Whilst having a read of:
the 'Closure' section mentions "During its 35 years of operation,
Hinkley Point A generated more than 103 TWh of electricity, giving
a lifetime load factor against design of 34%."
What does this mean? Is it the percentage of actual electricity
generated against the theoretical amount it could have generated?
Or is it something else?
Thanks in advance,
It ought to be theoretical versus actual: Capacity Factor (what
percentage of full load it runs at) times Availability Factor (what
percentage of the time it's not in service for maintenance or
The number 35% suggests it was seriously underperforming, compared to
Except if you bother do Do Sums, Roland, it comes out as 336/470 or 71%
capacity factor against its derated capacity or 336/500= 67.2% capacity
factor against its design capacity .
Oddly enough 1-67.2% is 33.8%, or 34%.
So what is probably the case is that it performed at 34% less than its
full nameplate capacity ignoring that it was in fact designed to be
taken offline for refeuelling and maintenance from tome to time and was
in fact derated due to issues with iot.
saying 34% makes fools who cant do sums think it was shit, whereas the
actual data says it was, for a magnox, pretty good for one of the early
This is of course how false news starts....one might consider how to
take the real data and present it in such a way as to give a completely
false impression. And why a wikipedia author would want to do that...
“it should be clear by now to everyone that activist environmentalism
(or environmental activism) is becoming a general ideology about humans,
In that particular case, the figure just looked wrong. Nuclear
Engineering International used to publish a table every month giving the
factors for every single operating plant (and, IIRC, national averages).
Back in the 1970's and 80's the UK and USA generally ran in the 70 to
80% region, Indian plant was often down in the 30's, while the Canadian
CANDU plant ran consistently better than 90%.
On Fri, 30 Jun 2017 09:01:53 -0700 (PDT), David Paste
I would interpret it as just that. HPA had a lot of problems, so it
wouldn't surprise me if it didn't meet it's original design
expectations. Load factors (aka Capacity factors) of nuclear power
stations in the UK in general run in the range 70-80%. If it all works
as it should, the only stoppages are for routine maintenance and
refuelling etc. which happen every 12 - 18 months depending on the
individual plant and design.
Mearns has data on Load Factors for different power sources in the UK
and scroll down. Although his data only goes up to 2012, I was
surprised to see the Load Factor for CCGT dropping away in recent
years. I assume this is a consequence of having to vary the output of
CCGT stations to accommodate the variability of wind and solar. Put
another way, renewable energy power sources force the backup power
sources to run inefficiently a lot of the time, but they have to be
there to cope when TWDB&TSDS. Unintended consequences?
PS: reading to the bottom of Mearns' blog, I see in his conclusions he
says "There is absolutely no evidence from these numbers that the
efficiency of large coal and CCGT plant is being impaired through
cycling to balance the increasing load from wind and solar". He knows
much more about it than I do, so I'll go with what he says.
Actually, Hugh Sharman who writes there as well co authored a paper
that says the EXACT opposite.
50% of all Irish windpower emission gains were wasted in terms of gas
used to ramp the turbines up from warm starts.
They were only able to measure that by actually measuring gas usage on
all the turbines, which required co-operation from eirgrid.
Unless you have figures for gas usage per MWh on calm days versus gas
usage per MWh on days with wildly fluctuating high winds, you cannot do
Euan has no access to that data, and neither do I. I had always hoped to
get it for gridwatch, but it never appeared.
Hugh only gotr it by virtue of being in a position of trying to sell
fast ramp gas turbines to Eirgrid, and them making the data available in
order to see whether the extra cost was justified.
Any fool can believe in principles - and most of them do!
On Fri, 30 Jun 2017 21:01:17 +0100, The Natural Philosopher
or http://tinyurl.com/yd4zx3l4 Interesting, and a lot to digest, but
"The main conclusion of this study is that wind balancing and infill
power generation is far more costly than is generally believed at high
wind penetration. The results throw light on the expected performance
of incumbent, frame-type CCGTs in Great Britain (GB) where wind
penetration, by TWh, is expected to be greater than 20% by 2020, up
from 10% in 2015. GBs fuel mix and weather conditions are
sufficiently similar and its dependence upon CCGTs to balance wind is
identical to that of Ireland"
Someone can't do sums.
104 TWh over 35 years is an average power of 336 MW.
Taking the Wikipedia derated figure for the two reactors together of 470
MW gives an overall lifetime factor of 71%.
I think someone did the sums assuming 470 MW per reactor.
Incidentally, over its lifetime it produced exactly the same amount of
power as it would have done had it run continuously at the derated
output for the design life of 25 years.
Changing the subject slightly, here is quite an interesting "insider"
view of the current UK nuclear strategy.
A very interesting read. Thanks for the link.
The author isn't optimistic about Hinkley C, and discusses the
possibility of building several smaller reactors of a proven design
(='.'=) "Between two evils, I always pick
It's a personal view. You do find all sorts of views within the
industry, but the preference for AP1000 over EPR is not unusual.
At the end of the day, it's EDF who are stumping up most of the capital,
followed by the Chinese. They have both elected to go down the EPR
route, as has Finland (which is pretty clued up technically).
And the UK regulator, probably the toughest in the world, has signed off
on the safety features.
Only time will tell whether it was a good call. With the lessons learned
from the other four I am guessing the build should go fairly well.
I share a certain amount of the "deja vu" expressed over the prospect of
having two or more different reactor types started in the next decade or
so, having spent much of the past 45 years switching between the
multiple designs of Magnox and AGR plant. Not to mention seeing the
amount of money put into SGHW and Fast reactor designs.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.