By taking advantage of its abundant natural gas reserves, Saudi Arabia can easily produce hydrogen through processes such as Steam Methane Reforming (SMR), paving the way for the immediate development of hydrogen cities while building green hydrogen production capabilities, says Alberto Boretti, a New Zealand-based independent scientist.
Saudi Aramco can leverage these resources to provide low-cost hydrogen solutions, making the concept of a hydrogen city financially viable and immediately attractive, Boretti said in a letter first published by the International Journal of Hydrogen Energy.
Saudi Aramco recently announced plans to set up a hydrogen hub in Jubail Industrial City, about 100 km north of Al Khobar along the Arabian Gulf coast. The complex could be operational in 2027.
Boretti said pv magazine that Al Khobar is unique for a number of reasons: natural gas production, average income level, strategic location, enormous solar and wind potential, regional expertise in oil and gas projects, economic diversification goals and a focus on innovation and technology.
“Al Khobar Hydrogen City could be the world’s first eco-city powered by a mix of light blue, white and green hydrogen, plus solar and wind energy,” Boretti wrote, adding that natural gas should be used instead hydrogen. hydrogen in the initial phase of the project. “The best interim solution would be to build up wind and solar generation capacity and hydrogen production from electrolyzers.”
The missing electricity to meet the demand on the electricity grid be produced by combined cycle gas turbine plants running on natural gas and hydrogen mixtures. The fuels required for the use of non-electrical energy could do so are produced use of hydrogen and natural gas.
If wind and solar power generation exceeds grid demand, the electricity will power electrolyzers to produce hydrogen.
Boretti presented two possible configurations for a city with an energy demand of 200 MW. This assumption serves as a starting point for estimating the required capacity, but is subject to revision “as further studies are carried out and as the city develops.”
Possible configurations
The first configuration focuses exclusively on supplying renewable electricity to the city. It involves the development of renewable energy generation capacity, such as wind and solar power, along with energy storage systems to ensure reliable electricity supply even when renewable sources are intermittent. This configuration would require the city to install 1 GW of wind and solar capacity.
This second configuration goes beyond supplying dispatchable renewable electricity also include additional production of renewable fuels, especially green hydrogen. The city would need 1.3 GW of solar and wind energy and 73 MW of average renewable energy production.
“In addition to renewable energy generation and storage infrastructure, this configuration includes the development of additional hydrogen production facilities using electrolysis, powered by renewable energy sources,” said Boretti. “The green hydrogen produced can then be used for various applications, such as transport, industry and heating.”
The electrolysis capacity would be 997 MW in both cases, decreasing to 509 MW with parallel battery adoption.
“In the event that no batteries were used, the electrolysis capacity would indeed have to correspond to the maximum excess renewable energy generation in order to use all available excess energy for hydrogen production.” said Boretti. “In the case of eliminating outliers and using batteries to filter out oscillations of excess energy, the need for electrolysis capacity can be drastically reduced.”
The final amount of electrolysis capacity would depend on several factors, such as the efficiency of the storage system, the frequency and duration of excess generation events, and the desired level of hydrogen production.
In his model, Boretti says hydrogen storage capacity should reach 145,000 MWh.
“The capacity of the hydrogen storage is generally dictated more by the interannual and decadal variability than by the seasonal variability,” he said.
The scientist noted that annual fluctuations in electricity generation are between +15% and –15% wind, and +6% and – 4% for solar energy.
“A mix of 50% wind energy and 50% solar energy could yield annual fluctuations in the total annual energy produced between +18% and −8%,” he said, adding that the interannual variability would drastically increase the energy production might require. storage of hydrogen energy more than in the capacity of the electrolyzers.
Climate change is one of the factors increasing the seasonal, annual and decadal variability of electricity production from wind and solar energy.
“Climate change can affect calculations related to renewable energy production in many ways,” Boretti said.
He noticed a shift in long-term weather patterns and the increasing frequency and intensity of extreme weather events.
“Unfortunately, this long-term variability of the resource is difficult to predict because there is no certainty that past events will repeat with perfect periodicity in the future, and the exercise only gives a rough idea of the storage parameters,” said he.
Golf projects
Saudi Arabia has also started construction of the world’s largest green hydrogen plant in Neom City, on the Red Sea. The plant, expected to be operational in 2026, will produce up to 600,000 kg of green hydrogen per day.
“A successful hydrogen city requires a comprehensive approach, combining technological innovation, supportive policies, public involvement and collaboration between different stakeholders to create a sustainable and integrated urban environment,” said Boretti.
He claimed that the research could lay the foundation for similar projects in other Gulf countries.
“By adapting the research methodologies, taking into account local factors such as geography, climate, energy demand and regulations, similar zero-energy systems could be designed and implemented in other Gulf countries such as the UAE, Qatar, Kuwait, Bahrain and Oman . ,” he explained.
In the letter, Boretti assumes an efficiency of 75% for hydrogen production and 55% for the reuse of hydrogen for the production of electricity. An efficiency of 75% means that 75% of the electrical energy input is effectively converted into hydrogen gas, while the remaining 25% Is lost as heat or other forms of energy.
An efficiency range of 55% would mean that 55% of the energy stored in the hydrogen gas would be effectively converted into electrical energy, while the remaining 45% Is lost as waste heat or other losses.
This content is copyrighted and may not be reused. If you would like to collaborate with us and reuse some of our content, please contact: editors@pv-magazine.com.
