Abstract:
Abstract:The rural micro-energy-grid with electricity-heating-cooling-gas was a hot issue in the field of energy. Mostresearches have been done on the modeling, planning and operation of micro-energy-grid. But the planning evaluation systemof rural micro-energy-grid is still lacking. To evaluate the planning performance on rural micro-energy-grid, the planningevaluation system of rural micro-energy-grid was established in this study. The planning evaluation system contained fourprimary indicators, seven secondary indicators and fourteen tertiary indicators. Specifically, the four primary indicators werethe reliability, economics, environmental protection and benefit. The seven secondary indicators were the electrical reliability,heat and cool reliability, system economics, environmental protection of energy-supply equipment, environmental protectionof energy-storage equipment, stable benefit, environmental benefit. The fourteen tertiary indicators were the electricaldeficiency rate, heat deficiency rate, cool deficiency rate, initial investment cost, maintenance cost, ratio of price to availablelife on the equipment, pollutant emission, installation rate of renewable energy, installation rate of heating-cooling-electricityfor supply unit, replacement cycle rate of battery storage, replacement cycle rate of cool storage, replacement cycle rate of heatstorage, electrical power exchange cost with distribution network, environmental pollution penalty cost. The formula of eachindicator were given for these 25 parameters. The weightof each evaluation indicator was solved using an entropy method,indicating a flow chart for theimplementation. The weight distributions of these indicators were obtainedin the micro-energygrid, representing the evaluation value of each planning scheme. In the actual planning process of a project, it was usuallyfocused on small parts of the indicators, depending onthe environmental condition, funding and the needs of the project. It wasnot possible to select the whole planning scheme fully complying with these 25 indicators in the actual evaluation. Therefore,an expert evaluation method was also establish to show the weight table of expert evaluation indicators. The new weight/values of the different indicators in the planning schemes were obtainedcombining the entropy and the expert evaluationmethod, as well the new evaluation values of the whole planning schemes on the rural micro-energy-grid. Three planningschemes of a village in the western China were selected as a case study to verify the proposed planning indicators in thispaper. The loading data of the heating-cooling-electricity in four seasons was given before the simulation, as well the time-ofuse electrical price and equipment parameters of the rural micro-energy-grid. The results showed that the evaluation values ofthe scheme 1, 2 and 3 were 1.32, 1.14 and 2.47, respectively, according to entropy method. In the scheme 2, there was theminimums in the installed rate of renewable energy and heating-cooling-electricity supply unit, whereas in the scheme 3, themaximums considering all the evaluation indicators werethe reliability, economics, environmental protection and benefit.Therefore, the expert system 1, 2, 3 and 4 focused on the reliability, economics, environmental protection and benefit,respectively. The whole planning schemes of the rural micro-energy-grid were also re-evaluated by combining the method ofexpert evaluation and entropy. The comprehensive evaluation value of scheme 2 has the highest valuebecause the expertsystem 3 focused on the environmental protection indicators. In experts 1, 2 and 4, the comprehensive evaluation value ofscheme 3 has the highest value. If the project need is the reliability, economics and benefit, scheme 3 can be the best choice.The findingsdemonstrated that the proposedevaluation system can efficiently evaluate the planning scheme of the microenergy-grid, and provide aninsightful applied guidance for the construction and planning of micro-energy-grid inrural areas.