Applications & Pathways

Insular networks constitute ideal fields for investment in renewables and storage due to their excellent wind and solar potential as well the high generation cost of thermal generators in such networks. Nevertheless in order to ensure the stability of insular networks network operators impose strict restrictions on the expansion of renewables. Storage systems render ideal solutions for overcoming the aforementioned restrictions unlocking additional renewable capacity. Among storage technologies hybrid battery-hydrogen demonstrates beneficial characteristics thanks to the complementary features that battery and hydrogen exhibit regarding efficiency self-discharge cost etc. This paper investigates the economic feasibility of a private investment in renewables and hybrid hydrogen-battery storage realized on the interconnected island of Crete Greece. Specifically an optimization formulation is proposed to optimize the capacity of renewables and hybrid batteryhydrogen storage in order to maximize the profit of investment while simultaneously reaching a minimum renewable penetration of 80% in accordance with Greek decarbonization goals. The numerical results presented in this study demonstrate that hybrid hydrogen-battery storage can significantly reduce electricity production costs in Crete potentially reaching as low as 64 EUR/MWh. From an investor’s perspective even with moderate compensation tariffs the energy transition remains profitable due to Crete’s abundant wind and solar resources. For instance with a 40% subsidy and an 80 EUR/MWh compensation tariff the net present value can reach EUR 400 million. Furthermore the projected cost reductions for electrolyzers and fuel cells by 2030 are expected to enhance the profitability of hybrid renewable-battery-hydrogen projects. In summary this research underscores the sustainable and economically favorable prospects of hybrid hydrogen-battery storage systems in facilitating Crete’s energy transition with promising implications for investors and the wider renewable energy sector.

To reduce carbon emissions generation of electricity from combustion systems is being replaced by renewable resources. However the most abundant renewable sources – solar and wind – are not dispatchable vary diurnally and are subject to intermittency and produce electricity at times in excess of demand (excess production). To manage this variability and capture the excess renewable energy energy storage technologies are being developed and deployed such as battery energy storage (BES) hydrogen production with electrolyzers (ELY) paired with hydrogen energy storage (HES) and fuel cells (FCs) and renewable natural gas (RNG) production. While BES may be better suited for short duration storage hydrogen is suited for long duration storage and RNG can decarbonize the natural gas system. California Senate Bill 100 (SB100) sets a goal that all retail electricity sold in the State must be sourced from renewable and zero-carbon resources by 2045 raising the questions of which set of technologies and in what proportion are required to meet the 2045 target in the required timeframe as well as the role of the natural gas infrastructure if any. To address these questions this study combines electric grid dispatch modeling and optimization to identify the energy storage and dispatchable technologies in 5-year increments from 2030 to 2045 required to transition from a 60% renewable electric grid in 2035 to a 100% renewable electric grid in 2045. The results show that by utilizing the established natural gas system to store and transmit hydrogen and RNG the deployment of battery energy storage is dramatically reduced. The required capacity for BES in 2045 for example is 40 times lower by leveraging the natural gas infrastructure with a concomitant reduction in cost and associated challenges to transform the electric grid.

A substantial CO2-emmissions abatement from the steel sector seems to be a challenging task without support of so-called “breakthrough technologies” such as the hydrogen-based direct reduction process. The scope of this work is to evaluate both the potential for the implementation of green hydrogen generated via electrolysis in the direct reduction process as well as the constraints. The results for this process route are compared with both the well-established blast furnace route as well as the natural gas-based direct reduction which is considered as a bridge technology towards decarbonization as it already operates with H2 and CO as main reducing agents. The outcomes obtained from the operation of a 6-MW PEM electrolysis system installed as part of the H2FUTURE project provide a basis for this analysis. The CO2 reduction potential for the various routes together with an economic study are the main results of this analysis. Additionally the corresponding hydrogen- and electricity demands for large-scale adoption across Europe are presented in order to rate possible scenarios for the future of steelmaking towards a carbon-lean industry.

This paper presents a wind-methanol-fuel cell system with hydrogen storage. It can manage various energy flow to provide stable wind power supply produce constant methanol and reduce CO2 emissions. Firstly this study establishes the theoretical basis and formulation algorithms. And then computational experiments are developed with MATLAB/Simulink (R2016a MathWorks Natick MA USA). Real data are used to fit the developed models in the study. From the test results the developed system can generate maximum electricity whilst maintaining a stable production of methanol with the aid of a hybrid energy storage system (HESS). A sophisticated control scheme is also developed to coordinate these actions to achieve satisfactory system performance.

Clean energy technological innovations are widely acknowledged as a prerequisite to achieving ambitious longterm energy and climate targets. However the optimal speed of their adoption has been parsimoniously studied in the literature. This study seeks to identify the optimal intensity of moving to a green hydrogen electricity sector in Greece using the OSeMOSYS energy modeling framework. Green hydrogen policies are evaluated first on the basis of their robustness against uncertainty and afterwards against conflicting performance criteria and for different decision-making profiles towards risk by applying the VIKOR and TOPSIS multi-criteria decision aid methods. Although our analysis focuses exclusively on the power sector and compares different rates of hydrogen penetration compared to a business-as-usual case without considering other game-changing innovations (such as other types of storage or carbon capture and storage) we find that a national transition to a green hydrogen economy can support Greece in potentially cutting at least 16 MtCO2 while stimulating investments of EUR 10–13 bn. over 2030–2050.

The article presents a new carbon-free heat production technology for district heating which consists of a combined heat and power generation fuel cell (FC CHP) with CO2 capture and a two-stage cascade high-temperature heat pump (TCHHP). The FC generates heat and electricity the latter being used to drive the compressors of the TCHHP. During the winter period the water temperature achieved can occasionally be too low so it would be heated up with hydrogen gas boilers. The hydrogen would be produced by reforming natural gas synthetic methane or biogas. The results are presented with natural gas utilization—the ratio between the obtained heat flow transferred directly to the water for district heating and the input heat flow of natural gas. In the case of a return water temperature of 60 ◦C and district heating temperature of 85 ◦C the TCHHP whose heat source is groundwater achieves plant efficiency of 270.04% in relation to the higher heating value (HHV) and 241.74% in relation to the lower heating value (LHV) of natural gas. A case with a TCHHP whose heat source is low-temperature geothermal water achieves a plant efficiency of 361.36% in relation to the HHV and 323.49% in relation to the LHV

Hydrogen (H2) has rapidly become a topic of great attention when discussing routes to net-zero carbon emissions. About 14% of CO2 emissions globally are directly associated with domestic heating in buildings. Replacing natural gas (NG) with H2 for heating has been highlighted as a rapid alternative for mitigating these emissions. To realise this not only the production challenges but also potential obstacles in the transmission/distribution and combustion of H2 must be technically identified and discussed. This review in addition to delineating the challenges of H2 in NG grid pipelines and H2 combustion also collates the results of the state-of-the-art technologies in H2-based heating systems. We conclude that the sustainability of water and renewable electricity resources strongly depends on sizing siting service life of electrolysis plants and post-electrolysis water disposal plans. 100% H2 in pipelines requires major infrastructure upgrades including production transmission pressurereduction stations distribution and boiler rooms. H2 leakage instigates more environmental risks than economic ones. With optimised boilers burning H2 could reduce GHG emissions and obtain an appropriate heating efficiency; more data from boiler manufacturers must be provided. Overall green H2 is not the only solution to decarbonise heating in buildings and it should be pursued abreast of other heating technologies.

The oil refinery industry is one of the major energy users and responsible for a large proportion of greenhouse gas (GHG) emissions. This sector is facing multiple sustainability-related transformation pressures forcing the industry to adapt to changing market conditions. The transition to a low-carbon economy will require oil refineries to adopt decarbonisation technologies like advanced biofuels green hydrogen and carbon capture and storage (CCS). However the development and implementation of these technologies is not a straightforward process and may be inhibited by lock-in and path dependency. This paper draws on expert interviews and combines the Technological Innovation Systems (TIS) and Multi-level Perspective (MLP) frameworks to examining the niche level development of three emerging technologies in the context of deep decarbonisation of refinery. This research finds that the development of the three decarbonisation technologies shares some of the challenges and opportunities and exhibits technology interdependency to some extent. Among the three TISs advanced biofuel is the most mature in terms of knowledge base actor-network legislation framework and market function. Green hydrogen and CCS encounter stronger momentum than before and can benefit from possible synergies across various sectors. However the analysis also reveals the lack of market formation mainly due to the lack of policy instruments for niche markets. Here policy recommendations for accelerating deep decarbonisation of the oil refinery industry are discussed. Finally we contribute to the sustainability transitions literature by exploring the dynamics of emerging TISs for industrial decarbonisation.

Renewable energy technologies and resources particularly solar photovoltaic systems provide cost-effective and environmentally friendly solutions for meeting the demand for electricity. The design of such systems is a critical task as it has a significant impact on the overall cost of the system. In this paper a mixed-integer linear programming-based model is proposed for designing an integrated photovoltaic-hydrogen renewable energy system to minimize total life costs for one of Saudi Arabia’s most important fields a greenhouse farm. The aim of the proposed system is to determine the number of photovoltaic (PV) modules the amount of hydrogen accumulated over time and the number of hydrogen tanks. In addition binary decision variables are used to describe either-or decisions on hydrogen tank charging and discharging. To solve the developed model an exact approach embedded in the general algebraic modeling System (GAMS) software was utilized. The model was validated using a farm consisting of 20 greenhouses a worker-housing area and a water desalination station with hourly energy demand. The findings revealed that 1094 PV panels and 1554 hydrogen storage tanks are required to meet the farm’s load demand. In addition the results indicated that the annual energy cost is $228234 with a levelized cost of energy (LCOE) of 0.12 $/kWh. On the other hand the proposed model reduced the carbon dioxide emissions to 882 tons per year. These findings demonstrated the viability of integrating an electrolyzer fuel cell and hydrogen tank storage with a renewable energy system; nevertheless the cost of energy produced remains high due to the high capital cost. Moreover the findings indicated that hydrogen technology can be used as an energy storage solution when the production of renewable energy systems is variable as well as in other applications such as the industrial residential and transportation sectors. Furthermore the results revealed the feasibility of employing renewable energy as a source of energy for agricultural operations.

This paper proposes an energy management strategy for a fuel cell (FC) hybrid power system based on dynamic programming and state machine strategy which takes into account the durability of the FC and the hydrogen consumption of the system. The strategy first uses the principle of dynamic programming to solve the optimal power distribution between the FC and supercapacitor (SC) and then uses the optimization results of dynamic programming to update the threshold values in each state of the finite state machine to realize real-time management of the output power of the FC and SC. An FC/SC hybrid tramway simulation platform is established based on RTLAB real-time simulator. The compared results verify that the proposed EMS can improve the durability of the FC increase its working time in the high-efficiency range effectively reduce the hydrogen consumption and keep the state of charge in an ideal range.