Anaerobic Digester Cost and Efficiency

The video tutorial walks through solving a 2009 AP Environmental Science free response question. It focuses on calculating the electricity produced by using cow manure in an anaerobic digester, determining the cost savings from this electricity, and calculating the payback period for the digester installation. The tutorial emphasizes the importance of correctly setting up the math problems and explains how partial credit can be earned even with incorrect answers if the methodology is correct.

What is the main focus of the 2009 AP Environmental Science free response question discussed in the video?

• Math problems starting with part C

• Non-math problems in parts A and B

• The impact of electricity costs on farming

• The history of environmental science

How many kilowatt hours does each cow produce per day?

• 2 kilowatt hours

• 3 kilowatt hours

• 4 kilowatt hours

• 5 kilowatt hours

What is the total number of kilowatt hours produced in a year by 500 cows?

• 150,000 kilowatt hours

• 547,500 kilowatt hours

• 365,000 kilowatt hours

• 1,000,000 kilowatt hours

What is the purpose of using an anaerobic digester on the farm?

• To increase cow production

• To produce electricity

• To lower water usage

• To reduce manure

How much money does the farmer save in a year from the electricity produced?

• $50,000

• $60,000

• $55,000

• $54,750

What happens if you use a wrong answer correctly in subsequent questions?

• You have to redo the question

• You gain full points

• You gain partial points

• You lose all points

What is the cost of installing the anaerobic digester on the farm?

• $400,000

• $350,000

• $450,000

• $300,000

How many years will it take to recover the cost of the anaerobic digester installation?

• 5 years

• 6 years

• 7 years

• 8 years

What is the significance of rounding in the calculation of recovery time?

• It simplifies the problem

• It makes the problem more complex

• It increases the cost

• It is not necessary

What is the main challenge in solving the problems discussed in the video?

• The number of cows

• The complexity of the math

• Understanding the setup of the problems

• The cost of electricity