Applications & Pathways

The UK government’s plans to decarbonise residential heating will mean major changes to the energy system whatever the specific technology pathway chosen driving a range of impacts on users and suppliers. We use an energy system model (UK TIMES) to identify the potential energy system impacts of alternative pathways to low or zero carbon heating. We find that the speed of transitioning can affect the network investment requirements the overall energy use and emissions generated while the primary heating fuel shift will determine which sectors and networks require most investment. Crucially we identify that retail price differences between heating fuels in the UK particularly gas and electricity could erode or eliminate bill savings from switching to more efficient heating systems.

Singapore has committed to achieving net zero emissions by 2050 which requires the pursuit of multiple decarbonization pathways. CO2 utilization methods such as fuel production may provide a fast interim solution for carbon abatement. This paper evaluates the feasibility of green hydrogen-based synthetic fuel (synfuel) production as a method for utilizing captured CO2. We consider several scenarios: a baseline scenario with no changes local production of synfuel with hydrogen imports and overseas production of synfuel with CO2 exports. This paper aims to determine a CO2 price for synfuel production evaluate the economic viability of local versus overseas production and investigate the effect of different cost parameters on economic viability. Using the current literature we estimate the associated production and transport costs under each scenario. We introduce a CO2 utilization price (CUP) that estimates the price of utilizing captured CO2 to produce synfuel and an adjusted CO2 utilization price (CCUP) that takes into account the avoided emissions from crude oil-based fuel production. We find that overseas production is more economically viable compared to local production with the best case CCUP bounds giving a range of 142–148 $/tCO2 in 2050 if CO2 transport and fuel shipping costs are low. This is primarily due to the high cost of hydrogen feedstock especially the transport cost which can offset the combined costs of CO2 transport and fuel shipping. In general we find that any increase in the hydrogen feedstock cost can significantly affect the CCUP for local production. Sensitivity analysis reveals that hydrogen transport cost has a significant impact on the viability of local production and if this cost is reduced significantly local production can be cheaper than overseas production. The same is true if the economies of scale for local production is significantly better than overseas production. A significantly lower carbon capture cost can also the reduce the CCUP significantly.

Transportation is the sector responsible for the largest greenhouse gas emission in the UK. To mitigate its impact on the environment and move towards net-zero emissions by 2050 hydrogen-fuelled transportation has been explored through research and development as well as trials. This article presents an overview of relevant technologies and issues that challenge the supply use and marketability of hydrogen for transportation application in the UK covering on-road aviation maritime and rail transportation modes. The current development statutes of the different transportation modes were reviewed and compared highlighting similarities and differences in fuel cells internal combustion engines storage technologies supply chains and refuelling characteristics. In addition common and specific future research needs in the short to long term for the different transportation modes were suggested. The findings showed the potential of using hydrogen in all transportation modes although each sector faces different challenges and requires future improvements in performance and cost development of innovative designs refuelling stations standards and codes regulations and policies to support the advancement of the use of hydrogen.

Traditional charging stations have a single function which usually does not consider the construction of energy storage facilities and it is difficult to promote the consumption of new energy. With the gradual increase in the number of new energy vehicles (NEVs) to give full play to the complementary advantages of source-load resources and provide safe efficient and economical energy supply services this paper proposes the optimal operation strategy of a PV-charging-hydrogenation composite energy station (CES) that considers demand response (DR). Firstly the operation mode of the CES is analyzed and the CES model including a photovoltaic power generation system fuel cell hydrogen production hydrogen storage hydrogenation and charging is established. The purpose is to provide energy supply services for electric vehicles (EVs) and hydrogen fuel cell vehicles (HFCVs) at the same time. Secondly according to the travel law of EVs and HFCVs the distribution of charging demand and hydrogenation demand at different periods of the day is simulated by the Monte Carlo method. On this basis the following two demand response models are established: charging load demand response based on the price elasticity matrix and interruptible load demand response based on incentives. Finally a multi-objective optimal operation model considering DR is proposed to minimize the comprehensive operating cost and load fluctuation of CES and the maximum–minimum method and analytic hierarchy process (AHP) are used to transform this into a linearly weighted single-objective function which is solved via an improved moth–flame optimization algorithm (IMFO). Through the simulation examples operation results in four different scenarios are obtained. Compared with a situation not considering DR the operation strategy proposed in this paper can reduce the comprehensive operation cost of CES by CNY 1051.5 and reduce the load fluctuation by 17.8% which verifies the effectiveness of the proposed model. In addition the impact of solar radiation and energy recharge demand changes on operations was also studied and the resulting data show that CES operations were more sensitive to energy recharge demand changes.

Fuel cells and electric batteries are competing technologies for the energy transition in heavy transportation. We explore the conditions for the survival of a unique technology in the long term. Learning by doing suggests focusing on a single technology while differentiation and decreasing return to scale (cost convexity) favor diversification. Exogenous technical change also plays a role. The interaction between these factors is analyzed in a general model. It is proved that in absence of convexity and exogenous technical change only one technology is used for the whole transition. We then apply this framework to analyze the competition between fuel-cell electric buses (FCEBs) and battery electric buses (BEB) in the European bus sector. There are both learning by doing and exogenous technical change. The model is calibrated and solved. It is shown that the existence of a niche for FCEBs critically depends on the speed at which cost reductions are achieved. The speed depends both on the size of the niche and the rate of learning by doing for FCEBs. Public policies to decentralize the socially optimal trajectory in terms of taxes (carbon) and subsidies (learning by doing) are derived.

In this work we examine the possibility of converting a light propeller-driven aircraft powered by a spark-ignition reciprocating piston and internal combustion engine running on AVGAS into one powered by an electric motor driven by a proton exchange membrane fuel cell stack running on hydrogen. Our studies suggest that storing hydrogen cryogenically is a better option than storing hydrogen under pressure. In comparison to cryogenic tanks high-pressure tanks are extremely heavy and unacceptable for light aircraft. We show that the modified aircraft (including batteries) is no heavier than the original and that the layout of the major components results in lower movement of the aircraft center-of-gravity as the aircraft consumes hydrogen. However we acknowledge that our fuel cell aircraft cannot store the same amount of energy as the original running on AVGAS. Therefore despite the fact that the fuel cell stack is markedly more efficient than an internal combustion engine there is a reduction in the range of the fuel cell aircraft. One of our most important findings is that the quantity of energy that we need to dissipate to the surroundings via heat transfer is significantly greater from a fuel cell stack than from an internal combustion engine. This is particularly the case when we attempt to run the fuel cell stack at high current densities. To control this problem our strategy during the cruise phase is to run the fuel cell stack at its maximum efficiency where the current density is low. We size the fuel cell stack to produce at least enough power for cruise and when we require excess power we add the energy stored in batteries to make up the difference.

This paper presents an economic impact analysis and carbon footprint study of a hydrogenbased microgrid. The economic impact is evaluated with respect to investment costs operation and maintenance (O&M) costs as well as savings taking into account two different energy management strategies (EMSs): a hydrogen-based priority strategy and a battery-based priority strategy. The research was carried out in a real microgrid located at the University of Huelva in southwestern Spain. The results (which can be extrapolated to microgrids with a similar architecture) show that although both strategies have the same initial investment costs (EUR 52339.78) at the end of the microgrid lifespan the hydrogen-based strategy requires higher replacement costs (EUR 74177.4 vs. 17537.88) and operation and maintenance costs (EUR 35254.03 vs. 34877.08) however it provides better annual savings (EUR 36753.05 vs. 36282.58) and a lower carbon footprint (98.15% vs. 95.73% CO2 savings) than the battery-based strategy. Furthermore in a scenario where CO2 emission prices are increasing the hydrogen-based strategy will bring even higher annual cost savings in the coming years.

Roll-on/Roll-Off (Ro-Ro) vessels including those without and with passenger accommodation Roll-on/roll-off passenger (Ro-Pax) can be totally or partially retrofitted to reduce the greenhouse gas (GHG) emissions in maritime transport not only during hoteling operation at the dock but also during service. This study is based on data of the vessel routes connecting the Port of Piombino to the Elba Island in Italy. Three retrofitting scenarios have been considered: replacement of the main and auxiliary engines with fuel cells (FC) (full retrofitting) replacement of the auxiliary engines with FCs (partial retrofitting) and replacement of the auxiliary engines with FCs and hoteling only with auxiliary engines for one specific vessel. The amount of hydrogen the filling time and the energy needed for production compression and pre-cooling of hydrogen have been calculated for the different scenarios.

As one of the most promising renewable energy sources hydrogen has the excellent environmental benefit of producing zero emissions. A key technical challenge in using hydrogen across sectors is placed on its storage technology. The storage temperature of liquid hydrogen (20 K or 253 C) is close to absolute zero so the storage materials and the insulation layers are subjected to extremely stringent requirements against the cryogenic behaviour of the medium. In this context this research proposed to design a large liquid hydrogen type-C tank with AISI (American Iron and Steel Institution) type 316 L stainless steel as the metal barrier using Vapor-Cooled Shield (VCS) and Rigid Polyurethane Foams (RPF) as the insulation layer. A parametric study on the design of the insulation layer was carried out by establishing a thermodynamic model. The effects of VCS location on heat ingress to the liquid hydrogen transport tank and insulation temperature distribution were investigated and the optimal location of the VCS in the insulation was identified. Research outcomes finally suggest two optimal design schemes: (1) when the thickness of the insulation layer is determined Self-evaporation Vapor-Cooled Shield (SVCS) and Forcedevaporation Vapor-Cooled Shield (FVCS) can reduce heat transfer by 47.84% and 85.86% respectively; (2) when the liquid hydrogen evaporation capacity is determined SVCS and FVCS can reduce the thickness of the insulation layer by 50% and 67.93% respectively.

To solve the problems of low utilization of biomass and uncertainty and intermittency of wind power (WP) in rural winter an interval optimization model of a rural integrated energy system with biogas fermentation and electrolytic hydrogen production is constructed in this paper. Firstly a biogas fermentation kinetic model and a biogas hydrogen blending model are developed. Secondly the interval number is used to describe the uncertainty of WP and an interval optimization scheduling model is developed to minimize daily operating cost. Finally a rural integrated energy system in Northeast China is taken as an example and a sensitivity analysis of electricity price gas production and biomass price is conducted. The simulation results show that the proposed strategy can significantly reduce the wind abandonment rate and improve the economy by 3.8–22.3% compared with conventional energy storage under optimal dispatch.