Dispatchable Hydrogen Production at the Forecourt for Electricity Demand Shaping

Abstract

Environmental issues and concerns about depletion of fossil fuels have driven rapid growth in the generation of renewable energy (RE) and its use in electricity grids. Similarly, the need for an alternative to hydrocarbon fuels means that the number of fuel cell vehicles is also expected to increase. The ability of electricity networks to balance supply and demand is greatly affected by the variable, intermittent output of RE generators; however, this could be relieved using energy storage and demand-side response (DSR) techniques. One option would be production of hydrogen by electrolysis powered from wind and solar sources. The use of tariff structures would provide an incentive to operate electrolysers as dispatchable loads. The aim of this paper is to compare the cost of hydrogen production by electrolysis at garage forecourts in Libya, for both dispatchable and continuous operation, without interruption of fuel supply to vehicles. The coastal city of Derna was chosen as a case study, with the renewable energy being produced via a wind turbine farm. Wind speed was analysed in order to determine a suitable turbine, then the capacity was calculated to estimate how many turbines would be needed to meet demand. Finally, the excess power was calculated, based on the discrepancy between supply and demand. The study looked at a hydrogen refueling station in both dispatchable and continuous operation, using an optimisation algorithm. The following three scenarios were considered to determine whether the cost of electrolytic hydrogen could be reduced by a lower off-peak electricity price. These scenarios are: Standard Continuous, in which the electrolyser operates continuously on a standard tariff of 12 p/kWh; Off-peak Only, in which the electrolyser operates only during off-peak periods at the lower price of 5 p/kWh; and 2-Tier Continuous, in which the electrolyser operates continuously on a low tariff at off-peak times and a high tariff at other times. The results indicate that Scenario 2 produced the cheapest electricity at £2.90 per kg of hydrogen, followed by Scenario 3 at £3.80 per kg, and the most expensive was Scenario 1 at £6.90 per kg.

Assessment of the Potential for Green Hydrogen Fuelling of Very Heavy Vehicles in New Zealand

“…The levelized cost approach is simple, allowing greater flexibility in sensitizing important LCOH parameters such as electricity cost, CAPEX, and the utilisation factor [24]. Hydrogen cost is directly sensitive to changes in electricity cost, regardless of whether electricity is sourced from renewable or non-renewable sources, grid-connected or off-grid [11,[25][26][27][28][29][30]. The second most influential factor is capital cost (CAPEX), and particularly electrolyser costs.…”

“…The second most influential factor is capital cost (CAPEX), and particularly electrolyser costs. System optimization is necessary to avoid incorrect sizing of system components in the green hydrogen system [30][31][32]. Utilisation rate is significant in the overall price of hydrogen, despite not having a direct share in the hydrogen per unit cost.…”

“…The greatest future cost reduction opportunity is expected in the electricity cost. Fluctuations in electricity price will make the production cost of hydrogen highly variable and will reduce its economic competitiveness [30]. Nevertheless, hydrogen prices may differ according to its end use application, mode of production, and technoeconomic situations worldwide.…”

Dynamic Process Operation Under Demand Response – A Review of Methods and Tools

“…They show a clear emphasis on scheduling [6][7][8][9][10][11][12][13][14] aspects [15][16][17], investigate model reduction [18,12], and elaborate design towards flexibility [19][20][21]. Increasingly, electrochemical processes, e.g., chlor-alkali process [2,[22][23][24][25][26][27][28][29][30][31] and water electrolysis [32][33][34][35][36][37][38][39][40][41][42], come into focus.…”

Comparison between Three Off-Grid Hybrid Systems (Solar Photovoltaic, Diesel Generator and Battery Storage System) for Electrification for Gwakwani Village, South Africa

“…In multiple studies of the techno-economic feasibility of hybrid systems, optimizations techniques and modelling, the most viable option is predetermined by examining and evaluating the potential of available energy sources to location. The specific details of the results are not mentioned here but overall the result indicates strong potential for renewable energy production especially-from solar energy for electrification to wind power for hydrogen production [21][22][23][24][25].…”