micro hydro moving mountains

8/13/2019 Micro Hydro Moving Mountains

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Micro-Hydro 101Bob Fairchild

Soft Energy Associates

[email protected]

Growing Appalachia

Moving Forward in the MountainsSaturday, April 24, 2010
mailto:[email protected]:[email protected]


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http://science.howstuffworks.com/enlarge-image.htm?terms=hydropower+plants&gallery=1&page=6


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The ideal

hydroelectric site


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Power and Energy

Energy is work. It is what you pay for. It isgenerally expressed in kilowatt hours(kWh). Residential electricity costs around

$.06/kWh

Power is energy per time. It is generallyexpressed in kilowatts (kW) or horsepower(HP)


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In conventional

hydroelectric systems,Power is determined by

head and flowHead is the vertical distance from

inlet to outlet.Flow is the amount of water.


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Calculating power

Head *Flow/10,000= Power

(ft) (gal/min) (kWh)

Examples:

25 ft * 40 gal/min/10,000=0.1 kW

15 ft *1,000,000gal/min/10,000=1500kW


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Mother Ann Lee Hydro Station


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Micro Hydro

100 kW or less

(the average home uses about 1kW continuously on average)


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Dams and diversions

Structures to hold back and/or

divert water to hydroelectricinstallation


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Penstock/Canal

Penstock: pipe for carrying water

to a hydroelectric turbineCanal: open channel


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Trash rack/intake screen

Filter to prevent debrisfrom entering hydroturbine

Bar grille, screen,

perforated pipe

Coanda effect intake


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Waterwheels

Large, heavy, low speed

Good for mechanical power

Not good for electrical generation Generally lower efficiency than turbines


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Turbines

More compact

Higher speed

Better for electrical generation Higher efficiency


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Turbine types

Reaction turbines

-- Use pressure of water to turn turbine

Fully submerged

Generally for lower head sites

Impulse turbines

Turn pressure into speed with jets

Operate with some air around turbine

Generally for high head sites


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Reaction Turbines

Francis

Kaplan

Fixed blade

Adjustable blade


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Francis Turbinespiral or open inlet


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Kaplan Turbinepropeller with fixed or adjustable blades


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Impulse Turbines

Crossflow

Turgo

Pelton


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Crossflow Turbinecylindrical turbine, water flows in and out


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Turgo TurbineSingle spoons with angled jets


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Pelton TurbineDouble spoons with straight jets


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Generators

DC

Automotive alternator Cheaper

Less efficient

Custom wound forspecific speed

Permanent magnet More expensive

More efficient

Wide range ofapplicability

AC

Induction Requires only speed

matching to synch

Cannot operate alone

Synchronous

Requires speed andfrequency matching

Can operate standalone


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Pumps and Motors

Some pumps can berun in reverse asturbines

Lower efficiency Lower cost

Some motors can berun in reverse asgenerators

Lower efficiency Lower cost


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Controls

Water flow control with manual orautomatic grid connection

Battery powered shutoff for grid problems

Over/under voltage

Over current

Reverse power Over/under frequency

Other conditions


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Costs

Design work (engineering)

Licenses and permits

Civil works (concrete) Pipe

Turbine

Generator Controls

Interconnect (transformers, power lines)


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Net Metering

Offset retail rate power

30 kW maximum

Use grid as battery Carryover surplus production from wet

months


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Head vs. Flow

In general, more head is better than moreflow.

A given turbine can only handle a certainmaximum flow. More head will give morepower for a given turbine.

To get more power with more flow, you

need a bigger, more expensive turbine.


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Microhydro turbines forresidential installations

LH1000: low head, high flow(propeller turbine)

Stream Engine: higher head, lower flow

(Turgo turbine)


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LH1000 power curve


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Stream Engine Turbine

Generator $2500

Bronze Turgo runner

Head: 6 ft to 300 ft One to four jets

Flows to 100 gallons per minute


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BIG HYDROPOWER

Provides 90% of all renewable power

Provides 24% of the Worlds electricity

Provides 7% of electricity in U.S. Over 2000 Hydroelectric Plants in U.S.

Only 3% of Dams in the U.S. have

Hydropower Kentucky has 450 MW of potential at

37 non-hydro dams (larger sites)

micro hydro moving mountains

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