Help with a project

duanehaas
duanehaas Registered Users Posts: 3
I am new to all things solar, and was wanting some experts opinions.

I have a pond in Southern Indiana that I want to aerate. The air pump will run 4-6 hours and is a 280w pump. Would you guys have a recommendation for the type of system I should attempt.

Thanks!

Duane Haas

Comments

  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Help with a project

    Hi Duane, welcome to the form.
    Now some questions about your project.
    Are you looking to only have this pump running on sunny days, during the daytime? Will it only be used during the day, or will it also from time to time be needed at night? Do you need it to operate the pump during several days of cloudy weather? Is this an AC pump? If so, what voltage? Or is it a DC pump? And again, what voltage? So far, not including losses, you need something that will supply 1.7 kwh/day. This is not a small system for off grid, and depending on your needs, the costs could add up to a lot more than you might think.
  • duanehaas
    duanehaas Registered Users Posts: 3
    Re: Help with a project
    Hi Duane, welcome to the form.
    Now some questions about your project.
    Are you looking to only have this pump running on sunny days, during the daytime? Will it only be used during the day, or will it also from time to time be needed at night? Do you need it to operate the pump during several days of cloudy weather? Is this an AC pump? If so, what voltage? Or is it a DC pump? And again, what voltage? So far, not including losses, you need something that will supply 1.7 kwh/day. This is not a small system for off grid, and depending on your needs, the costs could add up to a lot more than you might think.

    Thanks for the reply, and to answer your questions -

    Only during the night time about 6hrs each and every night (including cloudy days). AC pump 110v 280w.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Help with a project

    am i missing something here? you only need to pump air into the water to aerate it so go with a 12v compressor with a hose into the water.

    why at night and not during the daytime?
  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Help with a project

    Sounds like a perfect job for a direct PV-to-pump setup, no need for inverter or batteries. But it will mean aerating during the day, less so on cloudy days.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • tmarch
    tmarch Solar Expert Posts: 143 ✭✭
    Re: Help with a project
    niel wrote: »
    am i missing something here? you only need to pump air into the water to aerate it so go with a 12v compressor with a hose into the water.

    why at night and not during the daytime?

    Good idea, but why not suggest a solar charger and battery?

    I'm NOT trying to pick on anyone, but if I was the owner of this forum and selling renewable energy products I wouldn't be happy with some of the comments made.
    It's either too expensive or too difficult or just won't work. How about why it won't work or what you need to do to make it work.
    Sell some products (hopefully for the sponsor) and educate everyone.
    I'm a beginner with solar and I've been told over and over here that it won't work, but for some reason there's more systems going in all over the country.
    Sorry for the rant but I for one am tired of the negativity. nuff said
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Help with a project
    tmarch wrote: »
    Good idea, but why not suggest a solar charger and battery?

    I'm NOT trying to pick on anyone, but if I was the owner of this forum and selling renewable energy products I wouldn't be happy with some of the comments made.
    It's either too expensive or too difficult or just won't work. How about why it won't work or what you need to do to make it work.
    Sell some products (hopefully for the sponsor) and educate everyone.
    I'm a beginner with solar and I've been told over and over here that it won't work, but for some reason there's more systems going in all over the country.
    Sorry for the rant but I for one am tired of the negativity. nuff said

    why, because i'm not a salesperson first of all and secondly, i don't know what compressor he may choose if he chooses one. 3rdly, i am not privy to his answer as to why at night either to really make good recommendations as running during daylight hours direct makes better sense to me. i also don't know if a battery may wind up being required by him or not.

    how was my post negative? i never said he can't, but i am trying to get a better handle on his requirements and if there's better options for him. is that a problem for you?
  • tmarch
    tmarch Solar Expert Posts: 143 ✭✭
    Re: Help with a project
    niel wrote: »
    why, because i'm not a salesperson first of all and secondly, i don't know what compressor he may choose if he chooses one. 3rdly, i am not privy to his answer as to why at night either to really make good recommendations as running during daylight hours direct makes better sense to me. i also don't know if a battery may wind up being required by him or not.

    how was my post negative? i never said he can't, but i am trying to get a better handle on his requirements and if there's better options for him. is that a problem for you?

    NOT a problem for me and VERY helpful I'm sure!!!!!!!!!!!
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Help with a project

    The short answer is that for X kWH per day, a pure Solar to DC pump motor that runs during the day is about 1/4 the cost (including ongoing maintenance/battery replacement) for the same thing that gathers power during the day and feeds the same exact amount of power to a pump at night.

    If--the application requires night time power delivery and the cost of such a system is worth it to the original poster--So be it.

    In the end, the details are important... Most DC pond air pumps I could find are brushed DC. Very fine motors with a limited run life due to brush wear. Can make a fairly straight forward solar panel to linear current booster to DC motor system that runs during the daylight.

    For night time, need larger solar array, charge controller, battery bank, possibly an AC inverter (AC pump will have much longer life).

    And depending on if this a 6-9 month a year or 12 month a year operation, what about generator/alternative power backup and some way to shut down before the battery bank is full depleted and damaged by over discharging/under charging (typically during bad weather).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • duanehaas
    duanehaas Registered Users Posts: 3
    Re: Help with a project

    Thanks guys! I didn't go with a DC air pump because they aren't nearly as reliable and about 4 times the cost as the same quality AC pump. Aerating at night provides many more benefits than aerating during the day due to raised dissolved oxygen levels at night since plant life in ponds tend to sap oxygen out of the pond during nighttime. I have actually found another AC pump that will fill my needs that only runs 80w if that helps any.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Help with a project

    Okay, so we know you want to run an 80 Watt AC load. The next question is: for how long?
    Depending on the type of motor/pump this will have a start-up surge that has to be accounted for in the inverter sizing.
    Then you multiply out the 80 Watt * hours run to get the Watt hours. Factor in the conversion efficiency (usually about 80-90%) and you have a fair idea of how much battery capacity is needed in terms of DC Watt hours (remembering to allow for no more than 50% DOD for most batteries). That will determine how much panel & charge controller you'll need to replenish.

    Example: 80 Watts @ 10 hours = 800 Watt hours. Conversion efficiency of 85% means about 940 Watt hours DC. Since the load is relatively light, you probably would use a 12 Volt system (inexpensive small inverter), so you have to have 78 Amp hours to use; at least 156 Amp hour 12 Volt battery. Replenishment in this case is more a matter of how much sunshine you can count on; you need roughly 1 kW hour worth. With the usual 4 hours expected, that would be about 250 Watts - less panel derating. About 325 Watts of panel over-all.

    Just a rough calculation to give you an idea. Niel's direct-DC suggestion was made because it would be much simpler and less expensive, if the results were satisfactory. Perhaps the less efficient aeration during daylight could be made up by the more efficient (simpler) DC only set-up?
  • Shadowcatcher
    Shadowcatcher Solar Expert Posts: 228 ✭✭✭
    Re: Help with a project

    Parts left out don't go wrong. A much simpler solution is to use a wind powered pond aireator http://www.pondaeration.com