Hydrogen Technology- The New Fuel for the Renewable Future?

1.Current Alternative Energy and Clean Technology Landscape

As many innovators and engineers would say, through the next 50 or so years the world is headed towards an energy revolution to adopt alternative energy sources and preserve the environment. This “energy revolution” comes after the two other global scale revolutions in the STEM fields whose benefits to humanity have been undeniable – The Industrial Revolution and The Digital Age. The Industrial Revolution expanded the use of mechanical machinery to perform work and produce goods with the help of construction facilities called factories industries in the late 19th and early 20th century. As the world entered the 1900s, the industrial innovations were started to be implemented to transmit electric power, improve transportation and expand industries. And through the 20th and early 21st century, the world witnessed the rise in popularity of the computer from desktop forms to portable and handheld forms. Advanced industries and manufacturing processes have allowed for this rapid expansion in the digital age.

However, with the rise of global warming and rising greenhouse gas levels across the globe the world now seeks a new revolution, one to help power implementations of renewable energy based systems and devices. This renewable energy or alternative revolution is currently in the works in various sectors of industry. They include modern transportation, electric grid transmission, energy storage, power generation, etc. Much of the past 100 or so years has seen various technologies and systems running on oil, natural gas and non-renewable resources capable of damaging the environment. Global warming and climate change are major effects of the continuous greenhouse emissions from industries and energy production facilities (like coal and natural gas). As we see newer and more advanced technologies such as Artificial Intelligence/Machine Learning, autonomous vehicles, smart communication systems and electric automobiles develop quickly, the search for better alternative and renewable energy resources has been on the rise. This new demand has given birth to new initiatives and a whole new industry by the name of ‘Clean Technology’.

Clean technology is centered around sustainable energy and reducing our dependency on fossil fuels, the provision of clean water, pollution reduction, recycling and waste management. Modern forms of clean energy production include wind power, solar photo voltaic power, nuclear fusion energy and hydro power. The advantages of these renewable energy sources serve the purpose to suppress greenhouse gas emissions from combustion and reduce the usage of important limited resources like oil, fossil fuels and coal.  Clean tech applications extend to the energy storage sectors too, where we see pumped hydroelectric storage, flywheel power storage, battery cell storage and hydrogen fuel cell storage continue to be deployed globally to drive down peak demand costs and usage of non-renewables. The mounting pressure from global communities and organizations is resulting in a widespread adoption of clean technologies across the world. Wind energy is the fastest growing source of power in the United States, creating jobs opportunities for thousands of Americans and boosting economic growth. Following are some statistics indicating this fast growing clean tech industry in the United States:

  • Wind energy is the fastest growing source of power in the United States. In 2012, U.S. wind capacity topped 60 gigawatts, enough energy to power more than 15 million homes.
  • 95% of U.S. energy storage is from Pumped Hydroelectricity, equating to 22.6 GW as of April 2017
  • In 2015, the US Department of Energy has announced a $15.8 million program to fund over 30 hydrogen fuel cell integration projects across the country.

Lithium-ion batteries are one of the fastest-growing energy storage markets due to their high energy densities, high power, near 100% efficiency, and low self-discharge. The U.S. has 38,000 tonnes of lithium in reserves alone, capable of powering 13-27 million electric vehicles (EVs) or 5-10% of U.S. vehicles. With this stark rise in research for new alternative energy sources, Hydrogen has been a highly debated one with many deeming it to be the future fuel during the energy revolution. Below we explain some of the basics of Hydrogen based power production and some of its key applications.

 

 

2.Hydrogen as a Fuel and Energy Storage Medium

As more research and development is put towards renewable energy sources, various technologies have been uncovered with unique advantages and applications. One of the most debated and polarizing energy storage and power production technologies have been Hydrogen Fuel Cell devices. Hydrogen (H2) is an alternative fuel that can be produced from diverse domestic resources. Hydrogen Fuel Cells function by combining Oxygen (O2) and Hydrogen to produce electric power with a by-product of water (the reverse process of electrolysis). This technology is currently seen implemented in fuel cell electric vehicles (FCEVs) and energy storage units for the electric grid. FCEVs are beginning to enter the consumer market in localized regions domestically and around the world. Below is a diagram explaining the workings of the Hydrogen Fuel Cell.

 

A hydrogen fuel cell electric vehicle is powered by a group of individual fuel cells, known as a fuel cell stack. The stack is designed to contain enough cells to provide the necessary power for the automotive application. A fuel cell stack produces power as long as fuel is available, similar to a combustion engine. The electricity generated by the fuel cell stack powers the electric motor that propels the vehicle. Each fuel cell is an anode, a cathode and a proton exchange membrane sandwiched in between. Hydrogen, from a tank onboard the vehicle, enters into the anode side of the fuel cell. Oxygen, pulled from the air, enters the cathode side. As the hydrogen molecule encounters the membrane, a catalyst forces it to split into electron and proton. The proton moves through the fuel cell stack and the electron follows an external circuit, delivering current to the electric motor and other vehicle components. At the cathode side, the proton and electron join again, and then combine with oxygen to form water, the only system emission.

Chemical reaction in a Hydrogen Fuel Cell

Shown below is a see-through view of one of the only mass production and most popular Hydrogen Fuel Cell vehicles, the Toyota Mirai. The Mirai is a HFCV that can store upto 5kg of Hydrogen in a carbon-fibre tank, can produce a maximum of 150 hp from its electric motor and have a range of around 300km from a full tank. This vehicle has been a part of Toyota’s goals of creating a fully Hydrogen based energy system in the future. The primary parts of a HFCV include a secondary battery pack for on demand power and a power control unit (PCU) that will monitor motor torque/speed and appropriately output power from the fuel cell or the battery. Since, both the fuel cell and battery can supply power directly to the PCU an HFCV can be more power efficient with different driving modes for varying loads, such as city, highway or high-power driving. Most automakers have placed fuel cell electric vehicles with customers, and many plan to introduce HFCVs to the early commercial market in the 2015-2017 timeframe. By 2020, automakers expect to place tens of thousands of fuel cell electric vehicles in the hands of California consumers. California has the quickest growing hydrogen infrastructure in the US with over 300 HFCVs on the road and multiple hydrogen refueling stations and hydrogen storage facilities across the state. Below are some advantages of Hydrogen Vehicles:

 

Advantages of Fuel Cell Vehicles over Gasoline powered vehicles:

  • Zero-emission platform for HFCVs, only water is produced as by-product.
  • A conventional combustion engine uses less than 20 percent of the chemical energy in gasoline, which means more than 80 percent of the fuel is “wasted.” HFCVs can max out at energy efficiencies of upward of 60%
  • Fuel Cells are significantly simpler and less complex to maintain than internal combustion vehicles due to not having block cooling, oil, water and liquid fuel systems.
    Battery Powered Vehicle Chassis

    Toyota Mirai HFCV

Advantages of Fuel Cell Vehicles over Battery powered vehicles:

  • HFCVs convert a chemical compound stored externally into electric ity that can be used to power the vehicle. A battery vehicle does not produce electricity, rather it stores electricity from an external charging source. A HFCV can produce electricity on the go, which allows for excess energy to be stored for later use under high demand, increasing overall efficiency of the vehicle.
  • HFCVs do not use external electricity to propel the vehicle. This prevents the usage of power of possible non-renewable sources from the grid (As of 2018, only 20% of the power in the US comes from renewable sources).
  • HFCVs are inherently quicker to recharge, as it takes around 2-3 minutes to fill up a 5kg Hydrogen tank from a refueling station. HFCVs can also be lighter and more agile due to the lack of a large battery pack under the vehicle.

Source Credits:

-https://www.driveclean.ca.gov/Search_and_Explore/Technologies_and_Fuel_Types/Hydrogen_Fuel_Cell.php

-https://www.bloomberg.com/news/articles/2018-03-23/the-hydrogen-powered-car-s-big-setback

-https://www.afdc.energy.gov/fuels/hydrogen_basics.html