One of the most disruptive technologies to impact global markets is the transition to electric vehicles, which is detailed and explained in this chapter.

There is a growing demand for renewable energy sources to power the net-zero-carbon transition. What are the sources and their benefits and drawbacks?

Hydrogen as a carbon-free fuel is amenable to utilization in all heat engines, including gas turbines and reciprocating internal combustion engines, which are the most efficient technologies for electric power generation from fossil fuels. Alas, H2 is not an energy resource. It is an energy carrier. Prior to its use as a fuel, it must be produced, stored and/or transported. There are significant problems associated with all three phases of the hydrogen fuel chain. Those aspects will be discussed qualitatively and quantitatively in the remainder of the present chapter.

In a talk given during the German occupation of the Netherlands, Henk van der Hulst discussed possible 21 cm radio emission from interstellar hydrogen atoms but pessimistically concluded that “the existence of the line remains speculative.” Nearly 20 years later, Harvard University PhD student Harold (Doc) Ewen surprisingly detected the 21 cm hydrogen line using a simple horn antenna sticking out the window of his laboratory and a novel frequency switching radiometer. van de Hulst had also calculated the possibility of detecting radio recombination lines from highly excited galactic hydrogen, but overestimated the effect of line broadening. Although he concluded that radio recombination lines are “unobservable,” they were subsequently detected in the USSR and the US. Observations of surprisingly strong radio emission from hydroxyl and water vapor were understood to be due to interstellar masers, which could have been detected much earlier if anyone had thought to look in the right place. Later discoveries of interstellar formaldehyde and carbon monoxide opened the door to a new and highly competitive field of astrophysics – molecular radio spectroscopy.

In this chapter we study the primordial process in which nuclei of atoms formed -- the Big Bang nucleosynthesis, or BBN for short. We show that BBN principally leads to the synthesis of hydrogen and helium, along with a trace amount of a few more of the lightest elements. We describe the basic thermodynamical and nuclear-physics conditions in the early universe, and explain how they determine the primordial origin and abundance of nuclei in the universe. Finally, we illustrate how the lightest-element abundances are in spectacularly good agreement with observations, making BBN one of the pillars of the hot Big Bang cosmological model.

Hydrogen will play an increasingly important role in the push toward greater use of renewable energy and the reduction in carbon emissions from the transportation sector, electrical energy generation and transmission, and the production of commodity chemicals, such as ammonia and polyolefins. In this chapter, the operating principles of fuel cells and electrolyzers are detailed. The main function of these devices is the interconversion of electrical and chemical energy.

Gas turbines play a preeminent role in the stationary power generation marketplace and are expected to remain a critical part of the market mix for the foreseeable future. Alternative technologies compete with gas turbines in certain size classes, but at power generation levels above 5 MW, gas turbines offer the most attractive option due to their relatively low capital, operating, and maintenance costs. The configurations for these systems involve high efficiencies as well. These engines are being looked to by the US Department of Energy and the major OEMs for clean power production, especially considering the use of renewable fuels. As a result, the market will continue to demand gas turbines for the foreseeable future.

Gas turbines are able to utilize a wide variety of fuels, including fuels with low- or zero-carbon content. This includes hydrogen (H2), ammonia (NH3), synthetic and renewable natural gas, as well as a range of biofuels. These are sometimes referred to as zero-carbon, net-zero-carbon, or near-zero-carbon fuels. A subset of these fuels have been used to produce power from gas turbines for decades. This chapter will review experience and practical challenges in the use of these fuels in gas turbines for power generation applications, describing case studies for utilizing these fuels in the field.

Gas turbines play a preeminent role in the stationary power generation marketplace and are expected to remain a critical part of the market mix for the foreseeable future. Alternative technologies compete with gas turbines in certain size classes, but at power generation levels above 5 MW, gas turbines offer the most attractive option due to their relatively low capital, operating, and maintenance costs. The configurations for these systems involve high efficiencies as well. These engines are being looked to by the US Department of Energy and the major OEMs for clean power production, especially considering the use of renewable fuels. As a result, the market will continue to demand gas turbines for the foreseeable future.

A major motivation for the development and ultimate replacement of petroleum-based fuels with alternatives is the desire to reduce the carbon emissions (i.e., CO2) created when burning hydrocarbon fuels in prime mover devices. In addition to CO2, combustion of hydrocarbon fuels in air will inevitably create a number of other emissions (e.g., NOx, soot, etc.), which can have detrimental effects on human health or the local (or global) environment. Furthermore, the desire for a more economic and stable fuel supply has also provided impetus for the identification of alternative feedstocks for fuels. With these motivations to find alternative fuels for power generation, it is important to understand how different fuels can impact pollutant formation. This chapter focuses on the fundamentals of pollutant formation in combustion, as well as the impact of various alternative fuels on the combustion generated emissions. This includes carbon monoxide, nitrogen oxides (NOx), and soot. These topics are addressed for a variety of candidate fuels, including hydrogen and ammonia.

Hydrogen will play an increasingly important role in the push toward greater use of renewable energy and the reduction in carbon emissions from the transportation sector, electrical energy generation and transmission, and the production of commodity chemicals, such as ammonia and polyolefins. In this chapter, the operating principles of fuel cells and electrolyzers are detailed. The main function of these devices is the interconversion of electrical and chemical energy.