1. Wind and Hydro Power Technologies Spring 2011

2. http://www.youtube.com/watch?v=IpaEGhjpZgc

3. CONCEPTS OF ELECTRICITY  Electricity is a form of energy that is caused be the flow of electrons through the atoms of a conductor.  Flow rate of electrons or the number passing a given point in a circuit per unit time is called current  measured in electrons per second

4.  Alternating Current (AC) – The type of electricity where the charge flows in one direction then the other direction.  EX: Homes, Wind Turbines, Microhydro Turbines, Alternators.  Direct Current (DC) - electrons flow in one direction.  Example: Batteries, PV modules, Generators http://www.youtube.com/watch?v=JZjMuIHoBeg&feature=related

5. CURRENT  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!

6. Time Delay?  Does it take time for electrons to flow from a switch to a bulb? Light Bulb --- -- - - - - - - -- 10 miles

7. Time Delay?  Does it take time for electrons to flow from a switch to a bulb?  NO!! Wire is already full of electrons! Light Bulb --- --------------- ------------- --- -- - - - - - - -- 10 miles ------------- ------------------ - - - - - - - - ------

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

9. Resistance  Measure of energy “used up”  Depends on the material (and temperature)  Resistance: opposition to electron movement  Unit: Ohm (  );  Wires: very low resistance (often neglected)  Insulators: very high resistance (often assumed to be infinite)  As resistance increases, it takes more “push” (voltage) to cause a current Ohm’s Law I = V / R

10. Power  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

11. Another Example:  A microhydro system is rated at 1000 watts @ 48VAC  What is the amperage that is deliver to the battery? 1kW @ 48volts AC

12. Another Example:  A microhydro system is rated at 1000 watts @ 48VAC  What is the amperage that is deliver to the battery? Power = Amps X Volts 1000 W = ?amps x 48V 1000 W = amps 48V Amps = 20.8 1kW @ 48volts AC

13. Power  Power: Rate at which energy is delivered Power = Energy Time  Measured in Watts (W), kilowatts (kW), or horsepower  Power is an instantaneous quantity  Power does not accumulate  Think gallons per minute

14. Energy  Energy: Ability to do something  Measured in kilowatt  Hours (kWhrs)  Why?  Since Power = Energy/Time, then Power  Time = Energy  Energy does accumulates over time  Think gallons  Gallons = (gallons/min)  minutes

15. How does this relate to microhydro?  Turbines are linked to generators/alternators  Which produce either AC or DC Power.  Used to power a load directly or,  Charge batteries for later use or,  Sell back to the grid for a profit  Power has to be transferred from the turbine to the load. We call this the“wire run”  More on this later!

16. Balance Of System

17. What is the BOS?  DC only system (small cabin)  Charge controller  Batteries  Conventional AC system (house)  Charge controller  Batteries  Inverter

18. Typical Off-Grid Battery Charging System

19. Off-Grid Batteryless System

20. Grid-Tie Batteryless System

21. ModelList 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

22. 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 Head lights as dump load for wind turbine

23. Dump Loads  All dump loads place a load on the turbine and transfer the energy to a form of a heater.  You have 2 options:  Air heating element  Water heating element

24. Outback Inverters

25. Xantrex Inverters

26. Batteryless Grid-Tie Options  Systems available for PV and wind  Still a special system for Microhydro  Contact Hydro Induction Power  www.hipowerhydro.com

27. Balance of System Design Outline  Wire run and its importance  Wire run sizing  System circuits  Battery bank sizing  System specs.

28. Wire Run  Need to know the distance from the turbine to the load to:  Determine system voltage and design  Calculate what type of wire/cable to use  How much it will cost.

29. Good location of turbine to load Turbine Powerhouse

30. House / Load 2,000 foot wire run

31. Why is wire size Important? Correctly sized wire: Saves on Installation costs & Conserves resources & Keeps the fire department away! Incorrect wire size

33. System Voltage and Design  System Voltage can be determined by the wire run distance.  Short wire runs can use lower voltage  Longer wire runs should user higher voltage  System Design and Configuration  Larger systems with long wire runs can be AC systems with transformers.

34. 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 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

36. Electrical Transmission on a large scale Microhydro systems can use this model!

37. Low voltag AC microhydro diagram Low Voltage AC Hydro Generator Step-up Transformer Step-Down Transformer Designed Balance of System AC Wire Run

38. Low voltag AC microhydro diagram High Voltage AC Hydro Generator Step-Down Transformer Designed Balance of System AC Wire Run

39. What do Transformers Do?  Transfers electrical energy from one circuit to another with a different voltage.  Known as mutual induction How is this beneficial to a microhydro system? Answer: allows for longer wire runs from turbine to the load with lower line losses.

40. Large Transformers (need cooling)

41. Wire Run / Wire Sizing  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.  Important Considerations  Diameter of wire (American Wire Gauge – AWG)  Length of wire  Free Air or Conduit  Type of insulation on wire  Temperature of location where wire located  Moisture where wire is located  Will conductor be exposed to sunlight  Color of insulation  Voltage Drop

42.  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 Ampacity

43. American Wire Gauge (AWG)

44. Wire Sizing for DC Applications  Voltage drop is caused by a conductors electrical resistance  This voltage drop can be used to calculate power loss  For DC systems – efficiency is paramount! Voltage Drop (Volts) = Electrical Resistance (Ohms) X Current (Amps) Power Loss (Watts) = Ohms X Amps² Power Loss (Watts) = Voltage Drop (volts) X Current (Amps)

45. 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

46. 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

47. VDI Chart 24V VDI = 28.9 2 AWG wire That’s pretty big wire What if we make it a 48 volt system?

48. 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

49. VDI Chart 48V VDI = 7.2 8 AWG wire That’s better (smaller, less $, same losses).

50. Energy Storage - Batteries

51. 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

52. Battery Capacity (Amp-Hours)  Battery capacity is rated in amp-hours. 1 amp-hour is the equivalent of drawing 1 amp steadily for one hour, or 2 amps steadily for half an hour.

53. Series Connections

54. Parallel Connections

55. Series & Parallel

56. Battery Cables

57. Life Expectancy and cost  At least 5 years  Often over 10 years or 1500 deep cycles  Shipping is expensive  Cost is about $200- $400 per 6V battery

58. Battery Care  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