Hydro vs Solar

KenZ71

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

Dave Angelini

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.

KenZ71

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.

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

mike95490

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.

KenZ71

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

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.

KenZ71

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!]