SASBE conference 2009, Delft


Published on

presentation of joined paper 'Expanding exergy concept to urban water cycle'

Published in: Technology, Business
1 Like
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide
  • Energy and water critical flows: vital for human well being and for functioning of cities e.g., most efficient dutch power plant reaches only an efficiency-level of 55 %, 45 % wasted as heat; for water: 30 % of potable water used for toilet flushing
  • Study un-used potentials, taking stock, conversion technologies, storage, demand & supply, recycle, re-use
  • Can learn from each other and strengthen each other
  • SASBE conference 2009, Delft

    1. 1. Expanding Exergy concept to Urban Water cycle Wouter Leduc, Claudia Agudelo, Adriaan Mels & Ronald Rovers Urban Environment Group – Wageningen University Polytechnic University Zuyd, Heerlen
    2. 2. Problem <ul><li>Growing urbanization  increasing pressure on available resources </li></ul><ul><li>Urban impacts on resource depletion + environment by use and waste production </li></ul><ul><li>Decreasing supply of resources, increasing dependency, more border conflicts </li></ul>
    3. 3. Background <ul><li>Energy and water cycles  vital to support urban life </li></ul><ul><li>Focal point of technology development </li></ul><ul><li>But, technological achievements not sufficient to guarantee urban sustainability </li></ul><ul><li>Cycles managed separately and non-efficient use of resources </li></ul>
    4. 4. Aim <ul><li>Urban resources management as key consideration of urban planning </li></ul><ul><li>Focus on harvesting potential urban resources </li></ul>
    5. 5. Concepts <ul><li>Exergy = non-used fraction of energy (notion of energy quality) </li></ul><ul><li>Urban Harvest Approach </li></ul>OUT IN Through Recycle
    6. 6. Research questions <ul><li>Can exergy concept be expanded to water cycle? </li></ul><ul><ul><li>Exergy = use of the non-used water </li></ul></ul><ul><ul><li>(-fraction)? </li></ul></ul><ul><li>To what extend are energy and water cycles comparable? </li></ul><ul><li>What + how to learn from each other to optimize management? </li></ul>
    7. 7. Approach <ul><li>Natural energy and water cycles modified by metabolic profiles of cities </li></ul><ul><li>For urban planning processes  shared framework required </li></ul><ul><ul><li>To model + understand dynamics </li></ul></ul><ul><ul><li>To achieve integrated management of resources </li></ul></ul>
    8. 8. Approach <ul><li>To optimize + close cycle at high efficiency level </li></ul><ul><li>Exergy used to cope with complexity of varying metabolic profile </li></ul><ul><li>Exergy used to understand energy cycle in built environment </li></ul>
    9. 9. Comparison <ul><li>Comparison of energy and water cycles on: </li></ul><ul><ul><li>Several levels </li></ul></ul><ul><ul><li>Less efficient vs. more efficient system (local scale = urban) </li></ul></ul>
    10. 10. Energy and Water cycles – global scale Oil/gas reserves Lake Geothermal energy Ground water Reflection Evaporation Infiltration Runoff Heat losses
    11. 11. Urban Energy and Water systems – local scale Input Output Transformation Supplier Emissions
    12. 12. Energy and Water qualities in Urban systems – local scale Use 1 Use 2 Use n Qs Q supplied ΔQr Qs = Quality surplus ΔQr = Un-used remaining quality ΔQr ΔQr Qs Q U A L I T Y High Low Supply Demand Source 1 Source 2 Conversion Emissions
    13. 13. Coupling supply and demand - local ΔQ High Water cascading in the urban area Heat cascading in the urban area Water system, quality Closed water loops in the urban area Multi-sourcing in the urban area Multi-sourcing in the urban area Energy system, temperature Residential areas Power Plant Industry Green houses Offices ΔT Low Solar energy High Residential areas Offices Green houses Industry Rain water Low
    14. 14. Urban Energy and Water Planning – current approach <ul><li>Existing developments: no focus on studying several problem solutions </li></ul><ul><li>Resources extracted from abroad, used, and waste released </li></ul><ul><li>Separate management of urban flows </li></ul><ul><li>Local potentials are overlooked </li></ul><ul><li> Change in urban planning needed </li></ul>
    15. 15. Urban Energy and Water Planning – new approach <ul><li>Study local potentials of primary and secondary resources </li></ul><ul><li>Aim for strategic urban resources management </li></ul><ul><li>Involves supply and demand (qualities and quantities), and spatial and temporal implications together </li></ul>
    16. 16. Guiding planning principles for urban flows <ul><li>Avoid converters, each conversion consumes energy </li></ul><ul><li>Promote cascading </li></ul><ul><li>Prefer local resources </li></ul>
    17. 17. Conclusions <ul><li>Urban energy and water flows comparable: </li></ul><ul><ul><li>Exergy applies for energy and water, both have un-used fractions </li></ul></ul><ul><ul><li>System on several scales comparable, global and local </li></ul></ul><ul><li>Better to </li></ul><ul><ul><li>Tackle Urban energy and water planning together </li></ul></ul><ul><ul><li>Apply similar approach </li></ul></ul>
    18. 18. Further research <ul><li>Reach integrated urban planning </li></ul><ul><li>Study real applicability </li></ul><ul><li>Develop detailed planning rules to maximize urban harvesting </li></ul><ul><li>Study applicability of exergy concept in other urban flows, e.g. materials </li></ul>
    19. 19. Thank You! Questions? Thursday 18 th , 9:00, SREX-workshop