Industrial Engineering Department , Stellenbosch University

1. Lilongeni KayofaSupervisor: Theuns D.van SchalkwykCo-supervisor: Robert DobsonTopic: Feasibility study and business plan for manufacturing a 3 kw-electrical solar Stirling engine and dish, for a stand-alone power supply unit Industrial Engineering Department , Stellenbosch University Energy Postgraduate Conference 2013

2. Energy situation in Africa • Africa has some of the best solar regions to harness solar energy • Solar energy remain largely untapped in some regions • A high number of people have no access to electricity (see Table 1) • Rural areas are particularly affected • Majority of this people live in off-grid areas • Grid extension is expensive and will take year in certain areas • North Africa has a reached a 99.4 % electrification rate using solar energy • Possible solution that Africa can explore: A solar Stirling dish system Table 1: Africa’s Electricity Access in 2010 (Source: IEA)

3. Solar source of Africa • A Stirling dish is economical in regions that receives a DNI > 1,700 kWh/m²/year ( Stine and Geyer ) • Therefore, Africa has a potential in most of the regions ( see figure below)

4. What is a Stirling dish system ? • Concentrated Solar Power (CSP) technology • Converts solar energy → heat energy absorbed by the receiver → mechanical energy by Stirling engines → electric energy by generator • Main components: Concentrator, receiver/ Stirling engine, tracking system,generator,storage (optional)

5. Why the Stirling dish? • Most efficient solar energy technology around – 31.25 % efficient • Modular : scalable power size • Currently from 3 -30 kW per unit • Stand-alone • Low maintenance and operation costs • Easy to operate • Favourable for remote areas: left unattended • No supporting infrastructure required • Can be used for all types of terrain • Can be hybridised • No water usage required except to clean to mirrors • Electrical storage : batteries Disadvantages • High start-up costs • No thermal storage

6. Purpose of study Problem • Potential exists • Business people are sceptical in investing • Risks are unknown • No local (African ) manufacturer exists Purpose Determine whether there is a viable market in Africa for the use of a Stirling dish

7. Research design • Literature studies • Questionnaires • Survey ( Likert Scale questionnaire) : communities without access to electricity • Second questionnaire: to verify and validate whether the produced business plan is satisfactory

8. Survey output Socio-economic • Various households use at least five different sources of energy to generate energy • Heat • Lighting • Main reasons why they have no electricity in their houses • The monthly quantity and costs of the energy sources • The average total monthly income per household is N$ 3800.00 • Majority of the households are headed by pensioners • 53 % of households have more than 7 occupants • Type of housing structures Interest and perception on Stirling dish • Participants are highly interested in the Stirling dish • 10 % of the households were will take out loan of > N$ 10 000.00 • Areas prone to theft and vandalism • Households interested in using the Stirling dish the whole day N$ 1.00 ≈ R 1.00

9. Manufacturing plan • Decide on: • Production time • Process to use • Machines and tools • Factory set-up • Workforce • Location of factory • Builds Stirling engines and dishes in the most cost-effective manner • Competitive with conventional • Preferably using local materials and labourer as much as possible

10. Research expectations Questionnaire results Manufacturing layout Logistic of factory Economic results Business plan

11. Print master Lilongeni KayofaSupervisor: Theuns D.van SchalkwykCo-supervisor: Robert DobsonTopic: Feasibility study and business plan for manufacturing a 3 kw-electrical solar Stirling engine and dish, for a stand-alone power supply unit Energy situation in Africa • Africa has some of the best solar regions to harness solar energy • Solar energy remain largely untapped in some regions • A high number of people have no access to electricity (see Table 1) • Rural areas are particularly affected • Majority of this people live in off-grid areas • Grid extension is expensive and will take year in certain areas • North Africa has a reached a 99.4 % electrification rate using solar energy • Possible solution that Africa can explore: A solar Stirling dish system

12. Table 1: Africa’s Electricity Access in 2010 (Source: IEA) A Stirling dish is economical in regions that receives a DNI > 1,700 kWh/m²/year ( Stine and Geyer ) Africa has a potential in most of the regions (see figure below)

13. What is a Stirling dish system ? • Converts solar energy → heat energy absorbed by the receiver → mechanical energy by Stirling engines → electric energy by generator • Main components: Concentrator, receiver, tracking system and Stirling engine, generator ,storage (optional) Why the Stirling dish? • Most efficient solar energy technology around – 31.25 % efficient • Modular : scalable power size • Currently from 3 -30 kW per unit • Stand-alone • Low maintenance and operation costs • Easy to operate

14. Favourable for remote areas: left unattended • No supporting infrastructure required • Can be used for all types of terrain • Can be hybridised • No water usage required except to clean to mirrors • Electrical storage : batteries Disadvantages • High start-up costs • No thermal storage Purpose of study Problem • Potential exists • Business people are sceptical in investing • Risks are unknown • No local (African ) manufacturer exists Purpose Determine whether there is a viable market in Africa for the use of a Stirling dish

15. Research design • Literature studies • Questionnaires • Survey ( Likert Scale questionnaire) : communities without access to electricity • Second questionnaire: to verify and validate whether the produced business plan is satisfactory Survey output Socio-economic • Various households use at least five different sources of energy to generate energy • Heat • Lighting • Main reasons why they have no electricity in their houses • The monthly quantity and costs of the energy sources • The average total monthly income per household is N$ 3800.00 • Majority of the households are headed by pensioners • 53 % of households have more than 7 occupants • Type of housing structures

16. Interest and perception on Stirling dish • Participants are highly interested in the Stirling dish • 10 % of the households were will take out loan of > N$ 10 000.00 • Areas prone to theft and vandalism • Households interested in using the Stirling dish the whole day N$ 1.00 ≈ R 1.00 Manufacturing plan • Decide on: • Production time • Process to use • Machines and tools • Factory set-up • Workforce • Location of factory • Builds Stirling engines and dishes in the most cost-effective manner • Competitive with conventional • Preferably using local materials and labourer as much as possible

17. Research expectations • Questionnaire results • Manufacturing layout • Logistic of factory • Economic results • Business plan