Question

Difficulty: HardSimultaneous Equations and Systems

A microgrid power station utilizes two types of energy storage units: Lithium-ion batteries and Flow batteries. A primary grid configuration consisting of 44 Lithium-ion batteries and 33 Flow batteries provides a total continuous storage capacity of 140 MWh140\text{ MWh}. An alternative configuration consisting of 22 Lithium-ion batteries and 55 Flow batteries provides a total continuous storage capacity of 126 MWh126\text{ MWh}. Assuming that each battery of a given type contributes a constant storage capacity, what is the individual storage capacity, in MWh, of one Lithium-ion battery and one Flow battery, respectively?

  1. 23 MWh23\text{ MWh} for a Lithium-ion battery and 16 MWh16\text{ MWh} for a Flow batteryAnswer
  2. B
    16 MWh16\text{ MWh} for a Lithium-ion battery and 23 MWh23\text{ MWh} for a Flow battery
  3. C
    20 MWh20\text{ MWh} for a Lithium-ion battery and 18 MWh18\text{ MWh} for a Flow battery
  4. D
    25 MWh25\text{ MWh} for a Lithium-ion battery and 14 MWh14\text{ MWh} for a Flow battery
  5. E
    21 MWh21\text{ MWh} for a Lithium-ion battery and 19 MWh19\text{ MWh} for a Flow battery

Answer

The storage capacity is 23 MWh23\text{ MWh} for a Lithium-ion battery and 16 MWh16\text{ MWh} for a Flow battery.
The system of equations 4L+3F=1404L + 3F = 140 and 2L+5F=1262L + 5F = 126 uniquely determines L=23 MWhL = 23\text{ MWh} and F=16 MWhF = 16\text{ MWh}. The option specifying 23 MWh23\text{ MWh} for Lithium-ion and 16 MWh16\text{ MWh} for Flow correctly matches the values of LL and FF in their respective order.

Step-by-Step Solution

1
Set up a system of two linear equations in two variables.
Let LL be the capacity of one Lithium-ion battery and FF be the capacity of one Flow battery:
Equation 1: 4L+3F=1404L + 3F = 140
Equation 2: 2L+5F=1262L + 5F = 126
Translate the physical battery configurations and total capacities into algebraic equations.
2
Eliminate variable LL by multiplying Equation 2 by 22.
Equation 2 scaled: 2(2L+5F)=2(126)4L+10F=2522(2L + 5F) = 2(126) \Rightarrow 4L + 10F = 252.
Align the coefficients of LL to subtract Equation 1 from the scaled Equation 2.
3
Subtract Equation 1 from the scaled equation to solve for FF.
(4L+10F)(4L+3F)=2521407F=112F=16(4L + 10F) - (4L + 3F) = 252 - 140 \Rightarrow 7F = 112 \Rightarrow F = 16.
Eliminating LL isolate the single-variable linear equation for FF.
4
Substitute F=16F = 16 back into Equation 2 to solve for LL.
2L+5(16)=1262L+80=1262L=46L=232L + 5(16) = 126 \Rightarrow 2L + 80 = 126 \Rightarrow 2L = 46 \Rightarrow L = 23.
Determine the value of LL once FF is known.

Key Concept

Simultaneous Linear Equations (System of 2 Equations with 2 Variables)
Estimated Time:2m 0s
Rate this question