The Anonymous Widower

Repurposing The Conon Hydro-Electric Scheme

The Conon hydro-electric scheme was built in the 1950s, by the North of Scotland Hydroelectric Board.

  • The scheme is now owned by SSE Renewables and has a page on their web site.
  • There are six individual power stations; Achanalt, Grudie Bridge, Mossford, Luichart, Orrin and Torr Achilty.
  • There are six dams; Glascarnoch, Vaich, Luichart, Meig, Torr Achilty and Orrin.

This map from the SSE Renewables web site shows the layout of the dams and power stations.

The sizes of the power stations in the scheme are as follows.

  • Achanalt – 3 MW
  • Grudie Bridge – 18.6 MW
  • Mossford – 18.6 MW
  • Luichart – 34 MW
  • Orrin – 18 MW
  • Torr Achilty – 15 MW

This gives a total power of 107.2 MW.

This Google Map shows the same area as the SSE Renewables Map.


  1. Inverness is in the South-East corner of the map.
  2. The red arrow indicates the Western end of Loch Luichart.
  3. Loch Fannich is the large loch to the West of Loch Luichart.
  4. Loch Glascarnoch is the East-West loch to the North of Loch Luichart
  5. Loch Vaich is the North-South loch to the North of Loch Glascarnoch.

Is Inverness a City substantially powered by renewables?

Strathclyde University And Pumped Storage Power For Scotland

This page on the Strathclyde University gives a list of the pumped storage potential for Scottish hydrogen-electric dams and power stations.

These figures are given for the dams and lochs in the Conon scheme.

  • Glascarnoch – 23 GWh
  • Luichart – 38 GWh
  • Fannich – 70 GWh

It would appear that based on research from Strathclyde University, that the Conon scheme could support up to 131 GWh of pumped storage.

This Google Map shows the three lochs and Loch Vaich.


  1. Lochs Fannich and Luichart are named.
  2. Loch Glascarnoch is the East-West loch to the North of Loch Luichart
  3. Loch Vaich is the North-South loch to the North of Loch Glascarnoch.
  4. The locations of several power stations are shown.
  5. Cuileig is a 3.2 MW power station built in 2002.

This Google Map shows Loch Fannich.

Wikipedia says this about the loch.

Loch Fannich was dammed and its water level raised as part of the Conon Hydro-Electric Power Scheme, built by the North of Scotland Hydro-Electric Board between 1946 and 1961. An underground water tunnel leading from Loch Fannich to the Grudie Bridge Power Station required blasting out a final mass of rock beneath the loch, a procedure which was referred to popularly as “Operation Bathplug”.

The dam appears to be at the Eastern end of the loch, as this Google Map shows.

I wouldn’t be surprised to find that to obtain the potential 70 GWh of storage, that the dam will need to be raised.

This Google Map shows Loch Glascarnoch.

Loch Glascarnoch may be more difficult to expand, as a road runs along the Southern side of the loch.

This Google Map shows Loch Luichart

Lock Luichart may have possibilities as it is wide and could be deep.

But it will all be about the shape of the loch and the mathematics of the water.

Water Flows In The Conon Scheme

Looking at the SSE Renewables map of the Conon scheme, water flows appear to be as follows.

  • Loch Vaich to Loch Glascornoch
  • Loch Droma to Loch Glascornoch
  • Loch Glascornoch to Loch Luichart via Mossford power station
  • Loch Fannich to Loch Luichart via Grudie Bridge power station
  • Loch Achanalt to Loch Luichart via Anchanalt power station
  • Loch Meig to Loch Luichart
  • Loch Luichart to Loch Achonachie via Luichart power station
  • Orrin Reservoir to Loch Achonachie  via Orrin power station
  • Loch Achonachie  to River Conon and eventually the Cromarty Firth via Torr Achilty power station

Note that all the power stations date from the 1950s.

Repurposing The Conon Scheme

Perhaps as the power stations are now over sixty years old, one simpler way to both increase the generating capacity of the Conon scheme and add a degree of pumped storage might be to selectively replace the turbines, with modern pump/turbines, that can both generate electricity and pump the water back up into the mountains.

It should also be noted that Loch Vaich, Loch Glascornoch, Loch Fannich and the Orrin Reservoir are all about 250 metres above sea level, with the others as follows.

  • Loch Achanalt – 111 metres
  • Loch Luichart – 56 metres
  • Loch Meig – 87 metres
  • Loch Achonachie  – 30 metres

Loch Droma is the highest loch at 270 metres.

These height differences could create opportunities to put in extra tunnels and power or pumping stations between the various levels.

As water pumped to a greater height has a higher potential energy, perhaps it would be an idea to give Loch Droma, which is the highest loch, a bigger role.


I believe these improvements are possible.

  • Adding a pumped storage facility to the Conon hydro-electric scheme, with a capacity of upwards of 30-40 GWh.
  • Increasing the generating capacity by replacing the elderly turbines.
  • Improving control of the scheme, by replacing 1950s control systems.

It may even be possible to substantially improve the performance of the scheme without any expensive rock tunnelling.






February 19, 2022 Posted by | Energy, Energy Storage | , , , , , | 1 Comment

Fracking Has a Bad Rep, but Its Tech Is Powering A Clean Energy Shift

The title of this post, is the same as that of this article on Texas Monthly.

It shows how former frackers are developing their techniques to do the following.

  • Extract heat and energy from shale using water.
  • Store energy safely underground.
  • Drill deeper and better geothermal wells.

One of the companies; Quidnet has been backed by Bill Gates and his friends. I wrote about Quidnet Energy a couple of years ago in How Do You Save Clean Energy? This Company Plans To Pump It Underground.

And all in environmentally-friendly ways, that would get a seal-of-approval from a committed anti-fracker.

It’s the best article I’ve read this week.

February 19, 2022 Posted by | Energy, Energy Storage | , , , , , , | Leave a comment

A Possible Balmacaan Pumped Storage System

This article on Power Technology is entitled SSE Proposes Loch Ness Hydro Power Plant.

These are the first three paragraphs.

Scottish and Southern Energy (SSE) has begun consultations to develop a 600MW hydro electric power plant on the shores of Loch Ness in Scotland.

SSE proposes to build a pumped storage scheme on the Balmacaan Estate between Invermoriston and Drumnadrochit.

The plan also includes construction of a dam and a new reservoir at Loch nam Breac Dearga, north-east of Invermoriston, according to

This Google Map shows the location of Loch nam Breac Darga.


  1. Loch Ness runs diagonally across the map.
  2. Invermoriston is in the South-West corner of the map.
  3. Loch nam Breac Darga is marked by the red arrow and is 452 metres above sea level.
  4. Drumnadrochit is at the North of the map, just to the West of Urquhart Castle.
  5. The Foyers Pumped Hydro scheme, which I wrote about in The Development Of The Foyers Pumped Storage Scheme is on the opposite bank of Loch Ness from Loch nam Breac Darga.

This could be Scotland’s largest hydro-electric plant.

I can’t find a value for the amount of energy that can be stored, but I suspect it could be in the order of 15-20 GWh.

The stories about this project seem to be thin on the ground, so could it be that this project has been placed on the back burner by SSE.

February 19, 2022 Posted by | Energy, Energy Storage | , , , , , | 1 Comment

Errochty Hydro-Electric Power Station

The Errochty hydro-electric power station is one of the stations in the Tummel hydro-electric power scheme.

This Google Map shows the relative locations of Lochs Errochty, Rannoch and Tummel.


  1. Loch Errochty is at the top in the middle.
  2. Loch Rannoch is in the West.
  3. Loch Tummel is in the East.

This Google Map shows the Eastern end of Loch Errochty.

Note the dam at the Eastern end of the loch.

  1. The dam is 354 metres long by 49 metres high.
  2. The dam was built in 1957 and the lake is man-made.
  3. The loch stands at 330 metres above sea level.
  4. Water flows from the loch to the Errochty power station at the Western end of Loch Tummel, through a ten kilometre long tunnel.

This Google Map shows Errochty power station and Loch Tummel.


  1. Errochty power station is at the top of the map in the middle on the channel connecting it to the River Tummel.
  2. Errochty power station has two turbines and a maximum output of 75 MW.
  3. There is what appears to be a large switching station at the Western side of the map.

This page on the Strathclyde University gives a list the pumped storage potential for the Scottish hydrogen-electric power stations.

It states that the Errochty power station and Loch Errochty have a potential to be upgraded into a 16 GWh pumped storage scheme.

I obviously don’t know for sure, but I suspect this could be an easier scheme to convert, if the current turbines could be replaced with pump/turbines.

Water Supply To The Loch

There is a section with this title in the Wikipedia entry for Loch Errochty.

This is said.

Loch Errochty’s main feeder streams are the Allt Sléibh and the Allt Ruighe nan Saorach which both rise in the high ground to the west of the head of the loch. Other small streams flow directly off the 892-metre-high (2,927 ft) mountain of Beinn a’ Chuallaich which stands just to the south. Supplementary water is diverted into the loch from the east by the Errochty catchwater, a system of tunnels and surface pipelines at a height of approximately 380 metres which redirects water from five small tributary streams of the River Garry, and the Garry itself. The catchwater then goes through a tunnel in the hill which separates the Garry and Errochty valleys to join the loch. This method of re-directing water allows it to be used more often to generate electricity. Some of the water within the Tummel scheme passes through five of the power stations and thus generates electricity five times.

That strikes me as being very sophisticated for the 1950s and if the engineering and tunnels are up to a high standard, it might be that conversion of this power station to a 75 MW power station with 16 GWh pumped storage is a distinct possibility.

It might even be possible to increase the generating capacity of the power station.

February 19, 2022 Posted by | Energy, Energy Storage | , , | Leave a comment