Microhydro Turbine ES&D SE-4

Microhydro 4 Nozzle  - Stream Engine Turbine  

The Stream Engine employs a brushless, permanent magnet alternator which is adjustable, enabling the user to match turbine output to the electrical load. It has higher efficiency than previous alternators, and is capable of outputs up to 800 watts continuous. It is equipped with a rugged bronze turgo wheel, universal nozzles (adaptable to sizing from 3 mm (1/8 inch) to 25 mm (1 inch), and a digital multimeter which is used to measure output current. The entire system is made of non-corrosive alloys for long life and durability. This machine can produce power from heads as low as 2 metres (6 feet) to over 100 metres ( 300 feet).

      A Quick Hydro History      

Using falling water to do work has been around for a long time. How long? Since before Christ was a carpenter, before Buddha was a baby, before Mohammed knew his mom, before well, you get the picture.

Making electricity, from falling water, called hydroelectricity, has been around since the turn of the century. Since that time, there have been many improvements in both the wheels that convert the falling water to a rotary motion, called runners, and in the generators themselves. Most of the generator and runner design work was done long ago. Current manufacturers of microhydro equipment have built on what was already available, adding relatively minor improvements. Hydro system designers need to match the runner correctly to the hydro site and the alternator to the battery system voltage.

Hydro Primer

Every renewable energy site is unique, whether it's for photovoltaic, wind, or hydro. Within the scope of renewables, hydro is the most site specific. You probably can't make the hill any higher, or the water flow any more. In order to assess the site for small hydroelectric capability, there are four questions that need to be answered:

1. What is the head (vertical fall), from intake to hydro plant placement?
2. How many gallons of water per minute (gpm) will you be able to devote to hydro power? Keep in mind that water flow will vary from winter to summer.
3. What is the length, size, and type of pipe from the intake to the hydro plant?
4. What is the distance from the hydro plant site to the batteries?

The ES & D Stream Engine

   The Turgo Runner  

The Stream Engine is designed to operate over a very wide range of heads and water flows. The ES&D machine uses a Turgo runner to achieve this. The Turgo is a vertically shafted turbine-type runner with the nozzles pointed downward at a 20° angle from horizontal. The great advantage of this type of runner is its ability to digest a lot of water efficiently. This can give us the ability to use more water during peak winter flows. Depending on the head and number of nozzles, up to 300 gpm (1160 liters per minute) can be utilized. Quite an accomplishment for a wheel with a 4.5 inch pitch diameter!

The PM Field Alternator

The ES & D alternator uses sixteen strong magnets embedded in a top plate which is spun by the runner. The twelve stator windings are stationary. Electricity is generated by passing the spinning magnets over the stator windings. The output is determined by the right mixture of rpm, configuration of the stator windings, and the distance between the magnetic field and the stator.

The field to stator distance is adjusted by a bolt within a bolt arrangement, which lowers or raises the spinning magnets. The stator windings can be configured into parallel, series, Delta or Wye wiring. The windings terminate on three studs for easy reconfiguration. The studs are before the rectifier, so it's easy to take the output as a higher voltage three phase ac for long transmission lines.

This may be a little confusing, but either the manufacturer or your system designer will provide the machine with the right configuration for your site. The beauty of this alternator is in its high efficiency and lack of moving parts. Since no electricity is required to energize the field, every watt generated goes towards output. The three ball type #6203 bearings supporting the shaft should last for years. They should be available from all bearing distributors. The machine can be disassembled for bearing replacement in about 15 minutes on a workbench. A bearing press and properly sized mandrel are suggested for removing and replacing the bearings. Any machine shop can do this very quickly.

Operation

Turn the water on. Aside from adjusting the air gap between the magnets and the stator, that's about it. Unlike a regular alternator, there is no need for a diode between the battery and the field windings. Should the alternator stop due to nozzle clogging, the output will just fall off to nothing. There is no chance of the field staying energized and actually discharging the battery.

Adjusting the air gap is a trial and error operation. It involves stopping the machine, holding the rotor with the provided pin, and loosening or tightening the bolt-within-a-bolt. This moves the rotor closer or further away from the stator. It's a case of making an adjustment, spinning the machine up, letting the water flow stabilize, and observing the ammeter. It may take a few tries, but once you find the maximum output setting, it will not vary unless you change nozzles.

( Picture not as shown - 2 Nozzle unit in Picture)

Power from Falling Water !

Energy Systems & Designs - Stream Engine 4 Nozzle