This project goes over the details on how you can set up and install a 300W Off the grid Micro Hydro System for your home. The water source mentioned in this project has a flow rate of 15 – 30 gallons a minute and the drop between the source and the house is about 150 feet.
STEP 1 : BUILDING A SCREEN BOX
The first step is to make an intake angled screen box for the system that helps in channeling the water from the source. The aluminum screen on the top blocks leaves, sticks, and other debris to pass through into the box. The box is made of a 24-inch 2X10,2X4 and a 2X8 angled piece of treated lumber.
We add 3 one and quarter inch attachment points on the lower side of the box for the HDPE poly pipes. The box is secured using exterior screws on the outside and inner tubes on the seam to prevent leaks.
The box is installed on the creek with help of a couple of three and a half inch concrete anchors and two boards are screwed on both the sides for support.
STEP 2 : CONNECTING THE SILT CATCHMENT BARREL
The outlet poly pipes from the intake screen box go to 55-gallon plastic barrel which acts as a silt catchment. The 3 outlet pipes are connected to the top of the barrel with the help of uniseal rubber gaskets. A 2-inch pipe is installed midway on the tank for the penstock.
We also install an overflow pipe near the top of the tank to take the extra water out and a three-inch cleanout pipe at the bottom. The cleanout pipe can be unscrewed to remove the silt and debris.
STEP 3 : INSTALLING THE PENSTOKE
To take the water from the intake to the turbine, the penstock used here is a 100PSI 1100ft 2-inch poly pipe. A threaded adapter is glued to the outlet coming out of the barrel. It is then connected to a two-inch full port shutoff ball valve followed by another threaded adapter and a pipe. The penstock poly pipe is attached to this pipe using barb fittings with hose clamps.
STEP 4 : CONNECTING SURGE TANK AND PRESSURE GAUGE
The next step is to install the pressure gauge and the surge tank to our penstock pipe. Water will come down through the poly pipe into another PVC pipe fitted with a pressure gauge, surge tank, two-inch closing ball valve, and a union to remove the turbine from the pipe. The surge tank is made of a standpipe that will prevent any water hammer from affecting the pipes.
The two-inch poly pipe coming out from the barrel is connected to the two-inch PVC surge tank and pressure gauge. If the main shut-off valve is suddenly closed, this tank will allow some of the surge to be absorbed.
STEP 5 : MICRO HYDRO TURBINE HOUSING
The next step is to build housing for the micro-hydro turbine. It is going to have a lid that opens up and a drain field pipe that goes out back to the creek. The housing for the turbine is made of three-quarter-inch plywood that is 2 X 2 feet wide and one foot tall. The turbine sits inside the hosing in the middle with the help of some 2x 4 scrap wood and a bucket lid piece. Then a 3-inch exit pipe comes out of here down through the middle of the housing. This drain pipe keeps the water from piling up under the turbine.
STEP 6 : ADDING THE TURGO TURBINE
The Micro Hydro Turgo Turbine is custom built based on the head pressure and the flow rate of the water source. It has three ball valves and four quarter-inch jet nozzles coming out of them. The ball valves can be separately turned off when there is not enough water. The turbine is wired up to be three-phase. The water coming out of the penstock hits jet nozzles that turn the Pelton wheel which is connected to 3 phase AC motor.
STEP 7 : WIRING THE SYSTEM
To connect the turbine to our house, we use a 10/3 underground feeder wire. The wire is enclosed in a one-inch conduit pipe. The proper way to install wire into a conduit is to get your conduit all glued together. And then you have a vacuum that pulls a string through. You tie your string to the wire and then pull the wire through the conduit. The wire goes into the house through a PVC conduit body.
We install a junction box on the housing of the turbine to join the 3 phase turbine output wires to the 10/3 UG feeder wires coming from the house. Inside the house, we connect a rectifier to the three legs of the three-phase coming from the turbine.This converts the AC generated into DC power.
STEP 8 : INSTALLING OTHER ELECTRICAL COMPONENTS
To generate useable power from this micro-hydro system we need to install certain electrical devices in our houses. These include the MPPT Charge Controller, Grid Tie limiter Inverter, breaker box, disconnect switches, and batteries. These components are mounted on a 2 X 2 foot, three-inch plywood board. In case there is some excess heat for one of these electronics at some point, we cover the plywood board with a piece of sheet metal so that it will act as a heat sink.
From the rectifier, the connection goes into a 25amp breaker box.The red wire goes into the breaker box and then further connects to the positive of the charge controller. The negative white wire is directly connected to the negative of the charge controller.
STEP 8 : CONNECTING THE BATTERIES AND COMPLETING THE WIRING
The five 12V AGM batteries are connected in series using four gauge cables. The positives from the batteries are connected to the charge controller and the inverter via DC switches. These switches allow us to isolate and disconnect the components individually. The negatives from the batteries are connected to the negatives of both the charge controller and inverter respectively. The inverter is further connected to the receptacle from where it goes straight to the main supply.
Image Credits : Land to House