Engineering Design: Seeking Sustainable Solutions

1. Engineering Design: Seeking Sustainable Solutions

2. Objectives By the end of this unit, students will be able to: • Broaden design alternatives by brainstorming sustainable alternatives. • Use the sustainable design tables to incorporate sustainability into alternatives analysis. • Incorporate sustainability into economic analysis by: • Conducting life cycle cost analysis • Including environmental benefits in cost-benefit analysis

3. Engineering Design: Seeking Sustainable Solutions • Review of sustainability and the engineering design process • 3 strategies for more sustainable design: • Broaden design alternatives • Incorporate sustainability into alternatives analysis • Incorporate sustainability into economic analysis

4. Review of Sustainability ConceptsWhat is Sustainability? • Meeting society’s present needs without compromising the ability of future generations to meet their own needs. (Brundtland Commission, 1987)

5. Review of Sustainability ConceptsTriple Bottom Line Solutions Good for the environment Good for economics Good for society

7. Review of Sustainability ConceptsThe 3 Pillars • People • Fair practices for all people and does not exploit interest of separate parties based on money, status or growth. • Planet • Management of renewable and non renewable resources while reducing waste. • Profit • Financial benefit enjoyed by the majority of society.

8. Steps in the Engineering Design Process • Define the problem • Product or customer requirements, functions and features • Brainstorm alternative solutions • Products, structures, or processes • Prepare preliminary/conceptual design for each alternative • Compare alternatives • Includes establishing criteria and conducting alternatives analysis • Includes economic analysis

9. Steps in the Engineering Design Process • Choose an alternative • Perform detailed design on chosen alternative • Build/test, modify as needed • Real-world example • At what steps could you consider sustainability?

10. Sustainability Sustainability Sustainability Sustainability Considering Sustainability in the Engineering Design Process • Define the problem • Product or customer requirements, functions and features • Brainstorm alternative solutions • Products, structures, or processes • Prepare preliminary/conceptual design for each alternative Steps in bright green will be considered in this lesson.

11. Sustainability Sustainability Sustainability Considering Sustainability in the Engineering Design Process • Compare alternatives • Includes establishing criteria and conducting alternatives analysis • Includes economic analysis • Choose an alternative • Perform detailed design on chosen alternative • Build/test, modify as needed

12. 3 Strategies for More Sustainable Design • Broaden design alternatives • Incorporate sustainability into alternatives analysis • Incorporate sustainability into economic analysis

13. 1. Broaden Design Alternatives • When brainstorming, consider “out of the box” alternatives that may be more sustainable than ordinary ones. • Sustainable options may or may not be justified in terms of capital cost or other factors. • Consideration important • More sustainable alternative may turn out to be superior, especially if sustainability is considered in alternatives analysis and economics analysis

14. 1. Broaden Design AlternativesTraditional CE Alternatives Asphalt Road Concrete Road

15. 1. Broaden Design AlternativesMore Sustainable CE Alternatives Recycled Asphalt Road Recycled Asphalt Road with a Bike Lane

16. 1. Broaden Design AlternativesTraditional CE Alternatives Concrete channel with a rectangular cross-section Concrete channel with a trapezoidal cross-section

17. 1. Broaden Design AlternativesMore Sustainable CE Alternative

18. 1. Broaden Design AlternativesTraditional CE Alternative Customary Site Design

19. 1. Broaden Design AlternativesMore Sustainable CE Alternative Implements Non-Structural Runoff Control

20. 1. Broaden Design AlternativesTraditional CE Alternatives

21. 1. Broaden Design AlternativesMore Sustainable CE Alternative

22. 1. Broaden Design AlternativesTraditional ME Alternatives Gasoline Powered Chevy Malibu Gasoline Powered Nissan Altima Coupe

23. 1. Broaden Design AlternativesMore Sustainable ME Alternatives Tesla Electric Car • 220 miles on a charge • 0 to 60 in 3.9 seconds • Smart Fortwo • 2 passengers • 3-cylinder engine • 33 mpg city/41 highway

24. 1. Broaden Design AlternativesMore Sustainable ME Alternatives Honda FC Hydrogen Car

25. 1. Broaden Design AlternativesTraditional ME/EE Alternatives Coal-fired power plant Natural gas-fired power plant

26. 1. Broaden Design AlternativesMore Sustainable ME/EE Alternatives Solar power facility Wind farm

27. 1. Broaden Design AlternativesMore Sustainable ME/EE Alternative Coal-fired plant with carbon capture and sequestration

28. 1. Broaden Design AlternativesMore Sustainable IE Alternative

29. More Sustainable IE Alternative

30. Practice Brainstorming Sustainable Design Alternatives

31. 2. Incorporate Sustainability into Alternatives AnalysisTraditional Engineering Design Criteria: • Function • Cost (capital and operating/maintenance) • Safety • Constructability • Durability • Aesthetic appeal

32. 2. Incorporate Sustainability into Alternatives AnalysisSustainable Engineering Design Criteria: The previous list plus: • Impact on people (society) • Impact on the planet (environment)

33. 2. Incorporate Sustainability into Alternatives AnalysisSustainability Aspects to Consider in Engineering Design

34. 2. Incorporate Sustainability into Alternatives AnalysisSustainable Design Tables • Handout • Exercise

35. 3. Incorporate Sustainability into Economic AnalysisMethods of Comparing Alternatives • Present worth, annual payments, future worth analysis • Break-even comparisons • Rate of return (ROR), incremental rate of return (IROR) analysis • Cost-benefit analysis Life cycle cost analysis Use a lower discount rate Quantify environmental benefits

36. 3. Incorporate Sustainability into Economic AnalysisLife Cycle Cost Analysis In choosing among engineering project/product alternatives, consider life cycle costs, or the total cost of ownership over the life of the project/product. Also called “cradle to grave" or "womb to tomb" costs. Useful in present worth, annual payments, future worth analysis (methods that compare costs of alternatives), and in break-even comparisons if benefits are not included

37. 3. Incorporate Sustainability into Economic AnalysisLife Cycle Cost Analysis • Phases of project/product life to consider: • Planning • Design • Construction/production • Operations • Maintenance, renewal/rehabilitation • Replacement or disposal

38. 3. Incorporate Sustainability into Economic AnalysisLife Cycle Cost Analysis What phases of project/product life cycle are traditionally considered in alternatives analysis? Why might using full life cycle cost analysis benefit the environment?

39. 3. Incorporate Sustainability into Economic AnalysisLife Cycle Cost Analysis Example problem

40. 3. Incorporate Sustainability into Economic AnalysisQuantify Environmental Benefits Methods of comparing alternatives that include benefits: • Rate of return (ROR), incremental rate of return (IROR) analysis • Cost-benefit analysis In evaluating benefits, be sure to quantify environmental benefits so they are not excluded.

41. 3. Incorporate Sustainability into Economic AnalysisQuantify Environmental Benefits • Suppose that a city is doing a cost-benefit analysis for how to use a piece of land. Two alternatives include: • Allowing a developer to construct a shopping mall, and • The “do nothing” alternative – leave the land as a forest. • How would you quantify the costs associated with each alternative? • How would you quantify the benefits associated with each alternative?

42. 3. Incorporate Sustainability into Economic AnalysisQuantify Environmental Benefits Quantifying environmental benefits is typically difficult, so environmental benefits historically have often been left out. Ways to quantify environmental benefits: Surrogate markets Surveys Willingness to pay to visit a park Willingness to pay to use an HOV lane

43. 3. Incorporate Sustainability into Economic AnalysisQuantify Environmental Benefits Ways to quantify environmental benefits: Health benefits Air pollution caused by an industry may cause people to miss work. A dollar value can be assigned to missed work using salaries. Installing an air pollution control device would have a quantifiable health benefit of fewer people missing work. Health care costs attributable to air quality Other

44. 3. Incorporate Sustainability into Economic AnalysisQuantify Environmental Benefits Cost-benefit analysis: Used to choose among engineering project/product alternatives For each project alternative, calculate the ratio of benefits to costs, with all benefits and costs adjusted for the time value of money (typically everything is adjusted to present). Choose the option with the highest benefit-cost ratio or net benefit

45. 3. Incorporate Sustainability into Economic AnalysisQuantify Environmental Benefits • PVB (present value of benefits) • PVC (present value of costs) • BCR (benefit cost ratio) = PVB / PVC • Net benefit = PVB - PVC

46. 3. Incorporate Sustainability into Economic AnalysisQuantify Environmental Benefits Example problem – Cost-benefit analysis

47. 3. Incorporate Sustainability into Economic AnalysisUse a Lower Discount Rate Another way to consider sustainability in all types of economic analysis: use a lower discount rate A high discount rate implies a very low value on the welfare of future generations

48. Summary