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First-Time Hydropower Project?
Learn basic design
principles in the
Guide to Hydropower
Micro Hydropower FAQ
Frequently Asked Questions about Water Turbine Systems
How much power can I get from my stream?
What information
do I need to determine whether a hydro system
makes sense for me?
Can I sell power back to my utility company?
What is the best type of turbine?
How do you control speed, frequency and voltage?
What can I do with lots of Flow but no Head?
What is the difference between AC and DC?
Why can’t I get a quick “ballpark” price for, say, a 10kW turbine system?
Why should I buy my system from Canyon Hydro?
How much power can I get from my stream?
Water power is the combination of HEAD and FLOW. HEAD is pressure, created by the vertical distance between your water intake and the nozzle at your turbine. FLOW is quantity, the amount of water that flows in a given period of time, such as cubic feet or meters per second. You must have both HEAD and FLOW to produce power. The Canyon Hydro Guide to Hydropower provides a full description of Head and Flow, and how to estimate power output.
What information do I need to determine whether a hydro system makes sense for me?
The most critical information is the HEAD and FLOW of your stream. This information not only determines how much power can be generated, but is also absolutely necessary to specify the size and type of turbine to use. You can learn how to measure Head and Flow in the Canyon Hydro Guide to Hydropower.
Can I sell power back to my utility company?
Many Canyon Hydro customers do supply power to the Utility Grid. Check with your power company to see what their policy is. There are generally additional costs associated with Controls and Switching that may affect your decision. We’ll be happy to discuss whether a connection to the Utility Grid is right for you.
What is the best type of turbine?
The best turbine design depends entirely on your HEAD and FLOW. For example, a Pelton-type turbine is most effective for sites with high Head. In contrast, a Crossflow turbine is only used with low Head, but high flow. Also keep in mind that for any given type of turbine, there can be significant design differences that depend on Head and Flow. The diameter of the turbine, the hydrodynamic design of its buckets or blades, its optimum RPM, and many other parameters must be considered when specifying the “right” turbine for your site.
A Pelton Wheel, developed in the mid 1800's by Lester Pelton, is a highly efficient, split-bucket turbine that is used for sites with high Head. It is a narrow wheel that can be any diameter, with a series of relatively small buckets around its perimeter. A high-velocity jet of water strikes each bucket at its center split, which forces the water both left and right. The inside curvatures on each side of the bucket play a critical role, causing the water to continually push against the bucket as it moves toward the outside. When the water finally exits, nearly all of its energy has been transferred to the turbine.
A Crossflow turbine is intended for low Head, but high Flow. In contrast to the Pelton Wheel with its many small buckets, the Crossflow uses long turbine blades to accommodate high volumes of water. Since the water velocity is often lower (because of lower Head), a Crossflow turbine may spin at a slower speed than a Pelton wheel, but may have more torque because of the volume of water pushing against it.
How do you control speed, frequency and voltage?
A Governor controls generator speed which, in turn, determines frequency and voltage. Higher generator RPM creates higher voltage and frequency. Most Governors for residential systems regulate generator speed by controlling the amount of electrical load. The generator tends to slow down as load is added (such as turning on a heater), and speed up as load is removed. The Governor monitors frequency or voltage, automatically adding or removing electrical loads to compensate for human power usage. You can learn more about governors in the Canyon Hydro Guide to Hydropower.
Not necessarily. You will need to build some type of diversion system to channel some of the water from your stream into the pipeline that feeds your turbine. It is very important that the water used for your hydro system be as clean as possible, and air-free. (Both grit and air can damage a turbine.) A diversion system will include screens to filter out dirt and debris, and a deep enough pool of water to prevent air from entering the pipeline. This pool of “quiet” water also helps waterborne silt settle to the bottom before it reaches your intake.
What can I do with lots of Flow but no Head?
Unfortunately, very little. Water power is the combination of HEAD and FLOW. Even very high Flow produces little usable power without any Head. For example, if you have a river running past your front door, it will be difficult to produce any practical power without first running a pipeline upstream to produce Head. While there has been some research into harnessing the energy of nearly-level rivers and tides, no feasible solutions are currently available commercially..
What is the difference between AC and DC?
AC stands for Alternating Current, which is output by most generators. DC, or Direct Current, is output from some very small generators, as well as all batteries. AC is almost always preferable, because it is easier to transmit over long distances and is required by most appliances. AC power can be cheaply and efficiently converted to DC power, but conversion from DC to AC requires a special inverter that will typically consume 10% or more of the power as it is converted. The cost of the inverter may also be a consideration; larger wattages are more expensive.
Batteries are common for very small DC output systems, where the output of the generator is not sufficient to handle peak loads. Batteries can store electricity for later use, and are usually recharged during off-peak hours. Multiple batteries can be wired together for greater capacity, but at some point the cost imposes practical limits. Keep in mind that battery power is always DC. This may not be a problem as long as transmission distances are short and you are using simple resistance-type heaters or lighting. Most household appliances require AC power, which will require an inverter if you have batteries.
Why can’t I get a quick “ballpark” price for, say, a 10kW turbine system?
You can if you know your project's HEAD and FLOW. The price of a turbine system will vary significantly depending on your HEAD and FLOW, which determines the type and size of the turbine. For a given power output, a turbine designed for high-Head is radically different (and often less expensive) than one designed for high-Flow. Once we know HEAD and FLOW of your stream, however, we can quickly estimate a price for your system. You can learn more about HEAD and FLOW, and how to measure it, in the Canyon Hydro Guide to Hydropower.
Why should I buy my system from Canyon Hydro?
Expertise and quality. Canyon Hydro has been making small hydroelectric turbines since 1976, and we have highly satisfied customers all over the world. We love what we do, and it shows. Turbines, shafts and nozzles are machined to exact tolerances for maximum efficiency. Housings are epoxy or powder coated to minimize corrosion. All components, from bearings to electrics, are selected for quality and durability. And we back it all up with a team of engineers and technicians dedicated to making your project a long-term success.
Got a question? Send it to us at info@canyonhydro.com, and we’ll get back to you.
Want to learn more about hydro systems? The Canyon Hydro Guide to Hydropower covers everything from HEAD and FLOW to electronic control systems.