SHORT COURSE ON HYDROGEN
There are many
ways to isolate hydrogen. The easiest is
to electrolyze water…electricity is applied to 2 electrodes to split H2O into H2
and O2 gas. Basic high school chemistry lab.
It takes energy to do this, but energy is stored in the H-H molecules
that are formed. Oxidizing the hydrogen
molecules releases that stored energy.
H2 can be sequestered and stored in a variety of ways…compressed gas,
liquified, etc., and made available when the release of energy is demanded
When H2 is
recombined with O2, you release energy, and the basic waste product is H2O
(water!) You can combust it (burn) in an
engine, boil water with it, mix it with natural gas, etc. Combustion with air oxidizes the nitrogen in
that air, producing NOx emissions, and waste heat.
A better way
is to use a fuel cell, where 2 electrodes recombine the H2 and O2 to create a
flow of electrons (electricity) just like a battery. The release of energy always
produces waste heat, depending on the efficiency of the conversions. Fuel cells can vary in size, and are around
80% efficient in converting the energy in the H2 into electricity with current
technology.
A lot of new
research is going into splitting water.
Today’s electrolyzers are around 50-60% efficient. Many directions are being explored to split
water, the simplest is exciting new research into using the sun’s energy to
directly split water. If a zucchini
plant can do it, hopefully, we can eventually figure out how to do it too.
When we talk
about efficiencies, we need to keep a wide perspective. An automobile engine is about 20% efficient,
meaning that 80% of the energy in the fuel is wasted as heat…hence the
radiator, etc. A typical steam power
plant (coal, gas, nuclear) is about 33% efficient, with cooling towers needed
to remove the 66% waste heat. A
photovoltaic cell (or module) is about 22% efficient, but the value here is the
fuel is free, and the waste heat is natural and is released back into the
environment. Other fuels produce excess heat being dumped into our air and
waters. A fuel cell puts out about 20%
waste heat. Our bodies put out ?? waste
heat. A FUSION reactor in the future
would put out hundreds of millions of degrees into our environment!!! It is
interesting how the hydrogen atom will play a key role in our energy future.
The use of
hydrogen has been toyed with on the international stage for years. Most of the work has focused on its replacing
oil in the transportation sector.
Toyota, Nissan, GM, Ford, BMW have all played with hydrogen fuel
vehicles, which proposes a daunting infrastructure to make it a viable option. I think we will see hydrogen play an
important role in aviation, shipping, trucking, and other vehicles that have
set routes from point A where they are initially fueled to point B where they
can again be refueled. I don’t see gas
stations all over the US or other countries in the world offering gasoline for
the existing fleet of cars as well as hydrogen for new vehicles. That would involve an enormous infrastructure
to move the hydrogen into place. Charging
battery-powered electric vehicles is easier, and moving electrons is easier and
cheaper than moving liquid or gases.
I believe
the largest role hydrogen will have in the future is to support the renewable
electrification of society. Simply put,
we generate electricity from intermittent solar and wind and use any excess or
what we don’t immediately need to manufacture hydrogen, which is then stored to
be used in fuel cells to generate electricity when and where it is needed.
Humboldt
State proved the viability of this at the Marine Lab in Trinidad back in the
early 90s. A PV array was constructed,
and 1/3rd of its output is used to power aerators in several
saltwater fish tanks. The remaining 2/3rds
of the PV electricity went to an electrolyzer which split water into H2 and
O2. The hydrogen gas was compressed and
stored in a tank. At night, the hydrogen
was recombined in a fuel cell (which the students themselves built) and that
electricity was used to power the aerators.
The waste products are WATER and a bit of waste heat. This system still operates today. It is a relatively simple 30-year-old
technology, but it failed to grab the attention of the energy industry until
now.
Hydrogen is
a BIG play now in the renewable energy world.
As the US lags, Australia, Northern Europe, China, Saudia Arabia, and a
slew of other countries are investing enormous amounts of money in a multitude
of research directions. Even the nuclear
industry is looking into producing Blue hydrogen (non-renewable) as opposed to
Green hydrogen. It is all very exciting,
and the technologies are developing at an incredible rate.
Just a few
examples that are being reported in the media:
https://www.bbc.com/future/article/20190327-the-tiny-islands-leading-the-way-in-hydrogen-power
https://e360.yale.edu/features/green-hydrogen-could-it-be-key-to-a-carbon-free-economy
Some resources
that offer information on what is happening in the renewable energy world.
Facebook group
pages: Hydrogen
Fuel Cells
Hydrogen
and Fuel Cell News
Plug Power (corporate news, they’ve been in the game for many years.)
Websites: many offer daily newsletters
E&E news
Elecktrek
T&D world
Energy tech
Insideclimatenews
Daily climate
A lot of
information is also coming up in the more traditional media, such as Bloomberg,
BBC, etc. As with everything, it is an
interesting mix of technology, politics, and money. Let the sun shine and the wind blow!!!!!
