I am back after my first version of solar powered water tank
I moved and lost the convenience of my previous system but I have plans for a larger garden this time. The new owners of the house and water system absolutely love it! I decided to replicate and upgrade the design to match the needs of where we now live due to higher summer water restrictions. First thing you need is something to hold your recovered rainwater in. My new design uses two recycled FOOD GRADE water totes of 250 imp. gallons (275 US gallons) each. They cost about $150 each and I easily sourced them though www.used.ca You You can see whats available in your area by simply googling "1000 liter water tote near me". You can get them much cheaper if you don't care about what they were used for originally (lubricant, pesticide etc).
I would HIGHLY recommend that you DO NOT USE ANYTHING OTHER THAN A FOOD GRADE CONTAINER if you are watering plants, animals or storage for consumption. Only use the non-food grade containers to store water for firefighting, pressure washing or similar. The food totes that I've seen are 250 gallons and 300 gallons and all come with an integral valve at the bottom and a fill cap on the top. I'm sure there are other sizes out there but these seem to be the most common.
An important thing to remember is to connect all of your water barrels with a common manifold so that they all drain and fill at the same time if using a single supply source as I have. You can see the white PVC tube between the two barrel outlets that allows both filling and draining at the same time.
These barrels weigh a considerable amount when full, about 4150 lbs for the water alone, then another 140 lbs per tank! Make sure that when you design a stand you consider the surface you putting them on that it is firm enough not to sink, and if you are raising them above ground that you use wood that can support 2 cars!!! Remember that just because it doesn't fall down right away, doesn't mean it won't.....and normally at a time when you need the water really bad or when it can hurt someone or something.
Step 1: All Downspouts Rerouted
My new system uses the water collected from two sheds with a roof area of 450ftsq and all four downspouts (two from each roof) are rerouted into a single barrel opening.
The 'splicing' of the downspouts into a single pipe involved a set of small metal shears and a 1/2" drill bit to get the hole started. Once the pipes are connected they need to be held together with small metal screws (designed for downspouts) and a sealant (designed for gutters) that will prevent your recovered water from splashing out of your newly joined non-factory joints.
Step 2: Primary Filter From Downspouts
Roofs and downspouts collect all manner of debris and I would prefer it not be inside my water tanks and inevitably inside the pump.
I manufactured a primary filter by using two layers of 1/4" x 1/4" steel mesh slightly offset from each other to create smaller holes. This was then placed over the end of a piece of firewood with the same dimension as the tank top opening, and hammered until it produced a 'bowl' that would fit tightly inside the tank opening but still have a lip and not fall in.
Step 3: Secondary Filter Before Pump
while the primary filter removed the larger stuff like pine needles and leaves, there are things like seeds and other crud that can damage the pump or plug the hose nozzle. So this filter is inline on the tank output to filter all of the smaller stuff. It uses a reusable nylon mesh than catches the small bits and can be rinsed off.
I managed to find this item in one of our local hardware stores here, so don't know whats available in your area. Here is a link for information.
here is the ball valve that I used as a shutoff for both tanks
To enable connection of the tank to standard plumbing sized pipes and fittings I used the following parts to adapt the industrial tank opening down to 1" PVC.
The first part to connect to the output of the tank ball valve is the large end of the larger rubber coupling
The next part goes into the smaller opening of the larger rubber coupling
The next part connects between the reducer and the final 1" PVC piping.
Here is the smaller rubber coupling
Step 4: Outlet From Secondary Filter Into Garden Shed
simply a hole in the back of the shed for the hose to pass through :)
Step 5: The Hose Protection Tray
the hose runs along the back wall inside the shed, but may inadvertently have stuff placed on it. To prevent damage or loss of water, I ran the hose between 2x4's as protection.
Step 6: RV Water Pump and Battery
I used a full size car/marine battery in this version of the water system as the volume of water stored is much greater at almost 600 gallons (between the two tanks) if the tanks are topped right up to the top opening.
The water pump is a typical RV water pump with built in pressure switch so the pump is not always running unless the pressure drops when you squeeze the nozzle. This prevents dead-heading the pump (pumping a pressure in a closed system). Keep the consideration of battery size, water volume potentially pumped and current requirements of your pump when considering the pairing of pump, battery and solar panel.
The battery I used , when I bought it was on sale and good reviews.
The water pump I used, no sale but good reviews.
In these photos it does not show all the routed wiring and the protective wooden lid was removed for ease of viewing. Everything was connected as per my hand drawn schematic.
There has been some good dialog in the comments section as to safety when dealing with batteries and for cohesiveness I will restate the important parts below.
Open battery terminals are a hazard if they are in an open area that is potentially subjected to contaminants (liquid or solid) as these can lead to 'tracking' (where the battery finds a minor conductive path) or where they can directly contact a conductive material creating a short (create a current path between positive and negative).
Be careful when connecting to the battery to not short out the battery terminals as this can allow an excessive amount of current and vaporize (yes literally) the conducting object between them, whether this is wire, watch or even a screwdriver and cause burns and fires.
Do not forget that when a lead acid battery charges it produces small amounts of hydrogen gas which needs to be able to vent to outside as it is flammable. Do not smoke around a charging battery!
Do not store or subject your battery to direct sunlight or heat as this can cause your battery to dry out and/or potentially damage the battery case with warping and cracking causing acid leaks.
Any acid on or around the battery should be neutralized with baking soda first and then rinsed away with water before drying.
If you need to top up the electrolyte levels in a non-maintenance free battery, only used distilled water so as not to introduce contaminants into your battery acid and reduce it's longevity. Wear gloves and face-shield if adding water to a battery to minimize the potential for contact with acid.
Use an inline fuse with a current rating slightly higher than the maximum current of the pump you will be using, this will prevent the battery from potentially outputting massive current through the circuitry if a problem was to occur with any component of the system.
Step 7: 40W Solar Panel and Charge Controller
Here is the solar panel I bought that came with it's own charge controller. This is a 40 watt panel and will recharge the battery I selected in an afternoon. For a solar panel it is important to also have a charge controller as it regulates the charge to the battery and prevents damage. The package was on sale for about 90 bucks, and CT often has sales like this so if you're not in a hurry its worth the wait.
For the electrical connections any wire of 14 gauge or larger would be more than adequate. Be extra careful when connecting to the battery to notshort out the battery terminals (create a current path between positive and negative with no load) as this can allow an excessive amount of current and vaporize (yes literally) the conducting object between them, whether this is wire, watch or even a screwdriver and cause burns.
The circuit will function without an inline fuse, but can be dangerous should a short occur with the pump, wiring or switch. So for safety safe use an inline fuse with a current rating slightly higher than the maximum current of the pump you will be using. These can be picked up at any hardware or Canadian tire store.
I have included a sketched schematic of how to connect all the required items. Always follow the manufactures directions for connecting the solar panel and charge regulator as there can be slight differences in connection requirements. My drawing is a guideline. The important things to remember are to fuse the input supply from the battery at a slightly higher amperage than the maximum your pump can draw and to follow that with a switch before the pump. This is important as if you have to work on the pump for whatever reason you can shut off the supply voltage and remove the possibility of a short.
I ended up making a custom bracket to hold my panel away from the side of the shed and at about a 30 degree angle from vertical, aiming south to catch the afternoon sun.
Here is a link for the inline fuse.
Here is a link for the solar panel and charge regulator.
Step 8: Outlet From Pump to Hose Reel
Simply a hose reel that I found and liked.
Here is the one I used.