Energy Audit of Mining Company

This article provides a guide on conducting an energy audit of a mining company. It includes preliminary analysis, identifying strategies for energy savings, and energy consumption calculations. The article also provides a mass balance at the boundaries of each step in the process. The subject is energy audit, and the course code and college are not mentioned.

Energy Audit of Mining Company
Name
Course
College
Tutor
Date

Energy Audit of Mining Company
Part A. Preliminary Analysis
In your preliminary analysis, provide answers to the following questions:
1. Create pie charts for the energy cost and energy consumption data shown in Tables 1 and
Energy Cost pie chart1
Energy consumption
1 Andersson et al. Benchmarking energy performance of industrial small and medium-sized enterprises using an
energy efficiency index, 895.
21%
14%
58%
7%
Cost
Quarry Bulk storage Processing Others

2. Using the pie charts, answer the following questions:
a. Which areas of the company’s operations have the potential to achieve the greatest
savings and why?
According to the pie chart above, the bulk storage as the area of operation of the
company has the potential to achieve the greatest savings because its limited costs compared to
other areas of operation in the company2.
2 Johnson et al. The social cost of carbon: implications for modernizing our electricity system, 375.
Cost
Quarry
Bulk storage
Processing
Others

b. Describe the procedure you would use to identify strategies for energy savings for
the company. (Your answer should be around 1 page with single-line spacing i.e.
roughly 400 words).
Without underestimating the value of using the company staff in implementing the
strategies for saving energy for the company, the following procedure is significant to identify
the strategy itself: Auditing the energy consumption versus tasks: for ease of work, the company
should hire an energy audit company whose duty would be to audit the energy consumption by
the company3. For efficient use of energy, energy audit companies provide exclusive information
that helps in trimming down excessive use of energy. Establishing energy efficient practices in
the company: First step, is always the realization of the need to save energy through the efficient
practices for saving energy in the company. By examining the areas of operations in the
company, based on the utilities and their relative costs, the company should try its optimal best
to use excess energy during the low or off peak times. The company staff should be encouraged
to follow energy saving models to reduce the usage of energy with more initiative.
Benchmarking energy performance for the company: This is whereby the various tools of
management portfolios of energy savings are adopted to benchmark the performance of the
company’s facilities as far as energy consumption I concerned. Afterwards, the right incentive
that would help implement the identified improvements is adopted. Buy energy efficient devices:
the best solution, without interrupting the amount of work being performed in the company
(mining processes), it is best to use energy efficient devices. Most of these devices are known to
be cost effective especially in the areas of lighting, storage of bulk materials, and processing. On
lighting, use of energy saving bulbs, saving on energy by turning off the devices when not in
use, and such related practices help save energy consumption the company.
2. Using the data in Table 3, calculate the monthly average daily energy consumption and
plot this using a column graph. Are there any trends and anomalies in the data that you
would seek to explain? Suggest possible reasons for the month to month variations in
electricity consumption within the years and between the years.
3 Kaplan, Power plants: Characteristics and costs, 65.

Monthly Average daily energy consumption
Based on the graph above, the trend in the monthly average daily energy consumption was
relatively lower in the early months of 2016 and 2017 between January to April4. During this
period, the year 2016 exhibited higher consumption in average, except in the month of January.
In the month of May, the highest amount of energy consumption was registered in 2016
followed by a steady consumption throughout the year. Therefore, by considering the two years
of consumption in monthly average terms, there is no anomaly in the data seeking explanation.
However, the variations in the energy consumption between the months in the two years are
caused by the tonnes of ore processed, the different areas of operations, as well as the energy
sources.
3. Using Table 4, plot gas consumption versus tonnes of ore processed using an X-Y
scatter plot. Fit a line through your plot. What do the intercept and the slope of the
graph represent? Why is the intercept not equal to zero?
4 Thollander and Mikael Ottosson. "Energy management practices in Swedish energy-intensive industries, 1133.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
5000
10000
15000
20000
25000
30000
35000
2016
2017

According to the scatter graph below of gas consumption against tonnes of ore processed,
the slope of the graph is 2.95 which represent the degree to which tonnes of ore processed affect
the amount of gas consumed during mining, and vice versa. The y-x intercepts represent the
value of the various variables that are constant in causing the change. Therefore, the intercepts
are not equal to zero because they are real numbers that actually causes the effects between the
two variables5.
os
Part B: Energy
Consumption Calculations
1 . Using the electrical power output to heat power output ratio, and the heat output of
the μT-CHP, determine the electrical power capacity, Ec of the μT-CHP.
5 Lu et al. "An assessment of alternative carbon mitigation policies for achieving the emissions reduction of the
Clean Power Plan, 672.
Y=2.95x+ 0.009
CHP efficiency= ratio of net electrical output
net fuel consumption ,

CHP efficiency= ratio of net electrical output
net fuel consumption ,
Therefore, μT −CHP=EFF FERC =
P+ Q
2
F
But
Ratio of electrical power output ¿ fuel power input , Ec /Qo = 25.5%
Also, Ratio of electrical power output ¿ heat power output , Ec /Qc = 51.85%
Hence,
CHP efficiency= 51.85
25.5 = 2.033
2 If the μT-CHP runs at full load when operating, what is the annual amount of
electricity it will produce? What is the annual amount of heat it will produce?
The amount of electricity to be produced is given by
Annual Energy heat Demand for Electricity6 = Coefficient Performance x heating
Cod=COPab x Thi
= 25.5
51.85 x 54 kWh .
=26.55737705kwh.
Amount of electricity produced annually = 6.55737705 kwh x 7000
6 Moya et al. "Analysis of the Ecuadorian energy audit practices: A review of energy efficiency promotion, 296.

= 185,901.63kW.
Amount of heat produced = 2.033 x 54 kWh
= 109. 782kWh
Amount of heat produced annually = 109. 782kWh x 7000 hours =
= 768,474kW.
3 How much heat will remain to be produced by the boiler?
Total Energy produced annually = 455,814.7 kWh x 185,901.63 kW
= 641,716.34kW.
But Annual total demand = 926,600 kW
Hence, amount that will be produced by the turbines= 926,600 kW −641,716.34 kW
= 284,883.4kW.
4 Using the electrical power output to fuel power input ratio, and the electrical power
capacity of the μT-CHP , calculate the fuel power input of the μT-CHP in kW?
Electrical Power Capacity CSHP=(C¿¿ f x Fb ).( Eld + El1)¿
= 2.9 cents
kWh x 185,901.63 kW
= 539114.727 cents
But it is assumed that the overall input electricity amount is equivalent to fuel power input
Hence, fuel capacity7 = 539114.727 cents
8.7 cent /kWh el
= 61,967.21 kWh.
5 How much fuel energy (in kWh) is needed to run the μT-CHP for a whole year?
7 Bawua and Richmond Owusu. "Analyzing the effect of Akoben programme on the environmental performance of
mining in Ghana, 19.

Fuel required per hour is 61,967.21 kWh
Fuel Energy Required = 61,967.21 x 7000 = 433,770, 470kW.
6 Calculate the yearly capital cost of the μT-CHP assuming a life time of 20 years and
discount rate of 5.25%, using the annuity formula, which converts capital cost, C
into an equivalent annual payment, A using a Capital Recovery Factor, CRF. Ignore
the effects of inflation.
CSHP−CCHP .Ceq F x 8760−Crf ( l , i ) . CeqCHP . Eld+ Ceqab .Cod ¿ ≥ 0
Where
C eq CHP thecapital costs of CHP unit ( EUR /kW e)
C eq ab( EUR /kW c )the capital costs of absorption chiller
crf ( – ) the capital recovery factor used ¿ convert a present value into a stream of equal annual payments
a specified tim
But assuming that Crf ( l , i ) . CeqCHP . Eld +Ceqab .Cod ¿ is negligible = 0
Then, the equation can be written as
CSHP−CCHP .Ceq F x 8760
= (26.5573770−2.033) x $ 2150
kW e x 8760
= 461,364,842.3 cents
7 Determine the yearly profit of the μT-CHP by completing the table below
Cost components of μT_CHP Yearly costs ($)
Total Yearly Capital cost 2150

Consumption-bound costs
Cost of natural gas 438
Cost of auxiliary electrical energy 150
Other cost 30
Storage cost 0
Total yearly consumption-bound 19,516,000
Cost 19,516,000
Operation-bound cost
Annual maintenance, including spare
Parts 106
Annual overhaul/maintenance &other
Components 900
Annual insurance 200
Total yearly operation bound cost 1206
TOTAL YEARLY COST 27,958,000
Cost Savings

Electricity 678.6
Heat 248.4
Total yearly revenue 21,469,000
YEARLY PROFIT 35,369,614
8 Assuming the consumption-bound costs, operation-bound costs and cost savings are
constant over the lifetime of the μT-CHP, calculate the Net Present Value and the
Simple Payback Period for the project. List any other assumptions you have made.
Other costs = ( 0.8+2.9+8.7+4.6 ) cent
kWhth x 284,883.4 kW .
= 4843017.8 cents
Net Present Value = ¿ 433,770 , 470 kW +4843017.8 cents
= 438,613,487.8 cents
9. Based on your work, comment on the option of installing a μT-CHP at the mine site to
provide part of the heating load and offset electricity consumption from the grid. Do you
support the previous consultant in their recommendation that the company should
purchase a μT-CHP?
I would like to recommend an offset feeding of electricity into the plant from the grid system.
This is because it will help in ensuring that there is constant flow of power into the system and
thus, hastening the production process. Although, purchasing a μT-CHP is a good idea, it is not
economical for the plant as the mine will have to incur additional costs for both installation and
maintenance of the system and this tends to lower the overall profit margin.

Part C
Show the mass balances at the boundaries of each step in the process. A spread sheet is
suggested as a good way to neatly layout all the input and output masses for each of the
processes
The diagram below shows the layout for the output masses8
The inputs and outputs at the system boundary are presented in a single flow diagram
shown in Figure 3. Assuming 15 MJ of energy is required to produce 1 litre of the biofuel
and that 1 litre of the biofuel weighs 0.789 kg; determine the numerical values of all the
inputs and outputs shown in Figure 3.
Given that
Energy is 15 MJ, Biofuel produced = 1 litre
8 Riahi, et al. "The shared socioeconomic pathways and their energy, land use, and greenhouse gas emissions
implications: an overview, 168.

1 litre of biofuel is equivalent to 0.789 kg in terms of weight
Electricity use by
month
Month (MWh)
2016 2017 2016 (MW/Kg) 2017 (MW/Kg)
Jan 19643 26660 6227 8451
Feb 22942 21420 7273 6790
Mar 25223 18910 7996 5994
Apr 26863 25200 8516 7988
May 32352 25730 10256 8156
Jun 24462 22500 7755 7132
Jul 24912 28520 7897 9041
Aug 27701 30690 8781 9729
Sep 23263 25500 7374 8084
Oct 23363 21080 7406 6682
Nov 26862 24000 8515 2699
Dec 18712 23250 5932 1880
Tabulate the amount of thermal and electrical energy (in MJ per kg organic crop) required for
each of the steps shown in Figure 4.
9Ore
processe
d
Gas
Consumptio
n
Mont
h (tonnes) (TJ) MJ
MJ/
Kg
electrical
energy
thermal
energy
Jan 2500 25
2500000
0 10 9.33 0.67
Feb 2800 28
2800000
0 10 9.33 0.67
Mar 3000 30
3000000
0 10 9.33 0.67
Apr 3200 32
3200000
0 10 9.33 0.67
May 2800 27
2700000
0 9.64 8.997 0.643
Jun 2900 30
3000000
0 10.71 9.772 0.938
Jul 2700 26 2600000 10.38 9.688 0.692
9 Stimmel, Carol L. Big data analytics strategies for the smart grid. Auerbach Publications, 2016.

0
Aug 3500 34
3400000
0 10.29 9.604 0.686
Sep 2850 28
2800000
0 10.17 9.492 0.678
Oct 3000 32
3200000
0 9.375 8.75 0.625
Nov 2900 27
2700000
0 10.74 10.024 0.716
Dec 2500 27
2700000
0 9.25 8.63 0.62
How much land would the company require so that their trucks can be run completely on
biofuel for the entire year?
Given that
1ha= 25kg of bushels =180 = organic crops (80%)
But from table 1, diesel quantity is 1,765,226 L
Diesel utilized by the truck = (1,765,226 L x 80
100 ) = 1,412,180.8 L
Also, density of biodiesel = 0.8746g/cm3 = 8746kg/L
Hence, mass = density x volume
= 8746 kg
L x 1,412,180.8 L
= 1.235 x 1010 kg
Land Required = = 1 ha
25 kg x 1,412,180.8 L
= 494,037,331ha
Outcome as a result of increase of 62% = 162
100 x 494,037,331ha
= 800,340,476.3 ha
a) Based on your work, comment on the feasibility of Rocky Mines establishing a biofuel
plant onsite.

The feasibility study on the land size depicts that it require extensively large vast of land which may
not be available for such production due to population and infrastructure and thus, makes it
impossible for the biodiesel production10.
b) What factors have been ignored in this assessment of land requirements? Are these
factors likely to be important?
i. Market availability is a key and critical factor which have been ignored in this feasibility
study and thus, ought to have been incorporated in the analysis
ii. Also, the trends associated with the biodiesel lubricity has been left out and ignored
though it is a critical aspect which need critical evaluation
iii. The current trends in the biodiesel as well as their impacts also need to be incorporated in
the norm, although this analysis has been left it out
iv. Alternative in line with the element has been ignored in the feasibility study
v. Evaluation of the available opportunities in line with the biodiesel has not been
incorporated
vi. The design , set up as well as construction process in line with the proposed biodiesel is
not mentioned in the analysis
vii. Expected production capacity is also a vital aspect though it has not been included in the
study11
10 Lu et al. "An assessment of alternative carbon mitigation policies for achieving the emissions reduction of the
Clean Power Plan, 672.
11 Lu, Liwei, Paul V. Preckel, Douglas Gotham, and Andrew L. Liu. "An assessment of alternative carbon mitigation
policies for achieving the emissions reduction of the Clean Power Plan, 661.

References
Andersson, Elias, Oskar Arfwidsson, and Patrik Thollander. "Benchmarking energy performance of industrial small
and medium-sized enterprises using an energy efficiency index: Results based on an energy audit policy
program." Journal of Cleaner Production 182 (2018): 883-895.
Bawua, Serwaa Akoto, and Richmond Owusu. "Analyzing the effect of Akoben programme on the environmental
performance of mining in Ghana: A case study of a gold mining company." Journal of Sustainable Mining 17, no. 1
(2018): 11-19.
Johnson, Laurie T., Starla Yeh, and Chris Hope. "The social cost of carbon: implications for modernizing our
electricity system." Journal of Environmental Studies and Sciences 3, no. 4 (2013): 369-375.
Kaplan, Stan. Power plants: Characteristics and costs. DIANE Publishing, 2011.
Kirsch, Stuart. "Sustainable mining." Dialectical anthropology34, no. 1 (2010): 87-93.
Lu, Liwei, Paul V. Preckel, Douglas Gotham, and Andrew L. Liu. "An assessment of alternative carbon mitigation
policies for achieving the emissions reduction of the Clean Power Plan: Case study for the state of Indiana." Energy
Policy 96 (2016): 661-672.
Moya, Diego, Roberto Torres, and Sascha Stegen. "Analysis of the Ecuadorian energy audit practices: A review of
energy efficiency promotion." Renewable and Sustainable Energy Reviews 62 (2016): 289-296.
Riahi, Keywan, Detlef P. Van Vuuren, Elmar Kriegler, Jae Edmonds, Brian C. O’neill, Shinichiro Fujimori, Nico
Bauer et al. "The shared socioeconomic pathways and their energy, land use, and greenhouse gas emissions
implications: an overview." Global Environmental Change 42 (2017): 153-168.
Stimmel, Carol L. Big data analytics strategies for the smart grid. Auerbach Publications, 2016.
Thollander, Patrik, and Mikael Ottosson. "Energy management practices in Swedish energy-intensive
industries." Journal of Cleaner Production 18, no. 12 (2010): 1125-1133.