Download PV 101: Basic Photovoltaics revision exam test and more Exams Advanced Education in PDF only on Docsity!
1 / 18
PV 101: Basic Photovoltaics revision exam test
- Resistance: A material's opposition to the flow of electric current. Measured in ohms.
- Ohm's Law: For any electrical circuit, current is directly proportional to voltage, and is inversely proportional to resistance.
- Voltage: Electromotive force (EMF), or a ditterence in potential between two points.
- Current: The flow of electrons. Measured in amps.
- True or False: Alternating current (AC) has a magnitude and intensity that is always switching from positive-to-negative, multiple times a second.: True
- 22,400 watts can also be expressed as kW.: 22.4 kW
- Which of the following is a measurement of electrical ENERGY?
- Which of the following is a measurement of electrical POWER?
2 / 18 -Amps: kW
- How many watts are in 10 kW?: 10,000 watts
- How much electricity does the average American home use each month, according to the EIA?: 750-1,000 kWh
- It takes one to push one through one .: Volt, Amp, Ohm
- How many amps of current are in a 10-volt circuit that has 2 Ω of resistance?: 5 Amps
- How many volts are in a 10-Ω circuit that uses 11 amps of current?: 110 Volts
- A 40-volt circuit measures 2 Ω. How much current will it use?: 20 Amps
- If a 120-volt circuit is expected to pull 9 amps, what's the resistance of the circuit?: 13.3 Ohms
- What is the voltage of a 2-Ω, 80-A circuit?: 160 Volts
- How many watts are consumed if a 115-volt appliance draws 5 amps?: 575 Watts
- How many watts of power are used in a 110-volt circuit that pulls 15 amps?- : 1,650 Watts
- What's the voltage of a 150-watt circuit with 5 amps of current?: 30 Volts
- How many volts would be measured in a 40-W, 2-A circuit?: 20 Volts
- How much current does a 75 W light bulb pull when connected to
4 / 18 system's size and cost with maximum recommendations for and encouragement of: (Choose ALL that apply) a. Energy efficiency measures b. Energy Star appliances c. LED lighting d. Incandescent lighting e. Phantom load control: a. Energy eflciency measures b. Energy Star appliances c. LED lighting e. Phantom load control
- True or False: Exchanging a cooking range powered by electricity to one that instead uses natural gas is an example of "load shifting" or "fuel shifting.": True
- True or False: The load analysis for a grid-connected home is essentially the same procedure as one used for an off-grid home that runs on a battery bank.: False
- Select all of the potential "phantom loads" you may find in a home. a. Cable boxes and DVRs b. Cell phone chargers c. Microwave and range clocks d. Refrigerators
5 / 18 e. Garage door openers f. Programmable coffee pots: a. Cable boxes and DVRs b. Cell phone chargers c. Microwave and range clocks e. Garage door openers f. Programmable cottee pots
- True or False: Phantom loads can be controlled with power strips, switched outlets, or by unplugging when not in use.: True
- True or False: North windows have the greatest heat loss in the winter months.: True
- The process of converting DC to AC electricity requires a key PV system component called a(n):: Inverter
- This system is the simplest of all PV systems and is comprised of only two components: a PV module or array, and a DC load.: PV-direct system
- True or False: If you have a grid-tied system and during the day, if your PV system produces more energy than you need, the excess generation is sent out to the utility grid and feeds your neighbors.: True
7 / 18 b. They may contain overcurrent protection devices (fuses). c. They should be capable of being locked in the open (off) position. d. The electrical utility may require additional disconnecting means on the AC side, near the kWh meter.: a. They isolate system components to safely service equipment. b. They may contain overcurrent protection devices (fuses). c. They should be capable of being locked in the open (ott) position. d. The electrical utility may require additional disconnecting means on the AC side, near the kWh meter.
- PV is a "modular" technology. When multiple modules are connected togeth- er in series or in parallel, this is known as a(n):: Array
- Electricity produced by PV cells is in the form of current.: Direct
- Amorphous: Least expensive of the three PV module types, but is also the least eflcient.
- Multicrystalline: Mid-range priced type, quite common. Not the most eflcient type, but also not the least.
- Monocrystalline: Most expensive of the three PV module types; also the most eflcient.
- True or False: How much power PV cells and modules produce depends on how much heat and light the cells are exposed to. This variability in energy production is why the solar industry has adopted Standard Test Conditions for rating the output of PV modules.: True
- Which of the following conditions would decrease a PV array's output? Select all that apply. Select one or more: a. Dust or dirt (soiling)
8 / 18 b. High irradiance c. Low temperatures d. Shading: a. Dust or dirt (soiling) d. Shading
- Output power divided by input power, or how well a PV module converts sunlight into DC electricity, is referred to as:: Eflciency
- Conductor: Easily allows current flow
- Insulator: Inhibits current flow
- Semiconductor: Can be doped to either allow or inhibit current flow
- True or False: PV cells are silicon-based semiconductors, and their manufac- turing process is similar to that of computer chips.: True
- What is the term for a watertight electrical enclosure located at or near a PV array that contains fuses for parallel strings of modules?: Combiner box
- True or False: Charge controllers protect batteries from being overcharged, which can be a dangerous situation.: True
- What's the function of the charge controller in a PV system?: To control the flow of electricity from the PV array to the battery bank
- Which BOS components below can provide Maximum Power Point Tracking (MPPT) and monitoring for each PV module in an array? (Select all that apply.) Select one or more: a. Combiner boxes
10 / 18 molecules in the atmosphere.
- Reflected solar radiation: Solar radiation which is bounced ott brightly colored surfaces.
- True or False: PV modules installed on adjustable racks should be tilted back (on less of an angle) during the winter months, and forward (on more of an angle) during the summer months for maximum energy production.: False
- What effect does the angle of the winter sun have on a PV array in northern climates? (Choose all that apply.) Select one or more: a. It reduces the power per square meter of sunlight. b. The distance the sunlight travels through the atmosphere increases, which decreases irradiance. c. The sun angle is closer to perpendicular to the earth's surface. d. There may be more reflection due to snow.: a. It reduces the power per square meter of sunlight. b. The distance the sunlight travels through the atmosphere increases, which decreases irradiance. d. There may be more reflection due to snow.
- True or False: Azimuth is the horizontal angle (difference) between a refer- ence direction (due north) and the direction that a PV module or array faces. North is zero degrees.: True
11 / 18
- The ideal PV array tilt angle for summer months is:: Your latitude, minus 15 degrees
- The ideal tilt angle of a PV array during the spring and fall equinox is:: Your latitude
- Where would you expect to see a ballasted racking system for a PV array?: On a flat roof
- Which of the following PV systems is most susceptible to damage from live- stock, vandalism, and stones thrown by lawnmowers and snowblowers?: Ground mount systems
- True or False: It's common to see adjustable racking systems installed on sloped roofs.: False
- Choices for mounting style are based on many factors, including: (select all that apply) Select one or more: a. Intergrated architecture design b. Performance optimization c. Shading considerations d. Space constraints e. Visibility and aesthetics: a. Intergrated architecture design b. Performance optimization c. Shading considerations d. Space constraints e. Visibility and aesthetics
13 / 18 at solar noon on a very bright, sunny day. Overcast days should be avoided.: False
- True or False: Sun path charts vary with latitude.: True
- According to the Solar Pathfinder™ chart, when is this site most affected by shading from the neighbor's tree?: Winter mornings
- The PVWatts Calculator® can assess just about every parameter about the solar resource and energy production on a site, but does not account for:: Ob- structions that cause shade
14 / 18
- Which of the following statements are true regarding the Solar Pathfinder™? (Choose all that apply.) Select one or more: a. Batteries should be checked every six months. b. Software updates should be checked and installed regularly. c. Sun path charts for the correct latitude must be used. d. The base should be leveled before taking a final reading.: c. Sun path charts for the correct latitude must be used. d. The base should be leveled before taking a final reading.
- True or False: Shade on one PV module, when connected in series with other modules, can bring down production on the entire string.: True
- What is the average daily kWh consumption from a family that uses the following amount of electricity each month? January: 440 kWh February: 500 kWh March: 370 kWh April: 460 kWh May: 410 kWh June: 420 kWh July: 620 kWh August: 740 kWh September: 490 kWh
16 / 18
- True or False: Daylight saving time changes affect PV energy production.: - False
- Net metering policies and rates for a residential PV system may depend upon. (Choose all that apply.) Select one or more: a. Expected AC energy production b. Expected DC energy production c. AC rating of the inverter d. DC rating of the PV array: a. Expected AC energy production c. AC rating of the inverter d. DC rating of the PV array
- True or False: Investing in solar electricity is like buying your energy "in bulk" for the next 20-30 years at a fixed price.: True
- Which of the following is the "fixed charge" on an electrical bill each month, regardless of how much electricity was actually used or produced? Select one: a. Customer charges b. Energy charges c. Demand charges d. Time-of-use charges: Customer charges
- What is the renewable energy tax credit amount that can be claimed on income tax returns for PV systems installed through the
17 / 18 end of 2022?: 26%
- True or False: Installing a PV system on your home will always result in an increased resale value.: False
- Grants and loans for renewable energy systems are available through the for those who make 50% or more of their income in agriculture.: USDA
- True or False: All states and utilities offer net metering at retail rate.: False
- What is the current price per watt for a residential PV system, according to the Lawrence Berkeley Lab's report, "Tracking the Sun?": $3-
- What is the voltage of a circuit that uses 120 watts and pulls 10 amps?: 12V
- What is the power in a circuit that runs on 12 volts and pulls 25 amps?: 300W
- What is the current of a circuit that runs on 12 volts and is rated for 600 watts?: 50A
- If a homeowner installs an 8 kW (DC) PV system using 320-watt modules, how many modules are in the array?: 25
- What is the ideal tilt angle during the spring and fall equinoxes?: Your latitude
- Least expensive, most subtle, and most common in residential neighbor- hoods.: Roof mounts
- Requires the most excavation and concrete, and is often used in
