HELP ! What do i need if my consumption power in a day is 20kWh

morris96morris96 Registered Users Posts: 2
For everyone that expert about sollar energy, or knowing about that stuff

Please help me to choose the hardware of my systems, my consumption electricity in a day is 20kWh or 20000Wh is that possible to make an solar system that can afford to supply this 20kWh for one day simultaneously.

If that's not possible, how can i afford this supply at least for 12 hour or 10kWh is that possible ?

How many solar panel do i need to afford this supply, what type of UPS Hybrid or Inverter do i need to control the supply, and how many batteries bank that i must have, if 24 hour is possible, please explain all things for me, if that's not possible, please explain that 12 hour thing.

I'm sorry, if my english is poor.

Please help me ASAP

FYI. My electricity consumption goes to run the computer server

Comments

  • mike95490mike95490 Solar Expert Posts: 8,803 ✭✭✭✭✭
    I have 5Kw of PV that can supply 20Kwh per day, cloud free summer days.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 30,625 admin
    Welcome to the forum Morris,

    There are basically two types of solar power systems that can supply power for your needs. One is a Grid Tied (or Grid Interactive). These are inverters that connect directly from a solar array to your main AC power panel. And you get an electric meter (kiloWattHour billing meter) from your utility. The meter turns forwards when you use more power than you generate (at night), and turns backwards when you generate more power than you are using (during the day). In many locations, GT systems are not liked by the utility and do not let you use this type of system.

    But GT solar system with "net metering" (at the end of the month, you pay only for the energy you have used that is over the amount you have generated), is the most cost effective.

    There is a variation where the GT inverter does not feed power back into the utility, but you can only "use solar energy" when the sun is up and shining (like 9am to 3pm/15:00 hours).

    But because you asked for a battery based solar power system--I will guess that you cannot use Solar GT + Net Metered with your utility. Just to start, a battery based system will probably cost you 4x as much to install, and will drive your power costs (battery repacements every 5-8 years or so, new electronics every 10+ years, etc.) up a lot. In the US, we pay something like $0.10 to $0.30 per kWH. Off grid solar can cost ~$1.00 to $2.00+ per kWH (including capital and maintenance costs).

    I will do a back of the envelope calculation here to roughly/quickly size the system. There are a lot of questions I will bypass and make some guesses/assumptions. Please feel free to ask questions--This is just to give you a very rough idea of what an "optimum" system could look like.

    A battery bank is the "heart" of the system. An optimum Lead Acid battery bank system will be around 2 days of storage (no-sun days) and 50% maximum discharge (for long life):
    • 20,000 WH per day * 1/0.85 AC inverter eff * 2 days of storage * 1/0.50 discharge * 1/48 volt battery bank = 1,961 AH @ 48 volt battery bank (a very good size battery bank)
    If you could justify a (for example) LiFePO4 battery bank, you might get away with 1/2 the AH capacity (closer to 1,000 AH @ 48 volt). LiFePO4 batteries are much more expensive than flooded cell (such as forklift/traction batteries).

    To calculate the size of the solar array, there are two calculations. One based on the size of the battery bank (ideally 10% minimum rate of charge). With lead acid batteries, you need ~10-13% rate of charge to refill the batteries with a constant 24 hours per day of loading. The second is based on the amount of sun your solar array will be exposed to.

    So, sizing based on battery bank:
    • 1,961 AH * 59 volts charging * 1/0.77 solar panels+charge controller deratings * 0.10 rate of charge = 15,026 Watt array nominal
    • 1,961 AH * 59 volts charging * 1/0.77 solar panels+charge controller deratings * 0.13 rate of charge = 19,534 Watt array "cost effective" maximum
    And then the "hours per day of sun". Say you have a fixed array in Jakarta Indonesia:

    Jakarta
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 84° angle from vertical:
    (For best year-round performance)
    Jan Feb Mar Apr May Jun
    4.20
     
    4.10
     
    4.50
     
    4.81
     
    5.00
     
    5.07
     
    Jul Aug Sep Oct Nov Dec
    5.28
     
    5.44
     
    5.37
     
    4.99
     
    4.61
     
    4.44
     
    Let us use 4.20 hours of sun as the minimum average amount. Assuming you are bit coin mining and can shut down the system in bad weather (or use utility/genset power):
    • 20,000 WH per day * 1/0.52 typical off grid system eff * 1/4.20 hours of sun = 9,158 Watt array minimum
    So, your solar array should be somewhere around 9.1 to 15 kWatt minimum (depends on how much "safety factor" you want for bad weather, running ventilation, etc.).

    The numbers above are first pass guesstimates. But they are fairly accurate and conservative (15kW+ solar array is conservative. A 9.1 kW array would be pretty "optimistic").

    Does this look "practical" for you?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • morris96morris96 Registered Users Posts: 2
    mike95490 said:
    I have 5Kw of PV that can supply 20Kwh per day, cloud free summer days.
    Thank you for the offer, i would like to build them my self.
    BB. said:
    Welcome to the forum Morris,

    There are basically two types of solar power systems that can supply power for your needs. One is a Grid Tied (or Grid Interactive). These are inverters that connect directly from a solar array to your main AC power panel. And you get an electric meter (kiloWattHour billing meter) from your utility. The meter turns forwards when you use more power than you generate (at night), and turns backwards when you generate more power than you are using (during the day). In many locations, GT systems are not liked by the utility and do not let you use this type of system.

    But GT solar system with "net metering" (at the end of the month, you pay only for the energy you have used that is over the amount you have generated), is the most cost effective.

    There is a variation where the GT inverter does not feed power back into the utility, but you can only "use solar energy" when the sun is up and shining (like 9am to 3pm/15:00 hours).

    But because you asked for a battery based solar power system--I will guess that you cannot use Solar GT + Net Metered with your utility. Just to start, a battery based system will probably cost you 4x as much to install, and will drive your power costs (battery repacements every 5-8 years or so, new electronics every 10+ years, etc.) up a lot. In the US, we pay something like $0.10 to $0.30 per kWH. Off grid solar can cost ~$1.00 to $2.00+ per kWH (including capital and maintenance costs).

    I will do a back of the envelope calculation here to roughly/quickly size the system. There are a lot of questions I will bypass and make some guesses/assumptions. Please feel free to ask questions--This is just to give you a very rough idea of what an "optimum" system could look like.

    A battery bank is the "heart" of the system. An optimum Lead Acid battery bank system will be around 2 days of storage (no-sun days) and 50% maximum discharge (for long life):
    • 20,000 WH per day * 1/0.85 AC inverter eff * 2 days of storage * 1/0.50 discharge * 1/48 volt battery bank = 1,961 AH @ 48 volt battery bank (a very good size battery bank)
    If you could justify a (for example) LiFePO4 battery bank, you might get away with 1/2 the AH capacity (closer to 1,000 AH @ 48 volt). LiFePO4 batteries are much more expensive than flooded cell (such as forklift/traction batteries).

    To calculate the size of the solar array, there are two calculations. One based on the size of the battery bank (ideally 10% minimum rate of charge). With lead acid batteries, you need ~10-13% rate of charge to refill the batteries with a constant 24 hours per day of loading. The second is based on the amount of sun your solar array will be exposed to.

    So, sizing based on battery bank:
    • 1,961 AH * 59 volts charging * 1/0.77 solar panels+charge controller deratings * 0.10 rate of charge = 15,026 Watt array nominal
    • 1,961 AH * 59 volts charging * 1/0.77 solar panels+charge controller deratings * 0.13 rate of charge = 19,534 Watt array "cost effective" maximum
    And then the "hours per day of sun". Say you have a fixed array in Jakarta Indonesia:

    Jakarta
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 84° angle from vertical:
    (For best year-round performance)
    Jan Feb Mar Apr May Jun
    4.20
     
    4.10
     
    4.50
     
    4.81
     
    5.00
     
    5.07
     
    Jul Aug Sep Oct Nov Dec
    5.28
     
    5.44
     
    5.37
     
    4.99
     
    4.61
     
    4.44
     
    Let us use 4.20 hours of sun as the minimum average amount. Assuming you are bit coin mining and can shut down the system in bad weather (or use utility/genset power):
    • 20,000 WH per day * 1/0.52 typical off grid system eff * 1/4.20 hours of sun = 9,158 Watt array minimum
    So, your solar array should be somewhere around 9.1 to 15 kWatt minimum (depends on how much "safety factor" you want for bad weather, running ventilation, etc.).

    The numbers above are first pass guesstimates. But they are fairly accurate and conservative (15kW+ solar array is conservative. A 9.1 kW array would be pretty "optimistic").

    Does this look "practical" for you?

    -Bill
    My first calculation is 20kW of solar panel, and i have one question that you don't mention. what types ups hybrid that can afford 15kW solar panel ? or until now, nothing yet can afford this supply, can at least combine them together ? or i must separate them for safety reason ? i ran the server is not for bitcoin, i just have a server domain. thank you bill much appreciate your response.
  • mcgivormcgivor Solar Expert Posts: 3,424 ✭✭✭✭✭
    edited July 2017 #5
    Basically producing power and using it during sunlight hours is the least expensive, overnight consumption the most expensive, batteries are the driving factor. The best way to provide this much power would be to use a quality  inverter, multiple charge controllers with a common battery bank. UPS inverters are generally used for short term outages on grid fed systems, sounds like you need to provide full time power. Do you have grid power? if so it would be by far the most cost effective, if not grid tied, at least grid supported.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.BB. Super Moderators, Administrators Posts: 30,625 admin
    A 20,000 WH per day system, is less than a 1,000 Watt AC inverter:
    • 20,000 WH / 24 hours per day = 833 Watt load
    It is the 24 hours per day that really kills us, energy wise, here.

    For charging, a 20,000 Watt array, assuming 80 Amp MPPT charge controllers, would need:
    • 20,000 Watt array * 0.77 panel+controller derating * 1/59 volts charging * 1/80 amps per charge controller = 3.3 ~ 4 MPPT charge controllers
    The configuration would be:
    • ~5,000 Watt array -> 80 amp MPPT charger -> 48 volt Battery Bus
    And you would have 4 of the above (each attached to the same battery bus). A 20,000 Watt array would generate, roughly, a maximum current of:
    • 20,000 Watts * 0.77 panel+controller derating * 1/59 volts = 261 amps typical maximum middle of the day peak current.
    This does not include air conditioning power, lighting, etc.?

    Obviously, you want to make sure you use the most efficient processors and mother boards. And setup to reduce energy usage when processors are idle/low traffic times. etc...

    There are 48 VDC input ATX PC power supplies (bypass the need, and 85% efficient AC inverters and run directly from your battery bank) for PC:

    https://www.powerstream.com/DC-PC-48V.htm

    And there are redundant DC (or AC) input power supply options too.

    https://www.powerstream.com/dc-mini-redundant-pc.htm

    There are lots of options, but if this is your energy usage--You are sort of forced to have a minimum size of solar power system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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