The Basics of Micro Hydro and Power Production Calculations

MicroMicro Hydro Power in Hydro Power in WNCWNC

Oct 27, 2007Oct 27, 2007Andrews, NCAndrews, NC

Hydro, Driven by Solar PowerHydro, Driven by Solar Power

Existing hydroelectric plants (yellow) and potential high head/low power energy sites (orange) in the conterminous United States. Purple represents areas excluded from hydropower development due to Federal statutes and policies.

Source: Water Energy Resources of the United States with Emphasis on Low Head/Low Power Resources (p. 47), U.S. Department of Energy

Hydro power in USA, Canada and the WorldHydro power in USA, Canada and the World

US Supply

Most of that global hydro power is produced by large-scale hydroelectric plants

Today, we will be talking about

microhydro•Small in scale

•Minimum environmental impact

•Site specific: you must have the resource

•Affordable.

•Consistent: Produces continuously, 24/7

We don’t need a river, just some falling water

Types of SystemsTypes of Systems

Turbines can be of many forms. Turbines can be of many forms.

Listed are a few of the major types.Listed are a few of the major types.

  High head Medium head Low head

Impulse turbines Pelton Turgo

cross-flow multi-jet Pelton Turgo

cross-flow

Reaction turbines

  FrancisPump-as-turbine(PAT)

propeller Kaplan

Pelton and TurgoImpulse – jet of water

4 “

Banki

CrossflowBanki and Crossflow

Impulse – sheet of water

http://www.toshiba.co.jp/f-ene/hydro/english/products/equipment/index01_2.htm

Kaplan

http://www.waterwheelfactory.com/francis.htm

FrancisReaction Turbines

Submerged in the flow; driven by the pressure differential

Turbines are turned by water.

That turning motion drives a generator which produced electricity.

You need two things to make powerHead and Flow

Power Estimates

Gross Power Calculations

Power (watts) = Head (ft) * Flow (GPM) 10

The equation assumes a turbine efficiency of 53%. Actual efficiency varies with conditions.

Power output is proportional to the combination of head and flow

Examples

Turtle Island Mollies Branch

Turtle Island

Stream flow = 300 GPM(1/2 of flow is 150 GPM)Total Head is 140 feet

Gross Power Estimate = (140 ft * 150 GPM)/10= 2100 W

Mollies Branch

Mollies Branch has a flow of 300 GPM(1/2 of flow is 150 GPM)Total Head is 110 feet

Gross Power Estimate = (110 ft * 150 GPM)/10= 1650 W

Why is this gross power?

These are not accurate calculations because we used the gross or static head instead of the net or dynamic head.

A more accurate power calculation is made after calculating pipe friction losses.

Stay tuned................

...or Charts from ManufacturerP.M. Alternator output in watts

FEET OF NET HEAD 

GAL/M 25 50 75 100 200 3003 - - - - 45 806 - - 30 45 130 180

10 - 40 75 95 210 30015 25 75 110 150 320 45020 40 100 160 240 480 60030 65 150 250 350 650 94050 130 265 420 600 1100 1500

100 230 500 750 1100 1500 -200 - 580 900 1300 - -

Measuring Head

Measuring Head 5’ stick with carpenters level Sight level Water level Pipe with pressure gauge GPS Unit Transit Topo map Altimeter

Measuring Head

5’ stick with level (3 people)

5’

Measuring Head

Sight level (2 people)

Eye level

Remember, you don’t have to follow the creek.

Measuring HeadWater level and measuring tape (2 people)

Water level

Measuring Head Transit Most accurate if you have the equipment

Measuring Head

Pipe with pressure gauge at the bottom

Could use garden hose(s) 2.31 feet = 1 psi This gauge reads 38 psi 38 psi x 2.31 feet/psi = 88 ft

of static head

Measuring Head

GPS, altimeter, topo map

Difference in elevation readings

Measuring Flow

Measuring Flow Units

GPM: gallons per minute CFM: cubic feet per minute CFS: cubic feet per second

How much to use? Don’t take the whole creek! Use minimum flow Avoid taking more than ½ of the flow

Water temp could be effected!!! Let the ecosystem thrive

Methods of Flow Assessment

5-gallon bucketSmall stream, small waterfall

Float methodLarger, flat, uniform stream

V-notch Weir Rectangular Weir Make several measurements to assess

seasonal variation

5 gallon bucket

5 gallon bucket

If the measured flow using a 5 gallon bucket and a stop watch was 5 gallons in 1.5 seconds, how many GPM would this be?

5 gallon bucket

If the measured flow using a 5 gallon bucket and a stop watch was 5 gallons in 1.5 seconds, how many GPM would this be?

GPMgal 200min1sec60

sec5.15

Float methodBig, flat, uniform creek

Float methodFlow (ft3/s) = Velocity (ft/s) x Cross Sectional Area (ft2)

Float method1. Calculate the average depth

Lay a board across the stream, measure the depth every foot, average the depths

Float method2. Calculate the cross sectional area

Area (ft2) = Average depth (ft) x Width (ft)

Float method3. Calculate velocity

Measure where you measured the area, an orange makes a good float, start well upstream, a 10’ span is good, average multiple measurements

Float method

4. Correct for Friction

Flow (ft3/s) = Velocity (ft/s) x Cross Sectional Area (ft3) x .83

Multiply x 0.830.83 to correct for friction on the bottom of the stream

Float MethodSo, if these guys measure this 3’ wide

stream and get an average depth of 8” and it takes an orange an average 5 seconds to go 10 feet, what is the flow in GPM?

•Area = 3’ x 8” x (1’/12”) = 2 ft2

•Velocity = 10 ft/5 s = 2 ft/s

•Flow = 2 ft2 x 2 ft/ s = 4 ft3/s

•4 ft3/s x 7.48 gal/1 ft3 x 60s/1 min = 1795 gpm

•Correct for friction, 1795 gpm x .83 = 1490 gpm

Weir Method

For larger flows or more accurate measurements

Small V-notch

Larger Rectangular

All you needs is depth and the table

V-notch Weir

Rectangular Weir

“the pipe”

PenstockPenstock

The IntakeDiverting clean water into the penstock

Screen

Start of Penstock

Steam Flow

The intake’s job:

Filter and Settle

Build it either:Simple and easy

to repairOr

Bullet-proof

The IntakeDiverting clean water into the penstock

Screen Start of Penstock

Steam Flow

A dirty creek

may need more

settling time

Overflow

PenstockA full pipe; delivering clean water to the turbine

Pipe can be a Considerable Cost…up to 40%

Factors to Consider: Penstock surface roughness design pressure method of jointing weight and ease of installation accessibility of the site terrain design life and maintenance weather conditions availability relative cost likelihood of structural damage

Burying Pipe Burying a pipe line removes

the biggest eyesore of a hydro scheme.

It is vital to ensure a buried penstock is properly and meticulously installed subsequent problems such

as leaks are much harder to detect and rectify.

Penstock Support SystemPVC likes to stay straight

HDPE can follow the contour of the ground

Pipe Friction Losses

Must use charts to calculate head loss due to pipe friction

Flow varies with D3

4” pipe can flow 8x more water than 2” pipe

Lets do an example

Turtle Island 140 ft static head Pipe = 3” HDPE (High Density Poly Ethylene)

What is friction loss for 1300’ pipe for a flow of 100 GPM?

What is the dynamic or net head?

Lets do an example:PIPE FRICTION LOSS

Polyethylene SDR - Pressure Rated Pipe

Pressure Loss from Friction in Feet of Head per 100 Feet of Pipe 

Flow US GPM  

  0.5 0.75 1 1.25 1.5 2 2.5 3

1 1.13 0.28 0.09 0.02  

2 4.05 1.04 0.32 0.09 0.04  

3 8.6 2.19 0.67 0.19 0.09 0.02  

4 14.6 3.73 1.15 0.3 0.14 0.05    

5 22.1 5.61 1.75 0.46 0.21 0.07  

90   13.5 5.71 1.98

95   15 6.31 2.19

100   16.5 6.92 2.42

150   34.5 14.7 5.11

200   25 8.7

300   18.4

Lets do an example Turtle Island 140 ft head 3” HDPE (High Density Poly Ethylene) What is friction loss for 1300’ pipe for a flow of 100 GPM? What is the dynamic head?

Chart says we’ll lose 2.42’ of head per 100’ of pipe.

We have 13 x 100’ of pipe, so 13 x 2.42’ = 31.5’ of total head loss

Dynamic or Dynamic or net headnet head = 140’ – 31.5’ = = 140’ – 31.5’ = 108.5’108.5’

Nozzles

Nozzles

The flowrate from the penstock is controlled by properly sizing the nozzle(s) at the turbine.

Nozzles

What size nozzles and how many would you recommend if one wants to use about ½ of a stream with 300 GPM of measured flow with 100 ft of head (pelton wheel)?

Nozzles

Maximum efficient flow at various headsFrom Harris Hydro(FIGURES IN GALLONS/MIN)

FEET OF NET HEAD# of

nozzles 25 50 75 100 200 3001 17 25 30 35 50 602 35 50 60 70 100 1203 52 75 90 105 150 -4 70 100 120 140 200 -

NozzlesNOZZLE FLOW CHART – from ES & D

FLOW RATE IN U.S. GALLONS PER MINUTE

Head Feet PSI Nozzle Diameter, inches RPM

  1/8 3/16 1/4 5/16 3/8 7/16 1/2 5/8 3/4 7/8 1  

5 2.2   6.18 8.4 11 17.1 24.7 33.6 43.9 460

10 4.3   3.88 6.05 8.75 11.6 15.6 24.2 35 47.6 62.1 650

15 6.5   2.68 4.76 7.4 10.7 14.6 19 29.7 42.8 58.2 76 800

20 8.7 1.37 3.09 5.49 8.56 12.4 16.8 22 34.3 49.4 67.3 87.8 925

30 13 1.68 3.78 6.72 10.5 15.1 20.6 26.9 42 60.5 82.4 107 1140

40 17.3 1.94 4.37 7.76 12.1 17.5 23.8 31.1 48.5 69.9 95.1 124 1310

50 21.7 2.17 4.88 8.68 13.6 19.5 26.6 34.7 54.3 78.1 106 139 1470

60 26 2.38 5.35 9.51 14.8 21.4 29.1 38 59.4 85.6 117 152 1600

80 34.6 2.75 6.18 11 17.1 24.7 33.6 43.9 68.6 98.8 135 176 1850

100 43.3 3.07 6.91 12.3 19.2 27.6 37.6 49.1 76.7 111 150 196 2070

120 52 3.36 7.56 13.4 21 30.3 41.2 53.8 84.1 121 165 215 2270

150 65 3.76 8.95 15 23.5 33.8 46 60.1 93.9 135 184 241 2540

200 86.6 4.34 9.77 17.4 27.1 39.1 53.2 69.4 109 156 213 278 2930

250 108 4.86 10.9 19.9 30.3 43.6 59.4 77.6 121 175 238 311 3270

300 130 5.32 12 21.3 33.2 47.8 65.1 85.1 133 191 261 340 3591

400 173 6.14 13.8 24.5 38.3 55.2 75.2 98.2 154 221 301 393 4140

300 gpm/2 = 150 gpm usable flow

150 gpm/4 = 37.5 gpm per nozzle(4) 7/16” nozzles should do it(4) 7/16” nozzles should do it

Micro Turbines

Harris Hydro Efficient, durable, battery

charging pelton turbine with an adjustable permanent magnet generator.

20-600 feet of head 2-250 GPM of flow

1 nozzle $1800 2 nozzle $1950 4 nozzle $2150

707-986-7771delejo@humboldt.net

Energy Systems & Design Stream Engine Brushless, permanent magnet

alternator which is adjustable Capable of outputs over 1 kilowatt Heads from 6 to 300 feet. Equipped with a rugged bronze turgo

wheel, universal nozzles (adaptable to sizing from 1/8 to1 inch), and a digital multimeter which is used to measure output current.

www.microhydropower.com

2 Nozzle Bronze $23954 Nozzle Bronze $2545High Voltage Option $200 High Current Option $100

Energy Systems & Design Low Head Propeller Turbine Uses the same generator as the

Stream Engine, however the water turbine component uses a low head propeller design.

heads of 2 feet up to 10 feet. At the maximum head, the output

is 1 kW.

www.microhydropower.com

Water Baby Operates much the same as the

Stream Engine but requires very little water (pelton wheel)

Will operate on as little as 3 gpm but requires at least 100 feet of head.

At a head of 100 feet and a flow of 3 gpm the output is 25 watts; at 24 gpm the output is 250 watts.

Baby Generator, 1 Nozzle(12/24 volt) $1395

Extra Nozzles (installed) $120 ea

High Voltage (48/120 volt) $100

LH1000 with Draft Tube $1995

High Voltage Option $200 extraHigh Current Option $100 extra

Hydro Induction Power

Good for long wire runs, 60' - 500' head, 10 - 600 gpm

The units produce 3-Phase 120V, 240V, or 480V 'wild' (unregulated) AC, which is then stepped down to battery voltage.

The heavy-duty brushless alternator is housed on the Harris Housing

Uses the Harris bronze Pelton Wheel for flows up to 200 gpm and the bronze Turgo Runner for flows of 200 to 600 gpm.

www.hipowerhydro.com

HV 600 with 2 Nozzles $2500 HV 600 with 4 Nozzles $2600 HV 1200 with 4 Nozzles $3000 HV 1800 with 4 Nozzles $3500 HV 3600 with 4 Nozzles $5000 Turgo option $600

Hydro Induction Power Now offer a new LOW VOLTAGE

(12V/24V), brushless unit (48V coming in 2006).

It can generate either 12V or 24V with pressures from 20psi to 150psi (46' - 400'). Above this pressure, it will generate 48V.

Lots of accessories

www.homehydro.com

12/24V Hydro with 1 Nozzle: $1350 12/24V Hydro with 2 Nozzles:$1400 12/24V Hydro with 3 Nozzles:$1450 12/24V Hydro with 4 Nozzles:$1500

Upgrade from Harris Hydro: $500 Turgo option $600

Powerpal Low head model A simple AC single-phase, brushless

permanent magnet alternator is attached to a propeller turbine.

Electricity passes along a wire and into a house, where an electronic load controller stabilizes the voltage to 110V or 220V to protect electrical appliances during use.

Many models available (see chart, next slide)

www.powerpal.com

  MHG-200LH MHG-500LH MHG-1000LH

Water head (ft) 4.92 4.92 4.92

Water flow (gpm) 555 1110 2061

Output Power 200W 500W 1000W

The 200 watt unit needs 550 gallons per minute

Powerpal High head model The Same AC single-phase,

brushless PMt alternator that is used for the Low Head Series is used here and attached to a Turgo Turbine.

Also comes with an electronic load controller (ELC)

www.powerpal.com

 MHG-200HH  

MHG-500HH        

Water head (ft) 16.4 19.68 22.96 26.24 29.52 32.8 36.08

Water flow (gpm) 100 101 117 125 133 141 144

Output Power 160w 200w 275w 325w 390w 460w 520w

Canyon Hydro Serious engineering

1854084

1013335

362415

121665

 KWgpm

Canyon 2435

15340

8277

3197

1139

 KWgpm

Canyon 751

300

200

100

50

100 KW Canyon Crossflow

www.canyonhydro.com

Alternative Power & Machine

Economy models Permanent magnet units Accessories Exercise Bicycle Type Battery

Chargers, etc. Niche: Ease of maintenance

and adjustment

www.apmhydro.com

Make your own

www.otherpower.com

Otherwww.ampair.com....it’s a wind and hydro turbine $1300

The Jack Rabbit, just drop it into the river

$1295www.bali-i.com/hydro/jackrabbit-prod.htm

Turbine Housing

Many options. Main point: allow the water to fall away from the turbine runner and not bounce back onto the runner

and to divert the water back to the stream.

BOS…….Balance of System

What is the BOS? DC only system (small

cabin) Charge controller Batteries

Conventional AC system (house) Charge controller Batteries Inverter

Model List Price ($US)  C35 $119.00  C40 $159.00  C60 $199.00

ie. Xantrex “C” Series Charge Controller•12, 24, 48 VDC•automatically directs extra power to a dedicated load such as an electric water heater and ensures batteries are never over-charged.

Model # is rated DC current

www.xantrex.com

Diversion Load, aka Dump Load

Usually a resistive load like a heater At least as large as the full turbine

output and within the current limit of the charge controller

Small hydro system = small amounts of heat

Use waste heat for water heating, air heating…

Usually not enough heat for domestic use (1kW = 3412 BTU)

Head lights as dump load for wind turbine

Outback Inverters

Xantrex Inverters

Batteryless Grid-Tie Options

Systems available for PV and wind Still a special system for Microhydro Contact Hydro Induction Power

www.hipowerhydro.com

AC Systems Larger systems can be

AC, no battery If the continuous output of

a system is high enough to meet your needs for surging capacity, no battery/inverter subsystem is required, and AC can be generated directly.

Storing Renewable Energy: Batteries

“Chemical engines used to push electrons around”

Battery Bank Sizing

A battery based alternative energy system will not be effective if it is not

sized correctly

Battery Bank Sizing Battery storage for PV and Wind systems

typically require 3 or more days of battery storage

Hydro systems run all the time Batteries in a hydro system typically need to

store energy for less than a day Often, the battery is sized to provide

sufficient current to the inverter rather than an amount of storage

Life Expectancy and cost

At least 5 years Often over 10 years or

1500 deep cycles Shipping is expensive Cost is about $200 per

6V battery

Rest Voltage vs. State of Charge

Hydrometer

Measures density of liquid with respect to water

The electrolyte has greater specific gravity at greater states of charge

Careful opening cells, contamination of the electrolyte solution is possible

Temperature Batteries get sluggish

at cold temperatures Usable capacity drops

radically below 40° F Self Discharge

happens rapidly above 120° F

Keep them between 55° F 100° F

Rates of Charge and Discharge

Recommended rates are C/10 – C/20 Using a C/5 rate will cause much more electrical

energy to be loss as heat This heat can damage battery plates Example –

440 Ampere-hour batteryHow many amps added for a C/10How many amps added for a C/20

Equalizing Charge

After time individual cells vary in their state of charge

If difference is greater than .05 volts – equalize

Controlled overcharge at C/20 rate for 7 hours

Battery Care

Don’t discharge beyond 80% C/10 – C/20 rate Keep batteries at room temperature Use distilled water Size batteries properly Equalize every few months Keep batteries and connections clean

Connecting Cells

Amperage and voltage in battery can be increased by arranging the cells in two ways Series

One path for electrons to follow Connect + to –’ Increases voltage

Parallel Multiple paths for electrons to follow Connect (+ to +) and (- to -) Increases amperage

Wire Sizing

Wire Sizing for DC Applications

Voltage drop is caused by a conductors electrical resistance

This voltage drop can be used to calculate power loss

VDI Voltage drop Index

Easier method for determining wire size What you need to know

Amps (Watts/volts)Feet (one-way distance)Acceptable % volt drop Voltage

How to Use Formula and Chart

Example: 1 KW, 24 volt system, 50 feet, 3% drop

Amps = 1000 watts/ 24 volts = 41.67 amps

VDI = 41.67 amps * 50 feet = 28.9 3% * 24 volts

VDI Chart

24V VDI = 28.92 AWG wire

That’s pretty big wire

What if we make it a 48 volt system?

How to Use Formula and Chart

Example: 1 KW, 48 volt system, 50 feet, 3% drop

Amps = 1000 watts/ 48 volts = 20.8 amps

VDI = 20.8 amps * 50 feet = 7.23 3% * 48 volts

VDI Chart

48V VDI = 7.28 AWG wire

That’s better (smaller, less $,

same losses).

Load Assessment

Hydro Load Assessment How do you know how

much energy you need?Electric billAverage US household

uses 850 kWhrs/month = 28 kWhrs/day

Also need capacity: what is the largest load to run?

Do a load assessment!!

Load Assessment A house on RE must use less electricity

Use less energy! produce the Negawatt!Efficient appliances

CF lighting Newer models (EnergyStar)

Divert heating loads to solar, gas, etc…

Load Assessment You’ll need for each appliance…

Power consumption In Watts Rating will be stamped on appliance

Number of hours/day appliance is on

Simple example: a 15 W CF bulb is on for an average of 5 hrs/day

day: (15 W)(5 hrs/day) = 75 Whrs/daymonth: (75 Whrs/day)(30 days) = 2,250 Whrs

= 2.25 kWhrs

Incentives and Regulations

NC Renewable Energy Tax Credits

35% for all technologies Can take tax credit over 5 years No more than half of tax liability No refund based on tax credit

Credit Limits $1,400 residential solar domestic hot water$3,500 residential active space heating, combined solar hot water and space heating, passive space heating$10,500 residential biomass, wind, hydroelectric and photovoltaic or solar thermal electric

NC GreenPower ProgramTo improve the quality of the environment by encouraging

the development of renewable energy resources through consumers’ voluntary purchase of green power.

Premium paid if approved by the Low Impact Hydropower Institute (LIHI)

www.ncgreenpower.org

Other State Incentives

www.dsireusa.org

Regulations

The US Army Corps of Engineers has jurisdiction over virtually all waterways in the United States. Any discharge of dredged or fill material

into all waters of the United States, which includes rearranging rocks within a streambed, would require notification of the Corps per Section

404 of the Clean Water Act.

Contact the local Army Corps of Engineers office about your proposed project beforeyou begin construction. They will help decide whether or

not a permit is required.

Local Installers

Wrap up: Site Assessment

Head Flow Pipe Length Wire Run Goals

MicroMicro Hydro Power in Hydro Power in WNCWNC

QuestionsQuestions