Building the Anafon Hydro
Following a tendering process in 2014, two contractors were engaged to build the hydro: Gelli Civil Engineering to build the turbine house and the weir and Kevin Williams Earthworks to install the pipeline.
After a village ceremony on 4 May 2015 at which the oldest and youngest residents born in Abergwyngregyn together cut the first turf, Gelli arrived on site on 5 May to commence work on the turbine house. Kevin Williams started work on the pipeline in the Anafon valley on 11 May.
Construction proceeded smoothly in favourable summer weather and both contractors finished work at the end of September 2015.
However, Scottish Power failed to schedule the work to install their substation in the turbine house and to upgrade the power lines from the village to coincide with the completion of construction of the hydro. They commenced work on the substation in the middle of October but the work on the power line upgrade did not start until towards the end of that month, by which time the weather had broken, causing further delays.
The upgrade and connection to the grid were eventually completed on 27 November 2015 and work to commission the plant started immediately. Commissioning was completed on 30 November with the successful completion of the G59 test and the Anafon Hydro commenced full generation and export of electricity to the grid on 1 December, one month earlier than our original target date.
Potential contractors on the pipeline route with John Howarth Jan 2015
Potential contractors on the pipeline route with John Howarth Jan 2015
Final survey of the pipeline route.
Final survey of the pipeline route.
Derwent Hydro engineers carry out an independent technical assessment of the Anafon Project for Charity Bank, our probably main lender.
NRW ecologists, reserve managers and regulators meet John Howarth, Dr Rod Gritten and our contractors for a final site meeting to discuss the Construction Method Statement - 1 April
Paul discusses the work with Kevin Williams, pipeline contractor, John Howarth, project engineer, and Dr Rod Gritten. ecological clerk of works.
The Abergwyngregyn community gathers at the turbine house site for the ceremony to cut the first turf - 4 May.
Breaking ground the oldest and youngest residents born in Abergwyngregyn together cut the first turf. Eirlys Williams and Emily Jones (4 months old).
Alfa Tree Services complete tree felling along the pipeline route March 2015
The turbine house and weir contractors, Gelli Civil Engineering, arrive at the turbine house site - 5 May.
The site cabins go in.
Artist's impressions of how the turbine house will look by Aber resident, Helen Flook.
The view of the turbine house as you return from the Falls along the main footpath.
7 May 2015 - The access track to the Turbine House goes in
9 May 2015 - The bank is cut back to accommodate the Turbine House
12 May 2015 - Excavation for the Turbine House continues under the watchful eye of archaeologist, Ian Brooks, carrying out his watching brief. The only finds so far: two Northern Dairies milk bottles!
14 May 2015 - The outflow pipe from the turbine is installed.
16 May 2015 Shuttering for the foundations of the turbine base and the first concrete is poured.
29 May 2015 - John Howarth Inspects The Foundations
8th June - The brickwork for the sub-station underfloor cable ducts is completed.
In the meantime, Kevin Williams, our pipeline contractor, has been busy on the pipeline in the Anafon Valley.
Ten metre sections of the polyethylene pipe are welded together to form 130m lengths ready for installation.
The welding machine in action.
A temporary track is put in across the river.
2 June - Work starts on the installation of the pipeline on the mountain.
3 June - The trench for the first 130m length of pipe is opened
The pipeline is dragged up the mountain
And drawn into its trench.
The first section in position in its trench.
The trench is filled.
The trench for the second 130m section of pipe is opened.
The first 2 sections of pipeline are welded together.
15 June 2015 - Adjusting the reinforcement for the turbine house floor.
16 June 2015 - The turbine house floor is cast.
In the meantime, on the mountain: The first 400m of the pipeline is installed on the southern bank of the Anafon River.
And reinstatement is underway.
The reinstated pipeline route begins to recover.
The first section of pipe is installed on the north bank of the Anafon.
Work begins clearing the corridor through the forest for the pipeline.
23 June 2015 - The walls of the substation almost halfway there.
The base for the generator is cast.
Meanwhile, on the mountain: The pipeline on the south bank of the Afon Anafon is installed and the mountainside reinstated.
Levels for the pipeline along the initial sections of the pipe below the weir are particularly critical as the drop is only 1 in 165. John Howarth makes a final check of the levels.
The cut for the pipeline comes within sight of the weir location (by the trees in the background).
The pipe is eased into its trench. Kevin Williams has only one more short section of polyethylene pipe and the steel pipe crossing the river to install before he moves to the forest. Gelli will install the final section of the pipeline connecting to the weir when this is built.
The installation of the pipeline on the north bank of the Anafon nears completion with much of the route reinstated.
26 June 2015 - Emyr Roberts, CEO Natural Resources Wales, and Derek Stephen, Energy Deliver Programme Manager, visited the project yesterday. Aeron, Gelli's Site Manager, explains the site to Emyr Roberts.
Emyr Roberts and Gavin Gatehouse at the Turbine House site.
29 June 2015 - Last few courses of bricks on the turbine house substation.
Meanwhile, on the mountain: Steel pipe for the river crossing is delivered on site.
The pipe is positioned across the river.
30 June 2015 - The pipes are aligned for the final connection at the pipe bridge.
The connector is bolted up.
All connections completed on the pipe bridge.
The pipe bridge across Afon Anafon in position.
3 July 2015 - Turbine house substation roof slab is cast.
Last few courses of blocks on the turbine room walls.
Meanwhile, on the mountain: Pipe bridge completed and the surrounding slopes reinstated.
The pipe bridge.
and in Coedydd Aber Forest: Kevin Williams moves his team down from the mountain and the pipe welding station is set up again.
Welding the connector between thinner and thicker walled pipe.
6 July 2015 - The reinstated heath is recovering well after 3 weeks.
15 July 2015 - Rafters supporting the sedum (turf) roof of the turbine house are installed.
The turbine house comes into view as you return from the Aber Falls.
Meanwhile, on the pipeline route: The cutting for the pipeline trench from the forest reaches the end of the pipeline on the mountain.
The trench is cut and the pipe dragged up onto the mountain.
9 July - The pipes meet and the connection is made.
The pipeline reaches the forest track where it will be buried in the uphill bank.
The thin-walled pipe in the upper section of the pipeline is replaced by thicker-walled pipe for the lower sections to withstand the increasing pressure.
The bank of the forest road is cleared ready for installation of the pipeline.
And Gelli have started work at the weir site: The temporary access track to the weir site is put in.
And reaches the site of the weir.
The first channel to divert the river to the north bank is opened up.
The river is diverted to allow the digger to install the pipes on the south bank which will carry the flow while the weir is built in the river bed.
29 July 2015 - a memorable day! Our turbine arrives in Abergwyngregyn from the USA via Liverpool Docks.
The turbine is lifted from its container.
driven up through the village to the turbine house.
And manoeuvred through the doors.
It is aligned with its mounting
and lowered into position.
Meanwhile, at the weir site: The trench for the diversionary pipes is prepared on the south bank of the river.
The pipes are installed and the river is diverted through them.
4 August 2015 - The weir construction site
With the river diverted, the reinforcement for the weir foundation is installed.
and the foundation is cast with the reinforcement for the weir wall in position.
11 August 2015 - At the weir. The shuttering for the weir wall is in place
13 August 2015 - At the weir site. The shuttering is removed to reveal the structure of the weir wall.
Meanwhile at the turbine house The roof is on ready for laying the sedum turf.
The generator and control equipment cabinets are installed.
The manifold connecting the pipeline to the turbine is in position.
and the outlet returning the water from the turbine to the river nears completion.
19 August 2015 In Coedydd Aber Forest - The installation of the pipeline reaches the point where the overhead power lines cross the valley.
and the bank is reinstated.
The final strings of thick-walled pipe are welded.
and the last section of the pipeline awaits installation at the bottom of the forest road.
22 August 2015 - At the weir site. The tank and pipework are installed and the pipeline anchor block cast.
24 August 2015 - At the turbine house. The finished turbine house viewed from the gate into the Aber Falls Reserve
compared with the artist's impression published earlier.
The finished turbine house viewed from the path returning from the Aber Falls
compared with the artist's impression.
In Coedydd Aber Forest - The steel pipe to take the water down the bank to the turbine house is delivered on site while Alfa Tree Services carry out some last minute tree clearance.
28 August 2015 - On the pipeline. The steel pipe running down the bank to the turbine house is installed.
The last section of the polyethylene pipe is connected to the steel pipe down the bank to the turbine house.
The exposed section of steel pipe is encased in its plastic insulating cover.
8 September 2015 - On the pipeline Kevin Williams encounters rock in Coedydd Aber Forest.
The final section of pipe in its trench through rock.
At the weir - Stone walling in progress on the southern bank.
The oak cladding of the weir walls is complete.
6 September 2015 - Heavy rainfall overwhelms the diversion pipes and floods the working area temporarily.
The stone walling on the south bank is completed and the trench is dug for the last section of pipe to the weir.
The pipe connecting the buried pipeline to the weir in its trench.
9 September 2015 - At the Turbine House. The Ditch Witch, Scottish Power's directional drilling rig, is tracked up through the village to the turbine house.
The Ditch Witch in position behind the turbine house.
2 September 2015 - The rig starts drilling under the river for the grid connection cable.
The drill emerges near the pole which will receive the grid connection on the other side of the river after passing through bed rock 4 m below the river bed.
The drill head.
The red plastic duct for the grid connection cable and earthing wires are attached to the reversing head.
The drill rod and spinning reversing head, with the plastic duct and earthing wires attached, is pulled back down the drill hole.
The plastic duct for the grid connection cable is dragged back under the river to the back of the turbine house.
9 September 2015 - At the weir. The coanda screen through which water is extracted from the river flow and diverted into the pipeline is installed.
Detail of the coanda screen showing the slots through which water is abstracted.
The diversion pipes are capped and the weir is flooded.
Turbidity downstream 1 hr after the weir was flooded; by the time the flow reached the pipe bridge, the flow was clear.
The flow is clear at the weir 4 hr after flooding.
The weir in its landscape.
24 September 2015 - On the pipeline. The pipe is aligned for the final joint. Thirty metres of surplus pipe can be seen in the background, all that's left from the 3 km pipeline!
The connector is "eased" over the joint.
The welding coils built into the connector are activated to complete the final joint in the pipeline.
23 September 2015- The upper section of the pipeline is flushed with water.
The completed pipeline is flushed with water.
29 October 2015 - On the pipeline. Third valve lucky! Two by-pass valves proved faulty but the third, being installed here, works - 14 October
15 October - The now completed pipeline is filled and the pressure of 22.7 bar at the turbine house is maintained indicating that there are no leaks.
26-27 October - The pipeline is pressure tested. Water is pumped into the pipeline at the weir and the pressure raised to 23.7 bar. No faults are detected.
29 October - After the pipeline has been pressure-tested, all exposed joints are buried and the area behind the Turbine House reinstated.
29 October - The forest road above the Turbine House is reinstated
The bank over the buried pipeline through Coedydd Aber Forest recovers well.
20 November 2015 - At the Turbine House and on the Powerline Scottish Power contractors work to upgrade the powerlines above the village to take the power we generate - 16 November
17 November - The grid connection cable is passed through the duct under the river and buried in a trench up to the pole where it connects to the grid.
19 November - Emerging from the duct behind the Turbine House, the cable is connected into the sub-station.
20 November - Scottish Power complete the installation of the sub-station at the Turbine House.
14 November - Meanwhile, the heavy November rainfall means that we are missing significant generation time.
26 November 2015 - On the Powerline. Scottish Power contractors complete the upgrade of the powerlines from the village to the pole that will take the connection from the Turbine House.
26 November - The cable running under the river from the Turbine House is run up the pole to connect to the overhead line.
28 November 2015 - At the Turbine House. The underside of the turbine from the sump: the stainless steel Pelton wheel, the deflector which deflects water away from the wheel and stops the turbine if a fault occurs and, in the back wall of the housing, the spear valve which opens to direct the high-pressure jet of water onto the wheel to spin it at 1,000 rpm.
27 November - The turbine reaches its operating speed of 1,000 rpm during commissioning tests.
27 November - Generating 230 volts on each of the three lines.
27 November - The Anafon Hydro is 'on grid' and exporting electricity.
28 November - The 'Gang of Three' raise a glass!
28 November - From the left: our engineers, Dave Roberts and John Howarth (with Brock), Liz Gatehouse (with Molly - just visible), Hywel Thomas, Ian Crystal and Jacqui Bugden, Gavin Gatehouse.
30 November - Anthony Clark (Scottish Power) and Dave Roberts carry out our G59 test. We passed which allows us to register for Feed in Tariff payments from today.
1 December 2015 - Mission Accomplished! The Anafon Hydro is up and running a month ahead of schedule and exporting 270 kW to the grid.
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