This chapter focuses on developing and using models. In each chapter, the practice is dissected into distinct and clear learning tasks that serve as process goals for learning the practice. These tasks are then examined within the context of a self-regulated learning cycle and coaching strategies for instruction and assessment are emphasized. The instruction and assessment strategies are contextualized for students in grades 9–12 and focus on developing and refining a model for electrolysis. The tasks are reassembled into two case studies – one positive and one negative – to demonstrate how the learning tasks can be used by students and how teachers can support students learning how to develop and use models.

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.

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.

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.