Spring is here! I’m writing this at the end of March, but it has felt like March and April combined, with winds and showers but also some very welcome sunshine bringing lots of Spring flowers. After an unusually dry Summer and Autumn, we’ve had an unusually wet Winter; I think most people got increasingly fed-up with constant gloom and rain (with a bit of snow for variety), but from the turbine perspective all that rain gave us plenty of water to drive our generation, and by the end of a year that was starting to look as if it might be our worst, we have actually done quite well.

All that water coming downstream, with gales at times, brought a LOT of dead timber with it, and some of it ended up on our intake grid, or trying to block the fish pass. A couple of the bigger pieces were dragged round to lodge on the dam, but most of it was dragged out onto the decking above our intake. It was starting to get in the way, so we recently had a working party to saw it up and clear it. While we had plenty of people on site we took the opportunity to prune and tidy vegetation, and to clear the path to the grid kiosk; we need access to this (it’s where the power we generate goes into the national grid so it can be used) for meter readings, and we try to clear twice a year – early and late so that we don’t disturb any nesting birds.

Tree troubles: we still have a dead tree in the river, roped to the side of the fish pass, so that it can’t drift back and block fish pass or intake. It’s very heavy, with awkward branches, so we haven’t been able to either drag it out of the water or drag it round onto the dam. It’s doing no harm where it is, but will have to be dealt with eventually. We also had a tree half fall across the track to the turbine, but a bit of lumberjacking with Mike Ford’s chainsaw has cleared it.

Perhaps the best thing that happened recently was a school visit: we had about 30 year 5 pupils, split into two parties for an hour each, come to look round as part of a field trip. They all had a go at working the model, then split into smaller groups to see the real thing running. Four of us showed them round; we were all a bit nervous beforehand, but they were bright and interested and asked intelligent questions (and nobody fell in the river) so we hope we may have started some careers in science and engineering. We have another school visit planned for July. It’s always good to show people round the turbine – if anyone reading this would like a tour, please contact us and we will try to arrange.

Rory Newman, Chair of Esk Energy

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