Energy Storage at the Distribution Level – Technologies, Costs and Applications
Therefore, a battery energy storage unit coupled with solar can optimize sources, when the EV charging is in operation. The appropriate control strategy and power flow management schemes for EV charging have not been elaborated in detail in this study. The broad-level benefits of microgrids could be summarized as follows: »
RE integration
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Deferred network up-gradation
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Efficient demand-side management
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Savings under deviation settlement mechanism (DSM)
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Power backup during outages and black-start support
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Miscellaneous benefits: In addition to the above-mentioned benefits, these urban microgrids can have a more profound positive impact on DISCOM operations. First, the transmission and distribution losses would come down. Second, the availability of a firm RE capacity would reduce their generation capacity procurement under the power purchase agreements (PPAs), and in turn, the fixed charges.
Lastly, they could also cut the power procured from the contracted capacity to reduce the variable cost. Urban microgrids are an attractive value proposition to the consumers as well, as they can gain substantially from these systems in terms of reduced tariff and increased reliability of power supply. Energy storage enables society to use more variable and uncertain renewable generation, such as wind and photovoltaic. By storing the renewable supply that exceeds the demand, rather than curtailing it, the RE can be shifted to times when it is needed. However, under some circumstances, curtailment of excess renewable generation may be more economical, less expensive than adding energy storage to the system.
2.3.2 Supplying Firm and Dispatchable Power The feasibility study for the implementation of BESS has been carried out for a 26 MW hydro generating station, distributed in 3 segments of 8.825 MW each, erected in the Teesta canal of West Bengal. The generating station also has a 10-MW of solar PV plant which was commissioned in 2018 (refer to figure 29). At present, a dispatch from Teesta canal hydro is dependent on the irrigation schedule which is prepared by the irrigation department. Cleaning of garbage that accumulates over time, hindering the operation of the hydropower plant, also contributes to interrupted operations of the plant, thus resulting in an uncontrollable source of generation which eventually results in limited control in power scheduling. Besides, the solar PV plant is also a kind of non-dispatchable source of energy that is dependent on climatic conditions. It is therefore proposed to maximize the benefit to West Bengal State Electricity Distribution Company Limited (WBSEDCL) by using solar and other partial or non-dispatchable sources of generation herein canal hydropower plant and solar plant to supply firm/ dispatchable power, keeping in mind geographical constraints of PHS by utilizing the electrical energy storage capability of BESS. The proposed technological intervention will also have secondary benefits in terms of technical loss reduction as the net loading of power transformers will be reduced significantly, and line losses along the 133 kV line will also reduce up to some extent.
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