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Energy Production in the Yorkshire Dales National Park:
a guide for developers and householders
Hydropower
Water power in the past has been a widely used source of energy in the Dales, both directly to power
machinery using water wheels and indirectly to power turbines to generate electricity.
Any part of a watercourse which includes a significant fall in level can be used to produce
hydroelectricity. This fall is used to create a ‘head’ by pressurising part of the water flow by diverting it
through a pipe or narrow channel down to a turbine and back to the watercourse.
Main advantages and disadvantages of hydropower systems
Consistency of electricity production
Limited visual impact
Requires significant engineering works in and
close to watercourses
Can cause noise problems
Very low maintenance requirements
Can have adverse effects on the ecology of
watercourses and water levels
Very suitable for community ownership, as
promoted by the Government
High initial expense for larger schemes
A scheme may be described as ‘high head’, in which a relatively small quantity of water (flow) is piped
down a steep gradient (head), or ‘low head’, in which a large quantity of water is piped down a gentle or
short gradient.
A typical high head hydro-scheme involves water being taken from a river or stream and diverting it
through an intake at a weir along a pressurised pipe, or ‘penstock’, which can be buried or lain on the
surface. The water then runs through a turbine which is enclosed in a building called a ‘powerhouse’ that
also houses a generator and control equipment. The water is then allowed to flow back to the river down
a ‘tail race’.
This is the type of scheme which is most likely to be appropriate for those sites in the National Park
where water power has not previously been exploited. Very small-scale high head schemes can be well
within the scope of land managers with an average level of engineering ability to develop themselves,
yet can still produce a worthwhile electricity output.
Most of the best potential sites for low head schemes that require artificial watercourses (canals or leats)
are old watermills, most of which have become redundant or been converted to other uses. Where the
mill building remains but is unused, there is often potential to reuse the artificial watercourse - either to
take the water directly through a modern turbine housed within it, or to turn a refurbished or new water
wheel, which itself might power a generator.
If this is impractical, another alternative is a ‘barrage scheme’. A turbine is constructed either as part of
the weir, or immediately adjacent to it, involving no new watercourse construction or pipework.
Alternatively, where the artificial watercourse remains, but the building it serves is no longer available,
the artificial watercourse could be used for some of its length before diverting the water through a
suitably situated turbine.
Types of turbines
There are at least six principal types of conventional turbine in well established use in this country. They
are all variable in size that will suit particular site considerations.
In addition, there have been a number of recent schemes, including some within and close to the
Yorkshire Dales National Park, using a different type of turbine based on the Archimedean screw.
Yorkshire Dales National Park Authority, June 2011
www.yorkshiredales.org.uk/cc-renewableenergy
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Energy Production in the Yorkshire Dales National Park:
a guide for developers and householders
This type of turbine suits low head schemes, either within the watercourse or very close to it, and either
where leat construction would be difficult or where fish protection is particularly important and would be
difficult with a conventional system.
Small-scale hydropower is the renewable technology most favoured by the National Park
Authority. This is because of the widespread availability of suitable water courses and the fact that the
landscape impacts tend to be restricted to the immediate vicinity of the plant.
However, even with this relatively compatible technology, there is always some degree of associated
landscape impact, which has to be considered and weighed against the benefits of energy production
and emissions reductions. Sometimes changes to the natural appearance and character of an area, and
to its other qualities, can be potentially so severe as to be a determining factor in a planning assessment.
Some places, such as close to major waterfalls or where public access is well established, may be just
too sensitive to be interfered with at all.
PLANNING CONTROLS: micro-hydropower developments
There are no current (2011) permitted development rights covering micro-hydro developments except for
the change of use of existing agricultural buildings to accommodate generating equipment. Therefore,
the construction of weirs, channels, screens, leats and powerhouses, and the excavation of penstock
routes, will all need to be the subject of planning applications (although usually one application will
suffice for all elements of a proposed system).
It is possible that where there are existing elements of a former scheme, or where the turbine and
powerhouse are particularly small in scale, the works could be considered to be ‘de-minimis’, and not
need planning permission, although advise will still need to be sought from the National Park Authority.
Any hydro-electricity development could potentially require an Environmental Impact Assessment (EIA)
therefore, it is important that the relevant regulations are followed. These offer potential applicants the
opportunity to obtain a ‘screening opinion’ from the National Park Authority to determine whether the
application needs to be accompanied by an Environmental Statement. If it does, the regulations also
give the applicants the right to obtain a ‘scoping opinion’ from the National Park Authority to tell them
what the Environmental Statement needs to cover. EIA requirements can be difficult to understand and
are best discussed with planning officers as early in the planning process as possible.
In all cases it is important to contact Planning at the National Park Authority before works to install any
structures or equipment relating to micro-hydropower development are undertaken.
In addition to the need for planning permission, it is almost certain that detailed consents or licences will
also be required from the Environment Agency. The Agency has responsibility for most matters relating
to water courses, including abstraction, obstruction, impoundment and effects on wildlife. It is essential
that they are contacted before any planning application is submitted.
It is possible to use hydropower just to directly power an existing building or buildings. However, in most
cases it may be a much more viable proposition to feed the electricity produced into the public network
for direct financial return.
The National Park Authority will not seek to limit the scale of hydropower developments on the
grounds that they would exceed the energy requirements of the developer. The National Park
Authority positively encourages maximising the energy producing potential of hydro sites
wherever this is possible without radically increasing any adverse impact.
This approach is reflected in the terms and conditions of the National Park Authority’s Small-Scale
Hydropower Feasibility Fund – www.yorkshiredales.org.uk/renewables-hydrofeasibility – which is
available to encourage hydropower development. It was established following the completion, in 2009, of
Yorkshire Dales National Park Authority, June 2011
www.yorkshiredales.org.uk/cc-renewableenergy
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Energy Production in the Yorkshire Dales National Park:
a guide for developers and householders
a major research project looking into the practicalities of developing hydropower throughout the
Yorkshire Dales National Park.
Eligibility for funding is mainly limited to landowners, businesses and community groups who can
demonstrate that their project is of value to their communities and the businesses within the National
Park. It is not usually available to private householders unless wider public benefits would ensue.
Anyone contemplating a small-scale hydroelectric scheme is strongly advised, as a first step, to consult
the British Hydropower Association.
The next step is to seek independent professional advice on whether an initial site assessment suggests
that there is sufficient potential to warrant expenditure in conducting a full feasibility study to assess the
type of scheme most suitable to the site, and likely viability.
Planning and design considerations
Generally the challenges of assimilating hydro technology are ones for which solutions are much more
readily available than for those encountered with other technologies:
i.
ii.
The appearance of all of the elements of construction within and adjacent to the watercourse,
including dams, weirs, fish screens, fences, buildings and access tracks.
•
The design of the scheme should marry operational factors with those of landscape impact.
Special attention should be given to ways of assimilating a new development to the character of
the setting - for example, in locations where concrete or blockwork would be alien, but where it is
essential to include these materials for basic constructional purpose, stone facing needs to be
considered and assessed as part of the initial viability exercise.
•
Existing buildings should be used to house machinery wherever possible.
•
New buildings should be designed to fit in with the appearance and character of existing buildings
in the locality, and located as close as possible to them.
•
Metal structures should be kept to a minimum and painted in appropriate colours.
•
•
Signs should be as few and as discreet as possible.
Schemes should include landscaping proposals to help assimilation.
•
Breached walls should be rebuilt and not replaced with fences.
•
New access tracks, if needed, should be constructed of materials which will allow partial revegetation.
Disturbance to natural features of the landscape, including the river beds and banks, and ponding
behind weirs.
•
iii.
The choice of site for any construction within the river should be sensitive to its particular
characteristics and patterns of public access - for example, places used for recreational activities
should be avoided if possible, both to maintain the resource they provide and to minimise the
need to make special provisions for public safety, which is likely to add to visual intrusion.
Visual and ecological impact of loss of water from stretches of watercourse between inlet and outlet.
•
The Environment Agency controls the quantity of water which can be abstracted from most
watercourses, and takes into account the need to maintain certain flow levels to protect both their
ecology and their value to other users. The extent to which this may be an issue needs to be
given early consideration and the scheme tailored to meet likely constraints at the outset.
Yorkshire Dales National Park Authority, June 2011
www.yorkshiredales.org.uk/cc-renewableenergy
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Energy Production in the Yorkshire Dales National Park:
a guide for developers and householders
iv. Visual impact of leat construction.
•
v.
The construction of leats (engineered artificial watercourses) usually of bar concrete construction,
can add considerable visual impact. However, with care and appropriate site restoration, new
watercourses can enhance the landscape rather than detract from it. Adherence to a formally
agreed and detailed method statement is an important requirement.
Visual impact of pipeline burial.
•
In a high head scheme the route of the pipeline between inlet and powerhouse is an important
element capable, if handled insensitively, of greatly increasing the visual profile of the scheme.
Pipes do not have to be laid in straight lines or to descend continuously throughout their length they can be laid to closely follow the variations in ground detail. With careful planning and liaison
with National Park Authority staff, routes can usually be found which avoid important landscape
features and make best use of existing contours. Attention to detail at this stage, and commitment
to a detailed method statement for subsequent restoration, should usually make it possible to
produce a result which is visually acceptable.
•
There may be occasional situations where a pipeline would be more easily laid on the surface
than buried - for example, through woodland. This is likely to be unacceptable, apart from in
exceptional circumstances and when exposure to public view is minimal.
vi. Impact on the watercourse as a habitat for fish and other aquatic creatures.
•
The Environment Agency is responsible for ensuring that developments within watercourses do
not detract from their habitat value. Although this is an extremely important constraint to be aware
of, it is usually one which can be overcome through mitigation measures, including restrictions on
the time of year when initial development can take place, and the incorporation of features such
as fish ladders and screens. Early consultation with the Environment Agency is always very
strongly recommended. The need to protect fish can be an important consideration when
deciding upon the type of generator to be used in view of the alleged fish friendliness of
Archimedean screws, and the cost and other problems associated with providing screens for
conventional generators.
vii. Impact on ecological value of other land affected by the development.
•
If the location of the weir, leat, pipeline, powerhouse or tail race affects land known to support
plant communities or habitats of special value, this could, in exceptional circumstances be
problematic. However, it is much more likely that mitigation measures can be agreed. Early
consultation with the National Park Authority’s ecologists is therefore strongly recommended.
viii. Loss of trees.
•
Trees are important both as landscape features and as habitats for legally protected species,
including some species of bats. Their presence and retention can also make assimilation of a
development much easier. There must be as little tree loss as possible and if any is proposed it
has to be justified as being unavoidable. An assessment of the potential use of the trees by bats
will be required – this may result in the need for a full bat survey.
ix. Noise impact on residential properties and on public amenity generally.
•
This needs to be addressed through the detailed design of the powerhouse and the positioning of
the turbine within it. Although the noise that some larger generators cause can be extremely loud
when experienced close at hand, it is relatively easily reduced to an acceptably low level by
containment within a suitably designed building (especially where there is background noise from
the watercourse itself). The National Park Authority will consult the environmental health
Yorkshire Dales National Park Authority, June 2011
www.yorkshiredales.org.uk/cc-renewableenergy
pages 18-24
Energy Production in the Yorkshire Dales National Park:
a guide for developers and householders
department of the relevant district council and will act on their advice. Early consultation between
a developer and the relevant environmental health department is strongly recommended.
x.
Archaeological issues.
•
Most hydropower schemes will involve some ground excavation. It is always important that the
National Park Authority’s archaeologists are consulted as early as possible. Usually, mitigation
measures will overcome potential problems, but there may be cases where the site’s
archaeological value, especially if it is within a scheduled monument, present problems which are
insurmountable unless the scheme is re-located.
A high head scheme at
General and Coniston in
the Lake District National
Park. A building containing
both a powerhouse and a
bunkhouse – there has
been no complaints about
noise from people using
the bunkhouse.
A small high head
scheme at a farm near
Malham in the Yorkshire
Dales National Park. The
small stone shed
containing the generator
and other equipment for
the hydro scheme.
Halton Gill Hydro, a high
head scheme in the
Yorkshire Dales National
Park. The underground
route of the penstock can
been seen in front of the
trees, travelling down the
hill.
Bainbridge Hydro, a low
head scheme in the
Yorkshire Dales National
Park. The Archimedean
Screw turbine.
Bainbridge Hydro, a low
head scheme in the
Yorkshire Dales National
Park. The leat just after
construction was finished
Halton Gill Hydro, a high
head scheme in the
Yorkshire Dales National
Park. The water course
above the weir.
Yorkshire Dales National Park Authority, June 2011
www.yorkshiredales.org.uk/cc-renewableenergy
Halton Gill Hydro, a high
head scheme in the
Yorkshire Dales National
Park. The weir with a short
length of exposed
penstock.
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