Micro Hydro Power in WNC Oct 27, 2007 Andrews, NC

Hydro, 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 EnergyWater Energy Resources of the United States with Emphasis on Low Head/Low Power Resources

Hydro 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 micro hydro 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 Systems Turbines can be of many forms. Listed are a few of the major types. High headMedium headLow head Impulse turbines Pelton Turgo cross-flow multi-jet Pelton Turgo cross-flow Reaction turbines Francis Pump-as-turbine (PAT) propeller Kaplan

Pelton and Turgo Impulse – jet of water 4 “

Banki Crossflow Banki and Crossflow Impulse – sheet of water

Kaplan Francis Reaction 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 power Head 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 Manufacturer P.M. Alternator output in watts FEET OF NET HEAD GAL/M

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 Head Water 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

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 bucket  Small stream, small waterfall Float method  Larger, flat, uniform stream V-notch Weir Rectangular Weir Make several measurements to assess seasonal variation

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?

Float method Big, flat, uniform creek

Float method Flow (ft 3 /s) = Velocity (ft/s) x Cross Sectional Area (ft 2 )

Float method 1. Calculate the average depth Lay a board across the stream, measure the depth every foot, average the depths

Float method 2. Calculate the cross sectional area Area (ft 2 ) = Average depth (ft) x Width (ft)

Float method 3. 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 (ft 3 /s) = Velocity (ft/s) x Cross Sectional Area (ft 3 ) x Multiply x 0.83 to correct for friction on the bottom of the stream

Float Method So, 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 ft 2 Velocity = 10 ft/5 s = 2 ft/s Flow = 2 ft 2 x 2 ft/ s = 4 ft 3 /s 4 ft 3 /s x 7.48 gal/1 ft 3 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” Penstock

The Intake Diverting 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 repair Or Bullet-proof

The Intake Diverting clean water into the penstock ScreenStart of Penstock Steam Flow A dirty creek may need more settling time Overflow

Penstock A 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 System PVC 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 D 3  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 GP M

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

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 heads From Harris Hydro (FIGURES IN GALLONS/MIN) FEET OF NET HEAD # of nozzles

Nozzles NOZZLE FLOW CHART – from ES & D FLOW RATE IN U.S. GALLONS PER MINUTE Head Feet PSINozzle Diameter, inches RPM 1/83/161/45/163/8 7/16 1/25/83/47/ gpm/2 = 150 gpm usable flow 150 gpm/4 = 37.5 gpm per nozzle (4) 7/16” nozzles should do it

Micro Turbines

Harris Hydro Efficient, durable, battery charging pelton turbine with an adjustable permanent magnet generator feet of head GPM of flow 1 nozzle $ nozzle $ nozzle $

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. 2 Nozzle Bronze $ Nozzle Bronze $2545 High 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. 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 extra High Current Option$100 extra

Hydro Induction Power Good for long wire runs, 60' - 500' head, 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. 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 12/24V Hydro with 1 Nozzle: $ /24V Hydro with 2 Nozzles:$ /24V Hydro with 3 Nozzles:$ /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) MHG-200LHMHG-500LHMHG-1000LH Water head (ft)4.92 Water flow (gpm) Output Power200W500W1000W 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) MHG- 200HH MHG- 500HH Water head (ft) Water flow (gpm) Output Power160w200w275w325w390w460w520w

Canyon Hydro Serious engineering KWgpm Canyon KWgpm Canyon KW Canyon Crossflow

Alternative Power & Machine Economy models Permanent magnet units Accessories Exercise Bicycle Type Battery Chargers, etc. Niche: Ease of maintenance and adjustment

Make your own

Other a wind and hydro turbine $1300 The Jack Rabbit, just drop it into the river $1295

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

ModelList Price ($US) C35$ C40$ C60$ 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

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 

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 battery  How many amps added for a C/10  How 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 = amps VDI = amps * 50 feet = % * 24 volts

VDI Chart 24V VDI = 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 = % * 48 volts

VDI Chart 48V VDI = AWG wire That’s better (smaller, less $, same losses).

Load Assessment

Hydro Load Assessment How do you know how much energy you need?  Electric bill  Average 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/day month: (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 Program To 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)

Other State Incentives

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

Micro Hydro Power in WNC Questions