What will a solar system this size do?

Discussion in 'Bad Dog Cafe' started by teleman1, Mar 29, 2020.

  1. Dacious

    Dacious Poster Extraordinaire

    Posts:
    8,201
    Joined:
    Mar 16, 2003
    Location:
    Godzone
    Make sure they're not flogging old tech. Parallel DC micronverters are a better bet. Serial wiring can limit your system to least efficient panel and one failure puts it out of commission.
     
  2. Crafty Fox

    Crafty Fox Tele-Afflicted

    Posts:
    1,355
    Joined:
    Nov 25, 2011
    Location:
    Perth Australia
    I had a 24 panel (6kw?) system installed 2 years ago for AU$5,500. Average bi-monthly bill now is under $30, for 3 adults at home.
     
  3. Blue Bill

    Blue Bill Poster Extraordinaire

    Posts:
    7,218
    Joined:
    Feb 15, 2014
    Location:
    Maine
    I looked it up: an average refrigerator uses 1.5 - 2 kW-Hours per day, less than one tenth of the daily output of a 6kW PV system. It's a common point of confusion to say, as quoted above, that a reefer uses X Watts a day. The unit of consumption it Watt-Hours; a 1000 Watt device , running for one hour, uses one kW-Hour. A 1kW hair dryer, typically will only be used for 5 minutes or so each day, 1000/12 = 0.085 kW-H, or 85 Watt-Hours. Most power companies charge by the kW-H, so it's the most commonly used unit.

    In full sun, a 6kW PV system will produce 6 kW-Hours each hour. The average amount of full sun in AZ is 5 or so hours per day, hence the 25-30 kW-H per day estimate.

    (I worked in the solar biz for 3-4 years)
     
    Last edited: Mar 30, 2020
    DrPepper, aerhed and AAT65 like this.
  4. Obsessed

    Obsessed Telefied Ad Free Member

    Posts:
    23,721
    Joined:
    Nov 21, 2012
    Location:
    Montana
    You are correct on many aspects. If that system makes 6kW per hour, can you explain the cost? My system makes 100 watts/hour 24/7, so I am in a totally different league, but something doesn't add up here.
     
  5. Dacious

    Dacious Poster Extraordinaire

    Posts:
    8,201
    Joined:
    Mar 16, 2003
    Location:
    Godzone
    Here in Oz it's been a 70-75deg f day, mostly sunny, at 5pm. About another 2 hours of sun.

    We have a 3.3 Kw system. Height of summer on 40 deg F days we're pumping in 24kWh . Our biggest bill in winter is $200 a quarter. In summer it's $50. We're both home today with tv on and computer for me working from home.

    We pay 26c a kWh and get 11.5c on feedin.

    Cost us $6800 after rebates. 10 LG panels, Enphase inverters and control unit. Roof of second floor install.

    Screenshot_20200330-170006~2.png

    Screenshot_20200330-170819.png
     
    Last edited: Mar 30, 2020
    jvin248 likes this.
  6. otterhound

    otterhound Poster Extraordinaire

    Posts:
    8,128
    Joined:
    Dec 14, 2008
    Location:
    Manheim Pa.
    I noted both DC and the right equipment .
    No need for an inverter where running on DC or charge controller as I believe you reference it . Acquire panels that produce 24VDC and equip the house with matching items .
    24VDC is common in certain applications . Marine is one , if I recall correctly .
    Your automobile likely will not run , but a vehicle equipped with a magneto and a generator will . You don't even need the generator just to run . It is needed to charge a battery and/or operate accessories like lights .
    This would only work during daylight , but that is all you really need during an emergency . Switching to the grid during nighttime and non emergency situations would be the norm .
    One thing I am not sure about is converting AC line voltage to DC . There may be an issue there , but since I am not considering this , I don't bother to research it .
    Thinking within existing items and using them outside of the box .
     
    Blue Bill likes this.
  7. DrPepper

    DrPepper Friend of Leo's Ad Free Member

    Age:
    61
    Posts:
    3,047
    Joined:
    Nov 24, 2017
    Location:
    Texas
    In the states, telephone systems can run 8 hours or more off-grid, plus most have a generator... They really try to avoid outages. If a contractor causes an outage of service while doing work in a telephone central office, it could cost them up to a one million dollar fine...

    BTW, you have low current/low voltage DC in your landline...
     
  8. Blue Bill

    Blue Bill Poster Extraordinaire

    Posts:
    7,218
    Joined:
    Feb 15, 2014
    Location:
    Maine
    This is all true. There are practical issues that complicate things, so being totally prepared for prolonged power outages is both expensive and impractical, but not impossible. Switching from DC to AC requires an inverter; switching from AC to DC requires a rectifier, both lose a certain amount of power during the conversion. Plus, household-sized converters are costly. Plus, the switching mechanism is somewhat complicated and expensive, if it interfaces with the grid, there are safety and regulatory issues.

    You would either need to convert the AC/DC or have two refrigerators, and move all your food back and forth anytime you switch to the other system. Having a battery storage system solves many of these issues, but is also expensive, and bulky, and worse of all, chews up more that half of the power your panels produce in the process of storing, then retrieving the power. I wish it was better than this, but it's difficult to end-around the laws

    Let's see... Your question reflects the confusion I mentioned. It's just like asking: If a certain car gets 25 miles per gallon, how much gas does it use each day? There's info missing from the question. A PV system does not make 6kW per hour, it makes 6kW-Hours per hour. Saying a system produces 6kW per hour is like saying, the car gets 50 miles a day; it's a mis-application of terminology.

    Similarly, your statement that your system produces 100 Watts per hour is confusing because Wattage is a continuous thing; a generator can produce 100 Watts continuously for one minute or 60 minutes, like the car consuming 25MPG for one mile or 100 miles. The amount of power, produced or consumed, over a period of time, is measured in Watt-Hours, not Watts.

    What kind of generator are you using to produce 100 W, 24/7? Not solar, I expect. I hope I'm not coming across as a know-it-all, sorry if I am. I was a system designer and salesperson at a solar company and taught classes on electricity, so I can tend to babble on...
     
    TeleTucson and Obsessed like this.
  9. otterhound

    otterhound Poster Extraordinaire

    Posts:
    8,128
    Joined:
    Dec 14, 2008
    Location:
    Manheim Pa.
    I hear you .
    What about a basic 24VDC system kept separate from AC to use only when desired or necessary ?
    Don't mind me , I am, just pondering out loud .
     
  10. Obsessed

    Obsessed Telefied Ad Free Member

    Posts:
    23,721
    Joined:
    Nov 21, 2012
    Location:
    Montana
    Babble on, maybe I can learn the terminology better. I am running a Ford alternator in a homemade micro hydro pelton wheel off of a creek. At 13 volts times 10 amps minus loss over 300 feet to the house. Is this called "100 watt hours"?
     
  11. Toto'sDad

    Toto'sDad Telefied Ad Free Member

    Posts:
    44,643
    Joined:
    Jun 21, 2011
    Location:
    Bakersfield
    Solar power eah? Hmmmm, ya don't say.

    [​IMG]
     
    rocksmoot and DrPepper like this.
  12. teleman1

    teleman1 Tele-Afflicted

    Posts:
    1,447
    Joined:
    May 16, 2003
    Location:
    Arizona
    Ok I am starting to grasp some of this. And new topics have birthed here. Some have touched on this, but it is a marketing scam yanking tax credits and whatnot to have you buy solar at an inflated price and financed at numbers I don't see making the grade. THe only way I see to do this right living in a metropolis is to own a system on your roof that sells/trades the KWH to the utility company.I have seen folks who have a big arse system, FINANCED, with payback that were marginal. But worse, no newer A/C unit, aluminum single pane window. Just a home lacking in so many energy features, I see a better payback on that stuff, insulating the home. than financing a system. And if you buy it, it seems the more in the household the better the payoff. I wish there was a 20 X 15 panel you good mount in your yard angle adjusted and a big throw switch, like in Frankenstein, and you yell, honey, you can turn the dryer on. Its Free!
     
    DrPepper and Toto'sDad like this.
  13. Toto'sDad

    Toto'sDad Telefied Ad Free Member

    Posts:
    44,643
    Joined:
    Jun 21, 2011
    Location:
    Bakersfield
    A guy came by here pedaling Solar about a month ago. I told him that my house was pretty energy efficient and that I had crunched the numbers, and at my age there was simply no way I would ever recoup my cost of installing a system. He came right back with, well you know you could if you sold your house!
     
    DrPepper likes this.
  14. teleman1

    teleman1 Tele-Afflicted

    Posts:
    1,447
    Joined:
    May 16, 2003
    Location:
    Arizona
    I am a Realtor. And that sales guy you dealt is scum. I have witnessed solar situations where they have to sell. And they need someone to qualify for an extra $40,000 to assume the loan. They are upside down and don't know it.
     
    DrPepper and Toto'sDad like this.
  15. Toto'sDad

    Toto'sDad Telefied Ad Free Member

    Posts:
    44,643
    Joined:
    Jun 21, 2011
    Location:
    Bakersfield
    My brother in law is seventy nine years old, and just bought a solar system.
    I had no intentions of either buying solar, or selling my house. I just thought it was funny how quick he came up with something to "overcome" my objection. You know the drill, like when you're showing a house, and the wife says, I don't like the kitchen, and without even pausing you say, "well let me show you the master bedroom suite now, I know you're gonna love it!":lol::lol::lol:
     
  16. Blue Bill

    Blue Bill Poster Extraordinaire

    Posts:
    7,218
    Joined:
    Feb 15, 2014
    Location:
    Maine
    Theoretically, this is possible, but think about how you would plug things in, or switch things on and off. I've seen houses with two systems, both 48 Volt DC and 110 Volt AC, there's switches and outlets all over the place. Plus, you need two of any appliance you want to have available if one system is down, and expense and a storage issue.

    I love homemade micro-production! Watts = Volts x Amps, so 13x10= 130 Watts output. So, it produces 130 Watt-Hours per hour. With the resistance loss, that nets 100 Watt-Hours each hour, so it takes 10 hours to produce 1000 Watt-Hours, or 1 kWH. In Montana that costs about 12 cents, it shows how cheap our grid electricity is.

    An another analogy may help: You can picture electrical power production as water, being pumped through a pipe, filling a barrel: Watts are like the gallons/minute; a bigger pump (more Watts) will push more water per minute, and fill the barrel faster. Watt-Hours are a quantity of electrical power, just like the barrel is a quantity of water. 10 solar panels will "fill the barrel", i.e. deliver a number of Watt-Hours, about ten times faster than one PV panel of the same size.

    Like any business, there's honest purveyors, and there's scum. Also like most businesses, most of the Solar guys are honest and will let you know if a PV system will work for your situation. And, in my view, there are many situations where PV is a good deal. Otherwise, they would be going out of business. The Rebates and Credits cloud the water somewhat, but there are some situations that are a great deal.

    Also, there's more to things than, "What's the payoff?", or "How long does it take to pay for itself?" Sure that's part of it. People that buy solar-powered systems are also considering the quality of the source of their power. It feels good to some people to get their electricity from the sun, rather than fossil fuel, nukes, even hydro. When someone buys an expensive new car, nobody badgers them about the "payback". Sure, they could buy a cheap car that does the same task as their fancy one, but it feels good to drive a quality auto, doesn't it? Or a leather couch? Or Expensive Scotch? How about a Custom Shop Telecaster, what's the payback on that? Etc.
     
    Last edited: Mar 30, 2020
    Obsessed likes this.
  17. String Tree

    String Tree Doctor of Teleocity Ad Free Member

    Posts:
    15,053
    Joined:
    Dec 8, 2010
    Location:
    Up North
    I think any Solar System would be out of this World.
     
  18. teleman1

    teleman1 Tele-Afflicted

    Posts:
    1,447
    Joined:
    May 16, 2003
    Location:
    Arizona
    Actually, in that scenario, I ask what she does not like about the kitchen. I might walk here thorough Home Depot later.
     
    Toto'sDad likes this.
  19. Toto'sDad

    Toto'sDad Telefied Ad Free Member

    Posts:
    44,643
    Joined:
    Jun 21, 2011
    Location:
    Bakersfield
    Well, the way I told it is what happens nine out of ten times on he H&G channel!
     
  20. Guitarzan

    Guitarzan Poster Extraordinaire

    Posts:
    6,869
    Joined:
    Feb 28, 2006
    Location:
    Hotlanta, GA

    If it is over 14 Parsecs, I would not even consider it. The ones under 14 are a much better value, but sharpen your pencil!
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.