h Hydropower | Part 1 1 | h Hydropower In the Rainforest, Sri Lanka

3 | h Penstock for Hydropower Plant Szklarska Poręba, PL

4 | h GRP Pipes Prove Their Worth in Bulgarian Hydropower Plants

6 | Optimal Penstock Routing With GRP Pipe Systems

8 | h Pipes for Austria’s first Mining Cave Power Station

9 | h GRP Pipes at Hydropower Plants in the Czech Republic

10 | h Replaces Wood Stave Penstock in New Hampshire, US

12 | Other impressive h Hydropower Projects

PipeLineIssue 3/2013

In the southwest of Sri Lanka, 1000 households are reliably supplied with green energy as of a few months ago. 478 m HOBAS GRP Pipes DN 2000 to 2200 help make the hydropower project Upper Kokawita a powerful source amidst the rich green rain forest.

Since the commissioning of the first hydroelectric power plant in 1950, hydropower has played a major role in electricity generation in Sri Lanka*. Thanks to the country’s humid climate conditions and its hilly terrain, Sri Lanka offers excellent opportunities for generating hydroelectric power both through larger government-owned and private small hydropower plants. In 2012, a new small hydro facility was put into service at the river Wewa Ganga in the village of Kokawita, close to the city of Kalwana in the southwest of Sri Lanka. The client chose HOBAS to supply the required quality pipe system.

h Hydropower in the Rainforest, Sri Lankah Pipes help produce 1.2 MW of clean energy

h PipeLine | Issue 3/2013 | Page 02

The terrain on site posed quite a few challenges to the installation. It is hilly, made up of partly loose and partly very rocky soil, and the planned pipe route along the Wewa Ganga river bank was very difficult to access. By means of a 20 ton excavator, the pipe sections were transported to their required positions and then installed according to the soil conditions: Roughly half of the 478 m long pipeline was laid on supports above ground (275 m), the

other half was buried (203 m).

After 12 months, the installation was successfully finished. With a head of 17 m, a capacity of 1.2 MW

and a flow rate of 10 m³/sec, the hydropower plant Up-per Kokawita now supplies 1000 homes in Kokawita with

clean energy. The client Terra Aqua Kokavita (Pvt.) Ltd is more than satisfied with the minimal head loss in HOBAS Pipes

thanks to their mirror-like inner surface and very much appreciates their proven durability. This makes

them the perfect solution for a sustainable, environmentally friendly energy project.

Fmd: info@hobas.com

Year of construction

2012

Construction time

12 months

Total length of pipe

478 m

Diameter

DN 2000-2200

Pressure class

PN 1-4

Stiffness class

SN 5000 and 10000

Head

17 m

Flow rate

10 m3/s

Capacity

1.2 MW

Installation method

Above ground on

supports (275 m),

buried (203 m)

Client

Terra Aqua Kokavita

(Pvt.) Ltd

Designer / Constructor

Pacific Hydro Electric SL

(Pvt) Ltd

Advantages

Minimum head loss,

long service life

E Engineering GmbH | Pischeldorfer Str. 128 | 9020 Klagenfurt | Austria

T +43.463.48 24 24 | F +43.463.48 21 21 | info@hobas.com | www.hobas.com

* Source: Sri Lanka Sustainable Energy Authority 2013

h PipeLine | Issue 3/2013 | Page 03

Hydropower On the Rise In Polandh Penstock for Hydropower Plant Szklarska Poręba 1

Poland’s energy production is mainly based on coal and lignite. Hydropower covers only around 3 % of the total energy demand. In order to reach the EU target of increasing renewable energy sources from 10 to 45 % by 2030, the country is busily working on making its power supply system “greener”. One project in this regard is the renovation of the penstock leading to the hydropower plant Szklarska Poręba 1.

The hydropower station in Szklarska Poręba, a town in south-western Po-land, was built in 1934. In the course of the years, the performance of the almost 1-km-long steel penstock decreased significantly. By 2012 parts of it were damaged to a degree that they had to be replaced. The contractor compared different replacement materials and finally HOBAS was awarded the contract thanks to a variety of advantages. Apart from benefits such as small flow resistance, high stiffness and the possibility of angular deflections in the couplings, visual aspects also played an important role: As popular tourism resort, Szklarska Poręba needs to take particular care of its appearance. Since parts of the pipeline pass through forests above ground, the client asked for the pipes to be produced in a special shade of green in order to match the pipeline with its environment. No problem for HOBAS: A special pigment was added to the resin during the production process. This way the color is part of the pipe and cannot wash off or fade.

Joining the HOBAS Pipe DN 1500 to the existing steel pipeline posed a challenge to the installation team for the old penstock had ovalized. In order to re-establish and stabilize the round shape of the steel pipeline a stainless steel ring has been welded to it. Then the GRP pipe was connect-ed to it with a stepped coupling. A total of 240 m HOBAS Pipes DN 1500 were partly buried, partly installed on supports above ground with angular deflections in the HOBAS FW Couplings. The client is satisfied with his choice and glad to make a contribution to reduce Poland’s carbon footprint.

Fmd: hobas.poland@hobas.com

Year of construction

2012

Construction time

3 months

Total length of pipe

240 m

Pipe characteristics

DN 1500, PN 6, SN 10000

Client

TAURON Ekoenergia Sp.

z o.o.

Contractor

PPHU WAMAR

Installation

Above ground on sup-

ports, open trench

Advantages

Possibility of coloring

the pipe, corrosion resis-

tance, angular deflec-

tions in couplings, good

hydraulic performance,

quick and easy installa-

tion, tight connections,

sturdy structure

* Source: Sri Lanka Sustainable Energy Authority 2013

h PipeLine | Issue 3/2013 | Page 04

Green Energy from Bulgarian Mountainsh CC-GRP Pipes Prove their Worth in Hydropower Plants Kalin and Sokolna

Hydropower plants in Bulgaria play an important role in covering peak consumption. Two particu-larly interesting ones have been realized with HOBAS Pipes – and they are doing an excellent job in providing the country with clean energy.

The name “Rila” means “well-watered mountain”, which is definitely a suitable name for the highest mountain range of Bulgaria and the Balkan Peninsula: It features more than 200 lakes and a great number of mineral springs. Rila is also the name of the first complete cascade of hydropower plants in the Bulgarian mountains. The highest one among them is Kalin which feeds the other plants from 2394 meters altitude and, with a flow rate of 650 l/sec., generates 4 MW. Kalin was built in the 1940s. At the time, the reservoir was connected to the powerhouse with a 2-km-long steel pipeline DN 600 leading through a tunnel in the mountain on concrete supports.

Over the years the pipe corroded, weakened and could no longer withstand the water pressure. It became inevitable to replace at least 300 m of the pipeline in an altitude of approximately 2200 m. Drawing on very good experiences with HOBAS, the client BAD Granitoid AD decided to opt for HOBAS Products again for a variety of reasons – among them the pipe system’s reliable tightness, dimensional accuracy and low weight that facilitated the transportation via the narrow and steep way to the Kalin powerplant. The 3-m-long pipe sections were brought close to the construction site with trucks, then loaded onto trolleys and transported to the entrance of the tunnel on small rails, which lead all the way alongside the pipeline inside the tunnel. 375 m of steel pipes were dismantled and replaced by HOBAS GRP Pipes with the help of winches. In ad-dition, some of the old concrete supports had to be removed and new ones built. Despite all challenges, the installation works could be completed within one week only and the client was more than satisfied.

Year of construction

2012

Total length of pipe

375 m

Diameter

DN 700

Pressure class

PN 10

Stiffness class

SN 5000

Installation method

Above ground in a

tunnel on supports

Capacity

4 MW

Client

BAD Granitoid AG

Advantages

light weight, optimum

hydraulic properties,

leak-tightness, long ser-

vice life, easy and fast

installation

h PipeLine | Issue 3/2013 | Page 05

The village of Skobelevo is located in south-eastern Bulgaria on the fringes of the Sokolna reserve right in the heart of Bulgaria’s longest

mountain range the Balkan Mountains. At the hydropower plant Sokolna in Skobelevo, approximately 1.5 km of HOBAS Pipes DN

1200, SN 10000, PN 6 and 10, are reliably in service since 2008. The pipes were installed in the valley of Gabrovnitsa River, which originates at the foot of Triglaw in Balkan National Park and flows into one of the largest reservoirs of the country. The steep, stony and curvy route posed quite a challenge regard-ing planning and installation works.

To optimize investments as well as the plant’s efficiency, HOBAS recommended to the client to use angular cut HOBAS Pipes for the penstock. Most of the route’s curves (approx. 100) could be realized this way. The pipeline was mounted on concrete supports above ground. Apart from their various installation possibilities, HOBAS Pipes also

scored with their pressure resistance – an important quality, given the hydraulic head of 70 m. Thanks to the joint efforts

of the investor and HOBAS, the Sokolna power plant has now been supporting the power supply of the region 5 years with

optimized capacity.

Fmd: hobas.bulgaria@hobas.com

Year of construction

2007-2008

Total length of pipe

ca. 1500 m

Diameter

DN 1200

Pressure class

PN 6 and PN 10

Stiffness class

SN 10000

Installation method

Above ground

Capacity

1074 MW

Client

Forum Ltd.

Advantages

light weight, optimum

hydraulic properties,

leak-tightness, long ser-

vice life, easy and fast

installation

h PipeLine | Issue 3/2013 | Page 06

Ahead Of the Curve with h Optimal Penstock Routing with GRP Pipe Systems

From an economic and ecological perspective, the importance of hydropower is definitely on the rise as it provides an array of advantages compared to other conventional methods of power generation. Despite the initial investment obstacle, small hydropower plants prove cost-effective thanks to their long service life of often more than 70 years and low maintenance costs . Dams, canals, intakes and penstocks obviously cost a very different share of the total for different sites. A lot depends on the topography and the geology, but also on the construction method and the materials. The penstock often constitutes a major expense in the total budget, as much as 40 % is not uncommon in high head installations and it is therefore worthwhile choosing the material carefully in regard to surface roughness, design pressure, method of jointing, weight and ease of installation, service life and main-tenance. The trade-off is between head loss and capital cost. Regarding penstock design, there is, however, a possibility to save without compromise: curved HOBAS GRP Pipe installation with fewer or no fittings.

Curved InstallationSince penstocks of small hydropower plants are often set in remote places which are sometimes also difficult to access, the topography does not allow a fully straight pipeline, which for sure would be beneficial for the hydraulic properties (low head loss). The constructors are confronted with horizontal as well as vertical curves which can be realized with conventional elbows or alternatively by curved installation with for instance shorter angular cut pipe sections and flexible joints which accommodate a deflection that is higher than what relevant GRP product standards provide.

Economic and Hydraulic BenefitsWhile some deflection can be accommodated in the HOBAS FWC Joint to achieve curves with larger radii, shorter pipe sections will produce smaller ones, and angular cut pipes will reduce the radii even further, especially in larger diameter lines. The penstock, mounted above ground on saddles or installed underground, is this way optimally routed, no or fewer fittings and concrete thrust blocks are utilized. Regarding the often remote and difficult to access construction sites, each omitted cast in situ concrete block represents substantial cost as well as time savings. Besides the above mentioned economic benefits, curved installation, angular cut or not, substantially increases the pipe’s efficiency for there are less hydraulic losses than if elbows are employed.

h PipeLine | Issue 3/2013 | Page 07

Quality AssuranceTo verify the leak tightness of joints with angular deflected as well as angular cut pipes, stringent tests to ISO 8639 have been conducted at the TÜV and governmentally (ISO 17025) accredited TechCenter in Wietersdorf, Austria.

Apart from the pipe system itself, external factors play an equally decisive role and need to be carefully checked to verify if curved installation is suit-able for the respective project. Drawing from numerous laboratory tests as well as more than half a century of experience, HOBAS Experts provide support for such feasibility studies and make sure that each project receives a hydraulically as well as economically optimized pipe solution. Special attention also needs to be paid to the correct installation of the line and should always be conducted to the individually prepared method statement by HOBAS as well as latest respective standards: For underground con-structions appropriate pipe trenching and bedding, soil conditions (ground-water interference, soil type, etc.) and field conditions (slope, traffic, frost heave, etc.) need to be ensured. For penstocks mounted above ground, the saddle design as well as the fixation of the pipe or coupling need to be taken into consideration. During every project phase HOBAS Experts will provide support and know-how.

The approved long life, low maintenance and outstand-ing hydraulic properties of HOBAS GRP Pipes will bring out the best of every hydropower plant in terms of safety, efficiency and profitability – for you to stay ahead of the curve.

Fmd: info@hobas.com

1 www.energysavingnow.com2 www.microhydropower.net

h PipeLine | Issue 3/2013 | Page 08

Energy From Cavesh Pipes for Austria’s first Mining Cave Power Station

Water has always been of major significance to the traditional Austrian spa and mining village Bad Bleiberg. The nearby 2166-meter-high mountain Dobratsch has acted a big part in providing

spring water for centuries. On the mountain’s north side, 1015 meters above sea level, lays the Nötschbach Spring, which peaks at 500 liters per second. Amongst others, this spring

was to be used for the erection of a new hydropower plant in the abandoned mining caves 260 meters below ground.

The idea to construct a new small hydropower station at this old mining site origi-nates from Christoph Aste, an engineer who has been pursuing this project since 2004 with great endurance. 2009, he finally received the license to implement his plans. The Limited Liability Partnership AAE-Entwicklung who erected the station was founded together with AAE Energie in Kötschach-Mauthen.

One of the first jobs in the framework of the construction plans concerned the pressure pipe from the Nötschbach Spring, which had been erected for the mine in the 1890s. Since the old pressure pipes DN 360 made of English cast iron turned out to be tight, the first part of the old line was left as it is. Due to the mountainous area and since the pipe routing could not be altered the old line was continued with state of the art pipe technology: The old cast iron pipe was cut and

continued with HOBAS GRP Pipes DN 300, SN 10000, PN 16. The new pressure line now runs for about 980 meters through the spa town to the mining shaft build-

ing at the Rudolf Shaft. “The GRP Pipe System from HOBAS presented a functional solution. We could install almost the complete line without fittings. The required radii

were achieved with angular deflections in the joints and with angular cut pipe ends pro-duced at the HOBAS Factory. HOBAS Experts supported us during the complete

planning phase”, states Aste.

A distribution system was installed at the entrance to the Rudolf Mining Shaft, where all water leads into a cast iron pressure pipes. In turn,

this line leads into a pipe lined with cement mortar which vertically runs down along the wall of the Rudolf Shaft up to the old existing

hydropower station. A high pressure hydroelectric generating set for efficient electricity production was installed at a depth of 260 meters.

This hydropower project has been successfully implemented between May 2010 and September 2011. Meanwhile, the facility has been in service for 1.5 years and is supplying the network of KELAG – one of Austria’s leading energy provid-ers – with about 1.5 million kWh per year. For additional elec-tricity generation, a part of the naturally occurring thermal water is planned to be conveyed to the turbine. The rest of it will be warmed by a heat pump and fed into the local thermal baths.

Fmd: hobas.austria@hobas.com

Year of construction

2010-2011

Construction time

16 months

Total length of pipe

980 m

Pipe characteristics

DN 300, PN 16, SN 10000

Installation method

Open trench

Project operator & Designer

AAE-EntwicklungsGmbH

Christoph Aste

Advantages

Saving on fittings thanks

to the HOBAS Angular

Cut GRP Pipe System,

easy handling, long

service life, corrosion

resistance

h PipeLine | Issue 3/2013 | Page 09

A Customized Solution for Tanvald h GRP Pipes for Hydropower Plants in the Czech Republic

In 2011, HOBAS Czech Republic started cooperating with Kredit Cen-trum s.r.o., a Czech company that operates several hydropower plants throughout the country. That same year this partnership resulted in a first order: HOBAS Pipes were installed for two hydropower plants in the town Tanvald.

Working very closely with the designers of the projects the technical de-partment of HOBAS CZ slightly modified the original idea to make full use of the advantages HOBAS Pipes offer: angular cut shorter pipe elements of 2 and 3 meter length enabled the construction company to closely fol-low the route originally planned by the client. HOBAS Experts prepared a detailed layout plan to facilitate installation. To cope with the high ground-water level on site geotextiles were employed and fixed with gravel to secure the pipes and keep them in place.

In total 221 meters of HOBAS Pipes DN 1400, SN 5000, PN 6 were installed open cut: 91 m at one hydropower plant and 130 m at another facility 0.5 km from the first. In both cases, HOBAS Pipes were used to connect the future pipeline to the already existing structure of the hydro-power plants. HOBAS Fittings were delivered in addition to the pipes.

The client was very satisfied with the technical support prior to and during installation of the HOBAS Experts; the installation was fast and went smoothly.

Fmd: hobas.czech@hobas.com

Year of construction

2011

Total length of pipe

221 m

Diameter

DN 1400

Pressure class

PN 6

Stiffness class

SN 5000

Installation method

Open trench

Client

Kredit Centrum s.r.o.

Constructor

Kredit Centrum s.r.o.

Advantages

Long life service, leak

tightness, technical

support, custom-made

solutions

h PipeLine | Issue 3/2013 | Page 10

GRP Pipes For the Granite Stateh Replaces Wood Stave Penstock in New Hampshire, US

Public Service of New Hampshire (PSNH), the Granite State‘s largest electric utility, serves more than 475,000 homes and businesses by means of nine hydroelectric

plants. One of them is the Jackman Hydro Station in Hillsborough. Built in 1926, the station was supplied by a 1.52 km long wood stave penstock

with a diameter of 2300 mm. After serious leakage problems and con-stant maintenance works, a significant rupture of the wooden pipe in

2003 lead PSNH to opt for a new pipeline.

Kleinschmidt, a company headquartered in Maine and special-ized in energy and water resource projects, was employed

to engineer a replacement pipeline. They evaluated five pipe material options: wood stave, concrete, HDPE plastic, steel and fiberglass reinforced polymer (GRP). The materials were compared regarding their structural reliability, corrosion resistance, hydraulic capacity, ease of installation (pipe weight) and performance history. The fiberglass option proved the most favor-able. “The corrosion resistance and relative stiffness of GRP meant the pipes could be supported on the existing grade and half buried, rather than complete-ly placed on saddles or covered in a buried trench,” stated Keith Martin, engineer with Kleinschmidt’s.

The pipe design flexibility, combined with a long projected service life made the client purchase CC-GRP pipes manufactured by HOBAS PIPE USA.

The low frictional resistance of HOBAS CC-GRP Pipes allowed the replacement pipe to be reduced to a

2100 mm diameter.

The job site posed some challenges as it was a remote area and the installation point could not be

accessed by truck. “More than 300 m of HOBAS Pipes were unloaded near the

roadside. The individual pipe sections were then carried to the point of

installation with an excavator,” said Newell Porter of the build-ing contractor CCB. The first part of the installation was through a curve where 3 m joint sections were con-nected by a HOBAS FW

Above: The new HOBAS GRP Penstock

Below: The old wooden penstock

h PipeLine | Issue 3/2013 | Page 11

Year of construction

2007

Construction time

3 months

Total length of pipe

311 m

Diameter

DN 2100

Pressure class

PN 3.5

Stiffness class

SN 6400

Installation method

Above ground installation

Client

Public Service of New

Hampshire

Contractor

JML Trucking and Exca-

vating

Advantages

Design flexibility, corro-

sion resistance

Coupling and then deflected. After assembly, each single joint was suc-cessfully tested for tightness. Most of the pipe was half buried in the shallow trench of the existing penstock, minimizing excavation costs and environmental disturbance. Approximately 91 m of the new penstock were supported above ground on steel saddles to minimize the impact to the wetlands that the penstock crossed. To achieve the higher axial strength necessary for the aboveg-round installation, additional reinforcement had been placed in the pipe during the centrifugal casting process.

The pipeline was put into service two weeks ahead of schedule and PSNH was more than satisfied. Once the line was in operation, the leak-tightness of the joints was checked once again and reconfirmed. Butch Lane from JML Trucking and Excavating, the installation sub-contractor for CCB, echoed the general contractor’s sentiments: “It really is a good pipe. We’ve had people come by and look at the project, and they are all happy.”

Fmd: info@hobaspipe.com

HOBAS Pipes north of the polar circle in Helleren, NO

Other impressive h Hydropower Projects...

The first HOBAS Hydropower Pipeline in 1961, CH

HOBAS Pressure Pipes lead water to

Tyrolean hydropower plant, AT

Clean energy for Bella Italia with HOBAS Hydropower Pipelines

HOBAS Hydropower Pipeline in Andakill, IS

h PipeLine | Issue 3/2013 | Page 12

The next edition of the HOBAS PipeLine will be issued in August and will once more be all about Hydropower. You can look forward to interesting projects in Chile, Italy, Ruanda, Austria and other countries!