Project 2: Designing an alternative energy system for a cell phone tower

Team 4: Seyi Ajayi, Jonathan Whitehead, Patrick Bradshaw

EDSGN 100 Section 020 Professor Chiu

12/2/10

Cell-Phone Tower Project 2:

Abstract: This presentation focuses on the design of an energy system that utilizes solar energy as well as a back-up diesel generator to power a cell tower in Lagos, Nigeria. The energy system will be built to fulfill our customer’s needs. This energy system needs to be self sustaining; it must be able to work in an area with no available energy grid.

Mission Statement: Our goal is to design an energy system to allow cell phone capabilities in the outskirts of Lagos’ Nigeria. We will be utilizing solar energy, due to the constant sunlight from its location, to power the system.

Introduction: As previously mentioned the purpose of this project is to design an alternative energy system that fits the requirements of the consumer. The area that we are creating this system is Lagos’ Nigeria. Lagos’ Nigeria is a very large city with third world characteristics. We believe that it is a perfect candidate for the projects objectives. Lagos’ Nigeria’s third world characteristics mean that only a small portion of the population receives adequate power. By adding in an alternative energy system, one that does not require a grid to produce power, we will be able to provide cell phone capabilities to an extremely large untapped market. Adding a cell phone tower will help Lagos’ Nigeria develop into a much larger city by expanding outwards with new communications technologies. Communication is a vital part of everyday life and living without the technology of cell phones and instant communication does not make sense, especially for a city as big as Lagos’. This project is going to focus on the design and construction of the most efficient, alternative energy system possible to power this city. GE set up this task with environmental conservation in mind, its continuing objective to become more “green” is demonstrated by the number of new prototypes that utilize alternative energy sources.

External Literature Search:

Research on surround conditions:

Nigeria’s Energy Conditions:

Lagos, Nigeria Population=9,000,0000

Nigeria’s electricity accessibility=69%urban area, 26% rural areas. 81/150 million people without electricity

*In the outskirts of Lagos, Nigeria, 26% of people have electricity. Adding a cell-phone tower with an electricity source will help Lagos expand outward

Cell Tower Research:

Factors that affect cost: -cell tower location -cell tower type -height of tower

Cost range: -Low: $19,200yearly/$1,600monthly -High: $36,000yearly/$3,000monthly

*Our cost will be on the lower side, because of the ease of putting in a tower.

Lagos, Nigeria Climate Conditions:

Month Average Temperature (°F)

Average Direct

Sunlight hrs/ day

January 81 5.9

February 82 6.7

March 82 6.4

April 82 6.2

May 81 5.6

June 78 4.0

July 77 3.0

August 76 3.0

September 77 3.1

October 79 4.9

November 80 6.6

December 81 6.6

Lagos, Nigeria’s climate can be described as having a high, consistent temperature, due to the lake effect of the Gulf of Guinea, and a relatively small amount of direct sunlight, an effect of being located near the equator.

Benchmark Cell-Phone Tower:

Customer Need Lattice Tower Monopole Tower Guyed Tower Stealth Tower

Efficiency* 5 5 5 5

Reliability 5 3 3 4

Effectiveness 5 3 4 2

Simplicity 4 4 3 2

Durability 4 3 2 5

Cost 4 4 5 1

*Efficiency is based on the type of antenna, since the same antennae will be used for all towers it is neglected in this table.

**We chose the Lattice tower because of the ease of putting solar panels directly on the tower. Lattice towers are generally taller and work the best in high load conditions, giving more coverage area for the average antenna.

Benchmark Solar Panel:

Brand

Model LPC238SM MF125UE5N GEPV-85 BP375J SW225

Volts 30 17.3 17.5 17.6 29.5

Warranty (at 90% output)

10 years 10 years 10 years 12 years 5 years

Weight (lbs) 41 29.8 17 17 48.5

Made in: South Korea Japan USA China, India & USA

USA

Price $678 $415 $225 $490 $699

GE solar panels chosen because of low price, lightweight, and good efficiency

Customer Needs

Categories:

Efficiency -Is the system cost effective? -Does the system utilize the best possible resources?

Reliability -Does the system spontaneously shut down? -Does it provide enough energy to consistently power the cell phone tower?

Effectiveness -Does the design effectively fulfill the requirements? -Does the system create any energy/environmental wastes?

Simplicity -Is the system simple to create and maintain? -Will the design be easy to mass produce?

Durability -Will the system last for an extended period of time?

Customer Needs Weighted Hierarchies

1. Efficiency (0.26, 0.26)

1.1 Cost Effective (0.10, 0.40)

1.2 Resource Efficient (0.16, 0.60)

2. Reliability (0.19, 0.19)

2.1 Stays Powered (0.08, 0.40)

2.2 Provides enough energy (0.11, 0.60)

3. Effectiveness (0.21, 0.21)

3.1 Fulfills requirements (0.11, 0.53)

3.2 Environmentally Friendly (0.03, 0.16)

3.3 Utilizes Best Resources (0.07, 0.31)

4. Simplicity (0.21, 0.21)

4.1 Simple to create (0.05, 0.26)

4.2 Simple to maintain (0.06, 0.28)

4.3 Easy to mass produce (0.08, 0.36)

4.4 Easy to store plant (0.02, 0.11)

5. Durability (0.13, 0.13)

5.1 System lasts (0.07, 0.50)

5.2 Resources available (0.07, 0.50)

Customer Needs Ranking

Main Categories

1. Efficiency (0.26) 2. Simplicity (0.21) 3. Effectiveness (0.21) 4. Reliability (0.19) 5.Durability (0.13)

Sub Categories

1. Resource efficient (0.16)

2. Fulfills requirements (0.11)

3. Provides enough energy (0.11)

4. Cost effective (0.10)

5. Easy to mass produce (0.08)

6. Stays powered (0.08)

7. System lasts (0.07)

8. Resources readily available (0.07)

9. Utilizes best resources (0.07)

10. Simple to maintain (0.06)

11. Simple to create (0.05)

12. Environmentally Friendly (0.03)

13. Easy to store plant (0.02)

System Requirements:

Solar Position in Nigeria

Blue=Average Month Red=Time(Hours)

Optimal and standard solar panel position is 40° due to the majority of direct sunlight occurring in the 0° - 70° range above the horizon.

Calculation for ideal solar panel size:

Size of Solar Panel Required

E sol = It A η t

Required Load = E sol = 1.2 kW/hour = 28.8 kW / day

CGIS Solar cell efficiency ≈ 20%

Average direct Sunlight ≈ 5.167 kwh/m2-day

T= Time in days = 1 day

28.8 kW / day = (5.167 kwh/m2-day) A (0.2%)(1 day)

A= 27.869 m2 ß Surface area needed

5.279m X 5.279m square solar panel

Given our groups given climate conditions, if we used a solar panel with 20% efficiency, it would require around 28 m² of solar panels to continuously power the system.

System Diagram:

System Explanation:

Solar Panel

Diesel Back-up

Generator

Transfer

Switch

AC Distribution Panel/CPU

Hut AC LoadsLighting

HeatersAir Conditioning

Tower Power Necessities:Power for antennae, switches, Etc.Type A2 NaMx GE

DurathonTM Battery

Our telecom tower will primarily be powered by a solar panel charged battery and a back-up diesel generator will be installed in case the solar panel fails to produce the needed amount of energy. In either situation, the power source will be the type A2 NaMx GE Durathon battery that will be charged by either of the methods stated above.

System Power Cycle

Solar Panel Charges battery- ≈6 hours/day, (Sunrise – Noon)

Battery Power* (alone) – 18 hours

Back up Diesel Generator – When needed

*The type A2 GE Durathon™ Battery can store 24.8 kWh, which would be equivalent to about 20 hours of power with our 1.2kWh needs.

Black Box Model:

Concept Generation:

Energy Storage

Energy Source

Controls

Energy transferred from solar panels to batter

Electrical energy transmitted from battery to tower

Silicon based Solar Panels

Utilizes photons from sun to create electrical energy

Powers cell phone tower. Gives large area cell phone capabilities.

Control box near battery manages system

Turns power on/ off

Different energy systems-two separate systems

1. One sided solar panel attached to house containing battery

2. Two sided solar panel attached to house containing battery

3. U-shaped solar panel attached to house containing battery

4. Spherical solar panel attached to house containing battery

Different energy systems-underground energy systems

5. Two-sided solar panel connected to underground battery

6. U-shaped solar panel connected to underground battery

7. One-sided solar panel connected to underground battery

Different energy systems-systems combined

8. Multiple smaller panels attached to tower

9. One large panel attached to tower

10. U-shaped panel attached to tower

11. One large panel attached to tower, supports added to enable gradual panel angle

12. One large panel attached to tower, supports added to enable gradual panel angle, battery system and generator located directly underneath tower

Concept Selection:

Innovations on our Project:

Our design is simple to produce and easy to maintain, a high priority for our given location.

By combining systems, there is no need to create a separate storage system and underground energy transfer wires. Our system can also be added on to existing towers.

Our design has strategically placed solar panels that optimize total sunlight. These solar panels are placed at ideal angles.

Estimated Financial Costs

Projected Initial Costs

Initial costs of Diesel Backup Generator ≈ $5,000 Initial costs of Type A2 DE Duration battery ≈ $2,500

Initial costs of Solar panels ≈ $20,000 @ $4 per Watt Initial costs of Steel support beams ≈ $3,000 @ $300 per ton

Initial costs of base station on tower ≈ $20,000 Initial costs of Wiring ≈ $1,500

Initial Labor and product transportation costs ≈ $10,000 Initial Miscellaneous costs ≈ $1,000

Finial estimated initial costs ≈ $63,000 Yearly maintenance costs (including cost to replace equipment in the future and rental costs) ≈ $5,000 per year

Projected Revenue and Investment Effectiveness

Cost of Diesel per liter= $1.19= $4.5046 per gallon. Energy load= 0.6 gallons per hour

Diesel cost per year= $39,460.65 per year Initial investment/ Energy cost per year= Years required to break even.

$63,000/ $39,460.65 = 1.597 years

Final time for investment to pay off is based off of opportunity cost of powering the system. We compared the money we would save from using solar panels to the reoccurring cost of buying diesel to power the system.

Final Design:

Design description

Patent Tables

Our final design incorporates a lattice cell phone tower with a solar panel attached to it. As you can see through the picture, the solar panel is attached to the lattice tower off of a platform running through the middle of the tower. The platform length can vary in size, depending on the angle of the tower and size of the solar panel needed to power the system. In our case, the angle between the solar panel and the edge of the platform is 40°. 40° is the optimal angle, for our given location, for producing the most solar energy. Depending on the size of the battery system and backup generators, the housing system, in very rare cases, can be located on the platform. However, in most cases, the housing system will be too large and have to be moved to below the solar panel and under the tower. This drawing’s power comes in displaying our main concept. The idea of attaching a solar panel to the cell phone tower at a unique angle is our group’s main focus.

Function Single Antenna Phone Tower Sends Out Signal

Multiple beams supporting tower

Angled Solar Panels, Solar Panel Design

Antennas Mounted to Cell-Phone Towers

US 5239744

Stationary Communication System

US 6434372

Lattice Tower US 6745539

General Electric Solar Panels

US 4167644

Patent Descriptions:

US 5239744 :

-Patent of antenna mounted to a cell-phone tower to communicate with the cell-phones. In our tower we used a singular antenna connected to the platform.

US 6434372:

-Patent of an apparatus that communicates with portable telephones over a coverage area. This is simply a patent for a cell-phone tower that provides coverage for cell-phones.

US 6745539:

-Patent of a lattice tower, which consists of multiple poles. Our tower was based off of the design of a lattice tower.

US 4167644

-Patent of General Electric solar cell panels. Our tower uses GE solar panels in order to collect energy from the sun.

Social Implications:

Cell Tower Solar Energy UsedLagos residents will have very good cell-phone reception Global energy resources are conservedMay have to tear down buildings or natural habitats to create room for the tower

The energy is safe

Low-level radio-frequency emissions may cause cancer or other health issues

The energy source can never run out

Towers can be dangerous for workers

Conclusion:

After analyzing the problem and the customer needs, we were able to find a cheap and effective solution. Our challenge was to design

an alternative energy source that would power cell phone towers in remote locations. Our three main customer needs were Efficiency, the

system had to get the task complete with limited resources, Simplistic, the system needed to be able to be mass produced and assembled very

easily, and Effective, the system needed to utilize outside resources to their full potential. We strongly believe that our design incorporates all

three of these ideas into one. Our idea for a new cell phone tower powering station incorporates two main concepts. The first is using a

photovoltaic solar panel to power the system. The second is attaching that system to the cell phone tower at a different angle.

To address the need for an efficient system, we decided to go with solar panels. When we analyzed the surrounding conditions of our

given location, Lagos’ Nigeria, we came to the conclusion that solar panels were the best option to power the cell phone tower. Lagos’ Nigeria

has a lot of natural sunlight and a lot of areas with an unreliable grid. A cell phone tower on the outskirts of Lagos’ Nigeria will help the city

expand deeper into the country. We believe that setting up a cell phone tower in this location has high potential to generate a lot of revenue.

Nigeria is a third world country with extremely limited resources, utilizing its excess solar energy is an extremely efficient solution to the

problem.

To address the need for a simplistic system, we have decided to attach the solar panels to the cell phone tower. Attaching the solar

panels to the cell phone towers is an extremely simplistic solution. Instead of creating a separate housing system, and wiring to the cell phone

tower, attaching the solar panel to the tower is a lot simpler. By attaching the solar panel to the tower we eliminate inefficiencies of transferring

energy between systems. Adding the solar panel to the tower also makes it easy to reproduce the system and attach the system to existing cell

phone towers.

To address the need for an effective system, we have decided to add an angle to the solar panel on the cell phone tower. By attaching a

platform to the cell phone tower and decreasing the solar panels angle from about 70° to around 40°, we generate more electricity. A more

efficient angle towards the sun will allow the solar panel to collect more energy at the peak hours of sunlight during the day. This solution is

effective in taking our original concept and tweaking it to receive its full potential.

In conclusion, we designed a system that was efficient, simplistic, and effective all while meeting the requirements of the project. With

our total costs taken into consideration, our estimate is around a $63,000 start up fee. This fee is including the right sized solar panel to produce

the necessary amount of power, wiring, a base station with the battery, a platform to support the panel, and instillation fees. We compared this

cost with the opportunity cost of powering the cell phone tower. The opportunity cost is the cost required to power the tower using diesel, this

cost is around $40,000 per year. By dividing the initial cost of the solar panel system by the cost of the reoccurring fee of using diesel power, we

have concluded that in around 1.6 years the system will start paying for itself. Taking that into consideration, along with all of the perks of using

a solar powered system, we believe that our solution effectively solves the problem.

References/Sources

Lau, Andy “Energy Sources in a Nutshell” Fall 2008

http://www.climatetemp.info/nigeria/lagos.html

http://www.mapsofworld.com/lat_long/nigeria-lat-long.html

http://www.jhsph.edu/bin/t/c/Africa_map.jpg

https://www.cia.gov/library/publications/the-world-factbook/geos/ni.html

http://www.fao.org/ag/AGP/agpc/doc/Counprof/nigeria/nigfig2.jpg

http:// www.eia.doe.gov/emeu/cabs/Nigeria/Background.html

http://solardat.uoregon.edu/SunChartProgram.html

http://www.google.com/patents

http://www.wholesalesolar.com/solar-panels.html#BP

http://www.makeitsolar.com/solar-energy-information/04-sun-energy.htm

http://www.cancer.org/Cancer/CancerCauses/OtherCarcinogens/AtHome/cellular-phone-towers

http://tech.fortune.cnn.com/2008/05/28/fatal-bandwidth-6-cell-tower-deaths-in-5-weeks/