On Thu, 09 Feb 2012 15:48:03 +0000, The Natural Philosopher
wrote:

The Other Mike wrote:
On Thu, 09 Feb 2012 13:01:51 +0000, The Natural Philosopher
wrote:

By the way predictability is irrelevant. We knwo the sun always goes
down at sunset and isn't there much in winter. That's predictable. It
doesn't mean that solar power is any the more useful as a result. We
still have to burn the coal in winter and at night to cover its
deficiencies.

By predictable renewables I was referring to tidal barrages.

I am sure you were. They predictbility however is IRRELEVANT. Its the
variability that means they have to be balanced - and don't tell me 'its
always high tide somewhere' it may be, but tidal flows are pathetic on
the east coast.and you would STILL need a massive extesnion cable to
balance teh things.

The balancing is done by the conventional generation, just as it
always has been done for decades.

Occasionally the peak of tidal generation will coincide with the
demand peak and if there are a few dozen nukes it may even mean
pumping rather than generating at the pumped storage stations . When
the peak is at other times, then some conventional generation will
drop off the bars, no different to what happens overnight at demand
minimum.

If nearly all the fossil fuelled coal fired stations have to shut down
for a few hours say from mid afternoon till 8pm rather than at 10pm
until 6am, because of the tidal barrrage generation then it matters
not a jot. At one time the big fossil fuelled units 500/600/660MW
were base load and all the others like 60/120/275/300's were up and
down like a whores drawers, but for 20+ years the big coal units have,
with one or two exceptions, not just been base load. They have two
shifted, and load followed. The load min to max recently has been
about 18GW. There is currently 18GW oil/coal/CCGT/OCGT reserve above
peak. 14GW of tidal would be useful regardless of when it was
delivered.

14 GW of predictable peak generation, (Severn and Morecambe Bay) is
far preferable to a remote maybe of 10GW of wind

Of course it may not work. They were talking about doing this 30+
years ago. F*ck all has happened, not because it isn't feasible, but
because no one wants to say just do it. If it doesn't work then we'll
have a nice dam to cross and admire the mudflats.

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