The evergreen theme
of skills shortages was
brought to the fore during
The Engineer’s Skills Week
23 April 2020 / www.theengineer.co.uk
Is it high time for
hydrogen trucks?
Mailbox
Our report on the development of hydrogen
fuel cell heavy duty lorries - and the
infrastructure required to support them –
split readers into two camps
The mass energy density of
hydrogen is not necessarily the
important issue but the
volumetric density. Liquid
hydrogen has a very low specific
gravity of about 0.07 as compared
with (I think) about 0.8 for liquid
methane or natural gas. So, this
suggests much larger (about 4
times) tanks are required for
hydrogen than for other fuels.
And, of course, better
insulation is required. Or,
alternatively, trucks would
need to refuel more often. I
believe that it is quite feasible
to have super insulated tanks
for hydrogen; though I am not
aware of them being
commercially available.
Julian Spence
How does the price of
hydrogen produced from
electrolysis compare to the cost of
natural gas? For electricity @ 8.8p
per kW-h and natural gas @ 4.3p
per kW-h, the 25.2 g H2 (= 56.4g
natural-gas-equivalent) costs 8.8p
and the actual cost of 56.4g natural
gas (2.82 MJ; 2820 kJ; 0.784 kW-h) is
3.4p. In other words, hydrogen
from electricity costs about 2.6x
the equivalent amount of natural
gas. Trevor
Getting H2 in the first place takes
energy. Compressing it takes more
energy and problematic highspec
pressure vessels. Liquefying
it also takes more energy plus
high-spec insulated vessels and
yet more energy to boil it off for
use. Weight is not an issue so why
not use ordinary natural gas at
NTP (normal temperature and
pressure) held in a plastic bag
fitted inside a lightweight trailer?
Recharge might be more frequent
at, say bus-stops and garages,
but will be quick and cheap.
The Natural Gas distribution
infrastructure already exists and
does not need special trucks to
deliver it to special storage tanks.
This solution was fully developed
and used in Germany in WWII,
and could be on our roads by next
month if the ‘problem’ was actually
urgent.
TonyN
We have been ready to install
a UK hydrogen network for a year.
No company or investor is
stepping up with our offer. Lack of
interest over fossil fuels.
Leslie Osborn
Hydrogen is just as much as
a fuel as petrol. It can be created
from hydrocarbons just like
petrol or diesel, or produced in a
more environmentally friendly
manner from green energy. The
efficiency of which is slowly
improving with potentially
some dramatic improvements
on the horizon. Unfortunately,
this might be the fuel equivalent
of the VHS/Betamax wars with
the worst option winning!
Brian
(March 2-6, 2020)
Augmented Reality (AR) can
help accelerate a reduction in
the UK engineering skills gap.
We are working closely with
UK engineering companies
deploying ready made AR
applications that really speed
up the training process and
allow skills to be transferred at
a fraction of traditional costs.
Michael Bird
In the UK, depending on
the engineering sector it might
be a problem due to low
salaries. In the building
services engineering sector,
the businesses don’t utilize the
personnel available on the job
market. I know many contract
engineers that are not given
the opportunity of a position,
due to cheap overseas
engineers, vague IR35
knowledge, short term
permanent employment. Also,
many of the older engineers
get fed up and move to other
sectors or retire, leaving a
major gap in experience
people.
Some of us actually like our
sector and would like to work
longer and pass on our
knowledge to the up and
coming engineers.
Trevor Hutchinson
How about putting freight back
on the rails and just having the
trucks for the last leg of the journey.
Surely we could use EV trucks then
and have a fully electrified railway.
It’d free up road space and reduce
the amount of repair needed on the
roads too. What’s not to like? Ben
The skills shortage will only
worsen with the UK closing down
the flexibility of a contracting
workforce, many of whom may
take their skills abroad to benefit
other countries or possibly cease
trading altogether.Eur ing N
Humphries BEng(Hons) MSc
CEng MIET MIGEM
/www.theengineer.co.uk