Hydrogen is the latest emerging superstar of the clean energy industry, the technology that promises to provide low-cost, abundant energy with zero pollution.
The idea is to use renewable energy to split water into hydrogen (H2) and oxygen (O2), then burn the hydrogen in power generation plants that can supply a growing, plugged-in population. The emissions? Water.
Sunlight, wind, energy, water – sounds perfect. But putting the various technologies together is complicated, and some of the developing technology is still years, if not decades, away from producing volumes to satisfy the growing demand for power generation in the United States. In fact, nearly all hydrogen used in the US today comes from coal and natural gas. All this excitement about a hydrogen future could divert plans to reduce carbon dioxide emissions right now.
For centralized power generation, there are other economically viable and readily available options to quickly reduce emissions while hydrogen production spins up. Hydrogen is surely a long-term tool for reducing greenhouse gas emissions. However, the way some hydrogen is produced, such as blue hydrogen, involves putting natural gas through a hydrogenation process combined with carbon capture, requiring upgrades to infrastructure all along the supply chain, which adds significant cost to power generators. It is currently more cost-effective to just use the original natural gas with carbon capture, especially with the passing of the Inflation Reduction Act (IRA).
Until a large supply of hydrogen is made using renewable energy, power generation companies will need a range of resources to meet short- and medium-term emissions goals. The tools must include grid-scale renewables and distributed generation, energy storage, and, importantly, carbon capture, utilization, and storage.
Why hydrogen is a long-term solution
Hydrogen is in demand world-wide for a variety of uses. The element is critical for refining, metals, and other high-use processes, and that demand must be met.
The current global supply of hydrogen, approximately 90 million tons, is almost entirely produced from fossil fuel. That supply could be fully consumed yet still only generate about two-thirds of the electricity that is produced by natural gas-fired power plants in the US alone. That means, total global hydrogen output would only supply about a quarter of US power demand, whereas gas produces approximately 40% of US electricity. Clearly, the world needs more hydrogen, and to meet climate change goals, it ought to be emission free.
To make sense for power generation, however, the price of clean, or low-emission, hydrogen will have to drop. The initial buyers of clean hydrogen would be those industrial processes that need to reduce carbon dioxide emissions, and doing so without hydrogen would be very difficult. Once the supply of hydrogen is large enough to satisfy that demand with excess, the price could decline enough to be attractive for US power generation.
The US power plant fleet is heavily reliant on natural gas. A transition to a different fuel would be costly and require many years of new and different investment. Additionally, a hydrogen-fired power plant could be less effective than other types of dispatchable green energy and storage solutions because of the extra energy required to generate the hydrogen, store it, and use it in a turbine. So, while new turbine technology can run on a fuel mix that includes as much as 40% hydrogen, getting to 100% will take time.
And turning over the turbine fleet will take decades. Gas turbines usually have a 30- to 40-year lifespan, and the average age of the large gas turbines in the US, those larger than 100 MW, is nearly 18 years. In Canada, the average age is 16.5 years. That does not account for power plants in planning stages or under construction. This natural gas fleet will be generating a big chunk of North America’s power for many years.
The cost to replace the US natural gas fleet with some other form of electrical energy is $800 billion, according to US Energy Information Administration estimates, plus an additional $500 billion to replace power from coal. That does not account for transmission costs to connect to the grid or additional load from electrification, especially of the transportation sector – with costs potentially doubling.
Regulated electric utilities in the US spend about $100 billion per year on capital investment, with about $30 billion of that amount going to generation. That works out to about 26 years to replace the US natural gas fleet at the current rate of investment, without accounting for any growth in demand. Speeding up would require a significant increase in customer rates at a time when consumers are already grappling with higher energy costs.
The journey to zero emissions
A simpler way to cut carbon dioxide emissions quickly, without bulldozing functional natural gas plants, is to install carbon capture, utilization, and storage technology. While the technology may be controversial in some corners of the environmental industry because it does not totally eliminate carbon dioxide, it is a practical way to help meet climate goals with available, tested technology that can maintain grid reliability. The Intergovernmental Panel on Climate Change points to carbon capture as an important tool to cut emissions in the near-term, and the US Inflation Reduction Act boosted financial incentives for carbon capture, utilization, and storage.
Based on hierarchy of need, technical feasibility, maturity of technology, and reliance on additional infrastructure – plus federal tax incentives – it makes sense to focus on installing carbon capture technology on existing natural gas power plants over the next couple of decades until hydrogen technology and availability catches up.
The electric grid is an extremely complex technical marvel that makes nearly every aspect of modern life possible, and so ultimately a multi-pronged approach will have the greatest impact on decarbonization efforts. It is critical that policymakers and industry leaders examine the myriad options to drive technological advancement across a range of clean energy solutions. Diverting too much investment and attention to a distant goal such has hydrogen could undermine the good decarbonization work power generators are doing right now.
Carbon capture, utilization and storage technology is ready and affordable, and can cut carbon dioxide emissions right away. There is no need to wait for a perfect power generation technology before putting our best, current technology to use for today’s needs.