The Changing Landscape of Power Generation and Decarbonisation Pathways

The changing landscape of power generation and decarbonisation pathways presents a critical evolution in producing electricity. Power generation is the crucial process of transforming diverse energy sources into the electricity that powers our homes, industries and technologies. Historically dominated by fossil fuels like coal and natural gas, this sector also harnesses nuclear energy and an expanding array of renewable resources such as wind, solar and hydroelectric power.

As the global community intensifies its focus on sustainability and reducing carbon emissions, the methods of producing electricity are rapidly evolving. This momentum signals a future where renewable energy is set to surpass fossil fuels, fundamentally reshaping the landscape of power generation with greater authority and urgency.

Current Power Generation Mix

In 2023, the global energy mix for electricity generation reflected a growing shift towards cleaner, low-emission technologies, with 39% of global power generation coming from low-emission sources. This includes 9% from nuclear power and 30% from renewables such as solar, wind and hydroelectric power. While this marks significant progress, fossil fuels—especially coal—still dominate the global energy mix, although their share is steadily declining. In contrast, natural gas is growing in importance, particularly in regions like the United States.

Wind and solar power have experienced the fastest growth among renewables. These technologies have become more cost-competitive over the past decade, largely due to technological improvements, economies of scale and government incentives.

Forecast (2026 and Beyond)

Looking ahead to 2026, the share of low-emission sources is expected to rise to 46%, with renewables making up 37% of total generation. Wind and solar will continue to lead this growth, alongside other technologies such as bioenergy and geothermal power. In the longer term, the share of low-emission energy sources is expected to increase further, driven by technology advancements and supportive policy decisions. Achieving these targets will depend mainly on global efforts to address energy security and meet climate commitments, shaping the transition's pace and scope. A range of outcomes is possible, as reflected in scenarios published by organisations such as the International Energy Agency (IEA) and Bloomberg New Energy Finance (BNEF), which highlight different trajectories based on the level of renewable adoption.

Powering the Future: The Critical Role of Infrastructure and Storage Investments

As the global energy mix shifts towards low-emission sources, significant investments are required to modernise infrastructure and ensure the reliability of power generation. This includes upgrading transmission grids and expanding energy storage systems to support the integration of variable renewable energy sources like wind and solar.

Grid Infrastructure

Initially designed for centralised fossil-fuel-based power generation, existing grids must be upgraded to accommodate decentralised and variable renewable energy sources. Large-scale transmission grid enhancements are necessary to connect renewable energy sources located in remote areas to demand centres.

Energy Storage Systems

A key challenge for renewable energy sources like wind and solar is their intermittency, which can lead to frequency imbalances in the grid. Significant investments in energy storage systems are needed to ensure a consistent power supply. Battery Energy Storage Systems (BESS) and Long-Duration Energy Storage (LDES) technologies enable the storage of excess renewable energy for use during periods of low generation. These technologies will improve the reliability of renewable energy and ensure that power is available around the clock, reducing reliance on fossil fuels during peak demand periods.

Decarbonising Fossil Fuel Power Generation Pathways

Despite the rapid growth of renewable energy, fossil fuel power plants dominate global electricity production. These facilities, particularly in developing regions, are relatively young and are expected to remain operational for decades. This reality underscores the urgent need to invest in decarbonisation technologies to reduce emissions and ensure these plants operate more sustainably.

Fortunately, innovative solutions are emerging to meet this challenge. Technologies such as carbon capture, hydrogen-ready turbines and ammonia co-firing offer viable pathways to significantly lower the carbon footprint of these fossil fuel assets, extending their operational life while aligning with global climate goals.

Carbon Capture Technology

Post-combustion carbon capture is one of the main pathways for decarbonising existing fossil fuel power plants. This technology captures CO₂ emissions from the flue gas after combustion. For instance, amine-based carbon capture is a technically mature solution that more and more plants are adopting to reduce their carbon footprint. Some technology companies are actively working on refining this technology, making it more efficient and cost-effective.

Hydrogen-Ready Turbines

As the global energy mix shifts from coal to natural gas, hydrogen is emerging as a potential fuel source for power generation. New natural gas-fired plants are being designed with hydrogen-ready turbines, which means they can transition to burning low-carbon hydrogen as it becomes commercially viable. This could involve initially blending hydrogen with natural gas, eventually leading to 100% hydrogen-powered plants.

However, transitioning to hydrogen will require equipment upgrades, including modifications to fuel gas compressors and filters to ensure reliable and safe operation. Essential for successful upgrades are the right mechanical sealing solutions for the compressors and optimal filter design to protect the equipment and support the smooth and efficient operation of hydrogen-ready systems.

Ammonia Co-Firing in Coal Plants

In regions where coal remains a significant power source, co-firing with clean ammonia offers a decarbonisation pathway. Particularly in Southeast Asia, where coal plants are still relatively young, ammonia co-firing has garnered more interest. Japan and other countries are testing co-firing technologies that allow coal-fired plants to burn a mix of coal and low-carbon ammonia, reducing carbon emissions without decommissioning valuable infrastructure.

Though still in its infancy, ammonia co-firing has the potential to reduce emissions from coal plants. Currently, plants can co-fire up to 20% ammonia, with efforts underway to increase that dramatically to fully replace coal and utilise those assets at least to the end of their design life.

Supercritical CO₂ Power Cycles

Innovative technologies like supercritical CO₂ (sCO₂) power cycles, such as the Allam-Fetvedt Cycle, are emerging as highly efficient, low-cost methods of power generation that capture almost all CO₂ emissions by design. These systems use oxy-combustion and high-pressure supercritical CO₂ as a working fluid, producing only water and a stream of high-purity, pipeline-ready CO₂. This makes them ideal for reducing emissions from natural gas and gasified solid fuels such as biomass and municipal solid waste.

Other technologies, like the CEOX oxy-fuel combustion process, are designed to operate at lower pressures and temperatures, utilising widely available equipment and closed-loop power cycles to enhance emission reductions. Various technology companies are working on further designs and variations of sCO₂ power cycles. These innovative solutions are being piloted globally and show great potential for future low-emission power generation from fossil fuels.

Navigating the Energy Transition

The global power generation landscape is rapidly evolving, with renewable energy sources taking centre stage. However, fossil fuels will remain part of the mix for the foreseeable future, necessitating innovative solutions to decarbonise existing assets. Technologies such as carbon capture, hydrogen-ready turbines and ammonia co-firing are critical to achieving global climate targets while ensuring energy security.

As the world undergoes this energy transition, engineering advancements and specialised sealing technologies—like those from John Crane, which supplied dry gas mechanical seals for the first sCO₂ power cycle pilot plant—will play a vital role in ensuring the efficient and reliable operation of both renewable and fossil fuel power generation systems.

The Energy Transition presents a unique opportunity for the industry to drive innovation and ensure a sustainable, low-carbon future for power generation worldwide.

NOTE: This article first appeared on the Pumps & Systems website in November 2024.