Optimization Of The Design Of Distributed Energy Systems Under Uncertainty

Facing huge energy-related challenges in the whole world,since distributed energy system(DES)is an effective way to achieve sustainable development of energy systems,many countries have greatly accelerated the application of DES.DES is playing an important role in the energy field.At present,design of DES is mainly achieved by energy modelling.However,on the one hand,existing studies have not carefully considered the off-design characteristics of various equipment in DES.On the other hand,most energy system models are implemented and optimized under deterministic conditions and uncertainties are often ignored.Ignorance of off-design characteristics and uncertainties will affect the accuracy and reliability of DES design,which will lead to a suboptimal design and even fail in practical applicationTherefore,in this paper,not only a deterministic DES design model was proposed,in which the off-design characteristics of equipment were analyzed,but also a DES design model under uncertainty based on two-stage stochastic programming was developed,in which the uncertainties about energy carrier price,energy demand and solar radiation were considered.Besides,cases studies were implemented and the results of the above models were compared,the results showed that:(1)there were significant differences in the optimal DES configurations,the total annual cost and the CO2 emissions under the constraints of different CO2 emission limits;(2)the off-design characteristics of equipment had little effect on DES design,such as equipment selection and size,total annual system cost and CO2 emissions.However,during the operation of the DES,it was still necessary to pay attention to avoid frequent off-design operating conditions of equipment.otherwise it would lead to an increase in costs and CO,emissions related to off-design characteristics;(3)Science the extreme energy demand was not considered in the deterministic DES design model,the total heat capacity of the deterministic DES design model was less than the DES design model under uncertainty,so it could not meet the actual energy demand;Moreover,the deterministic DES design model would lead to an underestimation of the cost for the reason that the uncertainty of the parameters was not considered in it.In addition,in the DES design model under uncertainty,the total annual system cost and CO2 emissions varied greatly in different scenarios,and might be much higher or lower than the average expectations,however,the deterministic DES design model ignored the total annual system cost and CO2 emissions in extreme scenarios.Finally,through risk management,the effectiveness of the method of risk condition values to ensure the CO2 emissions below a given limit with a certain probability and to avoid some scenarios where CO2 emissions are too high was verified.In short,this paper evaluates the impact of off-design characteristics of the equipment and uncertainty.The results show that the impact of the main influencing factor uncertainty on the system design should be fully considered.In addition,the method proposed in this paper provides a general analysis framework for DES design,which can provide designers with accurate and reliable decision-making basis in practical applications.