• Energy Research
• 2021-2025close

Water photoelectrolysis cells based on photoelectrochemical water splitting seem to be an interesting alternative to other traditional green hydrogen generation processes (e.g., water electrolysis). Unfortunately, the practical application of this technology is currently hindered by several difficulties: low solar-to-hydrogen (STH) efficiency, expensive electrode materials, etc. A novel concept, based on a tandem photoelectrolysis cell configuration with an anion-conducting membrane separating the photoanode from the photocathode, has already been proposed in the literature. This approach allows the use of low-cost metal oxide electrodes and nickel-based co-catalysts. In this paper, we conducted a study to evaluate the economic and environmental sustainability of this technology, using the environmental life cycle cost. Preliminary results have revealed two main interesting aspects: the negligible percentage of externalities in the total cost (<0.15%), which means a positive environmental impact, and as evidenced by the net present value (NPV), there are potentially financial conditions that favour future investment. In fact, an NPV higher than 150,000 EUR can be achieved after 15 years.

Purpose: The aim of this research is to carry out a literature review on the use of life-cycle cost (LCC) approaches for hydrogen technologies, by analysing its evolution over a decade (2012-2021). Methods: The SCOPUS database has been used to select relevant literature on the subject. After adoption of inclusion/exclusion criteria, a total of 67 papers were selected for our review. Then, we analysed these studies in terms of hydrogen technologies (fuel cells, electrolysers, hydrogen storage approach, etc.) covered by the LCC approaches. In addition, we also performed an analysis of the LCC features -- type of LCC (conventional, environmental, social), integration with LCA/S-LCA, guidelines followed, system boundaries (cradle-to-farm gate, cradle-to-consumer, cradle-to-grave, cradle-to-cradle), functional units, financial tools (NPV, BEP, etc.), type of costs included, and life span -- to provide a comprehensive view of LCC studies applied to hydrogen technologies. We also discussed and interpreted the most significant findings. Results and discussion: Our main results can be summarised as follows: (i) the number of LCC studies for application to hydrogen technologies has increased in the decade 2012-2021; (ii) China is the leading country for number of publications on the subject (15 papers), even if the most prolific author and institution are Iranians; (iii) a large number of studies performed LCC analysis including fuel cells and/or electrolysers based on proton exchange membranes; (iv) the most widely used LCC approach is a cradle-to-consumer (37 papers); (vi) almost all the studies on LCC of hydrogen technologies included initial, operation and maintenance costs; while other costs -- replacement, external, end-of-life -- are included in a limited number of papers; (vii) the net present value (NPV) is the most used financial tool. Conclusions: LCC analysis for application to hydrogen technologies has gained interest in recent years. However, the number of studies that explicitly follow LCC or LCA guidelines is very limited (only 7). The life-cycle cost analyses performed are quite incomplete in terms of costs included in the life-cycle stages. Besides, there is a lack of information and uniformity in the use of functional units and financial tools.

Energy communities (ECs) are widely recognised for their potential to generate renewable energy. By contrast, the capacity of ECs to reduce energy demand and foster flexibility has attracted little attention to date, despite their theoretical potential to do so. To address this gap, we apply three perspectives - social representations theory, actor-network theory, and business models - to the analysis of nine case studies based in six European countries (Germany, Italy, Slovenia, Sweden, Netherlands, and United Kingdom). The core of the article comprises analysis of the nine cases from each perspective. Our results highlight the (un)intended effects of ECs on the energy representations of members; the configurational work required by focal actors to assemble new sociotechnical configurations; and the value creation and capture opportunities open to ECs in the creation of novel business models; These factors in turn impact whether and how ECs achieve demand reduction and flexibility. We summarise and discuss these results in a process of meta-theoretical triangulation to produce a multifaceted and relational account of the potential of ECs to develop demand-side solutions. This leads us to conclude that ECs have a distinct capacity to develop demand-side solutions, rooted in the creation of innovative sociotechnical configurations; and that this distinct capacity of ECs has the potential to complement and extend the contemporary focus on the use of market mechanisms to achieve demand reduction and increase flexibility.

Green hydrogen is considered the most suitable choice for the future energy market, both as energy storage media, energy vector and fuel for transportation, industry and other applications.In the last twenty years, increasing efforts have been dedicated to green hydrogen technologies development, but still today a number of issues are claimed in justifying the delay in its large scale application and the starvation of its market. Moreover, some new questions seem ready to be put on the table for justifying the delay in green hydrogen technologies applications.In this paper, a critical analysis of recent literature and institutional reports is carried out with the aim of understanding what is the real state of the play. In particular, peculiar advantages and shortcomings of different green hydrogen technologies (biomass pyrolysis and gasification, water electrolysis, etc.) have been analysed and compared, with a focus on the electrolysis process as the most promising method for large scale and distributed generation of hydrogen.Some geopolitical and economic aspects associated with the transition to a green hydrogen economy-including the feared exacerbation of the water crisis -have been widely examined and discussed, with the purpose of identifying approaches and solutions to accelerate the mentioned transition.

Producing green hydrogen by electrolysis is a goal at European and international level. But hydrogen production by water electrolysis is currently more expensive respect the steam methane reforming. Based on our previous studies, extra revenues in order to reduce the production costs could be obtained by considering the co-produced oxygen. Starting from the point of view of a hypothetical enterprise that needs gaseous oxygen for its activity, in order to meet a variety of requests or applications, a financial evaluation of different sizes of RES-based electrolytic plant (100 kW - 10 MW) is proposed. The most relevant result that emerged from our research is the economic sustainability of the investment if the market price of oxygen is at least 3 EUR/kg. In this case, the self-production of oxygen results to be convenient, whatever the size of the electrolyser. This is valid for both the two scenarios assumed, with the exceptions of the smaller electrolyser sizes (<300 kW), for which the threshold is 4 EUR/kg. This finding is obtained considering a selling price of hydrogen at 10 EUR/kg but, according to our analysis, this condition would not change even with a price of 6 EUR/kg.

The potential reshaping of global energy markets by hydrogen: Following the trend of interest in hydrogen in recent history, there is a growing belief that green and low-carbon hydrogen will play a critical role in the transition to a zero-carbon economy. This is evidenced by the breadth and depth of hydrogen strategies and roadmaps that have emerged around the world in recent years [1-2]. The goals of a new clean hydrogen sector go far beyond decarbonisation. Clean hydrogen offers the opportunity to develop new supply chains, jobs and innovation, and to radically reshape the global economy and the geopolitics of the energy sector more generally. For countries without fossil fuel resources, hydrogen could reduce their dependence on imports or even turn them into energy exporters. For countries that are rich in fossil fuels, hydrogen may be able to be used as part of a just transition to a more sustainable future. Hydrogen, by democratising the means of production, coupled with abundant and cheap renewable electricity, could help to reduce instability in global energy markets and alleviate energy poverty. For this reason, some researchers argue that the growth of green hydrogen within the global economy could lead to such geo-economic and geopolitical changes, in which new scenarios and interdependencies will be shaped [3,4,5]. In this scenario, traditional oil and gas trade is expected to shrink. According to the outlook drawn up by IRENA, green hydrogen will cover 12% of global energy consumption by 2050. This will be due to targeted investments in the sector that will increase economic competitiveness and change the current hydrocarbon-based relationships [6]. The consequences will be a different geography of energy trade with the emergence of new centres of geopolitical influence, based on the production and use of hydrogen. With regard to future value chains for the production of green hydrogen-based ammonia, methanol and green steel, according to Eicke & De Blasio [7], changes can be expected within the global market that will lead some countries to take other positions than they currently have. For instance, with respect to the production of green hydrogen-based methanol, four countries - Saudi Arabia, Trinidad and Tobago, Oman and the United Arab Emirates - with a total world market share of 39%, are limited in their potential for green methanol production. The consequence of this will be that these countries will have to rely on imports to maintain their position in the future green methanol market. On the contrary, countries such as New Zealand, Norway or Chile, which currently do not have significant market shares in this sector, could, given their resources and economic conditions, sharpen their positions. The issue of renewable fresh water: One issue that is at the centre of the debate on what the impacts of a widespread deployment of green hydrogen might be concerns water resources. Researchers from various scientific fields are comparing and assessing the effect of green hydrogen on the global water resource. The key question is: will there be enough water to meet our future demand for green hydrogen? The views and scenarios that can be drawn from the literature and reports by various international bodies make different predictions. A research conducted by Newborough & Cooley [8] states that if all current fossil fuels used were converted to green hydrogen, the need for water for electrolysis would amount to 1.8% of the current global water consumption. However, even if the consumption of water to produce hydrogen is less than that required to produce energy from fossil fuels, concerns over the scarcity of fresh water call for a reduction in the use of water sources. Some researchers see a feasible and concrete solution in utilising the Earth's vast salt water resources, which can further reduce the water footprint of hydrogen. Some of them, however, highlight the technical challenges that still need to be addressed in order for this technology to be fully deployed. But beside the technical issues, Khan et al. [9] noted that there are limited economic and environmental incentives in pursuing R&D on the up-coming technology of direct seawater electrolysis. For Pflugmann & De Blasio [4] the issue of water resources is particularly important for countries where fresh water is scarce. The authors focus on the case of Saudi Arabia, which can rely on an abundance of renewable energy but limited water resources. It would be possible to address this shortcoming by desalinating sea water. To produce an amount of hydrogen equivalent to about 15% of Saudi Arabia's annual oil production, 26 million tonnes of renewable hydrogen would be required per year. This amount of hydrogen would require 230 million m3 of fresh water. In order to obtain the freshwater Saudi Arabia's needs, at least five desalination plants would need to be added to its existing 31 large desalination plants. Referring to Africa, the World Energy Council [10] also points out that, in the short term, access to water suitable for electrolysers might require upstream investments to desalinate water in some parts of the continent. Terlouw et al. [11] argue that the large-scale spread of hydrogen production in combination with other factors - such as climate change, population growth, economic development and agricultural intensification - could lead to water scarcity. The World Economic Forum [12] carried out an analysis estimating what the impacts on water resources could be from the transition to a hydrogen economy. The research was carried out by analysing data, concerning energy demand and water withdrawal, from 135 countries. According to the estimates derived from the analysis, only nine of the 135 countries studied would need to increase their current freshwater withdrawal by more than 10% to fully switch to hydrogen-based energy, while 62 countries would need to increase their freshwater withdrawal by less than 1%. The average value for all 135 countries is 3.3%. The increased demand for water resources would affect desert countries with low annual rainfall (e.g. Qatar, Israel) or small island states (e.g. Singapore, Malta) which would also experience difficulties due to limited freshwater reserves. According to analysts at the World Economic Forum, the hydrogen economy can open up interesting prospects not only for the energy system, but also for addressing the issue of water scarcity. Countries with water shortages are unlikely to be able to produce their own hydrogen and will therefore have to rely on imported hydrogen. This, which can certainly be seen as a disadvantage, will however allow these countries to use the water produced by the conversion of hydrogen back into energy, either through combustion or fuel cell technology, and to reuse this high-purity water locally.

In the recent years, some experimental forms of housing (cohousing and social housing) have developed in Italy, which also take on the features of real energy communities. These initiatives have been planned and implemented thanks to the active participation and investments of the people involved in the project. Their primary aim is to implement new form of shared housing, but by adopting renewable generation systems and sharing both energy production and consumption, they are contributing to foster the energy transition process. In this research, we studied the management of the energy resource and the social interactions among the cohousers. Moreover, we analysed the social impacts on the surrounding territory in order to know as they can widespread the clean energy technologies and social innovation processes. To do this, we compared two experiences of collaborative housing: the first one, active since some years in Northern Italy, is a bottom-up initiative set up by the voluntary action of some families and individuals. Its goal is to share common spaces and activities, but also to produce and use renewable energy with a view to economic and environmental sustainability. The second one is a social cohousing, established in Messina (Southern Italy) and implemented by the Fondazione di Comunità di Messina. The project involves people who live in socio-economic difficulties. Through the ESCO Solidarity & Energy, the Fondazione has designed and applied energy systems to allow the tenants to become prosumers and prosumagers.