IWA 33-2:2019

Technical guidelines for the development of small hydropower plants — Part 2: Site selection planning

This document specifies the general principles of site selection planning for small hydropower (SHP) projects, and the methodologies, procedures and outcome requirements of SHP plant site selection.

Lignes directrices techniques pour le développement de la petite hydraulique — Partie 2: Titre manque

General Information

• Status: Published
• Publication Date: 09-Dec-2019
• ICS: 27.140 - Hydraulic energy engineering
• Technical Committee: ISO/TMBG - Technical Management Board - groups
• Drafting Committee: ISO/TMBG - Technical Management Board - groups
• Current Stage: 6060 - International Standard published
• Start Date: 10-Dec-2019
• Completion Date: 10-Dec-2019

Standards Content (Sample)

INTERNATIONAL IWA
WORKSHOP 33-2
AGREEMENT
First edition
2019-12
Technical guidelines for the
development of small hydropower
plants —
Part 2:
Site selection planning
Reference number
IWA 33-2:2019(E)
©
ISO 2019

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IWA 33-2:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Planning principles . 1
5 Planning scope . 2
6 Planning methods and steps . 2
7 Basic data collection and analysis . 3
7.1 Data collection . 3
7.2 Data analysis . 4
8 Computation of river basin or sub-basin hydropower potential . 5
9 Preliminary planning of site . 7
9.1 Planning content and main considerations . 7
9.2 Types of SHP stations and applicable conditions for development . 7
9.2.1 Dam-type hydropower station . 7
9.2.2 Diversion-conduit-type hydropower station . 7
9.2.3 Reservoir-based, run-of-river hydropower station (hybrid) . 8
9.3 Utilization of several special geographical conditions of rivers . 8
9.3.1 Utilization of natural waterfalls . 8
9.3.2 Utilization of rapids or natural waterfalls . 8
9.3.3 Utilization of river bends . 8
9.3.4 Utilization of the fall on an irrigation channel . 8
9.3.5 Utilization of kinetic energy of flowing waters in a river or canal . 8
9.4 Estimation of the development scale of a hydropower station . 8
10 Site surveys and investigations. 9
10.1 Hydrological surveys . 9
10.2 Surveys on the planning site .10
10.2.1 Dam site surveys .10
10.2.2 Plant site surveys .10
10.2.3 Water conveyance line surveys .10
10.2.4 Reservoir survey .10
10.3 Preliminary determination of available water heads for the hydropower station .10
10.4 Other construction conditions for investigation .10
11 Preparation of site construction plan .11
11.1 Selection of installed capacity .11
11.2 Selection of turbine types .11
11.3 Number of units .11
11.4 Selection of dam type .11
11.5 Selection of spillway structures.12
11.6 Selection of water intake structures .12
11.7 Selection of diversion structures .12
11.8 Types of powerhouse .13
11.9 Location of switchyard .13
11.10 Location of tailrace .13
11.11 Layout of main structures .13
12 Preliminary assessment of social and environmental impacts .13
13 Assessment of power demand .14
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14 Cost estimation and benefits assessments .14
15 Evaluation of planning site and development sequence recommendations.15
16 Preparation of site selection planning report .15
Annex A (informative) Computation of theoretical potential of river water energy,
estimation formula for installed capacity on a planned site .16
Annex B (informative) Schematic diagram of development types and special terrain
utilization of SHP stations.19
Annex C (informative) Outline of a site selection planning report .24
Annex D (informative) Workshop contributors .29
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
International Workshop Agreement IWA 33 was approved at a workshop hosted by the Standardization
Administration of China (SAC) and Austrian Standards International (ASI), in association with the
International Center on Small Hydro Power (ICSHP), held in Hangzhou, China, in June, 2019.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
A list of all parts in the IWA 33 series can be found on the ISO website.
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Introduction
Small hydropower (SHP) is increasingly recognized as an important renewable energy solution to
the challenge of electrifying remote rural areas. However, while most countries in Europe, in North
and South America and in China have high degrees of installed capacity, the potential of SHP in many
developing countries remains untapped and is hindered by a number of factors including the lack of
globally agreed good practices or standards for SHP development.
The technical guidelines for the development of small hydropower plants contained in this document
address the current limitations of the regulations applied to technical guidelines for SHP plants by
applying the expertise and best practices that exist across the globe. It is intended for countries to
utilize this document to support their current policy, technology and ecosystems. Countries that have
limited institutional and technical capacities will be able to enhance their knowledge base in developing
SHP plants, thereby attracting more investment in SHP projects, encouraging favourable policies and
subsequently assisting in economic development at a national level. This document will be valuable for
all countries, but especially allow for the sharing of experience and best practices between countries
that have limited technical know-how.
This document is the result of a collaborative effort between the United Nations Industrial Development
Organization (UNIDO) and the International Network on Small Hydro Power (INSHP). About 80
international experts and 40 international agencies were involved in this document’s preparation
and peer review. This document can be used as the principles and basis for the planning, design,
construction and management of SHP plants up to 30 MW.
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International Workshop Agreement IWA 33-2:2019(E)
Technical guidelines for the development of small
hydropower plants —
Part 2:
Site selection planning
1 Scope
This document specifies the general principles of site selection planning for small hydropower (SHP)
projects, and the methodologies, procedures and outcome requirements of SHP plant site selection.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
IWA 33-1, Technical guidelines for the development of small hydropower plants — Part 1: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IWA 33-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Planning principles
4.1 Site selection shall be carried out in accordance with the laws and regulations of the relevant state/
provinces/country.
4.2 Site selection shall follow the principles of localized planning, subject to overall national integrated
water resources planning and to comprehensive river basin planning with the systematic prospection of
potential sites.
4.3 Site selection shall meet the requirements of the environmental needs of the river and surrounding
areas and also have preliminary plans to mitigate the negative impacts likely to be caused by the SHP
projects to the river and its surrounding environment.
4.4 Site selection shall be determined based on the water resources and topography with the purpose
of sustainable development, utilization, and along with comprehensive consideration of all other factors.
4.5 Site selection shall consider comprehensively the correlation of hydropower resource development
over the entire length of the river, with due attention to the interrelationship of upstream and downstream
cascade development, so that the layout of upstream and downstream sites are properly coordinated.
For multipurpose requirements for water supply, flood control, irrigation, ecology, tourism, navigation
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and community development, the SHP projects shall be planned in accordance with the primary and
secondary development purposes.
4.6 Site selection shall take into account the long-term electricity demand projection based on the
social and economic development of the area. Where indirect selling of electricity to other region(s) is
foreseen through the power grid, the current status and development plan of the grid shall be considered,
and the growth potential of the external power market shall be evaluated. According to the development
needs of the power market, planning should be carried out accordingly to meet the relevant short-,
medium- and long-term development goals.
4.7 Site selection shall make a justification of the selection of SHP in relation to other possible rural
electrification technologies.
4.8 Site selection shall take into account relevant local, regional and international integrated
development plans relevant to the area under study.
4.9 Site selection shall be coordinated with other relevant development plans of the area under study,
including planning indicators, terminology, units of quantities and values, implementation plans, and
shall be consistent and avoid conflicts.
5 Planning scope
5.1 The planning scope for site selection of SHP development shall be based on the level (local/state/
national) of the planning organization of the country.
5.2 If the SHP resource development plan is part of the comprehensive planning of the administrative
area (local/state/provinces), the scope of the site selection planning shall be defined in accordance with
the administrative divisional plan.
5.3 SHP development planning shall be based on the detailed and homogeneous definition of the river
network and catchments in the river basins.
5.4 Within exclusive economic development zone and nature reserve areas, site selection planning of
SHP development shall consider the multipurpose needs.
6 Planning methods and steps
The methods and steps described in Clauses 7 to 16 shall be taken according to the actual process of
site selection planning of SHP resource development (see Figure 1).
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Figure 1 — Flow chart of activities for SHP site selection planning
7 Basic data collection and analysis
7.1 Data collection
7.1.1 Adequate basic data shall be collected and analysed. Consideration shall be given to the use
of digital natural resource databases and geomatics technology (remote sensing and Geographical
Information System [GIS]). The authenticity, accuracy, timeliness and applicability of the collected data
shall be tested and confirmed.
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7.1.2 The following basic data shall be included.
a) Hydrometeorological data, including series of measured data, such as precipitation, flow in rivers,
evaporation, water level, sediment and ice. For the locations lacking the measured data, relevant
data on adjacent river basins and hydrological maps issued by the national or regional authority
should be collected.
b) Data of natural geography of river basin and river characteristics, including the topographic map
of the river basin (scale not less than 1:50 000), road map of administrative area, longitudinal and
cross-sections of river. Data on digital elevation/terrain models are available at 30 m, and better
resolution may also be used. If the hydro-meteorological data of adjacent river basins needs to be
utilized, the topographic maps of adjacent river basins shall also be collected.
c) Geological data, including regional geological, tectonic, seismic zoning maps, geological reports,
and records of major geological events such as earthquakes in the planning area.
d) Resource information, including land use, minerals, energy, forestry, tourism, rare animals and plants.
e) Power system data, including power source, power demand, annual power supply, load structure,
load curve, power grid structure, power markets, regulations and power-development planning in
the area.
f) Existing facilities data, including as-built design documents of existing hydropower stations,
irrigation, water supply, rafting, navigation and other projects within the planning river reach.
g) Socio-economic data, including the demography, industrial and agricultural production, road
network, gross national product, per capita income, and national economic development plans in
the area.
h) Other data, including natural disaster records, legal requirements, archaeology, historic sites,
protected areas and natural heritage.
7.2 Data analysis
7.2.1 Analysis of hydrometeorological data shall include the following.
a) Qualitative analysis
1) The data series shall be accurate, reliable and have no data gaps as far as possible.
2) The data shall be applicable to the river basins under study.
3) The accuracy of the data shall meet the analysis requirements. The precipitation/rainfall data
should be, as far as possible, “daily rainfall”. The measured data of flow shall be as precise as
“average daily flow”.
4) Appropriate analytical methods shall be used for quality control.
5) A reliable long-term daily discharge series specific to every river reach in the network should
be determined, based on distributed hydrologic modelling that is appropriately calibrated.
b) Quantitative analysis
1) Frequency analysis: The measured flow data series should be analysed and calculated
according to the probability formula of statistics, and the frequency curve should be drawn
according to the analytical results.
2) Correlation analysis: Correlation analysis shall be done when the measured flow data are not
on the location of the selected site for SHP development.
3) Average flow duration curve: Based on the data of frequency computation, select the flows
corresponding to the frequency of high flow, median flow and low flow. Then select a similar
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year from the flow series for annual distribution, if available, and distribute the average daily
flow within the next three years, plotted as an "average flow duration curve ".
7.2.2 Topographic map data analysis shall include the following.
a) Scope analysis: The topographic map shall include the drainage area of the river basin under study.
If rainfall or flow data of adjacent river basins are utilized, the topographic map shall also provide
the drainage area of the adjacent river basin.
b) Accuracy analysis: The scale of the topographic map used for the site selection should be no less than
1:50 000. If the scale of the collected topographic map is smaller than the specified requirements,
encryption measures shall be taken to improve the accuracy of contours. Global geometric data of
30 m or better resolution may also be used.
7.2.3 Geological data analysis shall meet the following requirements.
a) Incorporating the conclusions of the regional geological structural stability assessment, major fault
lines and the ground motion parameters determined for the project area.
b) It can reflect regional topography and geomorphology, stratigraphic lithology, geological structure,
hydrogeological conditions and physical geological phenomena.
7.2.4 Power system data analysis shall include the following.
a) Present status of the power grid and analysis of the power grid plan: including power grid structure,
geographical distribution, voltage levels and the relationship with, and impact on, proposed and
planned SHP development.
b) Power source and demand (load) status and planning analysis: including power source and demand
(load) structure, annual maximum power demand (load), annual minimum power demand (load),
annual demand (load) distribution, annual power supply, power growth rate, power markets,
regulations, impact of integration with other renewable energy such as wind and solar.
7.2.5 Other data analysis shall include a comprehensive assessment on the authenticity, timeliness and
relevance of the data.
8 Computation of river basin or sub-basin hydropower potential
8.1 The theoretical water energy potential of the river (reach) shall be expressed in terms of average
annual output (power) (kW) or average annual energy (kWh). The average annual output and the average
annual energy shall be mutually converted by the means of Formula (A.1).
8.2 The theoretical water energy potential of the river (reach) shall be calculated in segments. The
river shall be segmented in accordance with the following criteria.
a) A larger tributary entry point should be used as a segmentation point for river water energy
computation. Taking the tributary entry point as the interface, the adjacent section upstream is
the lower section of the upper reach, and the adjacent section downstream of the entry point is the
upper section of the lower reach.
b) The reach with a large change in the longitudinal slope of the riverbed shall be regarded as a
segment.
c) The reach having particularly advantageous development conditions shall be regarded as a
segment.
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8.3 The annual average flow at each analysis segment of the river shall be calculated, with their area
ratios based on the collected hydrologic data series of the river and the catchment areas of each analysis
segment of the river. If the flow data of the river basin is inadequate or unavailable, the information
should be obtained by the following methods.
a) If there is rainfall data on this river basin, the appropriate runoff coefficient should be converted
to the runoff in the same period with reference to Formula (A.2) or any other suitable formula or
methods.
b) If there is hydrological flow data on an adjacent river basin, the correlation with the river basin
shall be analysed, and the relevant data after revision may be used for water energy computation.
c) The hydrological flow parameters of the river basin can be obtained by using the hydrological
contours or effective charts issued by the hydrological or relevant department.
d) On-site measurement method.
8.4 The topographic map with a scale of 1:50 000 or higher should be used to verify and calculate the
elevation difference between the upper and lower sections of the reach by appropriate interpretation.
Use of Digital Elevation Model (DEM)/Digital Terrain Model (DTM) is encouraged.
8.5 Based on the flow rate of the upper and lower sections of the river reach and the elevation difference
between the upper and lower sections, the average annual output N (kW) of the reach shall be calculated
i
by the means of Formula (A.3). The average annual energy E (kWh) is calculated by Formula (A.1).
i
8.6 With the average annual output of water energy in each reach being accumulated, N , and the
∑
i
average annual power energy in each reach being accumulated, E , the theoretical water energy
∑
i
potential of the river (reach) may be obtained.
8.7 According to the above computation results, the theoretical potential of river water energy can be
calculated:
a) The relation curve between river elevation Z (m) and river length L (km): Z = f(L). Calculate the Z
and L values and draw the Z = f(L) curve on the rectangular coordinates. The curve shall show the
gradient of river water surface (or thalweg) along the river length.
3
b) The relation curve between river flow Q (m /s) and river length L (km): Q = f(L). According to the
flow rate Q calculated in 8.3, the value L is verified and calculated by using a topographic map or
DEM/DTM. Draw Q = f(L) curve on rectangul
...