Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems
Abstract
:1. Introduction
2. Methodology
2.1. Top-Down Approach
2.2. Bottom-Up Approach
3. Case Studies
- The assessment of surplus energy helps evaluating excessive pressures in the system and may even indicate opportunities for water loss reduction and for energy recovery (especially in transmission systems).
- It is highly probable to have energy consumption (associated with water treatment and transport) that might be reduced at the systems upstream. For instance, if water losses are reduced through the reduction of energy associated with water losses, less energy needs to be treated and transported.
4. Results
4.1. Comparison of Top-Down and Bottom-Up Approaches
4.2. Water-Energy Balance Components and Performance Indicators
- [0,1]: good service level with total energy inefficiencies below 40%.
- [1,2]: median service level with total energy inefficiencies below 65%.
- [2,+∞]: unsatisfactory service level with total energy inefficiencies above 65%.
5. Discussion
6. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
- Barry, J.A. Watergy: Energy and Water Efficiency in Municipal Water Supply and Wastewater Treatment. Cost-Effective Savings of Water and Energy; Alliance to Save Energy: Washington, DC, USA, 2007; Available online: http//watergy.org/resources/publications/watergy.pdf (accessed on 19 March 2018).
- Mabhaudhi, T.; Mpandeli, S.; Madhlopa, A.; Modi, A.T.; Backeberg, G.; Nhamo, L. Southern Africa’s water-energy nexus: Towards regional integration and development. Water 2016, 8, 235. [Google Scholar] [CrossRef]
- Lenzi, C.; Bragalli, C.; Bolognesi, A.; Artina, S. From energy balance to energy efficiency indicators including water losses. Water Sci. Technol. Water Supply 2013, 13, 889–895. [Google Scholar] [CrossRef]
- Yoon, H.; Sauri, D.; Amorós, A.R. Shifting Scarcities? The Energy Intensity of Water Supply Alternatives in the Mass Tourist Resort of Benidorm, Spain. Sustainability 2018, 10, 824. [Google Scholar] [CrossRef]
- Suárez, F.; Muñoz, J.F.; Fernández, B.; Dorsaz, J.-M.; Hunter, C.K.; Karavitis, C.A.; Gironás, J. Integrated Water Resource Management and Energy Requirements for Water Supply in the Copiapó River Basin, Chile. Water 2014, 6, 2590–2613. [Google Scholar] [CrossRef]
- Aubuchon, C.P.; Roberson, J.A. Evaluating the embedded energy in real water loss. J. Am. Water Works Assoc. 2014, 106, 129–138. [Google Scholar] [CrossRef]
- Vilanova, M.R.N.; Balestieri, J.A.P. Exploring the water-energy nexus in Brazil: The electricity use for water supply. Energy 2015, 85, 415–432. [Google Scholar] [CrossRef]
- ERSAR. Annual Report on Water and Waste Services in Portugal; ERSAR (Portuguese Water and Waste Regulator): Lisbon, Portugal, 2017. [Google Scholar]
- Copeland, C. Energy-Water Nexus: The Water Sector’s Energy Use; Congressional Research Service: Washington, DC, USA, 2014.
- Cabrera, E.; Pardo, M.A.; Cobacho, R.; Cabrera, E., Jr. Energy audit of water networks. J. Water Resour. Plan. Manag. 2010, 136, 669–677. [Google Scholar] [CrossRef]
- Walski, T. Energy Balance for a Water Distribution System. In World Environmental and Water Resources Congress 2016; ASCE: Reston, VA, USA, 2016; pp. 426–435. [Google Scholar]
- Carriço, N.; Covas, D.; Alegre, H.; do Céu Almeida, M. How to assess the effectiveness of energy management processes in water supply systems. J. Water Supply Res. Technol. 2014, 63, 342–349. [Google Scholar] [CrossRef]
- Sarbu, I. A Study of Energy Optimisation of Urban Water Distribution Systems Using Potential Elements. Water 2016, 8, 593. [Google Scholar] [CrossRef]
- Mamade, A.; Loureiro, D.; Alegre, H.; Covas, D.D. A comprehensive and well tested energy balance for water supply systems. Urban Water J. 2017, 14, 853–861. [Google Scholar] [CrossRef]
- Loureiro, D.; Mamade, A.; Ribeiro, R.; Vieira, P.; Alegre, H.; Coelho, S.T. Implementing water-energy loss management in water supply systems through a collaborative project. In Proceedings of the IWA Water Loss Conference, Vienna, Austria, 31 March–2 April 2014. [Google Scholar]
- Covas, D.I.C.; Jacob, A.C.; Ramos, H.M.; Jacob, A.C.; Ramos, H.M. Water losses’ assessment in an urban water network. Water Pract. Technol. 2008, 3, 1–9. [Google Scholar] [CrossRef]
- Walski, T.M.; Chase, D.V.; Savic, D.A. Water Distribution Modeling; Haestad Press: Waterbury, CT, USA, 2001; p. 72. [Google Scholar]
- Vidigal, P.M.; Covas, D.I.C.; Loureiro, D.; Coelho, S.T.; Alegre, H. Extensive analysis of hydraulic parameters in a large set of water distrubution systems. In Proceedings of the Tenth International Conference on Computing and Control for the Water Industry, CCWI 2009, Sheffield, UK, 1–3 September 2009. [Google Scholar]
- Poças, A. Discolouration Loose Deposits in Distribution Systems: Composition, Behaviour and Practical Aspects. Ph.D. Thesis, Delft University of Technology, Delft, The Netherlands, 2014. [Google Scholar]
- Lambert, A. What Do We Know About Pressure: Leakage Relationships In Distribution Systems? In Proceedings of the System Approach to Leakage Control and Water Distribution Systems Management: IWA International Specialised Conference, Brno, Czech, 16–18 May 2001; pp. 1–8. [Google Scholar]
- Farley, M.; Trow, S. Losses in Water Distribution Networks. A Practitioner’s Guide to Assessment, Monitoring and Control; IWA Publishing: London, UK, 2003. [Google Scholar]
- HDR Engineering. Handbook of Energy Auditing of Water Systems; HDR Engineering: Omaha, NE, USA, 2011; p. 109. [Google Scholar]
E3—Ratio of the total energy in excess (-) | |
E3 (pumps)—Ratio of the energy in excess due to dissipated energy in pumps | |
E3 (losses)—Ratio of the energy in excess due to water losses | |
E3 (network)—Ratio of the energy in excess due to network operation and layout |
Approach | Abbreviation | Required Data | Assumptions | EWL Assessment |
---|---|---|---|---|
Top-down | M0 |
| Energy associated with water losses is proportional to water loss percentage from water balances (hypothesis). | % Water losses |
Bottom-up | M1 |
| Water losses are distributed proportionally to flow. | Demand multiplier, difference between simulation with and without losses |
M2 | Water losses are distributed proportionally to pressure and to pipe length. | Calibrated emitter coefficients, emitter exponent (set as 1.18) |
ID | Length | ∆z | Water Loss | Shaft Energy | Average Diameter | Average Pressure | Average Velocity | Average Headloss |
---|---|---|---|---|---|---|---|---|
(km) | (m) | (%) | (%) | (mm) | (m) | (ms−1) | (mkm−1) | |
1 | 114.6 | 66.2 | 37.1 | 99.3 | 106 | 17 | 0.19 | 1.2 |
2 | 58.6 | 28.5 | 35.0 | 0.0 | 99 | 35 | 0.05 | 0.2 |
3 | 9.6 | 47.5 | 36.0 | 76.5 | 64 | 44 | 0.10 | 0.4 |
4 | 9.1 | 47.5 | 15.0 | 0.0 | 64 | 31 | 0.05 | 0.1 |
5 | 9.1 | 47.5 | 15.0 | 0.0 | 60 | 47 | 0.09 | 0.5 |
6 | 69.5 | 50.7 | 4.0 | 99.9 | 114 | 43 | 0.10 | 0.4 |
7 | 34.8 | 32.7 | 10.2 | 0.0 | 100 | 34 | 0.10 | 0.3 |
8 | 57.3 | 37.9 | 27.2 | 10.9 | 124 | 31 | 0.09 | 0.2 |
9 | 72.5 | 55.5 | 8.4 | 52.0 | 107 | 37 | 0.07 | 0.2 |
10 | 51.2 | 74.2 | 44.8 | 0.0 | 87 | 45 | 0.02 | 0.1 |
11 | 9.8 | 6.7 | 40.7 | 0.0 | 85 | 23 | 0.02 | 0.1 |
12 | 4.8 | 57.9 | 49.6 | 0.0 | 106 | 46 | 0.04 | 0.1 |
13 | 76.5 | 40.2 | 2.5 | 0.0 | 135 | 37 | 0.04 | 0.1 |
14 | 76.5 | 40.2 | 2.5 | 0.0 | 135 | 35 | 0.12 | 0.5 |
15 | 22.3 | 96.0 | 29.0 | 0.0 | 117 | 41 | 0.12 | 0.4 |
16 | 5.2 | 26.7 | 20.0 | 0.0 | 109 | 30 | 0.25 | 1.6 |
17 | 4.4 | 30.0 | 20.0 | 0.0 | 112 | 44 | 0.08 | 0.1 |
18 | 10.2 | 48.7 | 20.0 | 0.0 | 149 | 45 | 0.07 | 0.2 |
19 | 16.9 | 41.3 | 20.0 | 0.0 | 131 | 38 | 0.04 | 0.1 |
20 | 9.3 | 41.4 | 45.1 | 0.0 | 151 | 55 | 0.20 | 0.8 |
Median | 19.6 | 44.5 | 20.0 | 0.0 | 108 | 38 | 0.08 | 0.19 |
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Mamade, A.; Loureiro, D.; Alegre, H.; Covas, D. Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems. Water 2018, 10, 577. https://doi.org/10.3390/w10050577
Mamade A, Loureiro D, Alegre H, Covas D. Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems. Water. 2018; 10(5):577. https://doi.org/10.3390/w10050577
Chicago/Turabian StyleMamade, Aisha, Dália Loureiro, Helena Alegre, and Dídia Covas. 2018. "Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems" Water 10, no. 5: 577. https://doi.org/10.3390/w10050577
APA StyleMamade, A., Loureiro, D., Alegre, H., & Covas, D. (2018). Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems. Water, 10(5), 577. https://doi.org/10.3390/w10050577