Energy recovery in water supplyBGENERGY-1.001-0001. Webinar on hydro power in water supply systems, 08.06.2021

About Norconsult

Jonas Jessen Ruud to present Norwegian experiences with hydro

power units in water supply plants

Hans Olav Nyland to present findings from analysis based on the

studies performed by SEDA, along with criteria and assumptions for

a successful project (lessons learned)

Contents

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Norconsult is Norway’s largest,

and one of the Nordic region’s

leading, interdisciplinary

consultancy firms within social

planning, engineering design,

and architecture. We contribute

to a more sustainable society

and generate benefits for the

community through innovative

and targeted consultancy

services.

About Norconsult

2020-12-01 3Corporate presentation Norconsult

Fakta

2021-01-01 4Corporate presentation Norconsult

* Pr. 31.12.2019

Ill.: LP

O a

rkite

kte

r

4 600 Employees

119 Offices

11 Business areas

20 000 Projects

6,3 Billion NOK revenues*

49 Countries in whichwe have projects

Key figures

* Per. 31.12.2019

119 offices on four continents

52020-12-01 Corporate presentation Norconsult

Mozambique

Philippines

Thailand

Malaysia

Zambia

Botswana

New Zealand

Sweden

Denmark

Norway

South Africa

PolandIceland

Countries with permanent offices

Countries with projects in 2019

Countries with projects since 1956Pr. 31.12.2019

Finland

Business areas

62020-12-01

Architecture Buildings Energy

IT

Industry

Oil and Gas Planning

Risk ManagementTransport Water

Environment

Corporate presentation Norconsult

Project: BGENERGY-1.001- 0001 ”Feasibility study of the use of hydroenergypotential of existing water supply systems and increasingthe potential of existing small hydroelectric power plants in water supply systems”

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• Relevant sites for combining water supply and hydropower in Bulgaria has been studied

and data about potential sites has been collected by SEDA

• Based on documents received from NVE/SEDA, Norconsult has performed an evaluation

of 60 potential sites relevant for the introduction of hydro power in water supply facilities,

and from these extracted the sites that appear to have the highest potential. For each of

these we have performed a brief cost benefit analysis indicating potential for annual power

generation and capacity, as well as cost

Document basis

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As basis for this project, the following documents has been received from Seda:

SEDA: Report of identified locations and energy potential assessment (Translated under

Contract РД 05-02-26/03.07.2020. The Bulgarian text of the report is approved by Ivaylo

Aleksiev, Executive Director of SEDA – beneficiary of the BGENERGY-1.001-0001 Project).

SEDA: Summary Database Sites_EN. This is a database over 60 sites with owner information

and plant data

SEDA: Summary Report_Sites_EN. This is a summary report of the results of the activity,

including an assessment of the possibilities for extension of the water supply scheme and the

possibilities to integrate hydroenergy generation to replace pressure reduction valves.

(Translated under Contract РД 05-02-26/03.07.2020. The Bulgarian text of the report is

approved by Ivaylo Aleksiev, Executive Director of SEDA – beneficiary of the BGENERGY-

1.001-0001 Project)

Intake and waterway

Already in place

Not causing excessive

headloss

Assumptions

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Turbine selection diagrams

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Ref: Andritz

Ref: JHD

Submergence requirements

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• NPSH

• Space constraints

Turbine selection, summary

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Turbine type Key features Comment

Pelton turbine Governable from 5%-100% of max flow. High efficiency over a

broad flow range. Typically to be used at heads above 80-100 m

or specific speeds nq<20-30. Needs a free surface outlet

Preferred type if possible, Expensive and space

demanding

Francis turbine:

A. Regular Francis turbine

Governable from 30%-100% of max flow. High efficiency above

60-70% load. Typically to be used at heads below 80-100 m or

specific speeds nq>20-30. Needs a submerged outlet, as

required by the turbine supplier

Expensive and space demanding if equipped with

guide vane apparatus

Francis turbine:

A. PAT (pump as turbine,

reversed pump)

Has no guide vane apparatus and thus only one operational

point near maximum flow (one flow, operation on and off).

Needs a relief shaft for water regulation and submerged outlet,

as required by the turbine supplier

Inexpensive and takes little space. Possibilities for

matching the system to actual demand are very

low. Lower efficiency than regular Francis.

Kaplan turbine Suited for the combination of low head and high flows.

Governable from 20%-100% of max flow.

Expensive and space demanding. The combination

of low head and high flow is not typical for water

supply facilities. Water contamination risk due to oil

filled parts in the waterway

Other “Smart» turbine solutions

and prototypes

Various turbine types are available Often low efficiency. No good experiences known

to Norconsult over time. Stick to proven technology

Turbine selection SEDA - Bulgaria

Site number 5 8 21 23 24 27 36 47 48 57

Name Burgas Burgas Dobrich Kardzhali Kardzhali Kuystendil Pernik Staga

Zagora

Staga Zagora Haskovo

Capacity m³/s 0.25 0.95 0.1 0.4 0.4 0.14 2 0.55 0.4 0.107

Head m 84 33 20 23 61 29 43 71 54 45

Density kg/m³ 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000

Gravitational acceleration m/s² 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81

Efficiency 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8

Electrical Power kW 164.8 246 16 72 191 32 674.9 306 170 38

Estimated Operating hours Hours 5000 5000 5000 5000 5000 5000 5000 5000 5000 5000

Yearly Production kWh 824 040 1 230 174 78 480 361 008 957 456 159 314 3 374 640 1 532 322 847 584 188 941

Eletricity price €/kWh 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

Depreciation 12 12 12 12 12 12 12 12 12 12

Total Production Value € 988 848 1 476 209 94 176 433 210 1 148 947 191 177 4 049 568 1 838 786 1 017 101 226 729

Turbine Type P F F F F F F F F F

Specific Price Electromechanical

Equipment

€/kW 800 880 1 600 1 200 940 1 400 700 830 900 1 150

Total Price Electromechanical € 131 846 216 511 25 114 86 642 180 002 44 608 472 450 254 365 152 565 43 456

Estimated Building Costs € 46 146 75 779 8 790 30 325 63 001 15 613 165 357 89 028 53 398 15 210

Estimated Consulting costs € 62 297 102 301 11 866 40 938 85 051 21 077 223 232 120 188 72 087 20 533

Estimated Power Plant Cost € 240 290 394 591 45 770 157 905 328 053 81 298 861 039 463 581 278 050 79 199

Comment

Has already

a turbine

Results

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The headloss in the penstocks analysed, appear to

be moderate and well designed, seen from a

hydropower perspective

General findings

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NOTE: The available information about each water supply plant site is limited.

Therefore, in the following description of suggested solutions introduced to

specific sites we will use SEDA’s own site numbers for reference to each site,

and present principal solutions only.

The following sites has been selected among the most attractive projects:

Site No 5 at Burgas municipality (Pelton turbine suggested)

Site No 8 at Burgas municipality (Francis turbine suggested)

Site No 47 at Staga Zagora municipality (Francis turbine suggested)

Detailed recommendations to each site

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Pelton unit configuration in water supply plants

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Load control of a Pelton unit

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©

Vertical small hydro Pelton unit with electric

actuators for injector control and no deflectors

Horizontal large hydro Pelton unit with straight flow injector with double

acting injector servomotor operated with oil pressure, with deflectors

Francis unit configuration in water supply plants

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PAT configuration in water supply plants

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PAT

Regular Francis turbine

PAT

Difference in load control of a regular Francis Vs. PAT

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Ref. EnergiTeknikk,

Norway. Horizontal

Francis turbine

Ref. KSB, Germany

𝑃𝑔 = 𝐻 ∗ 𝑄 ∗ 𝑔 ∗ 𝜌𝑤𝑎𝑡𝑒𝑟 ∗ 𝜂𝑔𝑒𝑛𝑒𝑟𝑎𝑡𝑜𝑟 ∗ 𝜂𝑡𝑢𝑟𝑏𝑖𝑛𝑒

Time t

Space

Limitations to the concept

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Dam safety

High voltage requirements

Municipal permits

Non-profit

Regulations and permits

07.06.2021 22

Positive focus on sustainable energy solutions in the organization, and willingness to pay more up front to achieve this

Acceptance for the project being engineering intensive, due to criticality, need for robustness and redundance, and good planning of operations to minimize outage and water supply cutoff

O&M staff are often heavily loaded already, new assets should thusnot tie up more resources. → Hassle free solutions and well proventurbine and valve technology! Bad experiences with turbines oftencause negative attitudes towards hydro power in water supply

When you go the extra mile with the engineering, safeguarding a robust function plan and turbine technology, the plant can generatestable income and green, short traveled electricity for generationsto come!

Hydro power in water supply also represents a positive SHA measure, as turbines generate less noise and vibrations thanthrottling/energy dissipating valves

Inouse electricity supply requires skilled, inhouse high voltagepower professionals. If not in place; sell the power directly in thepower market

Excess heat to supply the heating in the treatment plant offices

Power line removed and buried in trench. →Recreational benefit

Lessons learned. Premises for successful projects

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Goal: Robust plants with automatic operation and hassle free operation

Functional plans

Bypass line is the main line

Redundancy

A proper control system

A broad flow range enables even power/water production and high operational flexibility

If PAT is selected, even higher requirements to the control system

Robust solutions

Pelton unit at site 5, regular Francis units at sites 8 and 47

Conclusions

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Our knowledge contributes to a more valuable society