Introduction: Green Solar Powered Water Barrel

Picture of Green Solar Powered Water Barrel

A Green way of using rainwater with the convenience of city water. The attached solar regenerated pump enables you to water plants with pressure, even when the water in the barrels falls low enough that it barely passes the level of the faucet. The sun-warmed water also aids in the growing of plants as it does not shock them. The twin 85 gallon barrels are raised onto a very sturdy 4x4 box assembly from recycled wood, held together with new carriage bolts because the total weight of all the water when full is approx 1700lbs. This frame is resting on eight 2 inch thick 18 inch square cement pads to prevent sinking. The barrels are raised to increase the head pressure and decrease the work load on the pump.
Vote for me if you think my idea is worth passing on to show people being green doesn't have to mean sacrificing quality or convenience . Thank you for taking the time to look at my instructable!

Step 1: Water Supplied From Mother Nature

Picture of Water Supplied From Mother Nature

link barrel to downspout. ensure top of barrel remains below level of water entry. I found the Watersaver attachment for the 3x4 downspout pipe works perfectly. In order to enable adequate water flow to the barrel I adapted the Watersaver attachment by drilling out the side and adding a flange for a 1inch PVC fitting. I sealed this by using a rubber gasket and additionally using a silicone sealer. Ensure there is a downward slope between the downspout and the barrel entry.

Step 2: Overflow Back to the Downspout

Picture of Overflow Back to the Downspout

ensure you have a complete path for water from the downspout to the barrel or barrels then from the overflow to the downspout again.
1" pvc overflow line from last barrel back to downspout. ensure you maintain a drain angle towards the downspout or sediment could collect in the line.

Step 3: Downspout Drain Connection

Picture of Downspout Drain Connection

1" pvc entry back into downspout. ensure pvc pipe does not fully block 2"x3" downspout and keep the downward slope to the pipe to make the water flow towards the downspout.

Step 4: Manifold

Picture of Manifold

common connection point for using water.
this photo of the manifold is before I put the water gauge on. (shown on intro and last step)

Step 5: Water Filter

Picture of Water Filter

filter the water from the barrel to protect the pump. keeps the roof sediment from wearing out the pump. This water filter will last forever, as it has a reusable nylon mesh filter inside, that only requires periodic rinsing.

Step 6: Battery Box With Power Switch

Picture of Battery Box With Power Switch

keeping the battery and pump protected from the elements inside a full size battery case .

Step 7: Inside View of Battery Box With Motor

Picture of Inside View of Battery Box With Motor

An inside view of the standard size battery case and equipment layout. the solar cell was left with clamp connections in order to enable quick removal of the battery case lid for cleaning and maintenance.
The pump was recycled from an older sailboat. The battery is a standard size lawn tractor 12v, and with proper maintenance should last 6-10 years before being needing to be recycled at the depot.
An older car battery that just doesn't have the power to crank the car fast anymore would be more than adequate for this application, and a great alternative to buying a new battery.
The 5.5W solar cell was also recycled for a fraction of it's original cost from an online classified, and solar cells have a lifespan of aprox 15-20 years. I wanted this little project to last as long as possible before needing any repairs.

Step 8: Flowjet Pump

Picture of Flowjet Pump

closeup of Flojet 4405-143 pump particulars
another pump that I have seen that is almost identical to this is made by shurflo
This type of pump is used in RV's or sailboats to supply water pressure, as well as for using as a wash down pump on boats.
I chose this type because it had an internal pressure switch that stopped it from running all the time, only turning on when the water pressure in the hose drops. In addition I got a super deal on it secondhand.
There are many different styles of pump available that will be more than adequate for this application. It depends on your budget, and availability of secondhand pumps in your area.
Other things to consider would be whether or not you want the pump running all the time (lawn sprinkler) or only when you press the trigger on your hose nozzle. Without a built-in pressure switch, the pump would run all the time as soon as you turned on power. In all types of applications, make sure the pump output pressure does not exceed the pressure rating of your hose/pipe or you might burst it if the outlet was closed or blocked unexpectedly.

Step 9: Water Gauge

Picture of Water Gauge

As the water level changes inside the barrel the level inside the tube will follow the same level.
This was fun to install as I didn't want to waste all the nice rainwater and drain the tank before I drilled a 3/4" hole in the bottom of the tank to install the angled shut-off valve. Reminded myself to only use a battery powered drill :)
I reused some 1/2 inch plastic tubing that I had left over from another application and connected it to a 3/4 inch angle valve with a shut off (which came in handy during install)
I sealed around and under all penetrations into the barrel (valve and screws) with a two part epoxy that was a water proof filler and sealer.
It is important to not completely seal the tube or the level will not change to reflect the level in the barrel.


TijerasR (author)2016-12-27

Where did you get these tanks?

BilgeD (author)2015-04-05

Great project! I think I'll incorporate the pump and charger into our rain barrel setup. Can I make a suggestion? If you use one of the RainReserve diverters, and mount it in the downspout at the level that you want the water to fill the barrels to, you can eliminate the need for a drain line. Once that level in the barrels is reached, the water simply runs down the downspout. They're also very durable; ours has withstood four rather bitter Northern Illinois winters, and we don't do any winterizing with it, it just sits there. Just a thought, thanks very much for sharing.

GoLightLady (author)BilgeD2016-10-12

Hey there BilgeD,

I like your comment about the diverter. Makes kind of sense to me, but am a bit confused why that would mean no need for a drain line. Is it that the water overflow then just flows back out the diverter and down the rain spout, bc it's at the same height? Am i understanding the physics of that right? (otherwise if the diverter is too high, the pressure wouldn't allow that) Thanks a bunch :)

joecardio (author)2015-05-06

Thank you so much. I have had an old Flo Jet pump for some time now wondering just how I could use it in this type of situation. Your model is excellent. The water level meter is an excellent addition. I will definitely be building this bad boy. Be well.

Neckbone (author)2014-10-25

Great project..!! Thanks for taking the time to document, share and answer questions. Very much appreciated.

kennethf2 (author)2014-09-29

i was looking to put in a small submersible pump with a float that is solar powered so i don't have to do the hose siphon thing in the rain at night! any idea of a good inexpensive pump i might use?

iPodGuy (author)2009-05-06

So, you have the solar panel clamped directly onto the car battery and the pump wired right to the terminals, too? Could you go a little more in-depth on that? Something like this would be a perfect solution for watering my grass. Thanks!

damoelld (author)iPodGuy2009-05-06

from the battery positive it goes to a 10amp fuse, then it goes to a single pole-single throw switch then to then positive lead on the pump. battery negative goes directly to the motor negative lead. Solar panel positive is directly clamped to the battery positive, and panel negative is clamped directly to the battery negative.

PD6 (author)damoelld2014-09-11

Another question if you don't mind: can you please point me in the right direction with respect to the battery box? I'm having a hard time finding one like yours with a switch that's also reasonably priced (and doesn't have extra stuff I don't need, like 12V outlets on the outside). Failing one with an integrated switch, any advice on how to add a switch to the mix? Many thanks again!

PD6 (author)damoelld2014-09-11

Awesome setup! Thanks so much for posting this! I'm going to try something very similar with my rain barrels.

Question though: is the 10amp fuse something I would have to buy separately, or would it come with one of the other components (pump, solar panel, battery, battery box)? If separate, anything special I should look for in buying a fuse? Also, how is the fuse connected exactly? I'm new at this type of electrical installation. Many thanks!

kc0wys (author)damoelld2009-05-07

Is there a diode in series with the solar panel? It might be built in, but if there isn't one, the solar panel will drain the battery at night when there is no sunlight.

damoelld (author)kc0wys2009-05-07

the solar panel has an internal current regulator and diodes.

roadsendllamas (author)2014-05-23

Very clean design lines. It appears the battery is exposed to the elements? Other suggestion, is to consider a filter in front of the pump inlet to capture what will be some of the roof top deposits that may be mineral components of the shingles, moss build up that flows down the gutters or other 'stuff'. A good sized clean out on the bottom to access the tank as solids build might really be good as well. Unless I am missing those in the overall design and if so.....never mind. GREAT job

alisonb (author)2013-10-11

I have seen a good priced 10w solar panel, could I use this with your system? I know it needs to be 12 volt but that is about it :)

damoelld (author)alisonb2014-01-08

sorry for the delay. but to answer the question...yes!
Larger is better as it will decrease the recharge time of the batteries.

alisonb (author)damoelld2014-01-09

Thanks for your reply, I have sourced all of the items I need and have found a great 20W solar panel. This is going to be my spring project ready for the summer. Cheers.

Hoooowler (author)2013-06-04

Great idea. Have you considered alternative water sources when there is no or limited rain? Luckily, I live on a canal and am considering something like this to irrigate my yard so I could attach a low-volume pump to fill the barrels when rain does not. Another alternate method might be a sand point with a low-volume pump. This could have it's own solar powered unit or run off the main. I would set it up on a switch or one could put a level sensor in one of the barrels and put a limiter on the low-volume pump circuit so that it only runs when there is sunshine.

Csinger1120 (author)2012-09-28

Thanks for the idea very creative. Quick questions for you: would like to insulate it for winter but ignorant on that?

The Lightning Stalker (author)2009-05-07

If you look around, you can find an all plastic pump that won't rust out from the rainwater. It's important that it's a jet pump so you get enough pressure to run the attachments. Or you can get a submersible and put it in the bottom of one of the barrels. That will give you huge pressures though so you'll need a regulator. Either way, never start the pump with the attachment(s) turned off or you will get cavitation which wears out the impeller(s). If you hear a louder "swooshing" sound, turn if off right away. That means it's cavitating and you don't have enough flow on the output for that size pump.

I've found that a Diaphragm pump such as this one works great, it puts out 35 psi at a constant rate, is very quiet, unlike a jet pump and is very small, unlike a jet pump that would be capable of 3.3 GPM (12.5 lpm). This model of pump has an internal pressure switch and bypass to prevent water surging and hammer (pulsation) when the hose or attachment(s) are turned on or off. I have saved my pump from the rainwater by mounting it inside a waterproof battery box. Originally I thought of using a submersible or fountain pump, but the extra connections would have to be mounted internal to the barrel (aka more hassel) and I did not need to have the capability of emptying the barrel in a matter of minutes.

Csinger1120 (author)damoelld2012-09-28

Question for you: Could I also install a hand pump that may generate enough pressure. On top of the barrel, similar to old water table pump to fill horse troffs? What is your take or suggestions on that?

I'm not attacking your pump or your instructable or anything. I'm just trying to help out people who don't know anything about the pipe and the pump and the ppppp... If all someone can afford is a used jet pump, then it works good enough.

no worries, didn't mean to make it sound like I was mad. I appreciate all comments.....even the ones that contradict my opinions, gets me to thinking in a less linear fashion, and sometimes another solution to the same problem. This is after all a forum, and not a podium :)

jerhpk (author)damoelld2010-08-12

I'm looking for a part-time pump for a smaller application. What is the flow rate on the pump you have? I'm not planning on running the pump for more than 30 minutes at a time, and maybe once a week. (The planned height of this project is about 8 feet, maximum. It does not need to be high pressure at this location, but it does need to spray slightly. Yes, I realize this is contradictory.) I do appreciate this instructable; I find I reference it frequently for a variety of projects. as a question, do you have the "sight level indicator" going into a hole in the top of the barrel, or just tucked under the lid? And is the top of the tube higher than the "overflow" holes?

damoelld (author)jerhpk2011-01-12

Sorry for the delay, was away.
The tube is tucked up under the lid. This prevents the crawlies from getting into it yet allows the outside pressure from the water column to equalize.

T3h_Muffinator (author)2010-05-27

This is really neat!  The pump was a great idea! 

Do you think the water's drinkable?  If not, maybe adding a purifier might help with that.  (I understand that this is just for watering plants, etc., but the prospect of a rainwater purifier is tempting)

Awesome work!

toogers (author)T3h_Muffinator2010-09-17

i'd use quite a few filters on this, it was, after all, sitting in a storm drain.

damoelld (author)toogers2012-07-02

Only from the roof of the house, no storm drains on this one. No contaminants other than those included in the rainwater and the granules from the shingles. :P

kyuubiunl (author)toogers2011-04-06

BETTER filter, not more.

swilus (author)T3h_Muffinator2010-12-14

If you add a sediment filter and uv this water would be perfectly fine to drink. Rain water is naturally soft. If you are really nervous about drinking, add an under sink reverse osmosis system: or any hardware store!

kwazai (author)2012-04-26

NC made it legal a few years back to use this kind of water for flushing (free sewage treatment-normally payed for).

recommendations (I'm in the process too-for a hydroponic graden setup)-

a copper dish scrubber in the supply line to remove phosphorous (grows algae).
a p-trap to keep mosquitos out

most neighborhoods have 'covenants' anymore- this is about ideal size to fit in a 'shed' of sorts (fenced in?)

damoelld (author)kwazai2012-05-03

Yard is fenced in. Mosquito meshing built into barrel lid breathing vents.

kwazai (author)damoelld2012-05-04


gfwhell (author)2011-10-09

In order to keep water free of bacteria, (Stagnating). bubble air through it, better still, ionize the air first, This is called Ozonated air. check out ALIBABA for cheap ozonators or make your own with an ignition coil and a bundle of Fluorescent tubes used as electrodes. you will need a pump to mix the ozone with the water,so a solar cell, battery and inverter will probably be required, do what I did Scour the USPatent office for information on water sterilization and apply your brain to someones invention, your welcome to copy whats there provided you dont try selling it. Of course you could make a filter and force the collected water through it, if you make it properly the water will soon contain no bacteria after passing through the filter, a couple of layers of ordinary surgical lint should surfice. you could sterilize the first gallon or two with a spoonfull of hydrogen peroxide. the filter gets more efficient at trapping bacteria the more water that is passed through it. GF

damoelld (author)gfwhell2012-02-29

I like the idea of ozone for purifying the water if it was for consumption. My plants like the stinky water after it's been sitting in the tanks, and it's at the right temperature to minimize shock. All of the additional comments lead me to believe that someone wants to see an instructable on a water purifier system supplied from rain and powered from the sun + for human consumption. Mine is simply for the garden.

vov35 (author)2011-09-09

Here's a thought on saving some power:
1) make a T on the pump's output, and attach a small diameter vertical tube around a foot tall; allowing the remainder of the water to flow through the straight portion of the T and function like normal

2) To the vertical tube, attach an endcap with a hole in it to equalize air pressure.

3) Drive two screws into the vertical pipe at a reasonable height. Connect these to an inverting circuit, like used in:
You should use much larger resistances and a power mosfet.

4) the mosfet throws a relay to turn on a pump. This will only happen when the water level is below the screws you set.

The goal here is that the pump turns off if you're not releasing pressure from the hose; allowing you to use a watering handle for the end of your line. Depending on your pump you may also need to install a check valve, to allow the hose to stay pressurised with the pump off. The height of the screws installed in the vertical tube will be directly proportional to the water pressure that will be maintained in the line.

... If I actually made the system and had photots, I think it would be instructable worthy, however, I don't have a rain water system to experiment, and will instead suggest that you try it out with yours.

damoelld (author)vov352012-02-29

I do like the rube goldberg approach :) I however, use the pressure switch that is part of the pump. When the pressure drops, the pump turns on.

vov35 (author)vov352011-09-09

I hadn't read to the point when you mentioned that your pump had an automatic shutoff, but it's still worth considering in my humble opinion. :p

hhart (author)2011-05-30

Absolutely awesome. I'm definitely doing this and thank you for putting this up!

DavidM45 (author)2010-09-02

great project! I have found that valves on a plastic line are so much better with a support like a 2x4.

jerhpk (author)2010-08-16

FYI: Lee Valley has a downspout adapter for sale for under $20. It has two garden hose fittings on it, to hook two rain barrels up simultaneously. Biggest reason I'm considering it (the adapter) is that it is something that does not need to be removed to shut off water flow to the rain barrels. (Local codes state that rain barrels are ok on homes as long as they are emptied and disconnected during the winter months. "Winter months" is an unspecified length of time in the code as of last time I checked, but I assume it to be when the temperature is low enough to warrant frost warnings, or similar. Codes have no such restrictions on "Non residential or non commercial" buildings, such as workshops or garages.) .

Boyd Carl (author)2010-05-16

Good idea! What is Make & model of water filter? What is good source(s)?

damoelld (author)Boyd Carl2010-08-03

Hi Boyd, located an alternate place to buy the filter that should be available to everyone. Home Depot DripMaster 3/4 In. Mpt X Mpt Y-filter; Clm Model:: 61062 $20.99 hope this helps

rayzentz (author)2009-05-07

I like this. However, where I live, it is illegal to collect rainwater. How stupid is that?

WilderLust (author)rayzentz2009-05-11

most places that say it is illegal mean open containers... if you have a closed tank then they are ok. i live in one such place... it is illegal to have a rainwater collection but if you have a closed system it is ok. it is cold in winter here so i have a couple of 1000Gal tanks under ground which allow me to water all my fruit trees, flowers, greenhouse plants with only rain water with exception of rare extra long rainless summer months. i have old hoses underground watering the trees at the roots to minimize evaporation too... it is very efficient.

Hi WilderLust, could you post some pictures of the system you described?


hehe... well... it is all underground so pics are of no use; i did not take pics when i was making it years ago anyway. it is not really that hard, just dig a big hole, bury a big tank (or more depending on volume needed, and $), rum pipes from your gutters, place a pump in the tank to pump out the water when in need, and you have it. of course i have a pre-filter (55gal barrel) to get the junk cleared from the water before it gets to the big tank. you do not want to fill your tank with dirt, leaves, and other stuff washing off your roof into your tank. i also use a DC pump which i power with solar recharged batteries but that is an optional thing. some day i will make a wind powered pump too since we get decent wind around here. for big tanks, look at your building supply warehouses... they are not cheap when big but they are a permanent investment for you that will collect water for decades. i use PVC pipes in my system

Thanks for the info, i'm an engineer living in Mexico and I want to implement some simple sysytems in new homes, so thanks

here is the kind of tank i use
the best deal is the 1450 Gal @ $979 and 1700 Gal @$1149 both of which are .68/Gal

andy1917 (author)WilderLust2010-07-31


About This Instructable




Bio: 30 Year Retired Electrical technician from the Royal Canadian Navy
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