The Us Energy Transition: Replacing Fossil Fuels

Fossil fuels are the biggest driver of climate change, and transitioning to a more sustainable system is necessary to fight it. Fossil fuels are used to power cars, heat buildings, and keep the lights on. They are also used to create everyday products like plastics, electronics, textiles, and cleaning products. While fossil fuels are reliable and affordable, they release harmful CO₂ emissions into the atmosphere. To replace fossil fuels, we need to invest in alternative sources of energy that are clean, accessible, affordable, sustainable, and reliable. This includes renewable energy sources like wind, solar, and hydropower, as well as nuclear energy and biofuels. The transition to renewable energy will require significant investments and infrastructure changes but will lead to a healthier, cleaner, and more sustainable future.

Nuclear energy

Nuclear power plants produce no greenhouse gas emissions during operation, and over the course of its life-cycle, nuclear produces about the same amount of carbon dioxide-equivalent emissions per unit of electricity as wind power, and one-third of solar power. Nuclear energy has the potential to be the catalyst for delivering sustainable energy transitions, and France is a prime example of this. In just 15 years, France went from nuclear power playing a minor role in its electricity system to producing the majority of its electricity. Today, France generates over 70% of its electricity from nuclear power – the largest nuclear share of any country globally – and its electricity sector emissions are one-sixth of the European average.

Nuclear power could take a starring role in a future where energy production has net-zero emissions. According to an analysis by Dr. Charles Forsberg, an energy research scientist at the Massachusetts Institute of Technology (MIT), nuclear power plants can provide baseload electricity to the grid, meaning the minimum necessary. The reactors would include large-scale heat storage as a cheap battery that can take excess energy produced by wind and solar. Along with baseload energy, the reactors would also produce hydrogen that can replace natural gas. Nuclear heat and hydrogen can also convert plant biomass into liquid biofuels that can replace gasoline, diesel, jet fuel, and other fossil fuels.

Hydro power

Hydropower is one of the main sources of renewable energy worldwide, and its use is increasing as countries seek to reduce their reliance on fossil fuels. Hydropower is a renewable energy source derived from flowing water, and its history can be traced back to ancient Greece, where waterpower was used to operate wheels for grinding grain. Today, hydropower is one of the most cost-effective means of generating electricity. For example, in Norway, 99% of the country's electricity is generated from hydropower.

The basic principle of hydropower is using water to drive turbines. There are two basic configurations of hydropower plants: with or without dams and reservoirs. Hydropower dams with large reservoirs store water to ensure they can meet peak demand, while plants without dams and reservoirs produce at a smaller scale and typically operate in a constant flow of water, such as a river.

Hydropower has the largest electricity generation capacity compared to other renewable energy sources. According to the International Renewable Energy Agency (IRENA), hydropower is the largest contributor to electricity generation at almost 70%. In 2016, hydropower plants generated 4,000K GWh of electricity. Asia has the largest capacity for hydropower, followed by Europe and North America.

Hydropower is also a strong and competitive renewable energy source in terms of cost. The global weighted average levelized cost of electricity for hydropower is $.05 per kWh, compared to offshore wind at $.14 per kWh and geothermal at $.07 per kWh.

There are two main types of hydro turbines: impulse and reaction. The factors that determine which turbine is chosen include the height of standing water and the flow or volume of water at the site. Impulse turbines use the velocity of the water to move the runner and discharge to atmospheric pressure. Water impacts each individual bucket on the runner, and there is no suction on the downside of the turbine as water flows out. Impulse turbines are generally suited for high-head and low-flow applications and can be categorized into Pelton and cross-flow turbines.

Reaction turbines, on the other hand, draw power by combining pressure and moving water. The runner is placed in the water stream, allowing it to flow over the blades. Reaction turbines are typically used in lower head and higher flow conditions and can be categorized as propeller, Francis, and Kinetic.

Hydropower has several advantages as an energy source. It is a clean energy source, contributes to flood control and irrigation techniques, and can be used anywhere there is a natural flow of water. However, the use of hydropower also has some drawbacks and risks. For example, the construction of dams and reservoirs can have environmental and social impacts, including the displacement of communities and changes to river ecosystems.

While hydropower is a significant source of renewable energy, it is unlikely to completely replace fossil fuels on its own. A combination of renewable energy sources, including solar, wind, geothermal, and tidal power, will be needed to transition away from fossil fuels. Additionally, energy storage and grid infrastructure improvements are crucial to accommodating the intermittent nature of some renewable sources and ensuring a stable power supply.

Biomass energy

In 2023, biomass accounted for about 5% of US energy consumption, or about 4,978 trillion British thermal units (TBtu). The industrial sector was the largest consumer of biomass energy in the US, followed by the transportation, residential, electric power, and commercial sectors.

Biomass can be converted to energy through various processes, including direct combustion (burning), thermochemical conversion, chemical conversion, and biological conversion. Direct combustion is the most common method, with all biomass capable of being burned directly for heating buildings and water, for industrial process heat, and for generating electricity in steam turbines.

However, it is important to note that clearing forests to grow biomass can result in a carbon penalty, so it is best to grow biomass on previously cleared land, such as underutilized farmland.

Solar power

Solar panels are also a lot cheaper for the user in the long run. While there may be a significant initial cost, the amount of money saved on electricity bills over time is a huge benefit when compared to the unpredictable prices of electricity generated through fossil fuels.

However, solar energy alone cannot replace fossil fuels. The main issue is that solar panels are dependent on sunlight to generate electricity, and so their energy production is impacted by the weather. On an annual basis, the average North American solar farm generates meaningful power less than 20% of the time. This means that to cover the power gaps, utilities must keep their fossil-fueled generators running.

However, when you combine the potential for solar and wind energy, it is possible that we could someday give up fossil fuels worldwide. A report by the U.K.-based think tank Carbon Tracker in 2021 showed that modern wind and solar technologies are capable of capturing 6,700 petawatt-hours (PWh) of energy, while the world's current demand is only 27 PWh. If both the solar and wind industries can continue to grow by at least 15% a year, they could be responsible for providing all of the world's electricity as soon as 2035.

The transition from fossil fuels to renewable energy sources will not happen overnight, and it will not occur without setbacks and challenges. But the process needs to start as soon as possible, as it may take four or even five decades to get to a place where it's making a recognizable impact.

Wind energy

The US has been increasingly recognizing the potential of wind energy, with wind farms dominating new power plant builds in recent years. In 2019, wind energy accounted for 9.1GW of new generating capacity, and it is projected to surpass natural gas by 2023 and coal by 2024 in terms of total installed capacity. Wind energy is particularly efficient in windy areas, and wind farms can provide significant economic benefits to rural communities by generating revenue for farmers and ranchers while also contributing to county taxes that support local services.

However, one of the challenges of wind energy is that it is not suitable for urban areas due to the size and location requirements of wind turbines. As a result, wind turbines must be built in remote windy areas or offshore, which can increase the complexity and cost of infrastructure development.

While wind energy alone may not be sufficient to replace fossil fuels, it is an essential part of a comprehensive strategy that includes other renewable energy sources such as solar power, geothermal energy, and tidal energy. By investing in wind energy and other renewable sources, the US can reduce its dependence on fossil fuels, mitigate climate change, and create a more sustainable future.

Frequently asked questions