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I saw there really wasn't a topic for this, with society becoming increasingly aware of their carbon footprint or lessoning their impact on the environment.  Maybe this would be a good place to share info, knowledge, experience, equipment, suppliers, setup etc on solar applications......

In the next few weeks I'll try posting some basic solar info and general rules of thumbs, As and if this progresses, get into the sizing of equipment, types of equipment, pumps, panels, inverters, chargers, lighting and storage systems.


Hope to hear from others as well as input or questions.


the mad german


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I have been studying some on this and have decided on buying several 250 watt solar panel kits. The savings seems to be substantial over the cost of assembled panels.

Lets touch on the panels next, when considering this option.

A kit where you actually make the panels will provide substantial savings versus purchasing the panels, but this sin't something an amateur should try.

Commercial systems installed are going for around $4-5.00 a watt installed.

So say you are thinking about 3 250 watt panels. So take $4 X 3panels X 250 watts = $3000  is somewhat the price you'll pay installed which would include hardware and a 1000watt inverter.

But being prices have and are dropping, without a contractors markup you can buy the same panel on line for about $2.50 a watt or $600 each panel give or take and depedning on the type of panel.

Now lets look at the actual savings.

So say you have 3-250 watt panels you bought at $1800 and an inverter for $300.

Lets first look at the warranties, most panels have 90% production capability after 10 years which drops to 85% with a +/- of 3 to 5% variable at 15 years. Meaning your 250 watt panel will put out at least 90% of its rating +/- 3%.

So your panels 250 watt output is actually 225 plus or minus. Now the other issue that comes into play is outdoor air temp. These output ratings are ususally at a given temp in the lab, so lets say 72 F degrees. So in a sense you basically have no warranty when it comes to the actual production. If you were to call and or take legal action on the panels output not being up to the specs....good luck, you would have to show its been 72 degrees for the peak hours every day in order for your arguement to hold water, so anytime the temp is higher or lower then the tested spec.......the output rating is null and basically you have no warranty for anthing higher then 85% of its capacity, short of the panel putting out 50% less you'd have a hard time recouping any money in court.

Now lets look at the actual savings.

Lets say the average home uses around 1000 kilowatts a month, ( a kilowatt is 1000 watts) so 1,000 X 1,000 = 1 million watts of total usage.

If you were to install 3-250 panels you multiply that by the peak usage per day X 365.

So lets use my geographical region.

take 750watts (3-250) X 4.2 peak hours per day and 365 divided by 1000.

So it would be 750 X 4.2 X 365 / 1000. for kilowatts per year. 1149 kilowatts a year.

The rule of thumb for panels is less 10-20% minus 5% for the inverters.

So your output would be more like 600 watts an hour or 600 X 4.2 * 365 / 1000. or 919 kilowatts a year.

Now lets take that times the cost per kilowatt my utiltity bills me which is .0825 or 8 and 1/4th cents per kw.

So the total 919 X .0825 = $75.88 a year in savings. Not counting the SRECs which you could sell, wich I'll get into later as another form of income or revenue based on states RPS standards.

$75 is not much at all when looking at payback. Which means it would take 30 years for the panels to pay for themselves.

But being cost is coming down and projected to be $1-1.50 a watt by 2013 waiting would be advisable if you're looking for actual payback versus monthly savings.

Most states and the federal governemnt are giving incentives. On large commercial systems, here in the states until the end of 2012 the government is giving 30% cash grants plus 100% tax writeoffs for the actual upfront installed cost.


So if you're looking at making money......or payback......forget it.

If cost isn't a concern and you're looking more at your carbon footprint then its another option.

On my system, I got a good deal, can get batteries all day long, didn't want to string an extention chord across my yard or property, wanted my system to be mobile or portable, wanted to never worry about power outages, am somewhat of a survivalist that believes you should never count on anyone or anything (power or utilities included), plus my watt usage is very for me it works.

These are just some of the other sides of the coin when considering powering your system, backup power, or feasability.

the mad german

Thanks TC
TCLynx said:

Good info to have when figuring for Solar power.

Thanks Mad German

What I'm looking for is reliability and have decided to pay more up front for backup and simply run off the backup 24/7/365.  Will have it going in a couple of months and let you know how well it's working out.  I recently paid $560 for two 195 watt panels by going in on a pallet purchase.  I've yet to buy the charge controller, inverter and battery.  Will attempt to run the system from one 50-watt pump.

the mad german said:
So if you're looking at making money......or payback......forget it.

Sweet deal, thats like $1.43 a watt. Cost has been a problem with the entire solar movement....well that and batteries and their cost. Once the prices start coming down I believe alot more people will eventually make the transition.

Your production will actually be along the lines of 350-375 watt range. With an inverter you'll lose at least another 5%.

50 watts isn't that much, ever think of just using DC and not having the need for an inverter or another piece of equipment failing? Either way your going to need a big storage system for when the sun goes down. Because you're probably only going to get a continuous use of 6 to 8 hours via the sunlight hours anyways, which means you'll need enough storage capacity for an additional 16-18 hours. 

and what is your cycling rate going to be?  

Its definately workable with the panels you will be what decides how well it works or not based on pump cycling. Reliabilty is why I went the way I did being my pump wattage is minimal and it allows me to remote my system anywhere and not have to use power or run extension chords or worry about brownouts.

Keep us up to date

the mad german

George J. Thurmon said:

What I'm looking for is reliability and have decided to pay more up front for backup and simply run off the backup 24/7/365.  Will have it going in a couple of months and let you know how well it's working out.  I recently paid $560 for two 195 watt panels by going in on a pallet purchase.  I've yet to buy the charge controller, inverter and battery.  Will attempt to run the system from one 50-watt pump.

the mad german said:
So if you're looking at making money......or payback......forget it.
I'm open to the idea but would have to be convinced that the DC pump is reliable and it must be powerful enough to drive the indexing valve I intend to use.  I will probably pump less at night, if storage becomes a problem.  This is a new subject to me so I'll see how it goes and make adjustments as necessary.

the mad german said:

ever think of just using DC and not having the need for an inverter or another piece of equipment failing?

The DC pumps you've been using TMG, do you have any links to the pump curves for them?

The pump George is thinking of using has it's pump curves on page 2 of this pdf link it is the Quiet One 4000.  I Believe their pump curves and energy consumption is being modest which seems rare to me but the kill-o-watt meter told me the pump actually used 48 watts (though it was probably not fast enough to see the spike on pump start up so perhaps the paperwork is showing the peak.)

I've tested it with the gravity modified 1 1/4" indexing valve and it will work for it but it is the smallest pump I've gotten to operate an indexing valve without the use of a header tank and flush valve.


Anyway, my 300 gallon system with that pump would certainly be able to run on solar at least during the cooler half of the year.  During the hotter 6 months I have to add supplemental aeration beyond just the water returning to the tank to keep a full load of fish eating so that is another 20-35 watts usually. (Lower if I could find an air pump sized perfectly or a water pump for the job that wouldn't keep clogging.)


A timer will also be used in the operation of the pump but I expect that to pull minimal wattage but the way I run mine, the pumping is almost constant pump for 9 minutes off for a minute so I'm pumping to each of my six beds once an hour 24/7.


Now I would be interested in getting to know the pump curves of some of the DC pumps to see if any of them are comparable to the Quiet One 4000 in energy usage while still being able to produce the same flow/pressure.


I'd also be interested to see how a DC pump could compare with a Danner MD18.



I just shot a letter off to SeaSense asking them on their pump curves.

The 600gph wouldn't probably cut the cake but the 800 or 1100gph probably would, with  the latter being your better choice for your application. With the 600gph it did the job but ran 4-5 minutes and didn't have near as much pressure as when I switched to the 800gph.

I pump a little over 5 feet up, the differance between the 600 and the 800 being the 600 ran for about 4-5 minutes where my 800 runs about a minute to a minute and a half. With the pressure being strong enough it sends aerated bubbles half way down my 55 gallon upper storage tank and aerates the heck out of the water in the process (the reason I don't use a bubbler) because of the output pressure.

Fimco makes a nice 8 zone indexing valve that is 10gpm needing just 10 psi for 1" lines, the 800GPH Seasense would probably be pushing it but the 1100 series should work good for the application. The 800 would probably work and ensure  the indexing drive valve sealed if it was pumped into a discharge storage tank and had gravity behind it for proper sealing of the valves. They also make a low flow 6gpm for their 8-1 indexing valve which allows it to seal with less gpm.

I suspect the wattage of the 1100 probably wouldn't be 25-30 watts being my 800gph is only 18 watts.

My debris issue is practically nil. Originally I had the pump setting in a 4" pvc pipe sealed on both ends with about 30 - 1" holes in it but pulled in pooh...after a couple of weeks. I since put the 4" pvc pipe into a cricket basket, (from the fishing section of Walmart) it has a 4" opening, the pvc pipe fit into it perfectly and seals perfectly being it has a rubber gasket on the rim. This virtually allows for an unobstructed draw from every direction without allowing any sediment to  be pulled directly into the pump, if it does make it through the screen it acts like a trap and the debris to fall into the area between the screen and pipes

Its been over 6 weeks now and have had no problems since.

The only problem I had with their components is the float switch sticks occasionally (once every few weeks) which is how I cycle my pump on and off by the lower tank level. A bullfrog has been the culprit on a couple of those occasions sitting on it, so I since put styrofoam in the tank for him to float on. I need to get rid of him, I have about 3 dozen gold fish and 5 dozen minoows and it appears he's eating well on the minnows.

I'll post the pump specs when they get back to me.


I've actually got quite a bit of experience with the Fimco Indexing valves and what the minimum pumping requirements are for the valves.  The regular flow valves require a fair bit of pumping power to operate them reliably and I usually recommend something between a 1600-1800 gph pump for the Normal Aquaponics Indexing valves.  The gravity modified indexing valves I've worked with the manufacturer on I've been able to operate with the Quiet One 4000 which is nominally about a 1000 gph pump however more important than the nominal ratings are the pump curves since you need a pump that can provide the pressure as well as the flow so the pump needs to have the capacity to pump quite a bit higher than the height you have the valve installed at.
Hmm, still haven't got that pump curve....I'll have to send Seasense another email. Had any problems running the quiet one on an inverter?

Not so far but most of the time the pump is running on mains power and it only switches over to the inverter/battery backup power when the power goes out.  The Quiet One isn't pulling a big surge when it starts up though, it's only a 50 watt pump and it registers at 48 watts with the kill-o-watt meter.

Thinking of using sliding glass doors as my solar heating panels (I have 6 - 3' x 6'8").  Plywood on the back with insulating foam on the inside painted black.  1x4 or 1x6 for the frame and some kind of tubing inside - looking for something REALLY cheap. I'm actually thinking of using 1/2" thin wall PVC painted black since I'll only need to raise my water temp 20 deg F in the winter to keep it at 80F (raising Tilapia). Any other ideas for cheap pipe?


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