Hydro vs Solar

KenZ71
KenZ71 Solar Expert Posts: 58 ✭✭
TLDR: Solar vs Hydro which is easier, lower maintenance, more efficient? 

The details:
Bought a new house, south of Greensboro NC, with a pond that is about 3 acres of surface area with about a 10 foot drop or head on the drainage pipe. So I am considering the benefits of hydropower vs solar. Still need to measure the output volume - looks like about 1/4 capacity on a 6 inch drain line.

In my current home that I'll be selling in a few months I've got two grid tied solar systems rated at 6.2kw & 2.8kw. These solar systems have been in use for 6 years so we are used to the seasonal impact to efficiency & obviously no power at night.

The new home has several acres available for solar plus the above mentioned potential for hydro. 

Neighbors tell me street power goes out often so having a hybrid system with batteries for storage might be ideal. 

What I need to figure out
* actual reliability of utility power
* consistency of pond level & the drainage volume / pressure 
* how much maintenance is required of hydro

Saw this post with some good info.
https://forum.solar-electric.com/discussion/356370/hydro-with-grid-tied-inverter-and-power-outage

Comments

  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    The simple answer is solar is far easier ! 

     The longer answer from me, after just getting back from clearing leaves and twigs out of a customers hydro, is I got to spend 4 hours in a very beautiful place, being paid, and having easy work to do. Even had a beer after!

    It is a hard decision and I would look at cost on paper. There is the cost of replacing the water generator, and like a wind generator it becomes subject to damage just being installed there. That is the best part of solar. The panels can sit there for years, unused, and still be fine.
    "we go where power lines don't" Sierra Nevada mountain area
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  • KenZ71
    KenZ71 Solar Expert Posts: 58 ✭✭
    Is it realistic to think with proper screening clearing leaves & twigs would not be needed often?

    Looks like peloton wheels & nozzles are quite demanding of debris free water. While other types, with larger flow rates, can be more forgiving of debris.

    Hydro has the appeal of working 24 x 7 x 365 while solar is at best half that. But I am most likely missing something. 
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    No--You are not missing that solar "works" only when the sun is up and shining (no shade, no snow on panels, etc.).

    Hydro can also involve complex "water rights" issues (especially in the Western USA). Also, any dams can be a regulatory issue too (enough earthen dams have failed and killed people downstream that permits and inspections have become more prevalent--From the little I have read).

    Also for "low head" hydro systems... You have to move much more water for equivalent power. Need more average water flow, and more screens/cleaning of debris. A 10 foot head requires 10x more water (cu ft per minute) vs a 100 foot head.

    As Dave says--Do paper designs first--Much cheaper than buying hardware and starting an installation before you have done the design.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    KenZ71 said:
    Is it realistic to think with proper screening clearing leaves & twigs would not be needed often?

    Looks like peloton wheels & nozzles are quite demanding of debris free water. While other types, with larger flow rates, can be more forgiving of debris.

    Hydro has the appeal of working 24 x 7 x 365 while solar is at best half that. But I am most likely missing something. 
    Every screen and pre filter would need cleaning at least 2x a day in my creek areas, from all the tree debris..  Even the self cleaning ones, you should check EVERY Day

    And then you have lines to install, intakes, discharge.  Mechanical spinny things need maintenance, wires checked.

    But hydro is sure nice, if I had suitable hydro site, 500w /24/7 would make me very happy.  But it's high maintenance.

    Solar PV, just works when the sun is out, so you need larger battery bank for 20 hours of usage, and a larger array to recharge the batteries in 4 winter hours

    And any setup with batteries, will need a generator, to keep things going in cloudy weather.
    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 ||
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  • KenZ71
    KenZ71 Solar Expert Posts: 58 ✭✭
    Think I'll setup a barrel with a screen half way down to help gauge how much debris actually flows out of the drain line I am looking to harness.  At the same time it should give me a good idea for the flow rate.

    Showing my ignorance - what maintenance is required of a hydro setup that is not required of a solar?

    * Ensuring the turbine is free of debris
    * Would bearings be mostly maintenance free? Comparing to automotive where many axles are essentially lubed for life. Sure the manufacturer may recommend periodic greasing but many people simply forget that.

  • Horsefly
    Horsefly Registered Users Posts: 470 ✭✭✭✭
    If you want to see the successes and pitfalls of Hydro, check out this YouTube channel:  https://www.youtube.com/user/MrHydrohead

    This is a guy in Colorado who powers his home with hydro, and has since 1996. He documented all the work of his 2015 upgrade in a series of 18 videos. Pretty interesting, but not for the faint of heart.
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 8S (25.6V), 230Ah Eve LiFePO4 battery in a custom insulated and heated case.
  • KenZ71
    KenZ71 Solar Expert Posts: 58 ✭✭
    One year follow up

    Have not done anything yet. Got tied up with some major renovations that lead to unknown issues needing more repairs.

    Anyway still thinking the hydro might work. Pond level has been consistent aside from a 2 month period where it dropped a couple feet. Then after 3 to 4 inches of rainfall we are back to draining via overflow. That gives me hope this might work.

    One big downside Duke Energy (utility co) has a crappy Net Meter policy where if I overproduce they smile and say thanks for the gift, no rebate / purchase. Although I doubt would produce that much. If we did would offer free electric car charging in exchange for... [Humor!]