank account as I am using electricity for nothing. Not to solve this problem. I started to glance into renewable energy to pay off my unneeded losses and to take some pain left from my bank account. Wind power plant was no option due to the area I’m living in, hydro electricity plant is any option as I live in a flat country with next to no rivers so solar power was the best solution.
     
  3. remon7

    remon7 Active Member

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    Hi,
    Initially you have to collect all components(Home made solar)
    you will need
    A motor with gearbox
    A solar cell – at least 6V, 1 Watt
    2x LM393 comparator IC, can be any similar comparator
    A circuit board
    A L293D H bridge motor driver IC
    5k, 100k, 10k resistors
    A IRF9450 MOSFET, or any similar P channel MOSFET
    An IRF540 or similar N-MOSFET
    A 50k potentiometer
    One phototransistor (Darlington IR)
    Battery holder
    2 photocells or 2 photodiodes
    Some sort of housing – I used my iPod touch case
    Some 1N4004 diodes
    Wires
    I use NiMH here,
    And some batteries!!!! ThankS :)
     
  4. dave

    Dave New Member

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  5. audioguru

    audioguru Well-Known Member Most Helpful Member

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    My electricity rarely fails and costs little.
    You should see all the high power Christmas Lights on people's homes at this time of the year.
    My Electrical Utility Company traded modern low power LED Christmas lights for each string of high power incandescent lights brought to them. Then they will not need to upgrade the electricity system. They also gave away compact fluorescent light bulbs for free.
     
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  6. audioguru

    audioguru Well-Known Member Most Helpful Member

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    A guy has an advertising sign in a field beside a busy road. The sign is lighted at night. There is no electricity there and the utility will charge a fortune to install electricity wires to the sign.
    So the guy used a solar panel but the sign does not work following a cloudy day. Then he replaced the solar panel with a windmill and now it works fine.
     
  7. amberpeloe

    amberpeloe New Member

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    What brand of panels are you trying to install? I would love to help you out.
     
  8. atferrari

    atferrari Well-Known Member

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    Delete
     
  9. gary350

    gary350 Well-Known Member

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    I have a 400 watt panel it charges a 1000 amp car battery. It will run lights, small items, TV, computer for a few hours.

    I can run lights on a 300 watt DC to AC inverter.

    A 1000 watt DC to AC inverter will run the computer or TV for a few hours.

    A 1500 watt DC to AC inverter will start and run the tiny 2 cubic foot refrigerator for a few hours.

    My DC to AC inverters use electricity even when they are turned off so I have learned to disconnect them from the battery while they battery charges.

    When the battery dies nothing runs the rest of the day.

    If you have a cloudy over cast day the battery stays dead all day.

    If it is sunny with lots of clouds, the clouds can reduce charge time by several hours depending on how cloudy it is. Some days 30% to 70% .

    If you don't use the battery during the day and let it charge you can usually get 6 hours out of the battery in the evening.

    If you want to use the battery all the time you need 6 panels 400 watts each that assumes you have full sun all day and never have a cloudy day.

    To get closer to being realistic you need about 5000 watts of panels depending on what you use them for and about 8000 watts in batteries.

    I have this system on a camper trailer. I try not to use much electricity during the day. A little at breakfast, lunch, dinner then after dark. I don't get enough electricity to run the refrigerator full time so I use an ice chest.
     
  10. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Your inverter figures seem MASSIVELY over-rated - why are you using such big ones?.

    As for your lights?, why don't you use better lights - what are you using?.
     
  11. audioguru

    audioguru Well-Known Member Most Helpful Member

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    I think he wastes as much power heating old incandescent light bubs as is possible like lighting the entire neighbourhood (camper village) like my neighbours. My neighbours even leave TVs playing all night long.
    They probably have both the furnace and air conditioner running all the time.

    The guy in the camper might be using the massive inverter to heat his camper.
     
  12. gary350

    gary350 Well-Known Member

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    Run current is only 1.4 amps on the tiny refrigerator but start up current trips the 300 watt and 1000 watt converter. It seems to me the refrigerator would run on the 300 watt converter if I could figure out how to get the frig started. Surge current must be more than 8.3 amps on start up.

    I have the same problem with the electric chain saw surge current trips the 300 and 1000 watt inverter.

    The electric coffee maker is 600 watts, electric griddle 1400 watts, computer 400 watts, in the camper trailer. Lights will run for a week on the battery without charging the battery. I have 3 lights inside the camper 25 watts each, 1 light outside 25 watts. It does not take much power to run the camper trailer lights, the 400 watt solar panel and battery work GOOD. I like to cook outside on the picnic table using the Coleman camp stove, rarely use the electric griddle or electric coffee maker. I have to be careful how much power I use and keep a eye on the clouds and sun to make sure the battery is staying charged. Sometimes after a week of camping the battery is dead, problem is mostly too much shade from trees.

    This 400 watt system will not work at MY home, refrigerator is much larger, TV is larger, AC unit is large, kitchen stove, hot water heater, when I use them, they all trip the 1500 inverter but would probably run on the inverter if I could get the items started. The surge start up current is the big problem for AC and the refrigerator. We have 2 computers, lots of kitchen appliances, lights, TV, this all uses massive amounts of watts. I need about 6kw at home. If I could do without the AC unit, electric stove, electric hot water heater, I am guessing 2000 watts will run the house.

    I tried to run my house on a 5kw generator it will not work. Every time the AC unit comes on the generator over load trips. Kitchen stove trips the over load too. A few lights, TV, and computer will run fine until the kitchen refrigerator comes on then it trips the 5kw over load. I need to experiment with a 6kw and 7kw generator to see if it will run the house without tripping the generator over load. Probably the smart thing to do is rent a 10kw generator with a meter that reads how much power is being used but there is still the problem of how to read start up surge current for things like AC unit and refrigerator. An amp clamp that reads peak demand might work.

    All my inverters use power from the battery when they are turned OFF and still connected to the battery. I need to make sure they are never connected to the battery if they are not being used. I have not checked to see how many amps the inverters use but the small 300 watt one will kill the life of the battery in 2 days if I forget to disconnect it when not used. I use the 300 watt inverter 98% of the time. Only time I use the 1500 watt inverter is when I use the chair saw. We never use the refrigerator it kills the battery very quick. The generator circuit breaker is 20 amps 240 vac, the house circuit box mail breaker is 200 amp 240 vac.

    If you buy an inverter test it to see how many amps it uses connected to the battery. Maybe you can test several inverters to see if they all use amps while connected to the battery. Maybe certain brands or newer models are better. It sure would be a BIG advantage to find an inverter that uses no power when it is not being used.
     
    Last edited: Dec 14, 2014
  13. tcmtech

    tcmtech Well-Known Member Most Helpful Member

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    Hmm..... Your house has a 120/240 VAC 200 amp service running a ton of high power electrical loads and you can't follow why an inverter that produces ~3% of that capacity coming off of a 12 DC base power source cant run it or that a gen set that produces ~10% of that can't run things either?o_O

    Your average 24 hour running load may only be 2 - 3 KWh's per hour but your peak loads are more than likely 10x that with startup surges that go +15x over the base average.:facepalm:
     
    Last edited: Dec 15, 2014
  14. Scotophor

    Scotophor Member

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    Gary, is your trailer all-electric, or do you also have propane/LPG? A gas-fired refrigerator might solve your problem. To those who have never heard of such a thing, yes they do exist (Absorption Refrigerator at Wikipedia) and yes, they are fairly efficient once they get cold. My family took 2-week camping vacations about every year when I was young, and the propane refrigerator after the 2nd day was hard to keep it adjusted WARM enough to keep from freezing the milk and orange juice! Ours was a 3-way unit whose working parts looked a lot like the one about 2/3 of the way down the Wikipedia page on the right side, and could be powered by propane, 12 volt or 120 volt electric (using heating coils instead of the propane flame).
     
    Last edited: Dec 15, 2014
  15. gary350

    gary350 Well-Known Member

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    If you put solar panels on a roof they will need to be removed to repair the roof every 15 to 20 years and yearly maintenace to patch water leaks

    At my geographical location the sun is at 34 degrees on the shortest day of the year Dec 21 or 22 depending on when leap year is. Sun is at 89 degrees on the longest day of the year June 21 or 22. March 21 or 22 and Sept 21 or 22 is equinox sun is at 61.5 degrees. You need to consider cloudy weather some geographical locations are over cast and clouds 98% of the time all winter. You need to consider snow too solar panels dont work when they are covered with snow even on a sunny day.

    I live in Tennessee we have on average 300 days of rain every year and not much snow. But we do get snow sometimes. The sky here is over cast, cloudy, gray, almost every day f rom Nov to May so solar panels are basically worthless here until June and work ok until late Oct. Summer here we have lots of clouds if the sun is covered with clouds 40% of the time on 15 hours of sun light per day in the summer the solar panels work pretty well from about 8:30 am to about 7 pm. When the sun is low in the sky early morning and late evening solar does not do much.

    Check the yearly weather where you live, check the cloud situation, determine the correct angle of the panels, be prepared for all the required maintenance work. You will will have times when 5000 watts of panels will produce only 1500 watts of power. Do the math see how many utility bills you can save in a whole year.

    I took a business class in college it is generally considered if you can not get your money back in 2 years it is a bad investment.

    I am not trying to discurage you from putting up panels but you need to consider all the facts before you start.
     
    Last edited: Dec 25, 2014
  16. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Perhaps you should try fitting decent roofs? :D
     
  17. tvtech

    tvtech Well-Known Member Most Helpful Member

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    This is an interesting thread. I am really glad it was resurrected. Best part is this link that was posted by someone above: http://otherpower.com/

    No free energy junk. Just how to use batteries, wind, solar etc properly :)

    I think I learned more today than in all my years at ETO.

    Regards,
    tvtech
     
  18. gary350

    gary350 Well-Known Member

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    The life of 15 year roofing shingles is about 15 years.

    The life of 20 year roofing shingles is about 20 years.

    If the roofing shingles dry, crack, leak rain, they need to be replaced. There is no way to remove shingle under solar panels without taking the panels off the roof. The manufactures in the USA design their product to ware out so people like me have to buy more that keeps the company in business.

    If you live in a country where they make better roofing shingle then it might be a different story for you.
     
  19. Scotophor

    Scotophor Member

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    Also, if you have properly installed solar panels on your roof, the shingles underneath them should not need repair for a very long time, probably double the manufacturer's rating, because the panels protect the shingles from wind, sun, rain, snow, etc.

    If you get a new roof that needs yearly maintenance to patch water leaks, sue your roofing contractor. Maintenance to prevent leaks is normal, but if you're doing that and you still get leaks, the installation was faulty.
     
  20. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    We don't use such useless roofing as shingles :D

    Roofs are almost all either slate or tile, and usually last 100+ years.

    It's always totally baffled me why you would use such poor roofing materials?.
     
  21. audioguru

    audioguru Well-Known Member Most Helpful Member

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    When I was in England many years ago I saw some houses with only HAY on the roof. It made a poor roof.
    My home in Canada used tarred-felt shingles that cracked and curled (and leaked) after 10 or 15 years but the last time I got fiberglass based shingles that last a long time with no cracking or curling. No more leaks and they cost the same.
     

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