United Arab Emirates

Heating and cooling accounts for almost half of global energy consumption. With most of this relying fossil fuels however it contributes heavily to greenhouse gas emissions and air pollution. In parts of the world lacking modern energy access meanwhile inefficient biomass use for cooking also harms people’s health damages the environment and reduces social well-being.



The transition to renewable-based energy-efficient heating and cooling could follow several possible pathways depending on energy demand resource availability and the needs and priorities of each country or region. Broad options include electrification with renewable power renewable-based gases (including “green” hydrogen) sustainable bioenergy use and the direct use of solar and geothermal heat.



This report developed jointly by the International Renewable Energy Agency (IRENA) the International Energy Agency (IEA) and the Renewable Energy Policy Network for the 21st Century (REN21) outlines the infrastructure and policies needed with each transition pathway. This edition focused on renewable-based heating and cooling follows a broader initial study Renewable Energy Policies in a Time of Transition (IRENA IEA and REN21 2018).



The shift to renewables for heating and cooling requires enabling infrastructure (e.g. gas grids district heating and cooling networks) as well as various combinations of deployment integrating and enabling policies. The policy framework can demonstrate a country’s commitment to the energy transition level the playing field with fossil fuels and create the necessary enabling conditions to attract investments.



Along with highlighting country experiences and best practices the study identifies barriers and highlights policy options for renewable heating and cooling.



Key recommendations include:

• Setting specific targets and developing an integrated long-term plan for the decarbonisation of heating and cooling in all end-uses including buildings industry and cooking and productive uses in areas with limited energy access.
• Creating a level playing field by phasing out fossil-fuel subsidies and introducing other fiscal policies to internalise environmental and socio-economic costs.
• Combining the electrification of heating and cooling with increasingly cost-competitive renewable power generation scaling up solar and wind use and boosting system flexibility via energy storage heat pumps and efficient electric appliances.
• Harnessing existing gas networks to accommodate renewable gases such as biogas and green hydrogen.
• Introducing standards certification and testing policies to promote the sustainable use of biomass combining efficient systems and bioenergy solutions such as pellets briquettes bioethanol or anaerobic digestion.
• Reducing investment risks for geothermal exploration and scaling up direct use of geothermal heat.
• Improving district heating and cooling networks through energy efficiency measures and the integration of low-temperature solar thermal geothermal and other renewable-based heat sources.
• Supporting clean cooking and introducing renewable-based food drying in areas lacking energy access with a combination of financing mechanisms capacity building and quality standards aimed at improving livelihoods and maximising socio-economic benefits.

Hydrogen has emerged as an important part of the clean energy mix needed to ensure a sustainable future. Falling costs for hydrogen produced with renewable energy combined with the urgency of cutting greenhouse-gas emissions has given clean hydrogen unprecedented political and business momentum.



This paper from the International Renewable Energy Agency (IRENA) examines the potential of hydrogen fuel for hard-to-decarbonise energy uses including energy-intensive industries trucks aviation shipping and heating applications. But the decarbonisation impact depends on how hydrogen is produced. Current and future sourcing options can be divided into grey (fossil fuel-based) blue (fossil fuel-based production with carbon capture utilisation and storage) and green (renewables-based) hydrogen. Green hydrogen produced through renewable-powered electrolysis is projected to grow rapidly in the coming years.



Among other findings:



Important synergies exist between hydrogen and renewable energy. Hydrogen can boost renewable electricity market growth and broaden the reach of renewable solutions.

• Electrolysers can add demand-side flexibility. In advanced European energy markets electrolysers are growing from megawatt to gigawatt scale.
• Blue hydrogen is not inherently carbon free. This type of production requires carbon-dioxide (CO2) monitoring verification and certification.
• Synergies may exist between green and blue hydrogen deployment given the chance for economies of scale in hydrogen use or logistics.
• A hydrogen-based energy transition will not happen overnight. Hydrogen use is likely to catch on for specific target applications. The need for new supply infrastructure could limit hydrogen use to countries adopting this strategy.
• Dedicated hydrogen pipelines have existed for decades and could be refurbished along with existing gas pipelines. The implications of replacing gas abruptly or changing mixtures gradually should be further explored.

Trade of energy-intensive commodities produced with hydrogen including “e-fuels” could spur faster uptake or renewables and bring wider economic benefits.

As the world strives to cut carbon emissions electric power from renewables has emerged as a vital energy source. Yet transport and industry will still require combustible fuels for many purposes. Such needs could be met with hydrogen which itself can be produced using renewable power.



Hydrogen provides high-grade heat helping to meet a range of energy needs that would be difficult to address through direct electrification. This could make hydrogen the missing link in the transformation of the global energy system.  



Key sectors for renewable-based hydrogen uptake include:  

• Industry where it could replace fossil-based feedstocks including natural gas in high-emission applications.
• Buildings and power where it could be mixed with natural gas or combined with industrial carbon dioxide (CO2) emissions to produce syngas.
• Transport where it can provide low-carbon mobility through fuel-cell electric vehicles.  

Electrolysers – which split hydrogen and oxygen – can make power systems more flexible helping to integrate high shares of variable renewables. Power consumption for electrolysis can be adjusted to follow actual solar and wind output while producing the hydrogen needed for transport industry or injection into the gas grid.  



In the long run hydrogen could become a key element in 100% renewable energy systems. With technologies maturing actual scale-up should yield major cost reductions. The right policy and regulatory framework however remains crucial to stimulate private investment in in hydrogen production in the first place.

On average the shipping sector is responsible for 3% of annual global green-house gas emissions on a CO2-equivalent basis. International shipping represents around 9% of the global emissions associated with the transport sector.<br/>This report from the International Renewable Energy Agency (IRENA) explores the impact of maritime shipping on CO2 emissions the structure of the shipping sector and key areas that need to be addressed to reduce the sector’s carbon footprint.<br/>There is no clear-cut path to decarbonisation. Cutting CO2 emissions in half is therefore likely to require a combination of approaches including the use of alternative fuels upgrading of onshore infrastructure and reducing fuel demand by improving operational performance the report finds.<br/>The shipping sector is strategically important for global efforts against climate change and could be crucial in the long-term shift to a zero-carbon economy. Large-scale deployment of low-carbon fuel infrastructure for shipping could also help to build the necessary momentum to decarbonise other sectors.

The rapid increase in anthropogenic greenhouse gas concentrations in the last several decades means that the effects of climate change are fast becoming the familiar horsemen of a planetary apocalypse. Catalysis one of the pillars of the chemical and petrochemical industries will play a critical role in the effort to reduce the flow of greenhouse gases into the atmosphere. This Special Issue is timely as it provides a collection of high-quality manuscripts in a diverse range of topics which include the production of green hydrogen via water electrolysis the steam reforming of ethanol propane or glycerol the dry reforming of methane and the autothermal reforming of diesel surrogate fuel. The topic of the transformation of biomass waste to chemicals is also well represented as is the tackling of CO₂ emissions via novel utilization technologies. The Editors are grateful to all authors for their valuable contributions and confident that this Special Issue will prove valuable to scholars university professors and students alike.

This study presents a computational fluid dynamic (CFD) study of Dimethyl Ether steam reforming (DME-SR) in a large scale Circulating Fluidized Bed (CFB) reactor. The CFD model is based on Eulerian–Eulerian dispersed flow and solved using commercial software (ANSYS FLUENT). The DME-SR reactions scheme and kinetics in the presence of a bifunctional catalyst of CuO/ZnO/Al₂O₃+ZSM-5 were incorporated in the model using in-house developed user-defined function. The model was validated by comparing the predictions with experimental data from the literature. The results revealed for the first time detailed CFB reactor hydrodynamics gas residence time temperature distribution and product gas composition at a selected operating condition of 300 °C and steam to DME mass ratio of 3 (molar ratio of 7.62). The spatial variation in the gas species concentrations suggests the existence of three distinct reaction zones but limited temperature variations. The DME conversion and hydrogen yield were found to be 87% and 59% respectively resulting in a product gas consisting of 72 mol% hydrogen. In part II of this study the model presented here will be used to optimize the reactor design and study the effect of operating conditions on the reactor performance and products.

In April 2018 the International Maritime Organisation adopted an ambitious plan to contribute to the global efforts to reduce the Greenhouse Gas emissions as set by the Paris Agreement by targeting a 50% reduction in shipping’s Green House Gas emissions by 2050 benchmarked to 2008 levels. To meet these challenging goals the maritime industry must introduce environmentally friendly fuels with negligible or low SOX NOX and CO2 emissions. Ammonia use in maritime applications is considered promising due to its high energy density low flammability easy storage and low production cost. Moreover ammonia can be used as fuel in a variety of propulsors such as fuel cells and can be produced from renewable sources. As a result ammonia can be used as a versatile marine fuel exploiting the existing infrastructure and having zero SOX and CO2 emissions. However there are several challenges to overcome for ammonia to become a compelling fuel towards the decarbonisation of shipping. Such factors include the selection of the appropriate ammonia-fuelled power generator the selection of the appropriate system safety assessment tool and mitigating measures to address the hazards of ammonia. This paper discusses the state-of-the-art of ammonia fuelled fuel cells for marine applications and presents their potential and challenges.

This study provides H2 gas as a renewable energy source from sewage water splitting reaction using a PMT/Au photocathode. So this study has a dual benefit for hydrogen generation; at the same time it removes the contaminations of sewage water. The preparation of the PMT is carried out through the polymerization process from an acid medium. Then the Au sputter was carried out using the sputter device under different times (1 and 2 min) for PMT/Au-1 min and PMT/Au-2min respectively. The complete analyses confirm the chemical structure such as XRD FTIR HNMR SEM and Vis-UV optical analyses. The prepared electrode PMT/Au is used for the hydrogen generation reaction using Na2S2O3 or sewage water as an electrolyte. The PMT crystalline size is 15 nm. The incident photon to current efficiency (IPCE) efficiency increases from 2.3 to 3.6% (at 390 nm) and the number of H2 moles increases from 8.4 to 33.1 mmol h−1 cm−2 for using Na2S2O3 and sewage water as electrolyte respectively. Moreover all the thermodynamic parameters such as activation energy (Ea) enthalpy (∆H*) and entropy (∆S*) were calculated; additionally a simple mechanism is mentioned for the water-splitting reaction.

Hydrogen produced with renewable energy sources – or “green” hydrogen – has emerged as a key element to achieve net-zero emissions from heavy industry and transport. Along with net-zero commitments by growing numbers of governments green hydrogen has started gaining momentum based on low-cost renewable electricity ongoing technological improvements and the benefits of greater power-system flexibility.



Hydrogen-based fuels previously attracted interest mainly as an alternative to shore up oil supply. However green hydrogen as opposed to the “grey” (fossil-based) or “blue” (hybrid) varieties also help to boost renewables in the energy mix and decarbonise energy-intensive industries.



This report from the International Renewable Energy Agency (IRENA) outlines the main barriers that inhibiting green hydrogen uptake and the policies needed to address these. It also offers insights on how to kickstart the green hydrogen sector as a key enabler of the energy transition at the national or regional level.



Key pillars of green hydrogen policy making include:

• National hydrogen strategy. Each country needs to define its level of ambition for hydrogen outline the amount of support required and provide a reference on hydrogen development for private investment and finance.
• Setting policy priorities. Green hydrogen can support a wide range of end-uses. Policy makers should identify and focus on applications that provide the highest value.
• Guarantees of origin. Carbon emissions should be reflected over the whole lifecycle of hydrogen. Origin schemes need to include clear labels for hydrogen and hydrogen products to increase consumer awareness and facilitate claims of incentives.
• Governance system and enabling policies. As green hydrogen becomes mainstream policies should cover its integration into the broader energy system. Civil society and industry must be involved to maximise the benefits.
• Subsequent briefs will explore the entire hydrogen value chain providing sector-by-sector guidance on the design and implementation of green hydrogen policies.

Jordan's energy diversification strategy is centred around renewables which are expected will provide the low-cost reliable secure and environmentally sustainable energy required to power its new engines of economic growth – manufacturing transport construction and agriculture.

The National Energy Strategy 2020–2030 presents the evolution of the energy sector under its vision for stimulating demand achieving efficiency and improving electricity system flexibility.

This Renewables Readiness Assessment (RRA) highlights key actions for the short and medium-term that could create more conductive conditions for renewable energy development. It aims to help unlock Jordan's renewable energy potential and provide the means to meet the energy diversification goals of its national strategy.

The study was undertaken by the Ministry of Energy and Mineral Resources (MEMR) in collaboration with the International Renewable Energy Agency (IRENA).

Key recommendations:

• Provide the necessary conditions for renewables growth in the power sector.
• Foster continued growth of renewable power generation.
• Plan the integration of higher shares of renewable power.
• Incentivise the use of renewables for heating and cooling.
• Support renewable transport and mobility options.
• Catalyse renewable energy investment. Strengthen local industries and create jobs in renewables.