A Distant Dream : Hydrogen As A Backup For Renewables

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Credit: American Public Power Association/ unsplash
  • Hydrogen fueled power plants could function as a back up to intermittent renewables.
  • Renewable energy generation depends on wind and solar resources and will be critical to achieving net zero goal.
  • But it will require a lengthy coordinated effort to research and build the necessary infrastructure.

Today, as Germany has found after the invasion of Ukraine put a squeeze on gas imports and having closed down its nuclear plants, renewable power generation is still too unreliable to efficiently run an economy and coal-powered stations are being fired up to fill the gaps.

An Energy Storage Vessel 

Hydrogen is being touted as an energy storage vessel and eventually may form part of the solution for variable renewable energy, especially when produced from clean power through electrolysers. Almost a fifth of all hydrogen-based fuels produced by 2050 has been earmarked for the generation of electricity, or around 102 million tons out of a total 528 million tons, according to the International Energy Agency’s (IEA’s) Net Zero 2050 scenario.

“In the future, hydrogen re-electrification will be complementary to renewable energy, i.e., providing decarbonized power (and heat) at times where there is not enough renewable energy (mainly wind and solar) in the system…” says Vice President of Gas Services Sales – Hydrogen at Siemens Energy Erik Zindel. Building out a production, transport, and storage network is just part of the challenge when using hydrogen and its unique properties mean it cannot just replace natural gas on a one-for-one basis in existing infrastructure.

Gradual Approach

Siemens is working on hydrogen-ready power plants to limit future retrofit costs, while some companies are already planning on blending hydrogen into existing natural gas plants for a more gradual approach. The slow replacement of natural gas with hydrogen in power plants can help mitigate the problem of a lack of sufficient volumes of the gas before production is ramped up and transport solutions found, and also means the unique properties of hydrogen in existing technology can be properly explored.

In Britain, Centrica Business Solutions and HiiROC, a developer of hydrogen production systems, plan to begin injecting hydrogen into its existing gas peaking plant at Brigg, Lincolnshire as part of a 12-month trial which is part funded from the government-funded Net Zero Technology Centre’s (NZTC’s) £8 million ($9.2 million) Open Innovation Program. “As blending ratios increase various adjustments and modifications are likely to be required,” says Senior Hydrogen Development Manager at Centrica Chris Wright. Centrica is working on the project with HiiROC proprietary technology which converts biomethane, flare gas, or natural gas into hydrogen and carbon black, which is used in tires and other rubber products as a pigment and in electronics as a conductor of electricity.

Testing The Limits

The Department of Energy’s (DOE’s) HyBlend project is looking at potential technical barriers to blending hydrogen in natural gas pipelines with an eye on materials compatibility research and development, techno economic analysis, and environmental life-cycle analysis. The consortium working on HyBlend includes six national laboratories and over 20 companies working with an R&D portfolio of $15 million from 2021-2023 to examine the challenges and opportunities of blending.

Blend limits depend on the design and condition of current pipeline materials (including integrity, dimensions, materials of construction), pipeline infrastructure equipment (compressor stations for example), and applications that utilize natural gas, including building appliances, turbines and chemical processes such as plastics production, the consortium says. One cubic meter of hydrogen produces roughly one third of the energy produced by a cubic meter of methane, so in order to maintain the same energy supply you need to use many more molecules, which has its own technical issues, Elgowainy notes. Other concerns arise at higher pressures, such as the pressure rating of the pipeline, the adaptability of the compression station to reach such pressures, and the ability of the pipeline to withstand higher gas speeds.

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Source: Reuters