Development of a self-sufficient solar-hydrogen energy system

International Journal of Hydrogen Energy, 2011

Recently, the Solar-hydrogen energy system (SHES) becomes a reality thanks as well as a very common topic to energy research in Egypt as it is now being the key solution of different energy problems including global warming, poor air quality and dwindling reserves of liquid hydrocarbon fuels. Hydrogen is a flexible storage medium for energy and can be generated by the electrolysis of water. It is more particularly advantageous and efficient when the electrolyzer is simply coupled to a source of renewable electrical energy. This paper examines the operation of alkaline water electrolysis coupled with solar photovoltaic (PV) source for hydrogen generation with emphasis on the electrolyzer efficiency. PV generator is simulated using Matlab/Simulink to obtain its characteristics under different operating conditions with solar irradiance and temperature variations. The experimental alkaline water electrolysis system is built in the fluid mechanics laboratory of Menoufiya University and tested at certain input voltages and currents which are fed from the PV generator. The effects of voltage, solution concentration of electrolyte and the space between the pair of electrodes on the amount of hydrogen produced by water electrolysis as well as the electrolyzer efficiency are experimentally investigated. The water electrolysis of different potassium hydroxide aqueous solutions is conducted under atmospheric pressure using stainless steel electrodes. The experimental results showed that the performance of water electrolysis unit is highly affected by the voltage input and the gap between the electrodes. Higher rates of produced hydrogen can be obtained at smaller space between the electrodes and also at higher voltage input. The maximum electrolyzer efficiency is obtained at the smallest gap between electrodes, however, for a specified input voltage value within the range considered.

International Journal of Hydrogen Energy, 1997

We report on the performance, safety, and maintenance issues of a photovoltaic (PV) power plant which uses hydrogen energy storage and fuel cell regenerative technology. The facility, located at the Humboldt State University (HSU) Telonicher Marine Laboratory, has operated intermittently since June 1991, and in August 1993 went into full-time, automatic operation. After more than 3900 hours, the system has an excellent safety and performance record with an overall electrolyzer efficiency of 76.7%, a PV efficiency of 8.1%, and a hydrogen production efficiency of 6.2%.

Konya Journal of Engineering Sciences, 2017

Hydrogen is an important energy vector and a strong candidate for energy storage. It will be a useful tool for storing intermittent energy sources such as sun. The main objective of this work is to assess a system harnessing solar energy in electrical form and store it as hydrogen by means of an electrolyzer for small scale consumers away from the grid such as rural areas by computer simulation. Hydrogen then can be consumed in a fuel cell in order to generate electricity. The electrical energy obtained from solar energy via photovoltaic panels was used in order to charge a battery first and then hydrogen was acquired by using aforementioned energy in the electrolysis of water. In the second stage, electricity is generated in a fuel cell by using the generated hydrogen. A theoretical analysis was done via computer software by solving the constituted mathematical model. Data containing monthly average insolation values of Konya City according to years were used in this model. Electrolyzer temperature and pressure values and efficiencies of the photovoltaic panels were used as the input parameters. General system efficiency and effectiveness, generated electricity and hydrogen amounts were obtained as the output parameters. Among all, temperature was found to be the most effective parameter according to the obtained results considering the generated hydrogen amount, system effectiveness and efficiency. A wide range of electrical power between 400 W and 1800 W can be harnessed from the PV part of the system. Hydrogen production in the other hand can be attained in the range of 120-130 g/month. Power curve of the fuel cell at the start up of the system yields a 0.001 seconds reaction time. The proposed system can be utilized in rural parts of Konya and climatically similar regions in the world.

Energy Conversion and Management, 2016

In this paper an approach for the determination of the optimal size and management of a plant for hydrogen production from renewable source (photovoltaic panels) is presented. Hydrogen is produced by a pressurized alkaline electrolyser (42 kW) installed at the University Campus of Savona (Italy) in 2014 and fed by electrical energy produced by photovoltaic panels. Experimental tests have been carried out in order to analyze the performance curve of the electrolyser in different operative conditions, investigating the influence of the different parameters on the efficiency. The results have been implemented in a software tool in order to describe the behavior of the systems in off-design conditions. Since the electrical energy produced by photovoltaic panels and used to feed the electrolyser is strongly variable because of the random nature of the solar irradiance, a time-dependent hierarchical thermo-economic analysis is carried out to evaluate both the optimal size and the management approach related to the system, considering a fixed size of 1 MW for the photovoltaic panels. The thermo-economic analysis is performed with the software tool W-ECoMP, developed by the authors' research group: the Italian energy scenario is considered, investigating the impact of electricity cost on the results as well.

Advanced Materials Letters, 2020

This paper presents a case study concerning a plant for hydrogen production and storage, having a daily capacity of 100 kg. The plant is located in Cluj-Napoca, Romania. It produces hydrogen by means of water electrolysis, while the energy is provided using solar energy. We performed the calculations for four different technical solutions used for the hydrogen production and storage plant, and also we considered three scenarios regarding the subsystems of the hydrogen production and storage plant efficiency. The conclusion of this study is that one can maximize the conversion of solar radiation into chemical energy in the form of hydrogen by hybridizing the solar hydrogen production system, namely using both electrical energy as well as thermal energy in the form of steam.

International Journal of Hydrogen Energy, 2014

In recent years, hybrid photovoltaicefuel cell energy systems have been popular as energy production systems for different applications. A typical solar-hydrogen system can be modeled the electricity supplied by PV panels is used to meet the demand directly to the maximum extent possible. If there is any surplus PV power over demand, and capacity left in the tank for accommodating additional hydrogen, this surplus power is supplied to the electrolyser to produce hydrogen for storage. When the output of the PV array is not sufficient to supply the demand, the fuel cell draws on hydrogen from storage and produces electricity to meet the supply deficit.

Academia Mental Health and Well-Being, 2024

The global impact of mental health, specifically depression, is expected to be a top concern by 2030. Despite the growing number of medications and interventions, access to resources for well-being, psychiatric medications, and psychotherapy continue to be a long-standing barrier, regardless of a person’s socioeconomic status or wealth of the country. Additionally, there is a bidirectionality between mental health and physical illness as individuals with mental health have higher comorbid medical conditions and visa versa. The benefits of lifestyle interventions are often overlooked, but they are scientifically significant, well-tolerated by patients, and can address modalities of illness. Lifestyle psychiatry can become an integral tool for global mental health providers.

Effect of Covid-19 on International Trade. World trade is expected to fall by between 13% and 32% in 2020 as the COVID 19 pandemic disrupts normal economic activity and life around the world. The wide range of possibilities for the predicted decline is explained by the unprecedented nature of this health crisis and the uncertainty around its precise economic impact. But WTO economists believe the decline will likely exceed the trade slump brought on by the global financial crisis of 2008 09 (Chart 1). Estimates of the expected recovery in 2021 are equally uncertain, with outcomes depending largely on the duration of the outbreak and the effectiveness of the policy responses. "This crisis is first and foremost a health crisis which has forced governments to take unprecedented measures to protect people’s lives," WTO Director-General Roberto Azevêdo said. "The unavoidable declines in trade and output will have painful consequences for households and businesses, on top of the human suffering caused by the disease itself.” “The immediate goal is to bring the pandemic under control and mitigate the economic damage to people, companies and countries. But policymakers must start planning for the aftermath of the pandemic,” he said. “These numbers are ugly – there is no getting around that. But a rapid, vigorous rebound is possible. Decisions taken now will determine the future shape of the recovery and global growth prospects. We need to lay the foundations for a strong, sustained and socially inclusive recovery. Trade will be an important ingredient here, along with fiscal and monetary policy. Keeping markets open and predictable, as well as fostering a more generally favourable business environment, will be critical to spur the renewed investment we will need. And if countries work together, we will see a much faster recovery than if each country acts alone." (WTO press relase of 8 april 2020) The COVID-19 pandemic represents an unprecedented disruption to the global economy and world trade, as production and consumption are scaled back across the globe. One of the most effective means of addressing this crisis is through timely, accurate information. An informed public is better positioned to make sound decisions including on questions related to trade. This is why we have created this dedicated page on the WTO website. It will provide up-to-the minute trade-related information including relevant notifications by WTO members, the impact the virus has had on exports and imports and how WTO activities have been affected by the pandemic. World economic forum report on COVID19 IMPACT ON WORLD TRADE (INTERNATIONAL TRADE )