1. Appropriate Technology Product Development
Big need – 90% of world’s designers currently work for 10% of world’s rich population. Design for the Other 90% is a movement to reverse this; and is close to EMI’s DNA. We recognized last year there is lots of room for EMI to grow in Appropriate Technology expertise, and then through Don and CJ, in AT product development. So this Wedge Project is EMI’s first ever Appropriate Technology Product Development project. Excited to partner with Don & CJ in this. Expecting to make a few mistakes as we figure this out together.

2. Needs & Potential Needs
Only 2-5% of rural Sub-Saharan Africa served by electric grids
1.6 billion people in developing
countries currently live without electricity
International Energy Agency (IEA)
estimate that by 2020 developing countries
will need to double their electrical power output
Potential
4 million estimated micro-hydro locations worldwide
100,000 family size micro-hydro units in Vietnam
Estimated 100,000 household sites In Philippines
There is a huge need for Electrical Power worldwide, and a huge Potential as well.

3. History Invented by Don in Liberia Originally a Surf Model
River Model Adaptation
EMI Involvement
Existing Prototype Performance – 178W maximum at 60 RPM
Invented by Don in Liberia – on EMI trip despondent over poverty of LIberia. Sitting on beach. Lord say “Harness this power for the people”
Originally a Surf Model – ran into environmental hurdles trying to develop it on West Coast.
River Model Adaptation – with CJ’s involvement, turned to River Model bc less environmental hurdles and still broad potential.
EMI Involvement – Don came to EMI fall 2010 to share what he developed, then we hit on idea of EMI team to help develop further.
Performance – peak performance of river model was 178W maximum at 60 RPM in Navigators Glen Eyrie Camp Creek.

4. Ultimate Goals Ultimate User: Poor rural household in developing World
Desired Characteristics
Affordable – for rural farmer making $400/yr
Reliable & Durable – 24 hours/day for up to 3 years. Debris protection
Simple – easy to install, maintain and replace by poor rural developing world farmer
Safe
Secure – resistant to theft and vandalism
Environmentally Friendly
Modular – for scalability
Technical Requirements:
Stream Flow of 5-20 ft3/sec
Power > 300 watts – enough for lights, cell phone, computer
Ideal Cost < $100 (production model in developing world hopefully produce power for < $.08/watt
Purchase Plans: 3 year loan payback. Business charging cell phone batteries, etc.
Other Potential Models: Backpacker – smaller
Villager – larger or linked household models
Municipal – for North American municipalities: power or lighting for parks

5. Summer 2011 – Wedge 2.0 Refinement Goals
More efficient prototype: > 300 watts
Elegant design for future manufacturing simplicity
Cost < $500 (parts only)
Method:
EMI Design Intensive – this week April 19-22, 2011
Wedge 2.0 Fabrication - till end of May
Summer testing – throughout summer Colorado Springs Utilities (CSU) graciously interested
CSU/FMDC requirements –
Ultimate requirements, plus especially safe and environmentally safe
Not interrupt flow, normal operations or cause erosion.
Emergency removal capability.

6. Existing Wedge Dynamics
Impeller tilted allows for greater diameter, which equals more power
Converting velocity to head
Hydraulic Jump Effect
RPM
Existing Wedge Prototype Peak Performance: watts at 60 RPM (Glen Eyrie Camp Creek)

7. Hydrodynamic Modeling – Existing Wedge

8. Hydrodynamic Modeling – Housing Options
Best: Option 4 “Open Arms/Hugging”: increases velocity 13% over straight tube  40% power increase

9. Environmental Concerns and Anchoring
Environmental Concerns to address
Wildlife – bears, birds, etc. Little to no impact
Fish – Sediment/ Fish habitat. Little to no impact
Emissions – leaching of materials. Little to no impact
Shield Design
“Trash Rack” type design to divert debris and fish around wedge
Anchoring
Anchoring device integrated with shield for additional stability

11. Turbine Design – Turbine Dynamics
Relative Velocity
Angle of Attack
Variable Pitch
Direct Drive
Eliminate gearing loss and maintenance

12. Electrical Design Challenges
Low Torque (5-15 N-m)
Low Speed ( RPM)
Wet environment
Remote access
Inexpensive
Selected Design
Direct drive
Permanent Magnet Generator
Custom low-speed design

13. Ultimate Design – Custom PMG
Improvements:
Tube more efficient hydraulics
Wings capture more flow
Direct drive eliminates pulley losses
More efficient turbine
Better generator
Result: 300 watts (we hope)

14. Wedge Team
Wedge Team (from L to R): Don Sternitzke (Wedge Inventor), Andy Engebretson (Elec. Eng), Pat Godsell (fabricator), Darryl Byle (Mech Eng), Calla Suen (Envir. Eng), CJ Anderson (Wedge Co-Founder), Tim Godsell (Fabricator), Sam Loomis (Mech/Elec Eng), Phil Harshaw (Mech Eng), Steve DeLory (Elec.Eng), Craig Hoffman (Civil Eng), Steven Kwan (Hydrodynamic Eng), Chris (Fabricator). Not pictured: Mark Hopewell (Civil/Mech Tech)
Front Row: Proposed Wedge 2.0 Culvert Housing, Existing Wedge Prototype

15. Appropriate Day for Appropriate Technology
Fitting day to be presenting the Wedge as it is not only Good Friday but also Earth day. Fitting because the Wedge is intended to both bring renewable power for the world’s poor, but also to be a leading edge for the gospel.
Good Friday
Earth Day