A techno-economic model for optimising component sizing and energy dispatch strategy for PV-diesel-battery hybrid power systems

Abstract

This paper presents the development and application of a simple spreadsheet-based simulation model for sizing, energy performance evaluation and economic analysis of PV-diesel-battery power supply systems. The model is employed to generate a set of sizing curves that define the design space for hybrid systems using dimensionless generator component size variables, for a specified supply reliability and diesel energy dispatch strategy. The component size combination with the least unit cost of energy is selected among the many possible combinations satisfying a desired loss-of-load probability. Storage battery and diesel generator lifespan, as well as generator fuel efficiency, which depend on the operational loading stress of these components, are recognised as important variables in the economics of the system. The lifespan of the battery is premised to depend on the depth and rate of discharge of the operating cycles, while both the diesel generator lifespan and fuel efficiency are dependent on the degree and frequency of partial loading. The choice of diesel generator dispatch strategy was shown to be another important factor influencing the energy performance and economics of the system. The outputs of the model reveal several important sizing, operational and economic characteristics of the systems, and enables appraisal of comparative advantage of different types of designs and operational strategies. The merits of the hybrid concept are well demonstrated by the study results.

Optimal power flow management for distributed energy resources with batteries

“…The model is thus able to show the performance of the system in terms of battery dynamics and power flow from each sub-system at any given time interval. The sub-models in the following sub-sections are as described in our previous work [22,24].…”

“…The generator cost coefficients are specified by the manufacturer while the DG, PV and battery bank capacities are chosen based on a sizing model developed by Hove and Tazvinga [24]. The system is designed such that demand is met at any given time.…”

Optimal schedule of photovoltaic-battery hybrid system at demand side

“…The diesel generator has been excluded from the current system, because buying electricity from grid is cheap and green rather than consuming diesel for power generation. The sizing of PV and battery bank capacity were properly designed based on a sizing model in [8]. The parameters of this system are listed in Table 1.…”

“…At the offpeak period (0,6] and (22,24], only the grid provides customers power due to low electricity price. When the PV's output is sufficient, customers use the PV power in the highest priority, as shown in the period (8,16]. For other periods, including peak and standard periods, the power stored in the battery will be used.…”

“…The PV-diesel-battery hybrid systems are commonly installed in the standalone applications, in which the cost of installation and power generation is the main criterion of performance evaluation [2], [7], [8], [9]. An economic analysis and environmental impact model of a PV with diesel-battery system is proposed [9], in which the fuel cost is calculated over a one-year period and simple payback is worked out for the hybrid system.…”