The Challenges Of Distributed Hydrogen Blending

A growing number of hydrogen pilot projects are underway. These activities are often undertaken by gas utilities and signal that the industry is starting to move toward decarbonization. By executing these projects, the local gas distribution companies demonstrate hydrogen fuel’s ability to support a clean environment.

Already, dozens of low carbon renewable natural gas and hydrogen projects are preparing to either get underway or are in the final stages of rolling out. Others are producing essential data, helping offer insights into operations and possible shortfalls. The opening months of 2022 also showed that the industry’s hydrogen leaders, especially Southern California Gas Co., have ramped up their commitment to a low-carbon fuel beyond just piloting projects. Some are also already using renewable energy to produce green hydrogen.

While interest in distributed hydrogen blending technologies is accelerating, there are a few inherent challenges for end-users, utilities, and government regulators. The challenges aren’t just from naysayers. Some resistance is coming from first-hand from pilot products supplying hydrogen blends.

SoCal Gas’ Dedicated Hydrogen Distribution Via Natural Gas Pipelines

SoCalGas announced its plans to run a dedicated hydrogen gas pipeline within Los Angeles. The so-called Angeles Link would be the largest green hydrogen infrastructure in the US and be part of the gas utility’s green hydrogen plans for one of the largest cities in the country. Plus, it will not use the existing gas infrastructure, for reasons we’ll reference towards the end of the article.

This project gained widespread support and continues to attract strong interest from an array of stakeholders. Even skeptics agree that clean molecules are big business and can attract big money.

For the market to achieve scale, many hydrogen advocates have long stated dedicated hydrogen pipelines are necessary to link demand with supply. However, many gas utilities like SoCalGas have focused on blending methane with hydrogen in existing pipeline networks. The strategy is seen as a cost-effective method to get consumers acclimated to using hydrogen. Still, the current gas grid can only handle a certain concentrations of hydrogen without compromising the integrity of the existing gas line and potentially damaging users’ appliances.

While energy efficiency is a priority, hydrogen blends with existing fossil fuels can pose their own challenges. Some of these challenges can be handled by existing infrastructure, other challenges may require increased fuel costs.

The strength of the distributed hydrogen blending model is that it can make use of existing methane or natural gas lines. This means that new fuels can be deployed quickly and at very low cost. This can serve as an entry point for end users and gas utilities to rapidly and efficiently test their strategies about how to decarbonize their own businesses. If they want to step-up to pure hydrogen, they can then do so at much lower risk.

Distributed hydrogen blending projects are not meant to be permanent solutions. Rather, they are rapid ways to introduce a new fuel stream. Blended hydrogen and natural gas are also a cost-effective means to understand how to build and manage distributed methane pyrolysis networks in contrast to traditional centralized hydrogen supply chains.

Advancements In Blending Hydrogen

In Utah, Dominion Energy continues to pilot its hydrogen blending system. Early assessments from the distribution system suggest that it can handle a 5% hydrogen blend and possibly ramp up to 10% without adversely impacting existing systems or appliances.

Hydrogen blending is just one way that Dominion Energy intends to achieve its recently announced net-zero Scope 3 greenhouse gas emissions goal.

Another major player is CenterPoint Energy Inc, which has started its own green hydrogen and blending pilot projects including Minneapolis, Minnesota. The company has plans to produce hydrogen which will be pumped into the distribution system at a comparatively low volume at first. According to the company, the approach will help assess the potential risk of leaks and other impacts on existing infrastructure.

The company has already taken delivery of a special electrolyzer that splits water into hydrogen and oxygen as a first step of the project. The goal for the company is to produce hydrogen at a low enough price that it offsets the initial cost of investment without consumers having to pay significantly more for cooking and heating.

Challenges of Hydrogen Blending

Hydrogen is the smallest molecule in the universe. This can create challenges including leakage and integrity of pipelines, especially if existing US natural gas lines are to be used.

All existing natural pipelines are made from steel and are meant to hold up to the high pressures of natural gas transmission. However, hydrogen can exacerbate cracks in pipelines, leading to embrittlement and leakage above specific concentration. That’s one reason why many older natural gas pipelines cannot handle hydrogen gas concentrations of over 20% when blended with methane.

New gas distribution service lines and mains meant for pure hydrogen will need to be made from plastic, polyethylene, or high quality stainless steel. Pure hydrogen gas will also need to be piped at a different pressure than traditional natural gas.

Most of these requirements support recent distributed hydrogen blending work by leading gas utilities like Northwest Natural. These utilities are entering into supply contracts for distributed methane pyrolysis. This approach to generating and delivering clean turquoise hydrogen eliminates the need for hydrogen transportation and storage because the hydrogen is generated and blended right where you need it.

Final Word

Above are a number of the primary challenges and benefits of hydrogen blending. Many of the issues can easily be solved with distributed hydrogen blending. Other challenges are typical of new clean technologies in the energy transition.

As things currently stand, distributed hydrogen blending can make hydrogen introduction, production and distribution faster and more reliable. It can also make for a cheaper path to the hydrogen future.