Question

These questions are from reneable energy system, plz double check the answer.

Question 1
What amount should you invest each year to accumulate $482,739 at the end of 17 years, assuming that the money earns 6% interest? Approximate to the nearest dollar and answer without $ symbol.

Question 2
You have borrowed $430,370 to be repaid in  19 years, assuming that the money earns 6% interest, what is the annual repayment? Approximate to the nearest dollar and answer without $ symbol.

Question 3
A small scale 5 kW PV solar system costs $9,029 and has an annual capacity factor of 11%, assuming that the electricity produced is used in the household and the electricity costs $0.38/ kWh, calculate the simple pay back period considering the annual savings and answer to one decimal place.

Question 4
A small scale 6 kW PV solar system costs $8,252 and has an annual capacity factor of 12%, assuming that the electricity produced is used in the household and the electricity costs $0.4/ kWh.
If you use the system for 17 years, and the discount rate is 6%, you have 2% of the capital cost as annual maintenance cost and 10% as salvage value, determine the present worth considering the annual savings.

Question 5
A small scale 6 kW PV solar system costs $8,458 and has an annual capacity factor of 12%, assuming that the electricity produced is used in the household and the electricity costs $0.4/ kWh.
If you use the system for 19 years, and the discount rate is 5%, you have 2% of the capital cost as annual maintenance cost and 10% as salvage value, determine the annual worth considering the annual savings.

Answer 1

1). FV = 482,739; PV = 0; N = 17; rate = 6%, solve for PMT. Amount invested per annum = 17,111

2). PV = 430,370; N = 19; rate = 6%, solve for PMT. Annual payment = 38,570

3). Total energy produced per annum = annual capacity factor*capacity of system*number of hours in a year

= 11%*5*(365*24) = 4,818 kWh

Total savings per annum = total kWh per annum*cost per kWh = 4,818*0.38 = $1,830.84

Number of years for the system to break even = cost of system/ total savings per year = 9,029/1,830.84 = 4.9 years