Flexibility improvement evaluation of hydrogen storage based on electricity-hydrogen coupled energy model

To achieve carbon neutrality by 2060,decarbonization in the energy sector is crucial.Hydrogen is expected to be vital for achieving the aim of carbon neutrality for two reasons:use of power-to-hydrogen(P2H)can avoid carbon emissions from hydrogen production,which is traditionally performed using fossil fuels;Hydrogen from P2H can be stored for long durations in large scales and then delivered as industrial raw material or fed back to the power system depending on the demand.In this study,we focus on the analysis and evaluation of hydrogen value in terms of improvement in the flexibility of the energy system,particularly that derived from hydrogen storage.An electricity-hydrogen coupled energy model is proposed to realize the hourly-level operation simulation and capacity planning optimization aiming at the lowest cost of energy.Based on this model and considering Northwest China as the region of study,the potential of improvement in the flexibility of hydrogen storage is determined through optimization calculations in a series of study cases with various hydrogen demand levels.The results of the quantitative calculations prove that effective hydrogen storage can improve the system flexibility by promoting the energy demand balance over a long term,contributing toward reducing the investment cost of both generators and battery storage and thus the total energy cost.This advantage can be further improved when the hydrogen demand rises.However,a cost reduction by 20%is required for hydrogen-related technologies to initiate hydrogen storage as long-term energy storage for power systems.This study provides a suggestion and reference for the advancement and planning of hydrogen storage development in regions with rich sources of renewable energy.

Optimization of Multi-energy Microgrids with Waste Process Capacity for Electricity-hydrogen Charging Services

The highway service area,with facilities for electricity-hydrogen charging,includes multi-energy load energy demands and domestic waste process demands.Based on these needs,a fully renewable energy based multi-energy microgrid with electricity-hydrogen charging services and waste process capacity is proposed.This paper studies the energy input and output characteristics of multi-energy conversion and storage devices,and establishes the model for electricity-hydrogen charging microgrid(EH-CMG).The multi-energy conversion,storage characteristics and multi-energy flow coordination in the EHCMG are then studied.An optimization model and its algorithm solution,based on constraints such as the charging time of vehicles,the reliability of multi-energy load energy supply and the available grid regulation performance in the EH-CMG,are established.The proposed optimization of EH-CMG is illustrated with the actual multi-energy operation data of a highway service area in northwest China.The results demonstrate that the proposed EH-CMG and its optimization method can achieve economic benefits for a multi-energy system with the ability of waste process,electricity-hydrogen charging,and also provide better regulation characteristics for the power grid.

Whole system value of long-duration electricity storage in systems with high penetration of renewables

Energy storage is a key enabling technology to facilitate an efficient system integration of intermittent renewable generation and support energy system decarbonisation.However,there are still many open questions regarding the design,capacity,and value of longduration electricity storage(LDES),the synergy or competition with other flexibility technologies such as demand response,shortduration storage,and other forms of energy storage such as hydrogen storage.This paper presents a novel integrated formulation of electricity and hydrogen systems to identify the roles and quantify the value of longduration energy storage holistically.A spectrum of case studies has been performed using the proposed approach on a future 2050 netzero emission system background of Great Britain(GB)with a high share of renewable generation and analysed to identify the value drivers,including the impact of prolonged low wind periods during winter,the impact of different designs of LDES,and its competitiveness and synergy with other technologies.The results demonstrate that high storage capacity can affect how the energy system will evolve and help reduce system costs.