A new government report
discussed issues with
concentrated solar energy,
as it's being implemented today.
Concentrated solar energy
is a long way from
being standardized,
and having reliable high
performance installations.
The government’s
leading laboratory
for renewable energy
has released
a new report
detailing
the strengths
and flaws of
concentrated
solar energy.
The National Renewable Energy
Laboratory (NREL) published
the report with the goal
of using mixed feedback
on existing concentrated
solar projects to create a list
of suggested best practices,
going forward.
The NREL report is titled
"CSP Best Practices".
I view it as a list
of generic engineering
problems, and specific
problems at individual
plants.
Parabolic trough
CSP plants use
solar collectors
to heat water and
generate steam heat.
But in between
is a stage called heat
transfer (HTF), where
a fluid medium like oil
or liquid metals carries
the heat from the collection
area to the turbine.
The extreme and dangerous
heat of the HTF, and the waste
hydrogen produced by these
processes, are a root cause
of reliability problems.
I have great respect for
engineers, having worked
in product development
for 27 years.
But the CSP engineers
need to go back
to their drawing boards,
or admit that the physics
involved are a big problem
for this technology.
The other kind of CSP plant
is a tower design, where mirrors
concentrate the solar power
directly into a central reservoir,
usually made of molten salt.
These plants take
a very long time
to reach their
full operating
temperatures,
which means
frequent leaks
are a big deal.
Molten salt plants
have not yet reached
their promised
performance goals.
These plants usually exceed
their planned operating budgets,
because of surprise maintenance
costs, revealing significant
underestimates of actual
operating costs.
Even with just a few dozen
CSP plants in the U.S.,
the report notes that
many of them were
placed on poor sites.
Site selection
'in the middle
of nowhere'
includes making
compromises about
how to find a qualified
workforce to build
the project in the
first place.
And then how far
a construction crew
must travel to make
onsite repairs, which
have been far too
frequent.
“The very nature of fixed-price,
fixed-schedule, full-wraparound
performance-guarantee
EPC contracts has likely been
a main reason for issues
experienced at existing
CSP plants,”
the report concludes.
CSP contractors
and plant operators
are doing their best,
but the new technology
just isn’t understood
well enough.
The too rapid
development of
new CSP plants
with faulty designs,
has damaged
the reputation
of concentrated
solar technology,
for no logical reason.
... I avoided mentioning
the bird and bat deaths,
from concentrated
solar energy heat,
simply because
I just ate lunch !