Wind and Microhydro Power Technologies Fall 2009

 Nano<100 W  Pico<5 kW  Micro<100 kW  Mini<1000 kW  Small<10 MW  Large - 10MW and UP

Positive  Renewable source  Large outputs  Financially viable  No emissions  Domestic Source  Alter Local Economies Negative  Alters aquatic habitat  Effects fish populations  Impacts water quality ◦ Low 02 levels  Impacts flow  Temperature issues  Impacted by draught  Impact local community

 Fish ladders  Aeration

 Affordable  Reliable  No air pollution  No waste products  Can be a good resource in the mountains Microhydro is often the most cost effective way to renewably generating electricity - in many cases competing with the price of grid power - with no emissions.

 The US Army Corps of Engineers has jurisdiction over virtually all waterways in the United States.  If you plan on moving a rock in a stream you better ask first!

 Intake  Penstock or pipe  Turbine / power house  Tailrace  Balance of System ◦ Controller ◦ Batter bank ◦ Disconnect ◦ Dump load ◦ meter

 Is the elevation difference between the source of the water and the turbine, or the total vertical drop  Typically measured in feet.  Static Head  Dynamic Head

 Flow is a volumetric measure of moving water typically measured in gallons per minute (gpm), cubic feet per minute (cfm), or cubic feet per second (cfs).  Should be monitored throughout the year.

 Diversion/intake  Pipeline/penstock  Powerhouse  Turbine  Tailrace

 Supply water to the system  Intake must: ◦ Screen out rock and other debris ¼-inch and larger  High head – remove silt as well ◦ Keep out water creatures – like fish and others ◦ Keep air bubbles out of the system

 The component that delivers the water to the turbine.

 surface roughness  design pressure  method of jointing  weight and ease of installation  accessibility of the site  terrain  soil type  design life and maintenance  weather conditions  availability  relative cost  likelihood of structural damage.

 Steel ◦ Rust, rough (high losses) ◦ High wear and high pressure (road crossing, bottom of penstock)  AL irrigation pipe ◦ Low pressure rating ◦ Can’t be buried else it will corrode  Pressure Rated PVC ◦ Readily available and easily joined ◦ UV degradation and physical damage ◦ Buried, covered or painted  PVC sewer pipe ◦ Low-budget, not pressure-rated!  HPDE (Polyethylene) ◦ Toughest, you can drag it into place, can be exposed ◦ Joined by a fusion welder

At the heart of the micro hydro system is a water wheel or turbine enclosed within a structure. These wheels can be of many forms. Listed are a few of the major types. high headmedium headlow head impulse turbinesPelton Turgo cross-flow multi-jet Pelton Turgo cross-flow reaction turbines Francis Pump-as-turbine (PAT) propeller Kaplan

Kaplan Francis Reaction Turbines Submerged in the flow; driven by the pressure differential

Banki Crossflow Banki and Crossflow Impulse – sheet of water

4 “

Power output (watts) = Flow (GPM) X Static Head (ft) 10 – 12 Example: A site assessment showed the following:  140 feet of static head  100 gpm Power output (watts) = Flow (gpm) X Static Head (ft) 10 – 12 PO = 100 X PO = 1400 watts or 1.4 kW NOTE: This system will not achieve this output. WHY? Answer: friction System Efficiency

 Factors to determine: ◦ Material ◦ Diameter of Pipe

 Alternating Current (AC) – The type of electricity where the current flows in one direction then the other direction. ◦ EX: Homes, Wind Turbines, Microhydro Turbines  Direct Current (DC) - electrons flow in one direction. ◦ Example: Batteries, PV modules, Generators

 Flow rate of electrons or the number passing a given point in a circuit per unit time is called current. ◦ Measured in Amps           Count ‘um passing here!

 voltage (Volts, V). ◦ Electro-motive force (EMF) or electrical pressure  12v, 24v, & 48v common for DC systems  120v and higher are common for AC

 Power is the rate at which energy is being delivered or consumed Power = (Current)(Voltage) P = IV ◦ Units: Watt (W) ◦ So if 2 A of current is flowing through a load at 120 V, the Power used by the load is P = IV = (2A)(120V) = 240 W

 A microhydro system is rated at VAC  What is the amperage that is will deliver to the battery? 48volts AC

 Need to know the distance from the turbine to the load to calculate what type of wire/cable to use and how much it will cost.  Needed information: ◦ Distance from turbine to load ◦ Voltage of the turbine ◦ Max output of the turbine ◦ Type of output? AC or DC, 3 phase or single phase.

 The quantity of electrons or amperes that a conductor can safely carry ◦ Factors affecting ampacity  Size (diameter) of wire  Type of wire (copper or aluminum)  Insulation  Temperature

 Voltage drop is caused by a conductors electrical resistance  This voltage drop can be used to calculate power loss

 Easier method for determining wire size  What you need to know ◦ Amps (Watts/volts) ◦ Feet (one-way distance) ◦ Acceptable % volt drop ◦ Voltage

 DC only system (small cabin) ◦ Charge controller ◦ Batteries  Conventional AC system (house) ◦ Charge controller ◦ Batteries ◦ Inverter

Series Connections

 Don’t discharge beyond 80%  Charge at recommended rate  Keep batteries at room temperature  Use distilled water  Size batteries properly  Equalize every few months  Keep batteries and connections clean