In 2011 a comprehensive review was carried out of the FITs scheme and in February 2012 a consultation document was published by the Department of Energy and Climate Change (http://www.decc.gov.uk). The document includes all aspects of renewable energy however this summary concentrates on hydro-power generation.

Feed-in Tariffs Scheme
Consultation on Comprehensive Review Phase 2B: Tariffs for non-PV technologies and scheme administration issues:

http://www.decc.gov.uk/en/content/cms/meeting_energy/Renewable_ener/feedin_tariff/feedin_tariff.aspx

The comprehensive review document drew on information of uptake of FITs since its introduction and the benefits the FITs have had on hydro developments in the UK since then. The review was intended that, going forward, the scheme is based on up-to-date information, is regularly reviewed and “works smoothly and fairly for all participants”. In addition the scheme is designed for the development of small-scale hydro schemes by both private developers and communities.

For the review of the FITs scheme a financial model has been used which includes higher capital costs for developing hydro schemes, operating costs similar to those at the start of the scheme but load factors slightly higher than previously assumed. These factors were used to re-calculate the tariffs (pence per kilowatt (p/kW)) and assuming a target 8% rate of return the new tariffs were similar to the previous rates. Therefore the proposal is to maintain the middle tariff bandings at the same levels as previously while there will be a slight reduction in the low and high band tariffs. The table below shows the proposed changes which will become effective from October 2012:

The FITs are intended to support the development of hydro in the UK but only for a limited period of time i.e. a transitional arrangement. Therefore it is proposed that the tariffs will start to decrease in April 2014 at a rate of 5% per year. The proposed tariffs up to 2020/2021 are shown below:

There is however a capacity trigger so that the reduction in tariffs could occur before April 2014 if the total amount of hydro development reaches 55MW. In this case the reduction would start 3 moths after the total hydro reached 55MW. A similar trigger is being proposed for April 2015 if the total hydro development reaches 73MW.

The Wildlife & Countryside Act 1981 with amendments post devolution in the Nature Conservation (Scotland) Act 2004 provide legal protection to important species in Scotland. Further protection is conferred to particular species in the European Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora.  This directive, known as the EU Habitats Directive is translated into Scots law through the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended in Scotland).  These Regulations are commonly referred to as the ‘Habitats Regulations’. 

The EU habitats directive classifies species according to the following status:

ANNEX II: species of community interest whose conservation requires the designation of Special Areas of Conservation

ANNEX IV: species of community interest in need of strict protection (European Protected Species)

ANNEX V: species of community interest whose taking in the wild and exploitation may be subject to management measures

Geographic areas of particular importance for Annex II species require the designation of Special Areas of Conservation (SAC), however many of these species are mobile and not limited to particular areas; these species are designated as European Protected Species (EPS) under Annex IV.

The legal protections for mammals and their habitats are set out below: 

 Otters

The common or European otter (Lutra lutra) is a schedule 2 EPS and is classified as Near Threatened in the International Union for Conservation of Nature (IUCN) species red lists. The otter is also a priority species in the Scottish and UK biodiversity lists and Biodiversity Action Plans (BAP).

European Protected Species (EPS) are fully protected under the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended).   This lists a number of offences in relation to these protected species and the places in which they live as summarised below: 

It is an offence to deliberately or recklessly:

• Capture, injure or kill an EPS
• Harass an EPS or group of EPS
• Disturb an EPS in any structure or place it uses for shelter or protection
• Disturb an EPS while it is rearing or otherwise caring for its young
• Obstruct access to a structure or place EPS use for shelter or protection or to otherwise deny the animal use of that place
• Disturb an EPS in a manner that is, or in circumstances which are, likely to significantly affect the local distribution or abundance of the species
• Disturb an EPS in a manner that is, or in circumstances which are, likely to impair its ability to survive, breed or reproduce, or rear or otherwise care for its young.

It is also an offence to:

• Damage or destroy a breeding site or resting place of such an animal (note that this does not need to be deliberate or reckless to constitute an offence)
• Keep, transport, sell or exchange or offer for sale or exchange any wild EPS or any part or derivative of one (if obtained after 10 June 1994).

Licenses are available to allow specified people to carry out actions that could otherwise constitute an offence.   Licenses can only be issued for specific purposes that are set out in the legislation.  If any activities are planned that could affect EPS or the places they use, typically a survey will be required to determine whether they are present and likely to be affected by the proposed activity.   Should this prove to be the case a specific licence must be applied for and granted by Scottish Natural Heritage (SNH)before any work commences.

Badgers

Badgers (Meles meles) and their setts are protected by law in the Protection of Badgers Act 1992 (as amended) and by Section 11 of the Wildlife and Countryside Act 1998.  These acts have been updated by the Nature Conservation Act (Scotland) 2004.  Badgers are not an EPS species but are afforded protection in European law in Appendix III of the Bern Convention.   Offences under these Acts include:

• Wilfully kill, injure or attempt to kill a badger
• Cruelly ill-treat a badger
• Intentionally or recklessly interfere with a badger sett (includes damaging or destroying a badger sett or destroying a badger sett or any part of it, obstructing access to a sett, disturbing a badger whilst it is in a sett, or cause/allow a dog to enter a badger sett.
• Possess a dead badger or any part of a dead badger
• Mark, tag or ring a badger
• Dig for a badger

SNHis the authority responsible for issuing licences for the purpose of development as defined under Section 26(1) of the Town and Country Planning (Scotland) Act 1997.  Licences issued for development can permit the licence holder to interfere with a badger sett in a specified area and by specified means.  Licences cannot be issued for the purpose of development to carry out any other actions including killing or taking badgers.

 A licence must be obtained fromSNHfor any work that may cause disturbance to a badger or involves the damage or destruction of a sett. What constitutes disturbance depends on the nature of the activity proposed: as a rule a licence is normally required for any works within30 metresof a badger sett, but this distance may increase for more disruptive activities such as blasting or pile-driving.

 Water voles

Since 1998 the water vole (Arvicola amphibious)  has received legal protection through its inclusion in Schedule 5 of the Wildlife and Countryside Act 1981 (as amended), in respect of Section 9(4) only, which prohibits the following actions:

• Damage/destruction or obstructing access to any structure or place which a water vole uses for shelter or protection
• Disturbance while in a place of shelter

 This means that the water voles’ places of shelter or protection are protected, but not the animals themselves. Recently the Nature Conservation (Scotland) Act 2004 enhanced this protection by the addition of the term ‘recklessly’ in the offences quoted above. Furthermore, the current partial protection afforded to this species is under wider review and may be extended in future.

Red squirrels

The red squirrel (Sciurus vulgaris) was once widespread across the UK, however the species is now largely restricted to the north of England, Northern Ireland and Scotland. Scotland currently hosts about 75% of the estimatedUK population.

It is a priority species on the UKBAP and is included on the Scottish Biodiversity List. The red squirrel is classed as least concern (LC) on the IUCN Red List, and listed under Appendix III of the Berne Convention. Threatened in the UK, and protected under Schedules 5 and 6 of the Wildlife and Countryside Act, it is illegal to kill, injure or intentionally disturb a red squirrel in its place of shelter or to damage or destroy its place of shelter.

Bats

All species of bats in the UK and their roosts are EPS and are afforded full legal protection according to this status. Many of the species found in the UK are UK and Scottish Biodiversity Action Plan species and are listed in Local Biodiversity Action Plans.

It is an offence to deliberately or recklessly:

• Deliberately capture, injure or kill a bat
• Intentionally or recklessly disturb a Bat in its roost or deliberately disturb a group of bats
• Damage or destroy a bat roosting place (even if bats are not occupying the roost at the time)
• Possess or advertise/sell/exchange a bat (dead or alive) or any part of a bat
• Intentionally or recklessly obstruct access to a bat roost

Intake:
The proposal is for a run-of-river scheme (i.e. no water storage required), which would utilise water from the upper reaches of the Stank Burn.  The proposed intake location is on the lip of a broad corrie area, at a naturally stable section which is considered to be already considerably modified.  There is currently a large culvert crossing around 10 m downstream of the proposed intake.  The potential trapping effect of the intake weir on the sediments and fish will be mitigated through careful design and the use of a ‘Coanda’ type screen on the downstream face (installed using procedures set out by the screen manufacturer).  

Penstock:
The abstracted water will flow southwards through a 0.86 km pipe, or penstock, towards the turbine house.  The intake to the penstock will be integrated with the weir, and the pipe will then be buried along a route that descends along the northern side of the glen, down slope of the existing forestry track. The penstock access will first need to be cleared of trees and roots to within a distance of about 20 m from the pipe centreline, to accommodate the construction corridor.  This will involve removal of the triangular block of forestry and  at least part of the lower  forest block.  

The pipe will have approximately a 400mm internal diameter, and typically be buried in a 600mm wide trench to a buried depth of 700mm.  The trenching work will be completed by one tracked 360 degree excavator.  The pipe will be secured, if necessary, to bedrock or concrete thrust blocks.  If the pipe is to be buried below any small ditches or flushes, this will be done at locations which are as stable as possible, with sediment traps if necessary.  Once the site has been reinstated, the vegetation over this area will be left to regenerate naturally. 

Turbine house:
The turbine house will be located within 20m north of the Stank Burn, at the end of an existing derelict forestry track upstream of a waterfall. Although around 10 m of additional head could have been achieved by placing the turbine downstream of the waterfall, it was agreed with the statutory consultees, and the developers that the upstream site was simpler to engineer and would give Stank Farm more protection in terms of perceived noise issues and visual impact.  

The turbine is expected to be a high capacity turbine with an associated generator, designed to be efficient during low flows. The area of the turbine house is expected to be around 96 m².  It has been planned sensitively, with design and materials selected to blend in with the surrounding woodland environment.  The proposed structure will be constructed with timber,  with a shallow pitched sedum roof, and with the outer walls clad in locally grown Larch timber.  Sound insulation will be achieved through standard build techniques.  The floor of the building should be concrete, with the turbine set at ground level. 

The access track may need to be upgraded, and a turning area added beside the turbine house with a compacted Type 1 finish similar to the existing forestry track.  A cable will connect the system to the nearest suitable point on the power line which passes close to Stank Farm, via overhead wires and buried cable from the turbine house. Once the water has been used to generate power in the turbine house, it will be returned to the Stank Burn via a buried pipe to an open channel tailrace situated above the existing waterfall. 

Tailrace:
The tailrace, which returns water from the turbine house to the watercourse, will be carefully designed to minimise impacts on erosion, deposition and habitat quality.  Water will flow from the turbine house through a outfall pipe and then through an open channel approximately 6m long and 3m wide with rock gabion walls down the steep slope towards the Stank Burn channel. The structure will be contained within a treated timber post and rail fence. The tailrace channel has been intentionally sited to lie between two existing natural rock ridges.  The proposed siting of this tailrace in a relatively stable reach upstream of the waterfall (which is currently an obstacle to migratory fish) should minimise the impact of the outfall on the aquatic environment. 

Abstraction regime:
The abstracted water will bypass the natural channel between the intake and the tailrace for a distance of approximately 0.92 km.  The proposed water abstraction rates will vary depending on the natural discharge of water in the watercourse.  It will maintain adequate water in the affected reach of watercourse to sustain viable aquatic populations during natural low flow conditions, as well as maintaining the visual quality of the waterfall. High flow events (including channel-forming and flood events) should also remain relatively unchanged.  Downstream of the tailrace, the amount of water in the channel will be unaffected.   

Access:
The main structures can be accessed via the current network of forestry tracks, and so no new permanent access roads will be required for this development.  These roads are generally in good condition but may be need to be repaired. The development will require temporary access along the proposed penstock route.  Where possible, this route has been designed to follow natural contours to minimise potential environmental disruption. The access will be just wide enough to enable passage of a tracked machine along the penstock route.  It will be reinstated after construction and allowed to re-vegetate naturally.  These details will be agreed prior to development and be provided as part of the finalised Construction Method Statement (CMS).  

Construction Compound and Lay down areas:
A storage area is needed to store equipment and materials such as fuel and equipment.  It will be located on an existing area of forestry track to the northwest of the intake site.  This area is of low habitat value, and the potential significance of environmental impacts is relatively small.  Lay down areas will be required along the length of the penstock.  These will be sited at strategic points adjacent to existing tracks to facilitate the construction on relatively flat, free-draining soils. Pollution prevention guidelines will be followed, and the sites will be reinstated after the construction phase. 

Minimal construction facilities will be required on site, and will include a self-contained portable toilet, which will be discretely positioned for the duration of the construction.  All construction and storage areas should be sited to retain emergency access, and damage to road verges will be minimised.  The areas will be temporarily fenced off to protect walkers on paths where necessary, with adequate safety signage.

Construction Methods:
During construction there is more potential for impacting the environment than in the operational phase.  SNH recommend that a detailed CMS is submitted as part of the Environmental Assessment in support of the formal planning application.  The CMS will detail all proposed use of machinery in construction such as diggers, pneumatic drills, as well as the number and type of vehicles including all-terrain vehicles.  Working methods set out in the CMS will aim to mitigate the impacts of construction to ensure that there are minimal impacts on the natural heritage and public enjoyment of it.

Waste Management:
A site-specific waste management plan will be incorporated into the CMS to ensure that the proposed development does not introduce waste or pollutants to the natural environment.  Where possible all potential waste streams will be identified, and waste materials will be removed from site.  

SEPA encourages the recovery and reuse of controlled waste provided that it is in accordance with the Waste Management Licensing Regulations of 1994.   Developers are required to demonstrate that the development includes construction practices to minimise the use of raw materials and maximise the use of secondary aggregates and recycled or renewable materials.  Waste material generated by the proposal must also be reduced and re-used or recycled where appropriate on site (for example in landscaping not resulting in excessive earth moulding and mounding).

A small amount of rock blasting might be required, for instance, to clear bedrock from the penstock route.  However in most cases pecking is expected to be adequate given the type of stone found locally.  The impact of such activities (including dust, blasting and impact on water) will be appraised as part of the overall impact of the scheme. If crushing is to be required, then separate authorisation will be required. 

The following Pollution Prevention Guidelines (PPG) will be consulted from the Netregs and SEPA websites where appropriate:

• PPG 1 General guide to the prevention of pollution
• PPG2 Above ground oil storage tanks
• PPG 5 Works and maintenance in or near water
• PPG 6 Working at construction and demolition sites
• PPG 7 Refuelling facilities
• PPG 8 Safe storage and disposal of used oils
• PPG 13 Vehicle washing and cleaning
• PPG 21 Pollution incident response planning
• PPG 22 Incident response – dealing with spills

Town & Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2011 (‘EIA’):

The EIA regulations of 2011 transpose the EIA Directive into the Scottish planning system, and update the EIA (Scotland) Regulations of 1999.   These regulations determine the types of development that require an Environmental Impact Assessment to be carried out.  More information can be found in ‘A Users Guide to the Environmental Impact Assessment (Scotland) Regulations’ (Scottish Government, 2011).

Water Environment (Controlled Activities) (Scotland) Regulations 2011 (‘CAR’):

Activities influencing watercourses are strictly controlled by SEPA, together with guidance from SNH.  Three levels of authorisation are set out by the CAR system, depending on the potential significance of the impact (Table 1).  The controlled activities relevant to hydropower development include Pollution, Abstraction, Impoundment and Engineering.  The levels of authorisation required for activities potentially relevant to the hydropower development are listed in Table 2.

Table 1  Levels of CAR authorisation

Table 2 Authorisation for selected activities relevant to hydropower

 (Adapted from ‘The Water Environment (Controlled Activities) (Scotland) Regulations 2005: A Practical Guide, SEPA, 2008).  Potentially relevant activities for Stank shaded pale green)

Stank Glen lies within the administrative areas of both Stirling Council and Loch Lomond and the Trossachs National Park Authority (LLTNPA); in this case LLTNPA is the statutory authority for all planning applications, although Stirling Council’s plans are still relevant until the LLTNPA local development plan is formally adopted.  The plans listed in Table 2 set out policies for the development and use of land in the area in order to provide a basis for the determination of planning applications.

The regional strategy is currently laid out in the National Park Plan 2007-2012, which was approved in 2007 by Scottish Ministers.  An outline of the strategy for 2012 -2017 has been provided in Table 2, although it is still in the consultation stage. The Plan promotes the use of renewable energy, including hydropower, to enable the Park to meet aims to reduce energy consumption from fossil fuels, create sustainable communities, as well as benefitting the local rural economy.  For the National Park the key to the development of renewable energy technologies is to ensure that these developments are balanced against the need to protect natural and cultural heritage and landscape values of the Park.

The Finalised Draft Local Plan (February 2010) states that the LLTNPA supports the development of hydropower, in line with one of the four statutory aims of the National Park to ‘promote sustainable use of the natural resources of the area’.  It sets out detailed policies and site-specific proposals for developments, and recognizes that the Park’s forest resource can also potentially contribute to renewable power generation. While landscape sensitivities and unsuitable topography are constraints to large-scale hydro schemes, planning policies are designed to enable more small-scale renewable energy projects such as run-of-river hydro. 

It is generally recognised that hydropower forms the main existing source of renewable energy generation in the Park and is the technology which presents most opportunity at the present time.  New large scale impoundment is considered unlikely to be compatible with the Special Qualities of the Park.  Particular sensitivities are likely to include potential effects on salmonid fish species and landscape and visual effects of the intake, the pipeline, access tracks and turbine house.

The National Park Authority’s associated draft supplementary planning guidance on renewable energy offers a spatial framework for renewable energy projects in the National Park together with detailed technical guidance. 

Table 1 Selected Scottish Renewables Policies& Legislation

Table 2  Local Development Policies

Stank Glen

MNV has been working with the Callander Community Development Trust (CCDT) to develop plans for a small run-of-river hydropower development on the Stank Burn, a tributary of the Teith catchment, situated in the Breadalbane area of the Loch Lomond and the Trossachs National Park.  As part of the planning process, MNV Consulting Ltd was contracted to carry out a programme of hydrological monitoring and Environmental Impact Assessment relating to the scheme.  This work built upon feasibility studies previously carried out by MNV Consulting on behalf of CCDT. 

The extent of the work was agreed through a detailed screening and scoping process with the planning department of Loch Lomond and the Trossachs National Park Authority and statutory consultees (Scottish Environment Protection Agency and Scottish Natural Heritage).  The results were brought together in an Environmental Statement, which aimed to assist the planning application process and the Controlled Activities Regulations licence application.  

Following a thorough options appraisal, a preliminary design was developed by MNV Consulting Ltd, this aimed to balance the potential costs and benefits, to both environment and the developer.  The proposed scheme is a run-of-river system (i.e. no water storage involved), consisting of an intake, an 860 m pipeline (penstock), a turbine house and an outfall.  The current design is for a turbine of up to 384 Kilowatt (kW) capacity, aiming to generate around 1.28 Gigawatt hours of energy per year (GWh/yr).  This is enough to provide electricity for approximately 300 average homes; a significant contribution to the energy requirements of this part of the National Park.  It could also result in an annual saving of somewhere around 930 tonnes of carbon equivalent, when compared to the carbon released through traditional fossil fuel sources.  

To determine the application, the potential environmental benefits of the scheme on a national scale were balanced against the potential environmental impacts of the scheme at a local level.  The potential impacts were assessed under four broad headings: hydrology and river morphology, ecology, landscape and socio-economic.  Where impacts are anticipated, appropriate mitigation was recommended under each section to minimise the magnitude of the potential impacts. 

The Stank Burn is a relatively steep upland watercourse on the slopes of Ben Ledi, with a ‘flashy’ flow regime.  The proposed scheme will reduce flows particularly during medium flow conditions, but the abstraction regime is designed to protect low and high flows, which are important for both aquatic habitats and channel forming processes.  The reach of the watercourse which would be affected by the scheme is deeply incised and flows over metamorphic bedrock and boulders with frequent large falls, pools and cascades.  Sediments appear to be frequently mobilised, and so the potential morphological impacts of the scheme (mainly erosion and deposition around structures) are likely to be negligible when considered relative to the high level of disturbance naturally occurring in the Stank Burn. 

The terrestrial ecology of the Stank Burn catchment grades from upland heath, through a landscape dominated by coniferous plantation in the middle reaches, towards a mosaic of woodland, pastoral agriculture and settlement on the flat valley floor near Loch Lubnaig.  Habitat quality has been significantly modified through forestry and drainage. Constructed access tracks are a considerable component in most hydropower developments and can significantly impact upon soils, hydrology and terrestrial ecology; however in this case these impacts have been minimised through careful design, as both the intake and turbine locations are accessible via existing forestry tracks.  Temporary access will be required along the penstock route, although with appropriate design, construction and remediation this impact is not considered to be highly significant. 

The morphology of the Stank Burn profoundly influences the type and distribution of habitats for fish and the connectivity between favourable habitats.  The scheme was designed so that most of the affected reach would be inaccessible to migratory salmonids due to an impassable waterfall.  The potential impacts of the proposed abstraction regime on the aquatic ecosystem are not likely to be significant when compared to the natural level of disturbance experienced in this watercourse. 

The landscape in the area surrounding Stank Glen is very distinct, and protected through its designation within the Loch Lomond and the Trossachs National Park.  Located to the north east of Ben Ledi, rugged mountains shaped by glacial processes dominate the skyline.  The Stank Burn drains into Loch Lubnaig, which lies between the popular tourist towns of Strathyre and Callander.  The area is therefore a very scenic destination popular with recreational users, so it is vital that the natural landscape is not degraded by the development.  The developers are therefore keen to ensure that the scheme is designed to blend into the natural landscape as far as possible, and to protect the special qualities of the area. 

With a local economy highly dependent on agriculture, forestry and tourism, it is important to consider the potential effect of the scheme on local residents and visitors to the National Park.  In general, the development will not have a significant negative impact on the visual setting, noise levels or cultural heritage of the landscape.   It may also bring many benefits to the area, e.g. increased local employment opportunities.  Because the local community will own the scheme, the sustainable income generated will be put to good use in the surrounding area. 

The potential environmental impacts of the scheme are likely to be most considerable during the construction phase (typically around 9 months), and will diminish over time as the system recovers from the initial disruption.  These impacts can be minimised to an acceptable level by incorporating the recommended mitigation measures into the detailed design and Construction Management Plan of the scheme.

Stank Burn close to the proposed intake

Stank Burn below the tailrace

How representative the period of gauging was compared to a long term average can be analysed and adjustments made to scale the short term data up to represent a long term data set. This gives a good indication of the average flow regime in the river but what about the variability between years?

Four long term stations in different regions of Scotland have been analysed and the annual flow duration curves shown in the following figures:

West coast

East coast

 North

South West

For each of the four stations above, the 2011 flow duration curve is shown as the thick dashed line. It is interesting to see that for the year 2011:

1. The west coast site had average high flows but low flows were much higher compared to most previous years.
2. The east coast site had high flows throughout the entire flow range compared with the previous years.   
3. The northern site had higher high flows but average low flows compared with previous years.
4. The south west site had flows which were around average compared with previous years.

The regional differences are interesting however it is also important for any water resources project to be aware of the inter-year variability, especially the chance that a very dry year could occur.

Topographic data is relatively easy to access and it is usually of high quality. The selection of intake and turbine positions can however make a significant difference to the scheme. A balance needs to be achieved between locating the intake as low down the river as possible to use the greatest amount of water but the intake needs to be as high as possible to achieve the greatest head. Access, construction, penstock length and distance to grid connection also need to be taken into consideration. An initial assessment therefore should produce a matrix of options which are quantified and ranked in the further assessments. 

Flow data is critical in a hydro-power assessment. It is important to konw the amount of water available, its distribution through the year, and its likely variability from one year to the next. Estimated or short term flow data may differ in either direction from flows derived from 12 months or more of monitoring. In addition the long term averages and variability might show the 12 months of monitoring were not representative. Flows may also be affected by climate change or land use changes in the catchment area. Hydro-power assessments therefore need to consider all of the possible causes of variability in the flows and this needs to be converted to variability in generation and hence financial risk.

Flow duration curves derived by different statistical methods:

• Flow available across the flow duration curve and hence over the year
• Inter-year variability of the flow estimates
• Compensation flow required
• Flow available for generation
• Type of turbine specified
• Turbine efficiency from minimum generation to full power
• Intake to transmission efficiency

Yearly output can then be converted to an annual income using the current and projected revenue from sale to the grid and the feed in tarrifs.

Modified flow duration curve before and after abstraction: