I’m writing this on a cold wet evening so let’s have some good news. First after a very dry late spring and summer we have finally had decent quantities of rain, and as a result the turbine has been generating well – so much so that we have recently passed 1,500MWh generated. As usual, autumn has caused some problems with leaf fall, but the operations team have been keeping on top of intake screen clearance, so we haven’t lost much generation.

Perhaps the most time-consuming task recently has been an OFGEM audit. We were selected at random for what turned out to be a very exacting examination of our history and paperwork as well as the arrangements on site. While we had a few difficulties with locating documents and information from before we were commissioned 13 years ago and had to sort out a few anomalies we were eventually given a “satisfactory” rating. Thanks to everyone who put time into this.

One thing which did emerge from the audit was that our input-output meter was due to be recalibrated or replaced (more than 10 years old). Recalibration would involve several days away from site for the meter (during which time we would be unable to run), plus 2 visits from electricians, so we went for the easier option of just replacement – successfully done last week.

During the autumn we had some increase in vibration from the bottom bearing; after careful examination and testing (as much as could be done without draining the lower end of the turbine) the conclusion was that the bearing was starting to wear, but there was no evidence of imminent failure. However, this has stimulated discussion about potential improvements to access to the bottom bearing. There’s a section on the website detailing the problems we had last time in getting a good enough seal below the turbine for dry(ish) access…we ended up needing divers to achieve a reasonable seal. Mike Ford has designed some changes to the fittings of the outlet screen and the stop logs (the things we use to seal off the lower end of the turbine from the river). Installing the new fittings will need divers again but once installed we should be able to seal off and access the bottom bearing and lower chamber as and when we need. This is planned for the spring unless any problems arise sooner.  Meanwhile Mike is also looking at an improved bearing design which should prolong bearing life.

Finally returning to the theme of dry spring and summer, although this won’t be a record calendar year for generation, we have now exceeded our worst total with half of December still to come and a generally wet forecast, so things could be a lot worse!

Rory Newman, Chair of Esk Energy

Summer has come to an end, and Autumn is here, but the main theme – lack of rain – has been a fixture since late Spring until the last few days. The river has been too low for us to run all Summer; indeed at times the river has been the lowest I can remember – but we have finally had enough rain – just – to start running again, and more is forecast.

The warm dry weather has been good for butterflies, but I think other wildlife has struggled; certainly many trees are stressed, and this won’t be a year when tree rings show much growth. Lots of rain over the next few weeks wouldn’t just help the turbine, it would be a huge help to fish migration. Things are now much better, but we need a lot more.

We also need lots of rain to help with the disastrous moor fire which started on Langdale Moor weeks ago and is still burning; this has been another big blow to wildlife locally. Luckily most of the ground-nesting birds would have fledged before it started, but reptiles, amphibians and invertebrates will have suffered badly as well as the moorland vegetation; this will take years to repair – where the peat has been burned, potentially thousands of years. It really makes the case for renewable energy, as some of the conditions leading to the fire are almost certainly to do with global warming and consequent climate change. It concerns me that there are now calls for us to abandon any attempt to reach net zero….

Other Esk Energy news: we’ve just had our AGM: all the usual business got done, and we had an interesting discussion about possible surplus funds which I may come back to in the next blog. Having the AGM online does seem to encourage more attendance, which is great.

So please enjoy the Autumn sunshine, but let’s have some more rain as well.