OPEN ACCESS
Drinking water systems (DWSs) are huge electricity consumers, mainly due to pumping operations. In these systems, electricity costs represent approximately one-third of the total operating costs. because of the environmental impact of electricity generation worldwide (coal, gas, and diesel), water systems also implicitly contribute to global warming. However, these systems have flexibility thanks to water storage structures (tank and reservoirs) and variable speed pumps. The flexibility of DWSs is generally used to optimize energy costs. Furthermore, this flexibility can also be used to provide an environmental and operational service for the power system, by reducing peak power load and the volume of energy transactions on wholesale markets. Indeed, peak power reduction can be sold by water utilities on electricity markets, preventing the production of an equivalent amount of additional energy. In France, peak hours require a massive use of fossil energy sources, which makes electricity production at these periods extremely expensive, both economically and ecologically. using a mathematical opti- mization model, we optimize the management of these peak periods by shifting load at off-peak hours and selling the reduced energy on the French wholesale energy market. In this paper, we explore the ecological benefits that water systems could provide through this optimization process. We evaluate the CO₂ emissions that can be effectively reduced on three real DWSs in France. For these three sys- tems, avoided CO₂ emissions were estimated at 2,190 kg/day for the largest system and 194 kg/day for the smallest one, which is equivalent to the emission of 145–1620 cars during 10 km of driving. We also evaluate, based on some hypotheses, the potential for CO₂ reduction from water systems at the French scale.
CO₂ emissions, demand response, drinking water systems, peak energy load
[1] Fang, J., Zhu, J., Wang, S., Yue, C. & Shen, H., Global warming, human-induced carbon emissions, and their uncertainties. Science China Earth Sciences, 54(10), pp. 1458–1468,2011. https://doi.org/10.1007/s11430-011-4292-0
[2] John, R., Cumulative Carbon Emissions and Climate Change: Has the Economics of Climate Policies Lost Contact with the Physics, The Oxford Institute for Energy Studies,2011.
[3] International Energy Agency, Key World Energy Statistics, 2018.
[4] Ashok, S. & Banerjee, R., Load management applications for the industiral sector. Journal of Applied Energy, 66(12), pp. 105–111, 2000. https://doi.org/10.1016/s0306-2619(99)00125-7
[5] Thomas, V., Market design for demand response: the French experience. Energy Agency, 2014.
[6] R.T. d. (RTE), Règles Pour la Valorisation des Effacements de Consommation sur les Marchés de L'énergie, 2014.
[7] Bunn, S., Closing the loop in water supply optimization. IET Water Event, 2007. https://doi.org/10.1049/ic:20070562
[8] Bunn, S., Reducing the GHG Footprint at Water and Wastewater Utilities in the US and the UK, Derceto, 2011.
[9] Mkireb, C., Dembele, A., Jouglet, A. & Denoeux, T., Scheduling demand response on the french spot power market for water distribution systems by optimizing the pump scheduling. In Proceedings of the 13th Workshop on Models and Algorithms for Planning and Scheduling Problems (MAPSP 2017), pp. 172–174, 2017.
[10] Mkireb, C., Dembélé, A., Jouglet, A. & Denoeux, T., Robust optimization of demand response power bids for drinking water systems. Journal of Applied Energy, 238, pp. 1036–1047, 2019. https://doi.org/10.1016/j.apenergy.2019.01.124
[11] Menke, R., Abraham, E., Parpas, P. & Stoianov, I., Extending the envelope of demand response provision through variable speed pumps. Procedia Engineering, 186, pp. 584–591, 2017. https://doi.org/10.1016/j.proeng.2017.03.274
[12] Brac de la perrière, L., Jouglet A. & Nace, D., Optimisation de la gestion des réseaux
d'eau potable par la programmation linéaire en nombres entiers, Ph.D disseration, 2011.
[13] Réseau Transport d'Electricité (RTE), Bilan électrique 2016, 2017.
[14] Réseau Transport d'Electricité (RTE), Bilan Sûreté 2010, 2011.
[15] Réseau Transport d'Electricité RTE, Emissions de CO₂ par kWh produit en France [Enligne], available at https://www.rtefrance.com/fr/eco2mix/eco2mix-co2
[16] Commissariat Générale au Développement Durable, L'eau et les milieux aquatiques, chiffres clés, 2016.
[17] Emissions de CO₂ par les voitures en Europe, Planetescope [En ligne], available at https://www.planetoscope.com/automobile/311-emissions-de-co2-par-les-voitures-eneurope.html