Weekly Deliverables Summary

P08427

Weekly Deliverables Summary

LED Lighting Technologies for a Sustainable Lighting Solution in Developing Nations

P08427

Report Date: 20 May 2019

Prepared By: Ian J. Frank

List of Deliverables Included in Summary:

• Needs Assessment – currently still in need of actual customer feedback – Page 1
• Preliminary Specifications – Page 2
• Benchmarking Summary – Page 3
• WBS & team roles (Final) – Page 6
• Updated schedule – Page 6
• 1-Page Project Summary (Final) – Page 9
• Team Values & Norms (Final) – Page 10
  

Current Needs Assessment – Still waiting to hear from customers

Preliminary Engineering Specifications (Based Largely on DPM Work)

Notes on Engineering Specifications:

• The above potential values for the engineering metrics are a starting point and in most cases are simply estimates. The life time value of 100,000 hours come from the fact that LED's have a nominal life time of 100,000 hours, and it would be ideal if the entire lighting system were to have the same lifetime. Also the longest possible lifetime is desired as the end user of this product will not have the financial resources to be replacing the unit very often.
• Basic battery benchmarking was done base on the battery in my HP zd7000A laptop computer. The battery is a 12 cell 6600mAh unit. Taking a 24 LED light, we get a current draw of 20mA. Thus from such a battery our sample system could get an estimated 230 hours of battery life. Lard capacity batteries have a full fife time of about 500 charging cycles. A lower capacity battery (1800mAh) could also be used and would yield 90 hours of use per charge, and due to the lower capacity, could be used for 1000 charging cycles. Either choice could easily allow for 100,000 hours of battery life.
• Finally it should be explained what distribution of light entails. This metric will deal with the evenness of the lighting. Where the unit being used is the rate of change of the intensity of the light as one progresses further away from the source. Ideally this value should be as close to zero as possible - implying prefect distribution of the light. Clearly this is not a truly possible goal, but it is the direction that we need to head in.

Benchmarking Summary

Benchmarking work to date has consisted of researching various fields that will be useful to the team. The summaries of the individual research areas follow.

Useful Definitions for Lighting

Candela (SI unit- cd): luminous intensity (at light source)

This is essentially the power emitted by the light source. This is irrespective of whether any part of the light is being blocked or on what area the light is shining.

Lumen (derived unit- lm): luminous flux (perceived power)

1 lm = 1 cd sr or the flux of one candela into one steradian

*Lumens take into account only what the human eye can use to see

*If light is dispersed 360º, a 1 cd source will have 4π lm of flux.

*When reading LED spec sheets, use the following conversion:

lm = cd / (2π (1-cosθ)) where θ = ½ “spread angle”

*Lux (derived unit- lx): luminous emittance

THIS IS WHAT WE REALLY CARE ABOUT BECAUSE IT TAKES INTO ACCOUNT THE SPREAD AREA.

1 lx = 1 lm / m2

Typical Values: Kerosene lamp at 1 meter: 20 lux

Recommended Reading/Working: 150 – 250 lux

Luminous Efficiency: portion of emitted light source usable for human vision

ratio of luminous flux to radiance flux (about 5-12% for LEDs)

Conversion: 1 foot-candle = 10.764 lux

Capacitors and Light Output

Supercapacitors:

Not feasible for our application. Here's why:

If we estimate that we need to produce 10 Watts over 6 hours, we need to store 60WH of energy (assuming 100% efficiency).

In terms of Joules, 1 Watt is 1 Joule dissipated for 1 second. So 60WH = 60 J/s * 60 s/min * 60 min/hr = 216,000 Joules

The energy stored in a capacitor is calculated by E = .5*C*V*V where C is the capacitance in Farads and V is the voltage.

The highest voltage supercapacitor commonly available is 5.5V. This is the absolute maximum voltage. We'll use 5V for the calculations.

Solving 216kJ = .5*C*5*5 for C, we get 4320F. A 1F 5.5V capacitor costs roughly $2. Using these, it would cost $8000+ for what we need.

Light output of common sources:

Reading a paper by Mills, found on the Lumina Project website, the best performing kerosene lantern tested produced 82 lumens.

40W incandescent light bulbs produce between 280-375 lumens.

A Cree XR-E LED (about $7 when purchased singly) produces 120 lumens from 2.1 watts of input power. This is roughly 50% more than a good kerosene lantern.

To produce as much light as the best 40W light bulbs, we would need roughly 6.5 Watts of power, split between 2 or 3 LED's.

Continuing the estimate of total power storage needed, if we assume we need light for 6 hours, and that our system is 100% electrically efficient, we need to store 39WH, or 140kJ.

Environmental Impact

Lithium Ion:

• Made of basic metals: Cobalt, copper, nickel and Iron. It’s not considered hazardous by government standards, however it still contains toxic substances.
• May explode under certain types of mistreatment; can rupture, ignite and explode when exposed to high temperatures and moisture.
• Regulations apply when shipped in large quantities.

Lithium Ion Polymer:

• Similar in composition to Lithium Ion.
• ??? Battery University says it has low manufacturing costs, but is still a higher cost-to-energy ratio than Lithium Ion.
• Flexible form – not limited to conventional shapes
• More resistant to over-charging issues

Nickel-metal Hydride

• Nickel-metal Hydride contains Nickel Hydroxide, Potassium Hydride.
• Doesn’t seem as practical: more production cost, more toxic chemicals.

Production:

• Nickel, though easily recyclable, is very costing on the environment due to high percentage of toxic byproducts during smelting.
• Sulfuric Acid is the largest toxic byproduct of Nickel and Cobalt production.
• Battery production is limited to highly industrialized nations: would probably rely on production from Australia, South Africa, Hong Kong, and the U.S.
• Photovoltaic systems are produced in some “fourth world countries”, Haiti and Ethiopia included.

Recyclability:

• All three battery options are recyclable.
• Within the U.S., battery recycling can be free for the consumer.
• Sulfuric Acid is a byproduct of recycling nickel as well.
• The materials in Lithium Ion batteries are easily recycled, except the Lithium oxide which is very stable and requires a lot of energy to be liberated.
• Thus far I have been unable to find a complete Life Cycle Assessment of Lithium Ion Batteries, but I’ll continue searching.

Batteries

Lithium-Ion Batteries

• Better for the environment that NiMH, but could be toxic and environmentally “nasty” during production
• Low-cost – to buy ourselves
• Simple design (right cylinders)
• Ease of use
• Recyclable

Lithium Polymer

• More robust than Lithium-Ion
• Lower manufacturing cost – might be able to manufacture on site
• Lighter weight than Lithium-Ion
• Thin/Flexible Design

General Information and Comments

• Do multiple cells in series get more charging cycles?
• Does the use percentage affect the number of cycles?
• What should we know about NiMH? Are they worth looking into as an option?
• Batteries are generally produced in the US/South Africa/China
• Solar Cells can be produced in some 3rd world countries.

Spring and Crank System

The power production from a hand crank-dynamo system is largely dependent on the dynamo efficiency and the gear ratio. The gear ratio is essential to multiply the torque derived from the direct cranking or stored energy from a rotational spring.

The quantity of energy stored and time of use depends on the spring constant and the number of turns you are able to make as well as the gearing system.

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The rotational spring block represents an ideal mechanical rotational linear spring, described with the following equations:

T = K•φ

T Torque transmitted through the spring

K Spring rate

φ Relative displacement angle (spring deformation)

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Power produced

Power = Torque*(RPM)*(Gear Ratio)*(Efficiency of motor)

Torque calculated from Freeplay radio:

100W power – 30min run time – 60rev – 1000:1 Gear ratio – 80% motor efficiency

T = 3.75N-m ~or~ 33 in-lb (K = 0.596)

At 1” radius spring, 33 lb required from spring

At 1.5”, 22 lf required from spring

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To determine the lifespan of our system several factors must be known…

Winds per charge, length of charge, time of use per day

Could then determine the cycle requirements for the manufacturer

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Many direct factors for our problem are unknown and further research into gear rations, spring properties, and dynamo efficiencies is needed to solve this problem.

Figure 1. Organizational Chart for MSD I showing Team Roles/WBS

Currently Proposed 2 Quarter Schedule for Completion of Project

Weekly Deliverables Summary 20 May 2019Page 1 of 10

P08427

Project Description

Project Background:

The LED Lighting Technologies for a Sustainable Lighting Solution in Developing Nations Project represents a joint venture between RIT’s Multidisciplinary Senior Design and the United States Environmental Protection Agency’s People, Prosperity and the Planet Student Design Competition for Sustainability. Additionally, the team will be partnering with Sarah Brownell of Sustainable Organic Integrated Livelihoods (SOIL) in Haiti. It is through this newly forged alliance that the team hopes to find a clean, reliable lighting solution for use in developing nations. Previous projects in MSD have addressed the use of LED’s for replacement of current RIT lighting systems.

Problem Statement:

Currently two billion people live without clean or reliable space lighting. Many of these people use gas and oil lamps, which produce a great deal of soot and carbon dioxide in addition to consuming vast amounts of fuel to produce relatively little usable light. This project seeks to provide a clean, reliable, inexpensive, and self-sufficient source of light for use in developing nations.

Objectives/Scope:

1. Work with sponsors in the field to determine the needs of the end user of the lighting system
2. Provide clean, reliable, high-quality lighting at an affordable price with a design that can be built in the target nations
3. Construct and test lighting system
4. Demonstrate at National Sustainable Design Expo in April

Deliverables:

• LED Lighting solution/system ready for preliminary deployment by sponsors in Haiti
• Documentation of design and design process including drawings and sketches
• Presentation at National Sustainable Design Expo
• Stage II grant proposal for additional EPA funding
• Potential direction for future projects

Expected Project Benefits:

• Provide a much needed resource to the people of developing nations
• Establish RIT as an involved institution in the engineering needs of developing nations
• Basis for future MSD projects

Core Team Members:

• Ian Frank – Team Manager, General Engineering
• Matt Walter – Chief Engineer, ANSYS
• Nick Balducci – CAD, Mechanical Design
• Jesse Steiner – Power and Electrical Systems
• Mike Celentano – Power Storage, Circuit Boards
• Luke Spencer – Ergonomic Design, Life Cycle

Strategy & Approach

Assumptions & Constraints:

1. A low-cost solution is essential due to the limited available financial resources
2. Manufacturing technology may be limited to what is available locally
3. Time for the project is limited by the EPA deadline in mid-April
4. LED lighting technologies will be utilized
5. R&D Budget is limited to $2,500
6. No direct access to customers

Issues & Risks:

• Limited time for design-testing-design iterations
• None of the team members are all that familiar with the nuances of lighting systems, such as acceptable lighting qualities and light modeling
• Customer input will be difficult to obtain and the lead time may be extensive since it must be done through a middle man
• Several potential solutions for one problem – will need to determine the most applicable and “novel” form of the solution.
• Limited manufacturing technology and materials available for final production in target regions

Weekly Deliverables Summary 20 May 2019Page 1 of 10

P08427

Team Values and Norms

LED Lighting Technologies for a Sustainable Lighting Solution in Developing Nations

P08427

Weekly Deliverables Summary 20 May 2019Page 1 of 10

P08427

• Professionalism

- All team members will act professionally in all aspects of communications/interactions (e-mails, presentations, phone conversations, etc.

- Take ownership of what you do and say

• Punctuality

- Team members will be prompt to team meetings

- If an unexpected conflict arises, the absent member will notify at least one other member of the team

- All members should be prepared for meetings so that they may be as streamlined and concise as possible