Microhydro Systems: Advice From The Pros: Page 4 of 6

Beginner
Microhydro Intake
The right intake design will affect system performance greatly.
Microhydro Intake Site
Asian Phoenix’s Power Pal Low-Head Turbine
Asian Phoenix’s Power Pal low-head turbine in Honduras. At lower heads than this, things get tricky.
Altimeter
An altimeter is used to survey elevation. This measurement shows only 180 feet of head, but with a 12-inch pipe, this site will develop 75 kW.
Don Harris
Hydro guru Don Harris.
Measuring Head with the Bucket Method
The “bucket method” can be used to measure flow in small streams. Larger streams require an alternative measurement method.
Measuring Head with a Pressure Gauge
95 psi shows the static head of almost 220 feet of head.
Hugh Piggott, Scoraig Wind Electric
Hugh Piggott, Scoraig Wind Electric
David Seymore, Asian Phoenix Resources
David Seymore, Asian Phoenix Resources
Denis Ledbetter, Lo Power Engineering
Denis Ledbetter, Lo Power Engineering
Christopher Freitas, WiFu Energy
Christopher Freitas, WiFu Energy
Joseph Hartvigsen, Hartvigsen-Hydro
Joseph Hartvigsen, Hartvigsen-Hydro
Scott Davis, Friends of Renewable Energy BC
Scott Davis, Friends of Renewable Energy BC
Excavator Placing Pipe
An excavator lifting a 3,000-pound section of 8-inch steel onto a steep slope. The pipe was then pulled 500 feet up the hill using the excavator and a long steel cable through a pulley.
Microhydro Intake
Microhydro Intake Site
Asian Phoenix’s Power Pal Low-Head Turbine
Altimeter
Don Harris
Measuring Head with the Bucket Method
Measuring Head with a Pressure Gauge
Hugh Piggott, Scoraig Wind Electric
David Seymore, Asian Phoenix Resources
Denis Ledbetter, Lo Power Engineering
Christopher Freitas, WiFu Energy
Joseph Hartvigsen, Hartvigsen-Hydro
Scott Davis, Friends of Renewable Energy BC
Excavator Placing Pipe

Q: What financial incentives are available for those who install a microhydro system?

Microhydro systems seem to have the fewest incentive programs worldwide. The incentives vary widely, so a generalization is impossible. If you have a farm, you may qualify for financial incentives to use the same water for multiple purposes.

Incentive programs tend to come and go, and can be fairly arbitrary. If you are counting on government money, act on it sooner than later. The paperwork burden in some cases can be significant. Check out your local incentive situation as part of the site assessment process.

Long-term, low-interest financing is quite a powerful incentive. Microhydro rebates tend to not be generous enough to affect the payback time very much, and therefore often don’t work very well. Every incentive situation is unique as well. Off-grid electricity from fuel-fired generators may cost something like $1 per kilowatt-hour to produce. This is a powerful incentive because well-designed and implemented off-grid microhydro typically costs less over the long term. Generators are noisy, stinky, and expensive. By contrast, a microhydro system can quietly run for years on end, dependably providing energy with a minimum of hassle and no emissions.

Q: In what cases do you advise people to go with an alternative to microhydro? 

The decision on which resource to use for an RE system depends on:

  • Economic issues: what do they pay for electricity currently? How have rates increased over the years, and what’s their expected rate of increase?
  • Location
  • Grid availability and connection costs
  • Quality of the hydro resource
  • Household energy consumption 
  • Homeowners’ environmental philosophy

Q: What is the typical process required to get regulatory approval for home hydro systems, and where do potential users find information about it?

Local regulations vary widely. Water rights are regulated everywhere and must be respected. Wherever you are, check with appropriate authorities before spending significant money on construction. Start with the water resources department where you live. Some states have little to no requirements and some states have a great deal of red tape.

It should be about natural law and ecology with good sense, and most small hydro systems have a very minimal impact on the environment. From anecdotal reports, many home-sized systems are not permitted because the level of regulation is out of scale with the potential impact, and the value of the systems to small landowners exceeds their desire to work with bureaucracies. For larger grid-connected systems, it can run the gamut—from just getting local water regulator permits to having to appeal to the Federal Energy Regulatory Commission for licensing or exemption. Both levels seem to be arbitrary and indeterminate processes. Working the system seems to be much more practical abroad, such as in the U.K.

Comments (3)

Heetel64's picture

If you are lucky enough to have a water source, study it.
An example would be a water source with a bend. Consider putting two independent wheels, smaller one on the outside ( faster flow ) and larger one on the inside with reducer gearing ( slower flow ). Should you find that the water supply is reduced, then design your system to allow for moving the larger wheel into the outer bend.
Never think that your water source will never change.

Frank Heller's picture

For remote sites where the owner has access to enough water to generate 1+ KW; it may be advisable to install microhydro should the distance to the nearest power line be 2 or more poles away. In Maine, a pole typically costs about $9,000.

On the other hand going off the grid is not for the faint hearted.

Frank Heller's picture

Don't dismiss the water wheel so quickly. A large slowly turning water wheel can provide enough torque to power a transmission so that a 300:1 or greater increase in RPM can be obtained. A large wheel with a small amount of water may do the same. Depends on whether it is in the current or powered by the weight of falling water.

There are also large volumes of water impounded in tidal pounds that can power a modern equivalent of the Roman tub turbine. In Maine we have 11' tides and there is an infrastructure of tidal ponds which ran approx. 2,000 tidal water mills.

OREC and others now use variations of the Gorlov turbine in swift underwater ocean currents. Tidal barrages using compression waves can also drive large turbines, i.e. SEABELL of Tokyo.

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