This project goes into the build of a homemade alternative offgrid power generation system using a water wheel and flowing water source like a stream or creek. In order to catch the water from your spring or creek , the first step is to build a small dam. This enables us to produce maximum power from the running water wheel .
STEP 1 : BUILDING THE DAM
First, We use a 4 inch pipe to divert the water before starting the construction of the dam. With a solid concrete foundation ,we aim to make a 42 inch dam with 30 inch of head . A six inch 36 inches long PVC drain pipe is installed on the high water side .The dam is constructed using four layer of hollow blocks and quickrete blended mason mix .Try raising the water higher to see how much higher it needs to go before it overflow through the sides.
The dam board gates made of deck boards are installed in the middle .The back board and the front boards are spaced apart an inch and three quarters. The dam stop gate made of plywood with dimensions of one and half is inserted between the boards . To get a tight seal a half inch rubber tube is stuffed between these boards.
STEP 2 : BUILDING THE FLUME
With a 13 and half inch treated plywood and couple of 2X6 plywood side boards, the flume is built. The side boards are glued to the plywood base using adhesive sealant and screwed with exterior grade screws.
To resist twisting and to keep the width of the plywood steady , four cross spacers are installed on the flume board. To divert the water without having to drain the dam, we make a small trap door in the flume near the opening . The trap door is made seven inches back from the face of the dam. The door is supported by a flange around the back and a stainless steel hinge.
The flume is installed on the creek with the help of rebars and supporting deck boards. The rebars are attached to the boards using u-bolts and drill bit. Three more subsequent flumes are attached to each other. The gap between the flumes are sealed with poly foam caulk rope.
STEP 3 : MAKING THE WATER WHEEL
The waterwheel is made out of a section of 55 gallon HDPE drum . The blades are made of 4 inch PVC drain pipe. The blades are curved so that it retains most of the water making it more energy efficient. 24 blades are attached to the drum using 16th by half aluminum angle pieces.
A three quarter inch jack shaft from an old go-kart is used as the drive shaft. This is supported at both ends of the wheel with a help of pillow block bearings. Two 28 inch Circular end pieces made of plywood is bolted along both sides of the barrel using a 6 ten inch long half by thirteen carriage bolts to make the wheel build complete.
Two square collar blocks are mounted on to shaft to center them. The holes are larger than the shaft so that the wheel can be adjusted to get the runouts reduced.To center the waterwheel and to adjust the runout of the center shaft , we use four blocks and adjustment bolts around the center block like a four jaw chuck .
STEP 4 : INSTALLING THE WATER WHEEL
To install the water wheel securely, a support structure made of 2×4 boards are installed near the end of the flume. The water wheel is secured on these support boards with the help of couple of swivel block bearings.
STEP 5: CONNECTING THE MOTOR AND THE WATERWHEEL
We use an adjustable Unistrut to mount the bearings,sprockets and the motor. This can be adjusted for chain tension as well. The Unistrut will stand vertically on top of the cross support that is under the flume.The Unistrut’s are mounted onto the wheel on both the sides with help of bearings and T-nuts. A Number 35 sprocket with 72 tooth is mounted onto the center wheel shaft.
This sprocket is connected to a half shaft with 11 tooth sprocket with the help of a size 35 go kart roller chain. A Permanent Magnet Brushed DC motor mounted on 2×4 board is further connected to this shaft via another sprocket. This gear system has a ratio of 30.86:1
Using unistruct angled brackets, the wheel is mounted onto the support board near the flume. The wheel is positioned near the flume in such a way that the water where it meets the wheel is exactly at the top.
STEP 6: CONNECTING THE CHARGING SYSTEM
The charging system consists of a 12V DC standby battery, MPPT charge controller, and 300W sine wave inverter. The connection from the water wheel DC motor goes to the charge controller. The charge controller is also connected to the battery.
Finally, the inverter is connected to the battery which is further connected to a load. To make this charging system secure, make sure to make a fuse connection between the components. All these components are mounted on a temporary wooden board.
Image Credits : Joe Malovich