Author Topic: Have a running Hydro System. Want to add Solar for backup...Questions  (Read 1246 times)

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kcebcj

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I have a Stream Engine in a small creek that I installed 13 years ago that produces all the energy that I can use up until a couple years ago. I'm totally off the grid and the creek has been struggling during the last couple summers so was thinking I would like to install some solar panels just for summer use to back up the hydro and maybe allow for a A/C to run some. Loose the sun in here all winter.

What I have now is a 48 volt system with a Outback Inverter 600 Watts a Xantrex C40 charge controller and a Absolite 48 Volt Gel Pod 350 amp battery setup. I put all of this together with the guidance of a solar professional who has sense passed so I'm somewhat familiar with the components but would like some help.

What I need to know. Do I need to find a charge controller that will handle both solar and hydro or do I just add another controller for the solar? I have not checked with the Outback Inverter people yet but I would think after the controller connecting to the Outback would not be a problem but don't know.

So to those who know any response is appreciated.

DamonHD

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #1 on: September 14, 2017, 11:26:23 AM »
I'd say that as long as you never overcharge your batteries (or overwhelm any dump regulators) when everything is generating at once, it's not uncommon to have two entirely separate systems/controllers that touch only at the batteries.

For example in my tiny off-grid system that I write about here:

http://www.earth.org.uk/expanding-off-grid-PV-system.html

I have one big set of panels on a nice MPPT controller, and a few odds and ends on a separate cheap PWM controller.  They know nothing about one another.  They are both set to 'gel' battery charging.  It is not possible even in full sun to hurt my battery bank by charging too fast I believe.

Rgds

Damon

kcebcj

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #2 on: September 14, 2017, 02:42:15 PM »
Thanks for the response.

Kind of skimmed the article you posted and most of it is over my head.

I don't think it will over charge the batteries as the turbine has a diversion so the excess energy would get dumped I think. When batteries are full doesn't solar just kinda shut down? Don't know much about how solar panels operate.

Need to open up the Outback Inverter and see how I tied in the hydro and that might give me a clue as to what I need to do.

Anyone who has done something similar to my original post would sure appreciate your input.

DamonHD

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #3 on: September 14, 2017, 03:00:13 PM »
If you have a diversion load then the solar will generally attempt to dump through it, not stop charging, so would have to be rated for hydro+solar.

You could probably work round that by setting your solar to charge to a slightly lower voltage than the dump will run so that it will indeed give up charging before the dump cuts in, but you will have difficulties with the absorption/equalisation phases of solar charging.

But a grown-up will be along any minute to give you a better answer than I can!

Rgds

Damon
« Last Edit: September 14, 2017, 03:07:34 PM by DamonHD »

george65

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #4 on: September 14, 2017, 06:27:54 PM »

Just set up a seperate system for the solar. You can get controllers cheap and all you have to do is connect them to your batteries. When either the solar or the Hydro system senses the batteries are full, they will dump or in the case of the solar, just stop charging.
If you are dumping the excess with the Hydro, just set the cut off point on the Solar a couple of 10ths of a volt below that of the hydro so the solar won't be feeding the dump load.... unless you want it to for water heating or whatever.

Myself, given you have a backup source, I wouldn't spend a lot on a controller. I have used Fleabay controllers and they have been very good even though they were just PWM.  You can also have 2 controllers running off the one string of panels. they will divide the load and that way you can get more amps into the batteries.

It is simple, no hidden catches. Just have 2 separate systems both charging the same batteries. One will make up the shortfall of the other and if the batteries are full, the solar will turn off and the hydro can run as normal.

kcebcj

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #5 on: September 15, 2017, 09:25:48 AM »
Hey thanks for that.

That is how I kinda thought it would work but was not sure. Now just have to figure how it connects in the Outback Inverter. Can't be brain surgery right?

I don't remember what the diversions setting for the hydro are I think 56.6 volts so have the solar shut down at 56 or about that. Now will the solar start to run when the voltage drops below 56 or will I have to tell it to start with a setting? Probably will start on it's own right?

I'm totally off the grid so this hydro system is important. Are there any real risk I should watch for when trying to get the panels to work. The batteries pack is a Absolite 48 volt gel pod and sure don't want to screw it up.

Have a neighbor who is doing the same thing but in reverse. His main source is solar with the hydro as a winter backup so we are both trying to get it right.

george65

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #6 on: September 16, 2017, 09:44:29 PM »

I don't think there is any risk, pretty much the reverse. You'll be a lot better having your batteries at a higher charge rate than drained.
both the solar and the hydro should kick in and supply power on the fly so to speak so if you are using power through the day they will give you what they can and the battery reserve will never be touched.

The one thing I would suggest is setting your cutoff on the solar with a multimeter against the hydro controller.  Pretty much all meters, especially all the ones I have seen built into equipment read differently.  mate of Mine has good meters and gets them calibrated. I check my Cheap Chinese meters off his and they are usually within a volt which somewhat annoys my friend. His Meters, $400, mine $15-20. Difference, within a volt, if that.

Thing is, you get one reading off the meter and another which can be a fair way off on the inverters/ chargers/ plug in meters etc. You have 3 meters and no two agree. By using the multimeter at the battery, don't care what the controllers think the voltage is, you set it to the standard of the multimeter and then to each other so you know, the solar would be coming in half a true volt or whatever under the hydro and maybe not 2/10)'s over which will have you confused why they aren't doing what they should.

You may have one charger set at 56.6 or whatever and set the other at 56.0 but in fact the 56.0 may be higher than the 56.6 on the other gear.
I would meter one where it floats on the multimeter then the other and compare. Work out the margin of error ( and I'll guarantee there will be one)  on what they say to the meter and set by the meter so you know where the charge controllers really are in comparison and that your cutoff  points are also at the margin you want.

Other than making sure the voltages are metered at a standard ( separate multi meter) I see no issues.  The job of the controllers is to keep the batteries within specified parameters and given the input needed, that's what they will do.

kcebcj

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #7 on: September 17, 2017, 08:37:26 PM »
Thanks for the tip George.

I would never have given that a thought Would have trusted the settings on the controllers. Trying to figure what I want to do for panels and which new controller to purchase. I have the Xantrax C40 in the existing system now and will probably just get another one. Only want to get about 5-10 additional amps @ 48 volts to the batteries during the summer. The hydro puts out 11.5 steady amps @ 48 volts so it only needs help when the creek drops and it's really hot 3-4 months max so I use less water out of the creek by slowing the turbine down.

In everyone's opinion which is the best MPPT charge controller for the money in case I decide to go that way. Have looked at Outback and Xantrex MPPT's but they are a little more then I want to spend right now.

Any suggestions are appreciated and thanks.

thirteen

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #8 on: September 17, 2017, 09:54:21 PM »
easy to say but as a suggestion keep copy of the voltage and date of the setting you make. Gremlins like to change things.  13
MntMnROY 13

kcebcj

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #9 on: September 19, 2017, 08:04:56 PM »
Thanks thirteen, I note everything down.

I think I have most figured out and want to thank all for your input. Going to research all the components and build this next spring so there will probably be more questions.

george65

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #10 on: September 20, 2017, 04:49:53 PM »

Can you get used panels cheaply?
I just bought 20x 250W panels for $40 ea.  Went through and tested them all and not a lazy let alone dud one amoungst them.  Crunching the numbers, The ROI on the panels alone will be about 6 months on what they save me on power costs. Add in the DIY racking  ( which I have the steel for already sitting around)  and wiring ( have to buy most of that) and It might be 9 months. The inverters I already have which I picked up from the tip so it's a very sound investment.

Made 15Kwh yesterday with most of them lying flat on the grass in the back yard.  Wanted to test them and I figured I may as well have them doing something till I get them on the roof.
15Kwh day x.30C Kwh  = $4.50 day.  x90 days for the billing period, $405.00

Other panels I have sitting on some scaffolding to put them at the correct tilt are producing 4x their KW rating so If these do the same, which they should because they are newer and better quality panels, that would be 20kwh/ day or  $540 quarter saved.
Just ot to keep an eye on the power meter I'm spinning backwards. Don't want the next meter reading to be under what the last one was, they may tend to question that.  Another month and the air will be running a fair bit so I'll make credit while I can.

You should be able to look up the solar ratings for your area to get an idea of the return you will get. IE, here it's 4X the Kw rating which is what I am getting here in spring. Summer may be a bit higher and winter lower.  If you know the returns your panels should produce and how much extra power you want, you can size quite effectively.

That said, the new way of doing normal installs now because the utilitiys are limiting the amount of power you can install ( IE, limiting their revenue losses)  is to oversize the array on the inverter by 33%.  The idea of this is that that panels are never 100% efficent so by oversizing, you get longer at full output on the inverter. They don't care if say they are a 5Kw unit and you put 6.5 kw of panels on them and the panels produce 6Kw, the inverter just clips the excess current and runs full output.  As I have my inverters well over paneled as well, I find I have made 3Kw before the whole array is even in full unshadowed sunlight at 9am.  Just mucking round like this has shown me it's not the max output you want to worry about, it's the " Shoulder", the first 2 hours of the morning and last 2 hours in the evening.  The full sun isn't where the gains are, it's the ramp up and ramp down you want to cater for.
  I'm thinking of turning 50% of the panels away from perfect orientation and see how that goes. I think they will be fine in the middday sun but possibly may pick up a bit more morning and night. Or they may just average out the same which is what I think but nothing tested, no knowledge gained.

i'd definitely recommend looking for used panels. I'd also suggest don't go below 250W either. Smaller ones may be cheaper to buy but the installation costs make them end up costing more. Here I worked on .20C a watt for what I'd pay.  Gives you a comparison between different size panels for the output cost but again, be aware the smaller the panel, the more you'll need and the more framing, wiring etc which is the exy part.
I managed to get below the .20C/watt but other places will be cheaper and others more.
Work out what you want to pay in your area and stick to that.

kcebcj

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #11 on: September 23, 2017, 08:14:59 PM »
Thanks for the info George.

I live totally off the grid and have done so for 13 years now so don't deal or worry about anything to do with the local power company's. The solar system I have been inquiring about will be just a backup for the hydro system that is in place and mainly to increase energy to the batteries during the summers and heavy spring runoff when the turbine is handicapped with either low or high water.

I will probably buy the panels new get exactly what I want install them and not worry for the next 20 years.

SparWeb

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #12 on: September 27, 2017, 11:11:36 PM »
Hi kcebcj,
Sorry I didn't see this thread sooner.  Thanks for joining us!

I have a "mixed" system a little like the one you want to have.  Wind+solar in my case.

I really don't have much trouble with the combination of wind and solar.  I set it up so that I can use the solar in either one of 2 ways:
1- solar is PWM regulated by the solar charge controller without triggering the wind diversion load, or
2- solar dumps through the diversion load.

This can be managed when I take the covers off the charge controllers and set them carefully so that either:
1- the diversion voltage (on the wind CC) is higher than the bulk voltage (on the solar CC), or
2- the bulk voltage (on the solar CC) is higher than the diversion voltage (on the wind CC).

On the face of it, doing #2 is functionally the same as hooking the solar panels up directly to the battery and leaving the wind's charge controller to deal with it through the diversion load.  However, there are times that I don't want that to happen (summer especially; who needs the heat??) so it's more convenient to leave the cable connections alone and turn the knobs a few points.  If you get two Xantrex C40's side by side, then it's easy to see the comparison in the settings as you dial them in.

Currently, I'm running in setting #1.  I'm hoping to have a good reason to go to setting #2 this winter because I'd like to get back to running the water-heater diversion load that I've used in the past, instead of the air-heater that I have at the moment.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

kcebcj

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #13 on: September 29, 2017, 08:46:56 PM »
Hey SparWeb    Thanks for the post.

Been researching this for awhile now and here is what I have come up with. 3 panels 255 Watts 30.8 volts 8.28 amps. Wired in a series I come up with 92.4 volts and 8.28 amps.

Now I have to run 200-300 feet depending on where I decide to set the panels with no options closer. Checking the voltage drop I end up with 89.96 volts with #6 AWG copper wire little better with #4 aluminum and I have both. Now I want to utilize all the voltage so instead of another C40 (PWM) controller I'm going it install a Outback FM60 (MPPT) controller as to convert the extra voltage into amps going to the 48 volt battery pod, so the amps according to my figures end up about 15.45 amps at the inverter. That just about matches the amps coming off the turbine under perfect conditions.

Now thanks for the suggestions as to the settings in both controllers as that I have to do. I don't want the power from the panels going to the turbines diversion so the FM will have to shut the panels somewhere below the diversion settings in the C40. I'm a little foggy on this part but will figure it out before I get there..I hope ha-ha! Seems to me I had to set a bunch of things in the Outback Inverter when I installed it so will need to totally refresh my memory.

SparWeb

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #14 on: September 29, 2017, 11:23:58 PM »
I haven't set up an Outback FM before, so I won't pretend to know specifics.  The other CC's I've set up all expect the same basic info: that's the range of voltages to regulate on the batteries.  Since different battery chemistries and designs have different voltage ranges, you can take advantage of this to set up the "slightly wrong" settings in the CC for your Absolytes to get the most of this charge, without the diversion.  Also, mind the temperature corrections.  If one CC is corrected at a higher rate than the other, then the settings on the two machines could drift apart, or closer, or cross over as it gets colder (or warmer).

Once I got my Morningstar CC, I found myself fiddling with the settings often, trying things out.  Eventually I settled on what I wanted, and then wrote it all down, and stuck the notes on the wall beside the CC.  If I'm ever tempted to change the settings again, I have my notes to tell me what the previous settings were...

Since you regularly use your battery power, and have a continuous flow of hydro power coming it (is it continuous? changes yearly/daily?) then I think you can expect some days the solar is not needed, other days it is appreciated.  BTW, Have your needs increased recently?  Was the hydro enough a few years ago, but now something's been added and hydro doesn't always keep up? 
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

kcebcj

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #15 on: September 30, 2017, 02:10:30 PM »
Hello

Yep the turbine is continuous power 24/7 11.5 amps @ 48 volts. What has changed is I had a lesser snow pack up behind me and this summer was mid 90's for 3 months so the creek where the turbine is set up really got lower then I have ever seen it so to protect the creek and everything that lives in it between the catch and the turbine exhaust, I turned the turbine and everything in the house down that was not necessary and kept a decent flow in the creek. The turbine was producing about 9 amps

So with the panels I want to take up the slack during the summer if the turbine needs to be slowed down again. The panels would only need to run maybe 4 months max and maybe I could run a A/C couple hours a day just to cool things down.

Another thing the 48 volt battery pack I have just hit it's 20 year mark this year and I don't think it's holding the charge as well as it was as the diversion rarely comes on but it is still on the warm side so will see if that changes when it cools down.

As for the temp controls. I have one on the batteries that goes into the Outback inverter but nothing to the C40 controller. When I set up the panels next spring I will make sure all that stuff is right and coordinated properly. Thanks for the tip.

SparWeb

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Re: Have a running Hydro System. Want to add Solar for backup...Questions
« Reply #16 on: September 30, 2017, 04:38:09 PM »
You're welcome.  I have a stack of Absolyte 90A's myself and they're just about as old, too.  Excellent, aren't they?  Mine have swelled a bit over the years, but still going strong.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024