Seeking CLEWS – a case study (Transport biofuel in Mauritius?)

1. Seeking CLEWS – a case study(Transport biofuel in Mauritius?) M. Howells, 18 June 2009, Venice Contributors: IIASA, IAEA – PESS & NA, SEI + For copies of the paper please contact: our unit head h.h.rogner@iaea.org

2. Contents • CLEWS to meet the MDGs • Developing an approach • A CLEW case study • Elements modeled: Climate, Land, Energy and Water • Results • Conclusions • Next steps

3. The CLEW Nexus: Meeting the MDGs • Some important global sustainability challenges for the next decades are: • Limitingincreased burden on the Climate and environment • Land use competition straining food production for a growing population • Growing demand for affordable Energy • Ensuring fresh-Water supply These are all inter-linked demanding integrated approach: CLEW

4. Developing a prototype CLEW approach • Starting with a less complex system with limited and well-defined boundaries • Simple 'accounting framework' for CLEW relations • Providing first step before more complex trade-off and optimization analysis (e.g. Costs of water versus energy etc...) • Supporting a clear understanding of the relations • Similar to popular and useful approaches in resources assessments, such as LEAP for energy

5. Mauritius - A CLEW case study • The island of Mauritius in Indian Ocean is chosen • Excellent data availability, clear boundaries! • But the study is ultimately ONLY illustrative • The policy question: from a fixed area of crop land, should sugar-cane be processed into ethanol instead of sugar? • Consistent with current policy goals • Scenario analyses quantifying the resource (CLEW) and economic implications of this policy under different conditions (technological and others)

6. The elements modeled (Climate) • Local GHG emissions • Fertilizer use, farming emissions, land-use change • Electricity production • Substitution of gasoline with ethanol Foreign GHG emissions • Fertilizer production and transport • Indirect land use change • Extraction and supply of coal • Extraction and refining of oil

7. The elements modeled (Land) • Crop yield calculation • Carbon content changes • Input requirements (water, energy, fertilizer) • Land is a fixed reference and important for determining study boundaries • In this study: • 100 ha of cropland used for sugarcane production • hypothetical sensitivities on land type: • Tropical forest • Wetlands • Tropical savannah

8. Land: Crop yield calculations - General methods and databases available. (LHS) AEZ methodology: Crop type Thermal requirements Climatic conditions (rainfall) Land type and suitability Input (fertilizer, tilling etc.) Standard method developed by IIASA and FAO Aspects used by the IAEA-FAO joint division Other specific yield equations: Where other elements are known are available Equation below for this study Specific to Mauritius For appropriate fertilizer input, relates yield to water input (potential evapotransportation Ep)

9. Land: Carbon content changes

10. Land: Inputs – Energy, water, fertilizer

11. The elements modeled (Energy) • Local energy: • Energy for farming, • Electricity production/use (e.g. co-generation, pumping and distributing irrigation water) on site and (e.g. grid-production) off site • Petrol displaced by ethanol Foreign energy • Fertilizer production and transport • Coal extraction and transport for electricity production • Oil extraction and refining

12. The elements modeled (Water) • Local consumption • Water applied for irrigation • Water used for ethanol/sugar processing, • And grid power station cooling

13. Reference System Diagram (RSD)

14. Scenarios • SSM - Sugar production in conventional sugar-mills (no surplus bagasse) • ASM - Sugar production with high-pressure boilers (surplus electricity from bagasse) • SEP - Ethanol production with high-pressure boilers (surplus electricity from bagasse) • AEP - Ethanol production (2. gen) with hydrolysis of bagasse (electricity deficit)

15. Results • Results are in terms of: • On sight (sugar cane field + mill/ethanol plant) or Off-sight (national electricity grid) • Local (e.g. Burning bagasse to produce electricity) or foreign (e.g. emissions from fertilizer manufacture) • Results reported are: • Energy balances, local and total • Local water balances • GHG balances, local and global and cumulative • Selected economics and oil price changes • Changes in irrigation technologies • Use of “bio-fertilizer” • All in terms of costs • A negative cost is a benefit/gain

16. Comparing across scenarios:

17. Total energy balance (Local+foreign)

18. Local water balance

19. Local GHG balance

20. Is the world going to eat less sugar in Scenario 3 and 4? We assume sugar production causing land use change outside of Mauritius Source: IPCC (2004)

21. Local and external GHG balance

22. Accumulated GHG balance

23. Economics of 3SEP – Standard Ethanol Production

24. What oil price makes ethanol production economic?

25. Changing from flood- to drip- irrigation • Direct water savings: 177 000 m3, which represents 33 % of all water consumption • 162 GJ, or 12.7 % of all energy used in the agricultural steps is saved • Mitigates 13.7 ton of GHG-emissions, or 8.6 % of all farm related local emissions

26. Extra: Sensitivity of changing fertilizer type From 100% mineral- to 50% bio-compost fertilizer:

27. Shorter time before net GHG gains:

28. Conclusions • Inter-linkages between C-L-E-W-systems are evident and strong • External (foreign) effects may be considerable, especially for GHGs, where land use change plays a crucial role • Ethanol becomes economic at to days sugar-prices at an oil price of $120+ • Use of bio-compost increases yield, sequesters carbon and improves water-balance; but needs more detailed analysis • CLEW framework can address cross-sectoral (spill-over) effects of a policy and hence useful tool to improve policy making process

29. Next steps • Explicitly including local food provision as well as other CLEW services as “exogenous” drivers • Increase the number of case studies and practical application as well as interactions with stakeholders and policy makers • To include a variety of crops and connect the model with a database that keep track on site-specific issues related to climate, soil, water availability • Include generic crop yield calculator, for initial scanning of CLEW land strategies. (With that in place the accounting model could play a role as a first-order assessment model at the local/regional scale. A possibility includes merging the CLEW-accounting model with the IIASA/FAO model called AEZ (Agro-Ecological Zones)). • Develop a detailed function specification and collaboration • Allow for linkages to other models where higher resolution of CLEW representation is needed • Having demonstrated that CLEW relations can be quantified, the development of a formal framework for undertaking economic, social and environmental trade-offs may be feasible

30. IAEA …atoms for peace.