pre planning submission op05 derryduff ... - Organic Power

PRE-PLANNING SUBMISSION
PUMPED HYDROELECTRIC ENERGY STORAGE (PHES) SCHEME
OP05 DERRYDUFF - CAPPANABRICK

PRE PLANNING SUBMISSION
OP05 DERRYDUFF - CAPPANABRICK
Contents:
Scoping Document .........................................................................................................5
Project Description....................................................................................................... 11
Site Plan and Photomontages ................................................................................. 17
3

OP05
DERRYDUFF - CAPPANABRICK
SCOPING REPORT
5

Scoping Report for an Environmental Impact Assessment for a Proposed 45MW electric nominally rated Pumped
Hydroelectric Energy Storage (PHES) Scheme, at Derryduff-Cappanabrick, Coomhola, Bantry, Co. Cork.
This scoping report has been written in accordance with the Guidance on EIA Scoping from the European
Commission, June 2001, which states:
A scoping report should identify the content and extent of the information to be provided by the developer
to the competent authority. In particular, scoping reports and opinions will always identify the types of
environmental impacts to be investigated and reported in the environmental information.
Specifically the scoping report should cover:
1. Types of alternative which ought to be considered
2. Baseline studies which are required to characterise the existing environment
3. Any special requirements for baseline studies
regarding their geographical extent or timing e.g. because of seasonal changes in fauna and flora
4. Level of detail of investigations required
5. Methods to be used to predict the magnitude of environmental effects
6. Criteria against which the significance of effects should be evaluated
7. Types of mitigations to be considered
8. Any further consultations to be carried out during the environmental studies
9. Structure, content and length of environmental information EIS
10. Membership and management of the EIA team
11. Work plan and resourcing for the environmental studies
In summary there are three key questions to be answered:
• What effects could this project have on the environment?
• Which of these effects are likely to be significant and therefore need particular attention in the environmental studies?
• Which alternatives and mitigating measures ought to be considered in developing the proposals for the project?
EIS Scoping
1. Types of alternative which ought to be considered
The project will be assessed for alternative technology, alternative locations, alternative turbine insertion layouts,
alternative grid access options, and alternative input energy sourcing options, in the context of the constraints of
the existing environment and regulatory framework at national and local levels.
2. Baseline studies which are required to characterise the existing environment.
Studies will be carried out to examine the impacts in the various categories listed in Schedule 2 of S.I. No. 93 of 1999.
These impacts are:
1. Landscape and visual impact
2. Noise
3. Other impacts on human beings
4. Hydrology
5. Air and climate
6. Cultural heritage
7. Ecology
8. Land use
9. Soils and geology
10. Material assets
11. Electro-magnetic effects
12. Interaction of the foregoing
3 Any special requirements for baseline studies regarding their geographical extent or timing
3.1 Ecology
Studies to assess the existing environment in the context of species present will involve correct timing in respect to
seasonal behaviour, and will be timed accordingly.
The studies will involve the following:
1. Record species of conservation concern
2. Record breeding birds
3. Record breeding mammals
4. Assess potential impacts on aquatic species and habitat
4 Level of detail of investigations required
4.1 Ecology
Studies should examine the flora and fauna of the proposed site location, and refer to the presence or absence
of the below species on or near the site.
Species of Conservation Concern:
• Salmon
• Freshwater mussel
• Short-eared owl (Annex I on EU Birds Directive)
• Merlin (Annex I on EU Birds Directive)
• Peregrine Falcon (Annex I of EU Birds Directive)
• Otter
The aquatic environment of surface drainage will be assessed to quantify any risk to aquatic fauna, including
freshwater mussels and salmonids, from sedimentation.
4.2 Geology
The geological survey will investigate soil and rock conditions and stability at the proposed development
location and the access road.
4.3 Hydrology
The hydrological investigation will quantify the hydrological implications on wells, water sources, streams and
the Coomhola River that may result from the proposed development, if any.
4.4 Visual Impacts
Visual photomontage will be used to assess the visual impact of the proposal, and Zone of Theoretical
Visibility analysis will be carried out from the proposed development where potential visibility of the proposed
development exists.
4.5 Noise
Noise studies will include sampling of background noise levels and correlation with predicted noise emissions
from the proposed project as predicted outside occupied dwelling houses near the proposed development.
5 Methods to be used to predict the magnitude of environmental effects
Full energy chain analysis (FENCH) of carbon and nitrogen inputs and outputs of the proposal will be carried out.
Zone of theoretical influence (ZTV) and photomontages of buildings in the proposal will address visual impacts.
6 Criteria against which the significance of effects should be evaluated
The relevant criteria as established by the local authority regarding energy development are listed below:
6.1 Overall Strategy Objectives (from CDP 2003, Cork CC) (Quotes in Italics)
5.4.1 The energy industry, and utilities, generally have very specific land use planning requirements. In
particular, safeguards need to be put in place to ensure that strategic distribution corridors are not compromised
by inappropriate siting of other developments. The renewable energy sector requires more specific treatment
as it raises a number of planning issues, particularly in relation to the deployment of wind energy projects. In all
cases, however, it is necessary to ensure that energy projects do not in themselves constitute negative impacts,
particularly in areas of environmental or landscape sensitivity.
6

5.4.2 The context for including specific renewable energy policies in a county development plan is set by
a range of national and international initiatives and targets. It is a subject which is at the core of the entire
sustainable development idea. The governing national policy in this regard is the National Climate Change
Strategy published in October 2000.
5.4.3 As a planning authority, it is important to recognise the range of new and developing technologies that
can contribute to minimising greenhouse gas emissions and to securing a greater proportion of our energy
needs from renewable sources.
6.2 Bantry Local Area Plan objectives (from CDP 2003, Cork CC)
5.5.1 The energy industry, and utilities in particular, have very specific land use planning requirements. In
particular, safeguards need to be put in place to ensure that strategic distribution corridors are not compromised
by inappropriate siting of other developments. The renewable energy sector requires more specific treatment
as it raises a number of planning issues, particularly in relation to the deployment of wind energy projects. In all
cases however, it is necessary to ensure that energy projects do not in themselves constitute negative impacts,
particularly in areas of environmental or landscape sensitivity.
7.9.12 Values associated with the Ridged, Peaked and forested uplands (Landscape)
(The proposed development is located in this landscape zone)
Within County Cork this landscape is valued for its scenic amenity, particularly its rolling countryside, narrow
shallow lakes and complex topography, its expansive views and scenic routes, including the Cousane Gap. This
landscape is also valued locally as a place to live and for its farmland, much of which is of marginal agricultural
quality and is often used for commercial forestry.
18.1.2 It should be noted that the biological quality of this section of the Coomhola river currently meets the
standards set under the Local Government (Water Pollution) Act 1977 (Water Quality Standards for Phosphorous)
Regulations1998. There is a requirement that this good water quality be maintained.
6.3 Objectives General: Energy, Renewable Energy (from CDP 2003, Cork CC)
INF 4-1 Energy Networks and Infrastructure
(a) It is an objective to recognise the national importance of ensuring security of energy supplies for
servicing a whole range of economic sectors.
(b) It is a general objective, where strategic route corridors have been identified, to support the statutory
providers of national grid infrastructure by safeguarding such strategic corridors from encroachment by
other developments that might compromise the provision of energy networks.
(c) It is an objective generally to protect areas of recognised landscape importance from construction of
large scale visually intrusive energy transmission infrastructure. In such circumstances it is an objective
to seek alternative routing or transmission methods.
INF 4-2 Climate Change
It is an objective to support the National Climate Change Strategy and, in general to facilitate measures which
seek to reduce emissions of greenhouse gases.
INF 4-3 Renewable Energy Production
It is an objective to encourage the production of energy from renewable sources, including, in particular that
from biomass, waste material, solar, wave and wind energy, subject to normal proper planning considerations,
including in particular impact on areas of environmental or landscape sensitivity.
ZON 3-19 Utilities and Infrastructures
It is an objective to promote the provision of development to meet the operational requirements of utilities
and infrastructure operators.
7 Types of mitigations to be considered
• Siting and Design alternatives
• Water usage rates
• Routing of infrastructure
• Bank protection
• Habitat creation
8 Consultations to be carried out during the environmental studies
• Coomhola Residents Association
• CCC Roads Department regarding proposed alterations to the Rangaroe-Derryduff road
• Planning Department pre-planning discussion regarding: Scope of Visual Analysis, Grid Connection, submission format.
• CCC Environment section
• South-western fisheries Board regarding the Coomhola River
• NPWS regarding ecology
9 Structure, content and length of the environmental information EIS
9.1 Structure
The Environmental Impact Statement which will be submitted together with the Planning Application for the
Proposed 45MW (electric nominally rated) Pumped Hydroelectric Energy Storage Scheme will be composed of
two documents, both to be presented in A3 format.
The first document, the main body of the EIS will provide a coherent synthesis of the information gathered
during the baseline studies and design process following the prescribed contents as required under EIS
legislation; Statutory Instrument 349 of 1989: European Communities (Environmental Impact Assessment)
Regulations, 1989.
The second document, the appendices, will contain all the baseline and design studies and report which will
have informed the EIS.
The reason that it is proposed to submit as 2 documents and in A3 format is, firstly, to assist the planning
authority in referring between the EIS Main Body and the baseline and design reports, and secondly to avoid
folded maps and drawings within the documents.
9.2 Content
9.2.1 The Contents of the EIS as prescribed under EIS legislation, [Statutory Instrument 349 of 1989: European
Communities (Environmental Impact Assessment) Regulations, 1989], will contain the following headings for
baseline conditions and predicted impacts:
• Human beings
• Flora
• Fauna
• Soil
• Water
• Air
• Landscape
• Material Assets
• Cultural Heritage
Design Inputs required for the evaluation of the likelihood and significance of the above:
1. Existing Topography
2. Existing and proposed site levels
3. Plan and elevation drawings of development
4. Existing flora and fauna
5. Landscape photography and visual impact analysis
6. Ambient noise measurement
7. Hydro-geological survey
8. Archaeological survey.
9. Details of air treatment provisions (noise)
10. Employment requirements
11. Operations schedule, security, and environmental management provisions
12. Post operation management restoration proposal.
7

9.2.2 In addition, the following information will be provided, in the context of the EPA
(1995) Advice Notes on Current Practice in the preparation of Environmental Impact Statements: Water
Management projects for Agriculture, Water impoundment (including for hydroelectric generation),
Canalisation, Flood relief. (Project Type 12).
9.2.3 This document states: These project types can give rise to significant impacts,
which can be direct, such as changes in land use and habitats, or indirect, such as facilitation of new
developments (industry, agriculture, infrastructure) which may in turn impact on the environment.
Project Description
Checklist of items to be described
Construction
• Site evaluation/testing
• Time of year, duration and phasing
• Site preparation works
• Employment
• Accommodation
• Working hours
• Acquisition of lands and management prior to development
• Dredging/excavation and spoil deposition
• Construction techniques
• Water course diversions (temporary)
• Pipe laying
• Materials (including sourcing, transportation and storage
• Extensions of infrastructure (water, power, roads, etc.)
• Access
• Dust, Noise, traffic, vibration
• Power line connections
• Pipe laying
• Spoil deposition
• Fencing
Operation (including relevant alternatives)
• Operational range of water levels
• Operational range of flows
• Seasonal/Daily variations of operations
• Monitoring and control procedures
• Maintenance systems
• Principal structures, including impoundment structures, access, pipelines, power lines, diversion
channels, control mechanism, buildings and fences
• Maintenance
Decommissioning (if applicable)
• Safety
• Proposals for alternative usage/demolition following closure
• Reversibility of impacts
Growth
• Opportunities and likelihood of expansion
Associated developments
• Intensification of or new land uses
• Re-housing of displaced residences
• Connections to main transmission network (though this may be the subject of a separate application for permission)
• Water pipes
• Adjustment of affected infrastructure
Environmental Effects
Typical significant impacts likely to affect:
Human beings
• Displacement (major water improvement projects)
• Creation/loss of amenity
• Community severance
• Changes to land use and settlement patterns
Flora
• Alterations to habitats due to flooding/drainage
• Indirect impacts due to altered land use practices.
• Aquatic and terrestrial species should be considered
Fauna
• Displacement due to altered habitat
• Disturbance during construction
• Effects of changes in water quality and flow regime
• Effects due to changes in Flora
Soils (and geology)
• Erosion
• Excavation/deposition of soil
• Loss of/changes to soil
Water
• Changes to the physical, chemical, and biotic characteristics of water bodies
• Effects on flow regime
• Changes to water table
Air
• Dust generation (particularly during construction)
Climate
• Reduction in occurrence of mist and fog due to drainage of wetlands
• Local climatic effects, particularly regarding temperature and evaporation due to creation of a reservoir
The landscape
• Direct effects arising due to spoil deposition, dam construction and machinery presence during construction
• Indirect impacts occurring due to factors such as power lines, water mains and treatment works and
changes in land use.
Material assets
• Roads
• Power supply networks
• Water supply
• Potential uses of water resources
Cultural Heritage
• Flooding of monuments, artefacts and settlements
• Disturbance of items of historical importance such as bridges and weirs
• Significant changes in long established land-use patterns
The interaction of the foregoing
Possible Mitigation Options
• Siting and Design alternatives
• Water usage rates
• Routing of infrastructure
• Bank protection
• Habitat creation
8

9.3 Length
It is anticipated that the Main Body of the EIS will run to approximately 50 pages of A3 text not including
graphics, and that the appendices will run to several hundred A3 pages.
10 Membership and management of the EIA team
Erm21c Ltd Project Management, EIA management, and EIS production
Project Manager: Axel Fabritius
Energy Engineering James J. Nolan, Sean Wyse
Civil Engineering Brian Walsh, Niall Fitzsimons & Co.
Soils and Geology Robert Meehan
Hydrology Robert Meehan
Archaeologist Maurice Hurley
Noise & Vibration Dixon Brosnan
Ecology Dixon Brosnan
11 Work plan and resourcing for the environmental studies
• Baseline studies commenced June 2008
• Project defined June 2008
• Pre-planning consultations to be completed 30th September 2008
• EIS to be completed 30th September 2008
• Anticipated Planning Application 1st week October 2008
9

OP05
DERRYDUFF - CAPPANABRICK
PROJECT DESCRIPTION
(Excerpt from Draft EIS)
11

12
2 The Proposed Development (Section 2 of EIS)
2.1 Site Location And Suitability
2.1.1 Site Location
The proposed location of the project is in the townlands of Derryduff and Cappanabrick, Coomhola valley,
Bantry, Co. Cork. Specifically, the proposed development site is part of lands belonging to The Unicorn
Foundation and Patrick Murphy.
2.1.2 Site Selection Suitability Criteria
This site has been selected from 2 alternatives based the proposed development because of the following site criteria:
• Compatible land use zoning
• Adequate Length to Height (L/H) ratio and sufficient vertical head to use for gravity flow (>180m gross head)
• Impervious and structurally sound geological conditions
• Low hydrological impact
• Suitable topography to accommodate PHES with minimal landscape disturbance
• Proximity of 110kV grid access (

2.2.3 Positive Impacts
The following environmental benefits of the area will be positively affected by the development:
• Direct local income from sustainable use of the environment will increase significantly, enhancing the economic
integrity and security of the area, including a minimum 1 high quality sustainable job in monitoring, and indirect job
creation through management. Total permanent job creation will be equivalent of 2 full time jobs.
• The facility will require the construction of access roads, a turbine hall, penstock, upper and lower
reservoirs resulting in significant local economic activity during the construction period.
• The project will yield investment return for local and company investors. The facility will be financed
through a prudent combination of debt and equity.
• Strategic energy infrastructure which will be emissions free and imported fuel independent, consistent
with EU, State, and County policy will be commissioned, enhancing the future energy security of the
community.
• The catchment of the Derryduff stream will be increased by placing catching drains along the edge of
the access road to the upper reservoir. This will enhance the productivity of the watershed to the extent
that micro-hydro scheme proposed on the stream by the Unicorn Foundation becomes more viable. The
available penstock head for this micro-hydro scheme will also be increased as a result of the re-routing of
the stream bed around the lower reservoir. (Note: this stream has no fish life, due to its current ephemeral
nature which is caused by low catchment area)
2.2.4 Negative Impacts
The following environmental benefits of the area may be potentially negatively affected by the development:
• The local visual impact is expected to be minimal. Some visibility of the lower reservoir may be
observable from the vicinity of Lough Atooreen on the mountain road from Dromduff to Maugha road in
Tooreen townland. Otherwise visual impacts will be restricted to the outer bank of the upper reservoir
and the exposed sections of the penstock.
• The current use of the proposed site (approximately 30 acres) for grazing sheep will be lost of the site is developed.
• The existing blanket peat in the areas of the two reservoirs will be removed.
• The water supply to the Derryduff farm community and Unicorn Foundation is sourced on the mountain
from surface runoff. During construction of the upper reservoir and its access road, potential contamination of
this water supply could arise from soil and rock disturbance. This will be mitigated by the installation of a
sand & gravel filtering beds on the water supply, to be installed prior to the commencement of works at
higher elevation than the water supply intake.
As is evident from the above list of impacts arising, the benefits that would be foregone in a do-nothing scenario
are significantly greater than the loss of benefits which would result from the development. An attempt to
quantify the economic costs and benefits on an annual basis is given below.
Annual National Economic Cost-Benefit Proposed PUMPED HYDRO ELECTRIC STORAGE SCHEME.
Item Cost Benefit
National Fuel import costs avoided (60,000 barrels year @€75/barrel, based on gas power) 0
4,500,000
National Carbon Payments avoided €20 x 36,000 tonnes 0 720,000
Lost sheep grazing (1 sheep/2ha, 12.5ha lost, sheep @70) 400
National Economic Totals 400 5,220,000
• The net national economic benefits over 50 years will be in the order of €260,000,000.
• A Do-nothing scenario would result in the avoidance of potential savings on the national obligation to
purchase fuel and carbon emissions rights worth over €0.26 billion, over fifty years.
• The proposed development does not have nor will have any detrimental permanent environmental
impacts on the area or surroundings, if properly designed, and operated.
• There are no environmental benefits from a do-nothing scenario.
• In conclusion, a do-nothing scenario should not apply in this case. This is the century where the whole
world is starting to take corrective action against anthropogenic climate change, and to start developing
towards a sustainable future. In this new world paradigm, the generation of electricity, a commodity that
everybody enjoys and nobody wants to give up, will largely come from low carbon renewable energy.
The proposed project will provide a portion of that future energy requirement.
2.3 Construction
2.3.1 Public Road Access / Coomhola Bridge/ Ford
There are two access alternatives to cross over the Coomhola River from the main Coomhola- Borlin road, which
are currently under evaluation:
• Via Derryduff bridge - widen existing bridge, and widen road to Derryduff farm from bridge
• Improve private existing ford access to Derryduff farm from Rangaroe, upstream (~1km) of bridge
2.3.2 Site Compound, Temporary Site Offices
At the initial stages of construction, the proposed area for the site offices and compound will be stripped of
topsoil and this will be banked around the area. Teram geotextile will be placed on the subsoil to stop the
particles boiling up through the two layers of compacted clause 804. Included in the compound will be parking
for fifteen cars/vans, bunded diesel storage to 110% of the largest tank and a concrete area with gull to a grease
trap and silt trap to catch spills and sediment. A perimeter hoarding 2.4m high, will be constructed and painted
green to match the existing surroundings of trees and green area.
Temporary site structures will consist of ten port-cabins and six small lockable steel shipping containers for small
plant and hand held tool storage, and personel protective equipment (PPE) storage. One of the port-cabins will
be for the subcontractors that are expected during the construction period, and the other will be a larger one for
canteen and meeting room. A toilet unit will also be provided and regularly maintained and content disposed of
by a registered waste management company. The waste management will also provide a number of skips/ large
bins for recyclables and non recyclable materials that will be generated on site and within the compound.
2.3.3 Access Roads
The following sequence of on site road construction will be required
• Improve road from ford to Derryduff forestry road entrance (if using ford for access)
• Improve existing forestry road
• Build new road to access powerhouse/lower lake
• Build new road to reach top lake
• Roads on dam crest
• Ramps onto crest and ramp down to reservoir bed
Access roads into and within the site will range from 4.5m to 6m width and will be laid using 500mm of 50mm
aggregate down. Some sections of this road will be finished with tarmacadam. Stone will be obtained from
quarrying stone during lake excavation, and no imported stone will be required.
2.3.4 Structures.
The proposed project is a large civil engineering project, involving heavy structures to contain the forces of
standing and contained flowing water, in addition to the pump turbine. All structures will be designed by one of
the leading structural engineering practices in the country, Niall Fitzsimons and Company, Consulting Civil and
Structural Engineers. The structures required are described below. Detailed foundation design will be carried out
by, post obtaining planning permission.
Peat Storage
Two peat storage structures will be placed on site. The structural integrity of these stockpiles will be provided
by bunding structures and the gravtitational integrity of the peat which will improve with time as the moisture
content reduces. The stockpiles will be sealed by smoothing to allow precipitation to be shed from their surface.
Gravity Dams For Reservoirs
Dams will be constructed using excavated stone placed on appropriately designed rock benches. As the name
infers, the force of gravity is used to provide structural integrity.
Reservoirs
The reservoirs will be constructed on the existing bedrock, and foundations will be blasted partly into the rock.
A porous drainage layer will lie on top of the bedrock to allow for the cotrol of groundwater seepage. This is
overlaid by an impermeable flexible composite of bituminised concrete and bitumen. The leakage tolerance of
the reservoirs will be 5 l/s each from an economic point of view. Nevertheless, the performance of modern state
of the art sealings are better than 1 l/s.
13

Intake structures
A sluiced water intake/fill structure will be constructed at each reservoirs from re-inforced concrete to allow
water to be drained pumped between reservoirs. The intake structure for the bottom reservoir will be located at
least 15m below the lowest point of the lower reservoir to provide sufficient back pressure on the pump-turbine
to eliminate cavitation. The intake structure of the upper reservoir will be located at the level of the base of the
upper reservoir. Appropriate sluice controls and trashracks will be included
Penstock
A penstock pipe will transport the water at a rate of 25m 3 /s between reservoirs. This pipe will be situated partly
over-ground and partly underground, making maximum use of the topographical features of the site. The pipe
will be composed of pre-manufactured section of 18m long which are bolted together in series of 3 sections.
Each series is linked to the next by a massed concrete foundation haunch. Haunches will be soaced 54m apart.
Turbine
• Pump-turbine (Voith Siemens)
• 1 no.
• Rated output: 45 MW
• Turbine rated net head: 210m
• Required flow rate 25 m³/s
• Max. pump Head: 231m
• The power plant will run fully automatically.
Fig. 2 Pump Turbine Schematic Drawing (Indicative Only)
2.3.8 Construction Traffic
Project generated traffic will include deliveries of plant and machinery and of oversized loads. The oversized
loads will not require public road alterations. The transportation of these loads will require special permit and
the consent of ‘An Garda Siochana’. Once these have been obtained the components will be transported from
Ringaskiddy port to site. There will also be daily commutes of plant operators, office staff, electricians, engineers
and trades people. Assuming 30 no. workers, all travelling in their own vehicles, there will be an increase of 30
vehicles commuting daily.
14
Fig. 1 Powerhouse - “White Tank” (Indicative Only)
Powerhouse
A pit containing a wet cylindrical well approximately 37.5m deep will house the pumpturbine on the northern
side of the lower reservoir. The building pit will be enclosed by a bored piled curtain wall (~1m thick) forming a a
waterproof “white tank”. This structure will be underground, and covered by a low building (See Fig. 6).
Turbine Hall
The structural skeleton of the building will be erected, roofed, and clad once placing of the turbine plant
elements by gantry crane is complete.
2.3.5 External Service Pipes And Ducts
All telecommunicatons and electrical cables for the proposed development will be buried underground under
the access roads on site with a minimum of 1 meter cover from ground level, labeled with suitable yellow
warning tape at 0.5m from ground surface and 0.8m from ground surface at the top of the surround gravel
to warn off future excavations. Electrical cables will be run to a substation adjacent to the turbine hall. A
110kV underground cable will follow the route of the access road to the public road at the Unicorn foundation
entrance, and then follow under the public road over the Derryduff bridge to Rangaroe, Coomhola, Dromduff
west to Ballylickey Bridge and the connection at the ESB 110kV substation.
2.3.6 Site Works Surfacing
The access roads will be paved with tarmac or finished with crushed stone, and have kerb and gullies to collect
storm water runoff to sedimentation basins.
2.3.7 Plant Operational Technology Installation And Mechanical And Electrical Fit-Out
Design parameters:
• Location to minimize bends in the penstock pipes
• Location of turbine below lake bottom
• Deeper Pool at Power House containing outflow/intake structures
2.3.9 Construction Health and Safety
Relevant legislation includes, ‘The Safety, Health and Welfare at Work Act 1993-2003, Irish Construction
regulations 2001, and all of the other up to date Safety, Health and Welfare best practice Guidance Documents.
A number of these relevant documents include PPE, Manual Handling, Working with ladders, working at night,
quarrying and surface mining operations, quarry vehicles, working on in or near excavations, signage, slips
trips and falls at work, working at heights. This is not an exhaustive list however these are all relevant to a large
project such as a PHES development. Hazards identified associated with this project include, oversized loads,
lifting materials, pipe sections and turbine components to heights, working at heights, underground power
lines, electricity at commissioning, excavations, slips, trips and falls, moving vehicles and plant, etc. A 2.4m high
perimeter chain link fence will be carried out around the reservoir perimeters.
2.3.10 Land Use Requirements During Construction Phase
The approximate total land take required for the proposed project is given below. This area represents less than
12% of the existing upland site, which is defined as lands within the site boundaries of the property involved in
the project, which are not forested or improved for grazing (116ha).
Item Area [m2]
Access Road to Site 10000
Area of Surfaced Roads 33670.3
Buildings 3840
Upper Reservoir 30072.5
Lower Reservoir 41288.5
Penstock 4629.4
Stillin Basins 2699.4
Peat stock pile 1 8720.8
Peat stock pile 2 2690.9
Total land use requirement 133771.8

2.3.11 Waterworks
Top Reservoir
Design:
• Gravity Rockfill Dam with vertical steel enforced concrete walls on the upstream side – ring structure,
partly concrete gravity dam with buttresses
• Reservoir Bed: asphaltic liner (e.g. top to bottom: with mastic coating, asphalt concrete, bituminized
binder course, asphalt filter, asphalt binder, gravel layer)
• Drainage system to monitor possible seepage and a fibre optic leakage detection system
• Intake structure: side intake structure
• Trashrack
• Freeboard: 0.5 m (based on max. wind speed ever recorded in Ireland [56 m/s] 300m fetch, 15m depth)
• Wave wall 0.5m high on upstream edge of the dam
Penstock
Design:
• 1 pipe running through gorge with as few as possible direction changes. Changes of less than 10° are more
or less negligible in terms of friction, bigger changes will cause increasing friction meaning a loss in efficiency
• Internal Pipe diameter expected at 2.5m (depending on required flow rate (anticipated between 25 m³/s)
• Pipe partly over ground level; could be mounted on Stilts (anchored into the rock); partly bruied in a trench.
• Pipe material: glass-fibre-reinforced, polymer mortar or steel pipes
Fig. 6 Penstock - Steel Pressure Pipe (Indicative Only)
Fig. 3 Top Reservoir - Road on Dam Crest (Indicative Only)
Fig. 4 Top Reservoir - Gravity Rockfil Dam with partly vertical steel
inforced walls (Indicative Only)
Bottom Reservoir
Design:
• Two Gravity Rockfill Dams - one to the south and one small one next to the forestry; upstream face: asphaltic lining
• Reservoir Bed: asphaltic liner (e.g. top to bottom: with mastic coating, asphalt concrete, bituminized
binder course, asphalt filter, asphalt binder, gravel layer) on top of natural bedrock
• Drainage system to monitor possible seepage and a fibre optic leakage detection system
• Outlet structure: draft tubes, draft tube extensions serve as outlet (part of power house structure)
• Trashrack
• Spillway
• Freeboard:
• 0.5 m (based on max. wind speed ever recorded in Ireland [56 m/s] 300m fetch, 15m depth)
• Wave wall 0.5m high on upstream edge of the dam
Stilling Basins (sedimentation ponds):
Design:
• 3 basins in a row at three different height levels (“steps”)
• Position: Below main gravity dam – lower reservoir
Grid Connection (at Ballylickey Bridge 110kVGrid substation)
Via underground (under public road) 7km cable (110kV)
Rerouted Stream
The lower reservoir will be situated on the existing route of the Derryduff stream. Consequently the stream will
have to be re-routed to allow the construction of the lower reservoir. The new route will be west of the lower lake
parallel to its bank and bring the stream via a channel to the middle of the crest of the main dam and connect to
a “mini-penstock” for a Unicorn Micro-hydroelectric Scheme.
2.3.12 Construction Timetable
The following proposed construction schedule is anticipated to start within 12 months of receipt of planning
and grid permits. Once construction is started, commissioning is projected within 30 months.
Activity
Table 1: Proposed Construction Schedule - Derryduff - Cappanabrick
Duration (Month
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Fig. 5 Lower Reservoir - Rockfill Dam with Asphaltic Liner(Indicative Only)
1.) Construct access bridge off main road / ford
2.) Site access Clearance & Site Compound Setup
3.) Construct access road to lower lake
4.) Lower Lake soil/peat excavation
5.) Construct access road to upper lake
6.) Lower Lake rock removal & formation of banking/retaining walls
7.) Construction of Turbine Carvern to lower lake
8.) Upper Lake soil/peat excavation
9.) Upper Lake rock removal & formation of banking /retaining walls
10.) Construction of Upper Lake Inlet Structure
11.) Excavation & foundation works for pipe line path
12.) Laying of High-Pressure Pipeline from upper to lower lake
13.) Apply water tight asphalt lining to upper and lower lakes
14.)Fit-out of Cavern- Pump Turbine, Generator etc
15.) Construction & fit-out of Transformer building
16.) Laying underground/overground high voltage cable from site
to nearest local network
17.) Testing/Commissioning

The filling of the lakes to an operational level will take 15-24 weeks depending on the precipitation levels.
2.4 Operations
2.4.1 Overview
The proposed Cappanabrick-Derryduff PHES project will be commissioned to supply electric power from a
hydroelectric pump-turbine, to be produced by pumping 280,000 meters cubed water to a gravitational head of
210 meters using 49MW of electric power sourced from the grid during off peak hours of electricity demand, and
drawing down this head while producing 45MW of power from the turbine which power is delivered to the grid
during peak hours. All of the input electric power will be sourced from grid connected wind energy projects.
The process will transform unpredictable and variable windpower to reliable, dispatchable clean energy
delivered to the grid.
Electric Energy
The PHES scheme will deliver power 4 hours per day, corresponding to peak demand from 0600-0800 and 1700-
1900. The scheme will accept energy off peak for from 4 up to 20 hours per day depending on the available
wind energy. Energy is lost in the process through resistance and less than 100% efficiency in the pump and
turbine. These losses are more than compensated both in value and power quality, by the fact that intermittent
and unpredictable power is delivered via PHES as a predictable quality product in time and volume. The amount
of wind energy capacity that will need to be available to supply the scheme is approximately 30MW installed
capacity of wind turbines, assuming that the wind turbines are on average 35% efficient, and that the PHES
requires a minimum of 196MW hours per day over 20 hours.
2.5 Employment
When operational, the plant will require 1 part time supervisor, and the equivalent of 1.5 full time technical staff
for maintenance and management. The total full time job creation will be 2.
Fig. 6 Powerhouse (Indicative Only)
2.6 Decommissioning
It is current practice to re-commission PHES plants once the technical life of its components is over, due to the
increasing penetration of wind power into power grids. For example, many schemes in mainland Europe which
were built in the 1930s are now being re-tooled and upgraded after 70 years of operation (i.e. Waldeck 1 PHES,
Hessen, Germany, owned and operated by EON).
However, in the event that decommissioning is warranted for unforeseen superseding of the technology by
advances elsewhere in power systems, the following will be undertaken as decommissioning:
• All roads and structures will remain in place for future re-use
• The top reservoir be maintained empty
• The bottom reservoir will be maintained full to act as a semi-natural lake, and fish life encouraged
through the introduction of aquatic flora and soil to anchor them.
• Security fence around bottom reservoir will be removed to allow access for recreational purposes.
16

OP05
DERRYDUFF - CAPPANABRICK
SITE PLAN
AND
PHOTOMONTAGES
17

1
2
Legend
1
2
Grid Connection
Existing Public Road
Site Access Road
Photomontage 1 Viewpoint
Photomontage 2 Viewpoint
18

20
PHOTOMONTAGE 1
BEFORE
AFTER

View from accros the valley, top of Knockbreteen
PHOTOMONTAGE 2
21
BEFORE
AFTER