5. Making the Change to Renewable
Energy
Solar
Geothermal
Wind
Hydroelectric
6. Terminology
Voltage
– Measured in Volts
– Electrical potential
– “Height” of water on one side of a dam compared
to the other side
Current
– Measured in Amps
– Rate of electron flow
– “Speed” at which water flows through the dam
7. Terminology
Resistance
– The opposition of a material to the flow of an
electrical current
– Depends on
Material
Cross sectional area
Length
Temperature
8. Types of Current
DC = Direct Current
– PV panels produce DC
– Batteries store DC
AC = Alternating Current
– Utility power
– Most consumer appliances
use AC
– Electric charge changes
direction
11. Terminology
Watt-hour (Wh) is a measure of energy
– Unit quantity of electrical energy (consumption
and production)
– Watts x hours = Watt-hours
1 Kilowatt-hour (kWh) = 1000 Wh
18. Available Cell Technologies
Single-crystal or Mono-crystalline Silicon
Polycrystalline or Multi-crystalline Silicon
Thin film
– Ex. Amorphous silicon or Cadmium Telluride
19. Monocrystalline Silicon Modules
Most efficient
commercially available
module (11% - 14%)
Most expensive to
produce
Circular (square-round)
cell creates wasted
space on module
20. Polycrystalline Silicon Modules
Less expensive to make
than single crystalline
modules
Cells slightly less
efficient than a single
crystalline (10% - 12%)
Square shape cells fit
into module efficiently
using the entire space
21. Amorphous Thin Film
Most inexpensive
technology to produce
Metal grid replaced with
transparent oxides
Efficiency = 6 – 8 %
Can be deposited on
flexible substrates
Less susceptible to
shading problems
Better performance in low
light conditions that with
crystalline modules
24. Effects of Temperature
As the PV cell
temperature
increases above 25º
C, the module Vmp
decreases by
approximately 0.5%
per degree C
25. Effects of Shading/Low Insolation
As insolation
decreases
amperage
decreases while
voltage remains
roughly constant
26. Shading on Modules
Depends on orientation of internal module
circuitry relative to the orientation of the
shading.
SHADING can half
or even completely
eliminate the output
of a solar array!
33. Wire Components
Conductor material = copper (most common)
Insulation material = thermoplastic (most common)
Wire exposed to sunlight must be classed as
sunlight resistant
34. Color Coding of Wires
Electrical wire insulation is color coded to designate its
function and use
Alternating Current (AC) Wiring Direct Current (DC) Wiring
Color Application Color Application
Black Ungrounded Hot Red (not NEC req.) Positive
White Grounded
Conductor
White Negative or
Grounded
Conductor
Green or Bare Equipment
Ground
Green or Bare Equipment
Ground
Red or any
other color
Ungrounded Hot
35. Cables and Conduit
Cable: two or more insulated conductors having an
overall covering
Conduit: metal or plastic pipe that contains wires
36. Wire Size
Wire size selection based on two criteria:
– Ampacity
– Voltage drop
Ampacity - Current carrying ability of a wire
Voltage drop: the loss of voltage due to a wire’s
resistance and length
42. Solar Pathfinder
An essential tool in finding a good site for
solar energy is the Solar Pathfinder
Provides daily, monthly, and yearly solar
hours estimates
43. Site Selection – Tilt Angle
Year round tilt = latitude
Winter + 15 lat.
Summer – 15 lat.
Max performance is
achieved when panels
are perpendicular to the
sun’s rays
44. Solar Access
Optimum Solar Window 9 am – 3 pm
Array should have NO SHADING in this
window (or longer if possible)
45. General Considerations
Weather characteristics
– Wind intensity
– Estimated snowfall
Site characteristics
– Corrosive salt water
– Animal interference
Human factors
– Theft protection
– Aesthetics
47. Basic Mounting Options
Fixed
– Roof, ground, pole
Integrated
Tracking
– Pole (active & passive)
48. Pole Mount Considerations
Ask manufacturer for wind loading
specification for your array
– Pole size
– Amount of concrete
– Etc.
Array can be in close proximity to the house,
but doesn’t require roof penetrations
49. Tracking Considerations
Can increase system performance by:
– 15% in winter months
– 30% in summer months
Adds additional costs to the array
51. Passive Vs. Active
Passive:
– Have no motors,
controls, or gears
– Use the changing
weight of a gaseous
refrigerant within a
sealed frame
member to track the
sun
52. Roof Mount Considerations
simple and cheap to
install
offer no flexibility in
the orientation of
your solar panel
can only support
small photovoltaic
units.
53. Roof Mount Considerations
Penetrate the roof as little as possible
Weather proof all holes to prevent leaks
– May require the aid of a professional roofer
Re-roof before putting modules up
Leave 4-6” airspace between roof and
modules
On sloped roofs, fasten mounts to rafters not
decking
55. Solar Energy Incentives
Tax credits and deductions
– 30% tax credit
Local & state grant and loan programs
PA Alternative Energy Investment Fund
– Pennsylvania Sunshine Program
35% rebate
57. Improving Energy Efficiency in the
Home
Space Heating:
– Insulation
– Passive solar design
– Wood stoves
– Propane
– Solar hot water
– Radiant Floor/
baseboard
– Efficient windows
Domestic hot water
heating
– Solar thermal
– Propane/natural gas
– On demand hot water
58. Improving Energy Efficiency in the
Home
Washing machines
– Energy efficient front
loading machine
Cooling
– Ceiling fans
– Window shades
– Insulation
– Trees
– Reflective attic cover
– Attic fan
59. Lighting Efficiency
Factors effecting light efficiency
– Type of light
– Positioning of lights
– Fixture design
– Color of ceilings and walls
60. Incandescent Lamps
Advantages
– Most common
– Least expensive
– Pleasing light
Disadvantages
– Low efficiency
– Short life ~ 750 hours
Electricity is conducted through a filament which resists
the flow of electricity, heats up, and glows
Efficiency increases as lamp wattage increases
FROM THE POWER PLANT TO YOUR HOME
INCANDESCENT BULBS ARE LESS THAN 2%
EFFICIENT
61. Fluorescent Bulbs
Less wattage, same amount of lumens
Longer life (~10,000 hours)
May have difficulty starting in cold
environments
Not good for lights that are repeatedly turned
on and off
Contain a small amount of mercury
62. Light Emitting Diode (LED) Lights
Advantages
– Extremely efficient
– Long life (100,000 hours)
– Rugged
– No radio frequency
interference
Disadvantages
– Expensive (although
prices are decreasing
steadily)
– A relatively new
technology
63. Grid-Tied System
Advantages
– Low: Easy to install
(less components)
– Grid can supply
power
Disadvantages
– No power when grid
goes down
64. Batteries in Series and Parallel
Series connections
– Builds voltage
Parallel connections
– Builds amp-hour capacity
65. Battery Basics
Battery
A device that stores electrical energy (chemical energy to
electrical energy and vice-versa)
Capacity
Amount of electrical energy the battery will contain
State of Charge (SOC)
Available battery capacity
Depth of Discharge (DOD)
Energy taken out of the battery
Efficiency
Energy out/Energy in (typically 80-85%)
The Terms:
66. Functions of a Battery
Storage for the night
Storage during cloudy weather
Portable power
Surge for starting motors
**Due to the expense and inherit inefficiencies of batteries it is
recommended that they only be used when absolutely necessary (i.e.
in remote locations or as battery backup for grid-tied applications if
power failures are common/lengthy)
67. Batteries: The Details
Primary (single use)
Secondary (recharged)
Shallow Cycle (20% DOD)
Deep Cycle (50-80% DOD)
Types:
Unless lead-acid batteries are charged up to 100%, they will loose
capacity over time
Batteries should be equalized on a regular basis
Charging/Discharging:
68. Battery Capacity
Amps x Hours = Amp-hours (Ah)
Capacity:
100 amps for 1 hour
1 amp for 100 hours
20 amps for 5 hours
Capacity changes with Discharge Rate
The higher the discharge rate the lower the capacity and vice versa
The higher the temperature the higher the percent of rated capacity
100 Amp-hours =
69. Grid-Tied System
(With Batteries)
Complexity
– High: Due to the
addition of batteries
Grid Interaction
– Grid still supplements
power
– When grid goes down
batteries supply power
to loads (aka battery
backup)
71. Grid-Tied System
Advantages
– Low: Easy to install
(less components)
– Grid can supply
power
Disadvantages
– No power when grid
goes down
72. Controller Basics
To protect batteries from being overcharged
Function:
Maximum Power Point
Tracking
– Tracks the peak
power point of the
array (can improve
power production by
20%)!!
Features:
73. Additional Controller Features
Voltage Stepdown Controller: compensates for differing
voltages between array and batteries (ex. 48V array
charging 12V battery)
– By using a higher voltage array, smaller wire can be
used from the array to the batteries
Temperature Compensation: adjusts the charging of
batteries according to ambient temperature
74. Other Controller Considerations
When specifying a controller you must consider:
– DC input and output voltage
– Input and output current
– Any optional features you need
Controller redundancy: On a stand-alone system it might
be desirable to have more then one controller per array in
the event of a failure
75. Inverter Basics
An electronic device used to convert direct current (DC)
electricity into alternating current (AC) electricity
Function:
Efficiency penalty
Complexity (read: a component which can fail)
Cost!!
Drawbacks:
76. JAWAHARLAL NEHRU NATIONAL
SOLAR MISSION
Make India a global leader in solar energy and the mission
envisages an installed solar generation capacity of 20,000
MW by 2022, 1,00,000 MW by 2030 and of 2,00,000 MW by
2050.
The total expected investment required for the 30-year period
will run is from Rs. 85,000 crore to Rs. 105,000 crore.
Between 2017 and 2020, the target is to achieve tariff parity
with conventional grid power and achieve an installed
capacity of 20 gigawatts (Gw) by 2020.
4-5 GW of installed solar manufacturing capacity by 2017.
To deploy 20 million solar lighting systems for rural areas by
2022
82. 100 KW Rooftop Solar
Power Plant
Installed at Poornima University
83. Specification of Solar PV Module
MODEL ELDORA 300P
Make Vikram Solar
Maximum Power 300 W
Open Circuit Voltage 45.1 V
Short Circuit Current 8.74 A
Maximum Current 8.05 A
Maximum Voltage 37.28 V
Efficiency 15.63 %
Fill Factor 76.13%
NOCT 45 0 C
Number of Panels 334
84. Specification of Solar Inverter
Model STP 25000TL-30
Make SMA
Number of Inverter 04
V (DC, maximum) 1000 V
I (DC, maximum) 33A
V (DC, max. power point) 390-800 V
I (SC, PV) 43 A
Power 25 kVA
I (AC, maximum) 36.2 A
85. Power Generation (Trial Run)
Date Daily Power Generated
(kWh)
8:30 am to 4:30 pm
Total Power Generation
(kWh)
04/01/2016 (Plant Starts) 74.29 74.29
05/01/2016 414.71 489.00
06/01/2016 617.75 905.75
07/01/2016 391.43 1234.52
08/01/2016 426 1660
09/01/2016 378.06 2028.50
10/01/2016 433.56 2462.06
11/01/2016 406.86 2868.92
88. 100 KW ROOF TOP SOLAR
POWER PLANT
Capacity of Plant: 100 KW
Cost of Plant: 79.49 Lacs
Date of Production: Wednesday, February 10, 2016
Daily Power Generation: 400-450 KWH (On
Sunny Days)
Annual Power Generation:1,50,000 Units
Electrons bump into impurities in the metal as they move along the wire.
These impurities cause them to slow down and lose energy (mostly through heat)
Resistance is typically a bad thing, unless you want to waste energy
Advantages to AC:
Voltage can be stepped up or down with a transformer
Leads to less power loss, especially when transmitted over large distances
Rewrite with Equation Editor
Solar Panel – Collect energy from sun
Inverter – Converts DC from panel to AC (some loss)
Meter – Measures amount of power collected
Utility Grid – Sell extra back
Home – Segue to loads
Maximize power output by maximizing area under the curve.
Leave 6” space between roof and panel
Insolation is a measure of solar radiation energy received on a given surface area in a given time.
Surface temperature can be measured using laser thermometers
Insolation can be measured with a digital pyranometer
Attaching a battery bank to a solar array will decrease power production capacity
Insulation should always be
THHN: most commonly used is dry, indoor locations
THW, THWN, and TW can be used indoors or for wet outdoor applications in conduit
UF and USE are good for moist or underground applications
As with typical wire insulation, protective covering on cable is rated for specific uses (resistance to moisture, UV light, heat, chemicals, or abrasion)
PVC is a common conduit used
Using too many wires or too large overheating
The larger the wire, the greater its capacity to carry current
Wire size given in terms of American Wire Gauge (AWG)
The higher the gauge number, the smaller the wire
Function of wire gauge, length of wire, and current flow in the wire
Disconnect - Allow electrical flow to be physically severed (disconnected) to allow for safe servicing of equipment
Protect an electrical circuit from damage caused by overload or short circuit
Fuses
Circuit Breakers
Limit voltages due to:
Lightning
Power line surges
Unintentional contact with higher voltage lines
(attach all exposed metal parts of PV system to the grounding electrode)