SUMMARY:
There were U.K. blackouts
in the late afternoon
on Friday, August 9, 2019.
1.1 million customers
lost power, including
several major railways
and Newcastle Airport.
Ipswich Hospital lost power
because of its own internal
protection systems.
Roughly 5% of the
electrical load was lost.
Some customers
were restored
after 15 minutes
-- others had
no electricity
for an hour.
Back in April 2019,
National Grid had published
research warning that
using more renewable
power sources posed a threat
to the network’s ‘stability’.
Renewables increased the
‘unpredictability and volatility’
of the power supply,
which ‘could lead to faults
on the electricity network’.
The National Grid Interim Report
about the blackout leaves
many questions unanswered.
The Interim Report tried to
excuse wind power in general,
and Hornsea Offshore wind farm,
in particular, from any significant
blame in the event.
There was very
obvious bias
to avoid saying
anything critical
about wind energy.
Colin Gibson, a former
Power Networks Director
at National Grid,
with former colleague
Dr Capell Aris,
said that ministers
should impose limits
to new wind 'farms'
and solar 'farms'.
The consequences
more renewables
in the electric grid
startied with problems
in South Australia in 2016.
Grid instability is happening
more often, as more
renewables are added
to national electrical grids.
The electricity supply industry
used to use only proven designs.
But the rush for renewables
means ignoring that old
rule-of-thumb.
There are major
technical difficulties
delivering power
from off-shore
wind farms,
such as Hornsea.
Performance tests
that were carried out
using ‘models’
may not simulate
reality.
DETAILS:
The National Grid ESO
( Electricity System Operator )
is showing increasing
system fragility in the UK.
National Grid ESO
Director of Operations,
Duncan Burt, will be
remembered for saying,
in an interview, that the
“systems worked really well”.
There are three separate
inquiries into the event,
by:
(1) National Grid,
(2) the regulator, Ofgem, and
(3) Department of Business,
Energy and Industrial Strategy
(BEIS)
National Grid delivered an
Interim Report on the:
"Low Frequency Demand
Disconnection (LFDD)
following Generator Trips
and Frequency Excursion
on 9 Aug 2019", presented
to the regulator on August 16.
Much of the relevant data
are held by National Grid,
and they have been difficult
for external analysts
to get, for their own study.
The National Grid wants
the public to conclude that
the event was the result of
highly unlikely coincidences.
Not mentioned:
The system experienced
many “difficult days”
before Friday, August 9
National Grid claimed
the blackouts were the
result of a simultaneous
and highly unlikely fault
at two power stations,
Hornsea for one, and
the other a Combined
Cycle Gas Turbine (CCGT)
at Little Barford,
on the border
between Cambridge
and Bedfordshire.
The electricity network’s
frequency dropped below 50 Hz.
( 50 cycles per second )
Equipment can be damaged
if it is higher, or lower,
than 50 Hz..
To maintain that frequency,
local distribution networks
were forced to cut electricity
supply in some areas.
The Guardian newspaper reported,
on August 12th, that there were
“three blackout ‘near-misses’
in as many months before
Friday’s major outage”.
The Times published
on August 15 that
on August 15 that
"The gas plant
and wind farm
failed within seconds
of each other”,
but the lightning strike
that caused this
was an event
was an event
“which both
should have been
able to withstand”.
The Financial Times report
on Saturday August 17th said
the blackout was
“caused by the world’s largest
offshore wind farm accidentally
going offline”.
The Hornsea wind farm
“de-loaded”
instantaneously,
with output falling
from 800 MW to 62 MW
in 197 milliseconds.