PV Final - Study Guide based
Ohm's law calculations - ANS-V=IR
Power and energy calculations - ANS-
Standard Testing Condition - ANS-25ºC (77ºF) cell temperature & 1000 W/m2 irradiance
Describe peak sun hours and sun chart - ANS-equivalent # of hours at 1,000 W/m2
Identify a type of racking systems and benefits; fixed tilt, single-axis tracking, dual-axis
tracking - ANS-
Fixed tilt racking (3, pros) - ANS-Roof mounted
Pole mounted
Ground mount
No moving parts, simpler, less expensive
Single-axis tracking - ANS-Active tracking
N/S
More efficient in all months
More expensive
More complicated
More maintenance
Dual-axis tracking - ANS-Active tracking
N/S E/W
More efficient in all months
More expensive
More complicated
More maintenance
schematic of grid-tied PV system - ANS-*pic
grid-tied PV system benefits (7) - ANS-• Increased design flexibility because the system
doesn't have to power all the home's loads.
• It is the cheapest type of residential system-compared to stand-alone or multimode.
• It requires the least amount of maintenance.
, • If the system produces more than the home needs, then the extra energy is
exchanged with the utility.
• Grid-direct systems are more efficient because batteries are not included in the
system.
• This type of system allows for the use of higher DC voltages therefore decreases wire
size, potentially a cost savings.
• You can lock in your electricity costs for the life of your system
schematic of basic battery-based PV system - ANS-*pic
battery-based PV system benefits (6, 1 subpoint) - ANS-✸ Chemical energy storage
(reversible)
✸ Energy storage for night-time and cloudy weather
✸ System (voltage) stabilization
✸ Surge current
-For starting motors or other purposes
✸ Small batteries are "portable power"
✸ Many different configurations and applications
Identify various types of inverters - ANS-
Grid-direct inverter (4) - ANS-Watts output AC
DC input voltage window- voltage of array must be in this window
AC output voltage
Frequency
• 60 Hz (U.S.) or 50 Hz (Europe)
Transformer based inverter (5) - ANS-• Uses transformer to change voltage
• Heavier than TL
• Less efficient than TL
• Also called "isolated" inverters
• The transformer means the AC and DC sides don't "touch"
String Inverters (3) - ANS-• Connects to strings of modules in series
• Typically have one to three maximum power point tracking (MPPT) channels
• Typically 1.5 kW to 40 kW AC rating
Ohm's law calculations - ANS-V=IR
Power and energy calculations - ANS-
Standard Testing Condition - ANS-25ºC (77ºF) cell temperature & 1000 W/m2 irradiance
Describe peak sun hours and sun chart - ANS-equivalent # of hours at 1,000 W/m2
Identify a type of racking systems and benefits; fixed tilt, single-axis tracking, dual-axis
tracking - ANS-
Fixed tilt racking (3, pros) - ANS-Roof mounted
Pole mounted
Ground mount
No moving parts, simpler, less expensive
Single-axis tracking - ANS-Active tracking
N/S
More efficient in all months
More expensive
More complicated
More maintenance
Dual-axis tracking - ANS-Active tracking
N/S E/W
More efficient in all months
More expensive
More complicated
More maintenance
schematic of grid-tied PV system - ANS-*pic
grid-tied PV system benefits (7) - ANS-• Increased design flexibility because the system
doesn't have to power all the home's loads.
• It is the cheapest type of residential system-compared to stand-alone or multimode.
• It requires the least amount of maintenance.
, • If the system produces more than the home needs, then the extra energy is
exchanged with the utility.
• Grid-direct systems are more efficient because batteries are not included in the
system.
• This type of system allows for the use of higher DC voltages therefore decreases wire
size, potentially a cost savings.
• You can lock in your electricity costs for the life of your system
schematic of basic battery-based PV system - ANS-*pic
battery-based PV system benefits (6, 1 subpoint) - ANS-✸ Chemical energy storage
(reversible)
✸ Energy storage for night-time and cloudy weather
✸ System (voltage) stabilization
✸ Surge current
-For starting motors or other purposes
✸ Small batteries are "portable power"
✸ Many different configurations and applications
Identify various types of inverters - ANS-
Grid-direct inverter (4) - ANS-Watts output AC
DC input voltage window- voltage of array must be in this window
AC output voltage
Frequency
• 60 Hz (U.S.) or 50 Hz (Europe)
Transformer based inverter (5) - ANS-• Uses transformer to change voltage
• Heavier than TL
• Less efficient than TL
• Also called "isolated" inverters
• The transformer means the AC and DC sides don't "touch"
String Inverters (3) - ANS-• Connects to strings of modules in series
• Typically have one to three maximum power point tracking (MPPT) channels
• Typically 1.5 kW to 40 kW AC rating
