Encouraged by the proliferation of distributed renewable energy systems (DRESs), the concept of blockchain based Peer-to-Peer (P2P) energy markets has been gaining momentum in recent years. This promising concept, which allows consumers and prosumers to trade electrical energy directly on a blockchain network without the need for an intermediary, have proven various benefits such as the increase in energy cost savings, improvements in main grid resiliency and more importantly, decarbonization in the long term. Since wastewater treatment systems are known to consume a significant amount of energy to treat influent wastewater such that the effluent meets national discharge standards, the application of this P2P energy trading concept in this industry could prove beneficial to all involved stakeholders. This paper presents an integration of a hierarchical day-ahead P2P energy trading model to the industrial water-energy-nexus (WEN). The first stage introduces a continuous doublesided (CDA) auction market clearing algorithm with the Vickrey-Clarke-Groves (VCG) pricing mechanism deployed on a blockchain framework. The auction mechanism takes the forecasted energy demand/generation as inputs. The next stage proposes a demand-response energy optimization management system for the involved stakeholders. Simulation results show that a P2P-enabled energy market allows consumers to decrease their daily electricity costs by 3.37% – 5.17% and allows prosumers to increase their daily electricity profits by 54.08% – 56.90%. Furthermore, aggregated load demand during peak hours have been reduced by 11.38%.
Municipal wastewater treatment plants (WWTPs) consume lots of energy and produce large amounts of greenhouse gases (GHGs) to remove pollutants. Nowadays, the concept of energy self-sufficient WWTPs is attracting more attention. This study aims at proposing an evaluation framework for energy neutrality potential of WWTPs from an integrated dimension of water-energy efficiency and energy recovery. To achieve this, operational data of 970 WWTP samples located in Yangtze River Economic Belt (YREB) was extracted from China Urban Drainage Yearbook 2018. The chemical and thermal energy of WWTPs samples were estimated via the technology of combined heat and power (CHP) and water source heat pump (WSHP), respectively. Based on the results of CHP and WSHP, 2 key performance indicators (KPIs) were established to characterize the capability of WWTPs from aspects of basic function and energy recovery, respectively. The first one is comprehensive water-energy efficiency (CWEE) solved by data envelopment analysis (DEA) and the other is energy self-sufficiency rate (ESSR). In terms of the result, 98 samples were determined to be the benchmark, while 112 have potential to achieve the full self-sufficiency level. Moreover, there are 4 types of energy neutrality potential classified with the median of two KPIs set as the critical value. Besides, the explanatory factors were also analyzed, and results show that treatment capacity, influent concentration of chemical oxygen demand (COD), and influent ratio of 5-day biochemical oxygen demand to COD (BOD5/COD) affect the potential significantly. In addition, the energy neutrality potential of samples in the subregions differs distinctly. This study proposes the evaluation on the potential of WWTPs’ energy neutrality with 2 KPIs from both perspective of water-energy efficiency and energy self-sufficiency. The results could provide guidance for other WWTPs under optimization for energy neutrality.
As energy and environmental issues become more and more serious, we need to further improve the overall energy efficiency of modern cities. The operation of the urban energy system is affected by the characteristics of human social behavior, which increases the complexity of the problem. Therefore, cities must find how to conduct a comprehensive analysis of the energy use behavior of social residents from the perspective of smart cities and energy Internet, and then carry out effective guidance and management, assist the transformation and upgrading of the urban energy system, reasonable planning, and realize the improvement of urban comprehensive energy efficiency, cleanliness, and low carbon. The social-physical behavior model of residents formed by the corresponding population mobility attributes and energy attributes can reflect economic conditions and the behavior habits of various groups, thereby assisting the investment decision-making of urban infrastructure construction, and providing a basis for urban and power grid planning.