Can the Existing Natural Gas infrastructure foster a smooth transition to Clean Energy?
Grey, Blue and Green Hydrogen as alternative fuels for a Climate-Neutral Europe
Hydrogen can power automobiles and heat buildings and balance out wind and solar power in our grids. Germany sees it as a possible steel-making replacement for hard-coal coke. Coke is a grey, hard, and porous fuel with a high carbon content and few impurities, made by heating coal or oil in the absence of air in a process termed destructive distillation. Besides powering automobiles, hydrogen also provides energy producers with a potential market using processes that they are already familiar with. It can be liquefied, stored, and transported through existing pipelines and LNG ships, with some modifications.
However, hydrogen has yet to be widely adopted as a clean-energy solution. First, it entails a substantial upfront investment, which includes carbon capture capability, pipeline upgrades, industrial boilers that use heat rather than gas, and transportation fuel cells, as well as policies that facilitate the transition. Second, for hydrogen to be considered “green,” the electricity grid must emit no pollution.
The majority of today’s hydrogen is “grey hydrogen,” which is produced from natural gas. It’s made by splitting hydrogen from carbon atoms into methane with high-temperature steam. Grey hydrogen produces the same amount of climate-warming CO2 as natural gas unless the isolated carbon dioxide is stored or used.
The production of “Blue hydrogen” is similar to that of grey, but it absorbs and retains carbon dioxide, releasing just about 10% of it into the atmosphere. “Green hydrogen” is made from renewable energy and electrolysis, but it is twice as costly as blue hydrogen and is based on the cost of electricity and water availability.
To overcome its reliance on imported natural gas and high electricity prices, Europe has set ambitious net-zero energy goals that will include a combination of blue and green hydrogen, as well as wind, solar, nuclear, and a unified energy grid. Ramping up blue and green hydrogen as clean-energy solutions will require substantial investments and long-term modifications to energy infrastructure.
Effective long-term maintenance of pipeline infrastructure requires appropriate monitoring. SuperVision’s AI-based innovation enables regular and efficient infrastructure monitoring. The SuperVision Space (SVS) app uses earth observation and remote sensing technology to monitor threats along pipeline routes and transmission lines. SuperVision’s AI innovation is versatile enough to enable monitoring of underground Hydrogen and methane pipe-infrastructure and ensures the safety of renewable energy infrastructure.
Transport of Hydrogen
Hydrogen can be shipped as a gas in high-pressure containers, as a liquid in thermo-insulated containers, as methanol or ammonia in processed form, or as a chemical carrier medium. The pipeline, however, is by far the most economically viable choice, as it allows for extremely high energy transportation capability.
The electrical transmission system serves as a vital link in the transportation of renewable energy across nations. The gas system should, in theory, be able to supplement this.
A typical pipeline can transport up to ten times the energy of a 380-kilovolt twin overhead power line with a 1.5-gigawatt capacity at a fraction of the cost. But the effort required to repurpose existing facilities to make capacity for hydrogen has to be determined.
The German gas grid, with its dense national natural gas pipeline networks and location at the centre of Europe’s energy system and long-distance transmission network, provides unique opportunities to find out how the most cost-effective conversion of the gas infrastructure to hydrogen could function.
Existing Pipeline Infrastructure
Germany’s natural gas pipeline infrastructure is very well built, having more than 24,000 miles (40,000 km) of long-distance transmission lines and more than 292,000 miles (470,000 km) of the distribution grid. Furthermore, as a significant transit country for gas supplies to its neighbours, it has the largest storage capacity among EU members. With a working gas volume of about 943 Bcf (26.7 Bcm) and infrastructure that is well linked to the rest of the European gas market, it is a possible cornerstone of a safe and stable hydrogen energy system.
Christoph von dem Bussche is the CEO of Gascade, a German gas pipeline company that operates a 1,800-mile (2,900-kilometer) transmission system that is connected to Russia and North Sea ports through major European transit pipelines. Bussche is of the opinion that the existing gas infrastructure is of very high value for the EU Hydrogen Strategy for a Climate-Neutral Europe. “First of all, constructing new infrastructure takes much time. We can achieve our envisioned climate goals much faster using existing infrastructure. Second, using existing pipelines is very cost-efficient and can keep future energy prices low”, he said.
Compatibility of Hydrogen with Existing Infrastructure
Methane’s calorific heating value is three times that of hydrogen under normal conditions. In pipeline systems, however, due to its lower density, hydrogen has a flow rate that is up to three times that of methane.
This means that the same pipeline will carry three times as much hydrogen at the same pressure in the same amount of time, although the energy transportation capacity is only marginally lower.
The integrity of the steel pipes and fittings is another factor to be considered. Theoretically, embrittlement will increase the spread of cracks, decreasing the pipeline’s service life by 20% to 50%, depending on the quality of the steel and possible exposure to atomic hydrogen.
Nevertheless, this is only possible if the pipeline has already cracked and is subjected to complex pressures resulting from fluctuating internal pressure while being exposed to atomic hydrogen. However, the convergence of all three variables seems impossible.
There should be slight load variation under standard operating conditions, and only molecular hydrogen (H2) is transported.
Adapting Hydrogen for Cavern Storage
Compressor stations are required along the way to compress the Hydrogen to the pipeline’s operating pressure. Any section would need to be modified if Hydrogen is combined with methane and current natural gas compressors are left in place, depending on the hydrogen admixture.
If the hydrogen content reaches 40%, the compressors would need to be replaced. In order to deliver the three-times higher volume flow of Hydrogen compared to natural gas, a full transition to a 100 per cent hydrogen pipeline necessitates the installation of new and more turbines or motors, as well as more efficient compressors.
Since significant milestones in a large-scale hydrogen energy system transition are not planned in Germany until 2030, the first pilots to convert existing pipelines to hydrogen duty are already being considered, and hydrogen infrastructure should be installed alongside existing gas properties.
The long-distance gas network in northern Germany is supplemented by massive underground storage facilities for Hydrogen. These aquifer and cavern reservoirs retain nearly a quarter of Europe’s gas storage space, and they’re conveniently situated near the North Sea Coast’s major ports and offshore wind farms.
Feasibility of Energy Transition
With only minor changes to current transportation infrastructure and hardware, a transition to a hydrogen-based energy system could be accomplished quickly. In Germany, several companies and organisations have joined forces to form the GET H2 project, which aims to establish a sustainable hydrogen market and adapt legal and regulatory frameworks.
Nowega, a transmission system provider with approximately 932 miles (1,500 km) of high-pressure natural gas pipelines, is one such example.
Frank Heunemann, CEO of Nowega, claims that Germany’s hydrogen policy has set the right priorities. “Now it is important to set the concrete framework conditions as the basis for the development of green hydrogen as a fundamental element in the energy transition,” he says.
Despite subsidies possibly helping make the first steps toward implementation more financially viable, long-term development of this market will require stable political guidelines.
Although the circumstances are particularly favourable in Germany, the EU mentions in its strategy document that other member states may also minimise investment requirements by reusing pipelines and storage facilities. However, if this type of repurposing is possible in Europe, there’s no reason why it could not be done in other countries with adequate infrastructure.
Investing in hydrogen technology will assist governments in meeting their climate targets and provide a path to economic growth in a challenging global climate while maintaining a leadership position in renewable technology. Giving existing gas pipelines a new function of transporting hydrogen is a practical way to achieve sound energy policy, environmental stewardship, and economic growth.
