It's just Hinkley B and me now !

What an exceptional week: from scarcely enough flow to more than enough to meet peak generation.  So with all the energy I'm exporting, it's now just me and the nuclear boys keeping the grid from collapsing !

Going through four step-ups in generation in so short a time has minded me to take the four photos below of the meters monitoring the dc output of the SmartDrive, to emphasise two points made in an earlier post:

1.  the pv inverter (PVI) is not very efficient, especially at lower power levels but gets better as power increases
2. the dc system voltage falls as power output increases, and eventually it comes down to within the range  (100 ~ 320v dc) at which the MPPT function of the inverter can operate.

Just nice to see it so clearly illustrated.

Going with the flow

Today has been a good day: the increasing flow available, now up to about 1.75 lps, has meant I've needed to put a bigger nozzle in.  I kept the same one on the bottom and only changed the top one from ∅ 3.64 mm to ∅ 4.96 mm.  An early rule I learnt was only to change one nozzle at a time, - more drastic action usually led to the header tank emptying.

Doing this lifted flow delivered to the pelton from 1.48 to 1.74 lps, and power into the grid from 343 to 421 W.

Small hands are essential and good access to the front of the turbine is helpful.

Off with the glazing

The nozzle to be put in

Nozzle retainer spanner

It's a tight fit getting to the top nozzle

Note the cloth to stop anything dropping into the tailrace

There is space only in the bottom corners to remove a nozzle

The "whole arm in" technique to screw on the nozzle retainer

I use 9 different nozzles to give me flows from 1.18 to 3.43 lps

...and best of all: 421 W generated, thus exceeding usage by 8W

Happiness is...

... the start of a new generating year !  11 am yesterday saw all systems go, and so far everything is performing exactly as it should, right down to the in-house monitoring and on-line visibility of live-power (see link to right).

Now, all that remains is to get the capacity factor for the 2014 / 15 "water year" above the 59% recorded for last year.