SE Engr. Solar Policy, Economics, and Sustainability 5 — Questions and Answers
Question 1: Across their life cycle, how do the greenhouse gas emissions of crystalline silicon PV typically compare with coal generation?
- Roughly 20-50 gCO2e/kWh versus about 800-1,000 gCO2e/kWh (Correct answer)
- Zero, because PV has no emissions
- About half of coal
- Roughly equal to coal
Correct answer: Roughly 20-50 gCO2e/kWh versus about 800-1,000 gCO2e/kWh
Harmonized LCAs, such as NREL's, put c-Si PV at tens of grams per kWh, compared with roughly 1,000 for coal.
Question 2: Which part of a crystalline silicon module makes up the largest share of its mass and is the main material recovered in recycling?
- Silver
- Copper ribbon
- Silicon cells
- Glass (Correct answer)
Correct answer: Glass
Glass makes up about 70-75% of a c-Si module's weight.
Question 3: Some PV modules that fail toxicity testing may be managed as hazardous waste in the U.S. under which federal law?
- National Environmental Policy Act
- Endangered Species Act
- Resource Conservation and Recovery Act (RCRA) (Correct answer)
- Clean Water Act
Correct answer: Resource Conservation and Recovery Act (RCRA)
RCRA governs hazardous waste, and modules that fail TCLP testing for metals like lead or cadmium fall under it.
Question 4: Which U.S. law creates a presumption that goods made wholly or partly in Xinjiang were made with forced labor, which affects polysilicon supply chains?
- Section 201 of the Trade Act
- Uyghur Forced Labor Prevention Act (UFLPA) (Correct answer)
- Buy American Act
- Defense Production Act
Correct answer: Uyghur Forced Labor Prevention Act (UFLPA)
UFLPA lets CBP detain solar imports unless importers can show their supply chains are free of forced labor.
Question 5: Which IEEE standard sets interconnection and interoperability requirements for distributed energy resources such as PV inverters?
- IEEE 519
- IEEE 1584
- IEEE 1547 (Correct answer)
- IEEE 802.11
Correct answer: IEEE 1547
IEEE 1547-2018 covers DER interconnection, including ride-through and voltage/frequency support.
Question 6: How does a feed-in tariff (FIT) mainly differ from net metering?
- A FIT requires the system to be off-grid
- A FIT is a federal tax credit
- A FIT only credits energy at retail rates against consumption
- A FIT pays a set, often premium rate for every kWh generated under a long-term contract (Correct answer)
Correct answer: A FIT pays a set, often premium rate for every kWh generated under a long-term contract
FITs guarantee a set price per kWh of generation, while net metering offsets consumption at the retail rate.
Question 7: Which choice most directly lowers the land-use impact of a utility-scale solar farm while supporting biodiversity?
- Clearing and gravel-covering the whole site
- Spraying herbicide to keep vegetation away
- Agrivoltaics or native pollinator-friendly ground cover under the arrays (Correct answer)
- Using wider row spacing on prime farmland
Correct answer: Agrivoltaics or native pollinator-friendly ground cover under the arrays
Dual-use and pollinator-habitat designs keep the land productive and improve soil and habitat.
SE Engr. Solar Policy, Economics, and Sustainability 5
Across their life cycle, how do the greenhouse gas emissions of crystalline silicon PV typically compare with coal generation?