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Green Hydrogen Storage and Large-Scale Renewable Energy

A recent UN emissions gap report estimates that temperatures will rise to 4.5 degrees Fahrenheit above pre-industrial averages by the end of the century. This increasing threat of a climate catastrophe is driving a monumental shift to green, renewable energy.

Yet government and industry support of such initiatives, including the 2015 Paris Agreement, still isn’t having the desired outcome. Although there have been significant advancements in renewable energy sources such as wind and solar over the past decade, the world is still nowhere near hitting its 2050 climate targets. An urgent, system-wide transformation is needed to deliver the enormous cuts necessary to limit greenhouse gas emissions by 2030 and hit the net zero goal by 2050.

The production and storage of green hydrogen could be a vital component in achieving these large-scale renewable energy goals.

What is Green Hydrogen?

Green hydrogen is produced through the electrolysis of water using renewable energy sources. Splitting water into hydrogen and oxygen molecules through electrolysis allows for the storage or use of the resulting hydrogen and the release of oxygen into the atmosphere. Using wind or solar power to generate electricity for the process makes it green.

Once produced, green hydrogen can be transformed into synthetic gas or converted into electricity for use in commercial, industrial, and transportation industries.


Advantages of Green Hydrogen as an Energy Source

The fact that green hydrogen can be produced using excess renewable energy sources and leaves nothing but oxygen as a byproduct already makes it an excellent renewable energy source. However, there are additional advantages of green hydrogen.

  • Hydrogen is abundant. The universe has more hydrogen than any other element, and its supply is virtually limitless.
  • Pound for pound, hydrogen contains almost three times as much energy as fossil fuels. Therefore, less of it is needed to do the same amount of work.
  • It can be produced wherever there is water and electricity.
  • It can be used where it is produced, or it can be transported elsewhere.
  • Unlike batteries, green hydrogen can be stored indefinitely in large quantities.

Green Hydrogen Can Help Achieve Net-Zero Emissions by 2050

Green hydrogen is seen by many as the key component in the global drive to achieve net-zero emissions by 2050 because it addresses two significant challenges: decarbonizing heavy industry and expanding energy storage.

First, green hydrogen can help play a critical role in decarbonization. Many governments and business leaders worldwide have set targets and made commitments to reduce CO2 emissions as part of the 2015 Paris Agreement. That includes 131 countries, covering 88% of global greenhouse gas emissions, that announced net zero targets in April 2022. While energy efficiency, direct electrification, and renewable power can achieve 70% of the mitigation needed, reducing CO2 emissions will also require shifting from fossil fuels to green hydrogen. This is especially important in energy-intensive and heavy-emitting industrial processes like steel and cement manufacturing, long-haul freight, shipping, and aviation. These sectors are difficult to decarbonize because they require high energy-densityfuel or intense heat. Green hydrogen could meet these needs.

Second, and perhaps more importantly, green hydrogen can provide a stable renewable energy source. Current renewable energy sources aren’t consistent. The wind doesn’t always blow, and the sun doesn’t always shine. Green hydrogen can be produced using excess power generated on sunny and windy days and stored for future use. As green hydrogen can be kept for extended periods, it can provide an energy supply to fall back on when renewable sources are low or demand is higher than usual. In turn, green hydrogen can help stabilize increasingly volatile power grids. These factors, along with the declining costs of renewable electricity (which accounts for 70% of the cost of producing hydrogen) and advancements in electrolysis technology, make green hydrogen the best source of clean energy in the future. In fact, BloombergNEF’s Hydrogen Economy Outlook predicts that green hydrogen could meet as much as 24% of the world’s energy needs by 2050, with essentially no damaging emissions. In short, we will need green hydrogen to reach net zero emissions.

Green Hydrogen Storage: The Key to Large-Scale Renewable Energy Solutions

The key to mainstream adoption of green hydrogen as a large-scale, renewable energy solution hinges on expanding viable storage. We already know that the energy supply from wind, solar, hydroelectric, and geothermal sources is never perfectly balanced with demand. Therefore, long-duration storage is a key enabling technology for transitioning to a net zero carbon energy future. As green hydrogen has the capability to be stored for long periods, finding advanced storage methods for green hydrogen is a vital component of large-scale renewable energy.

One promising solution to green hydrogen storage is salt cavern storage. Although depleted oil and gas reservoirs can also provide green hydrogen storage, salt caverns offer the advantage of a low cushion gas requirement, high sealing capacity, and low investment cost. In addition, salt caverns are also a more flexible solution because they can ensure high hydrogen injection rates and withdrawal cycles. These unique geological features provide a safe, reliable, and economical bulk gas storage facility.

How Does Green Hydrogen Storage in Salt Caverns Work?

Before green hydrogen can be stored underground, salt caverns must be created in geological salt deposits. First, one must drill down into that salt to a depth of around 1,500 to 5,000ft. Next, water is injected into the hole to dissolve the salt. Then, the resulting brine (water mixed with salt) is extracted. The result is a salt cavern that provides a large, tight space where hydrogen can be stored under pressure. Due to their tightness, salt caverns can safely store large quantities of hydrogen under pressure. Depending on the cavern’s depth, salt caverns may be operated at pressures up to 200 bars and allow for large-volume hydrogen storage from 9 to 6,000 tons.

Northstar Technology: Helping Revolutionize Green Hydrogen Storage Viability

Expanding the use of salt caverns for hydrogen energy storage offers a significant opportunity to create an infrastructure for large-scale renewable energy reserves. However, before a salt cavern can be utilized, the geomechanical and reservoir properties must be evaluated to determine its candidacy for injection and storage of hydrogen. Historically, this has been a time-consuming and expensive process, making green hydrogen storage economically unviable.

However, technological equipment developed by Northstar has taken the time to determine a salt reservoir’s suitability for storing green hydrogen from weeks to hours. For example, in June 2022, Northstar used its Inflatable Packer System to perform multiple DFIT and DFIT-Flowback tests of the Appalachian Interbedded Salt Formation. Northstar tested five isolated zones in two runs that took less than 60 hours. The tests recorded precise pressure-time and flow rate data.

Such technological advancements bring down the costs of developing green hydrogen storage opportunities.

Large Scale Renewable Energy Solutions Will Require Investment and Working Together

The technology is already established to make green hydrogen the critical player in large-scale renewable energy solutions. However, investment and collaboration through the entire value chain are needed for success. At the heart of delivering this energy transition is creating large-scale green hydrogen storage facilities as the foundation of the hydrogen infrastructure.

If you’re ready to start your hydrogen storage suitability tests, Northstar is here to help! Let’s talk.