REPLACE POWERHOUSE ONE EMERGENCY DIESEL GENERATOR · diesel generator is properly sized to fulfill its first purpose, the risk of a black plant condition becomes much less likely

A REPORT TO

THE BOARD OF COMMISSIONERS OF PUBLIC UTILITIES

Electrical

OESSIQ Mechanical

CivilF,LRSM:VIOcfl

MARKBEST

Protection & Control

0'[)A rE Transmission & Distribution

Telecontrol

System Planning

REPLACE POWERHOUSE ONE EMERGENCYDIESEL GENERATOR

Bay d'Espoir

July, 2011

newfoundland labrador

hydroa nakor energy company

BDE – Replace Powerhouse One Emergency Diesel Generator

Newfoundland and Labrador Hydro i

Table of Contents

1 INTRODUCTION ................................................................................................................ 1

2 PROJECT DESCRIPTION ..................................................................................................... 3

3 EXISTING SYSTEM ............................................................................................................. 4

3.1 Age of Equipment or System ............................................................................... 5

3.2 Major Work and/or Upgrades ............................................................................. 5

3.3 Anticipated Useful life .......................................................................................... 6

3.4 Maintenance History ........................................................................................... 6

3.5 Outage Statistics .................................................................................................. 6

3.6 Industry Experience ............................................................................................. 7

3.7 Maintenance or Support Arrangements .............................................................. 7

3.8 Vendor Recommendations .................................................................................. 8

3.9 Availability of Replacement Parts ........................................................................ 8

3.10 Safety Performance ............................................................................................. 8

3.11 Environmental Performance ................................................................................ 8

3.12 Operating Regime ................................................................................................ 9

4 JUSTIFICATION ............................................................................................................... 10

4.1 Net Present Value .............................................................................................. 10

4.2 Levelized Cost of Energy .................................................................................... 10

4.3 Cost Benefit Analysis .......................................................................................... 10

4.4 Legislative or Regulatory Requirements ............................................................ 11

4.5 Historical Information ........................................................................................ 11

4.6 Forecast Customer Growth ................................................................................ 12

4.7 Energy Efficiency Benefits .................................................................................. 12

4.8 Losses during Construction ................................................................................ 13

4.9 Status Quo .......................................................................................................... 13

4.10 Alternatives ........................................................................................................ 13

5 CONCLUSION .................................................................................................................. 14

5.1 Budget Estimate ................................................................................................. 14

5.2 Project Schedule ................................................................................................ 15


Newfoundland and Labrador Hydro Page 1

1 INTRODUCTION

Newfoundland and Labrador Hydro’s (Hydro) largest hydroelectric generating station in the

Island Interconnected System is located at Bay d’Espoir. The Bay d’Espoir Hydroelectric

Generating Station (Bay d’Espoir) consists of seven generating units producing a total

capacity of 604 MW which is approximately 39 percent of the Island Interconnected

System’s generating capacity. Figure 1 shows Powerhouse 1 which houses six of the seven

generating units, each having a rated capacity of 75 MW.

Figure 1 – Bay d’Espoir Generating Station Powerhouse 1

As with Hydro’s other major generating stations, Powerhouse 1 in Bay d’Espoir is equipped

with a back-up emergency diesel generator, which is capable of producing 200 kW of

power. The purpose of an emergency diesel generator in a hydroelectric plant is to provide

the necessary power required to return one generating unit back into operation when all

units are shut down and no other source of power is available, a condition known as a black

plant. When one generating unit is restored the plant becomes self sufficient and the power

produced is able to be used to restore the other generating units and equipment.



The emergency diesel in the Bay d’Espoir hydroelectric plant has a dual purpose. The first

purpose is that it is the last chance source for station service (the system that supplies

electricity to the powerhouse). The diesel only supplies power to critical loads to keep the

units running and to provide emergency lighting for operations personnel moving around

the plant operating equipment to keep the plant in operation. Hydro Units can withstand

short power outages without shutting down. However after a minute or so, the units will

begin to unload (produces less and less electricity) as the governor oil pressure decays (no

power for the hydraulic oil pump) and the force of the water gradually closes the wicket

gates allowing less water through the unit until it eventually shuts down This happens

within minutes from the time power is lost. The second purpose is to provide black start

capability for the plant when it is in a black plant condition. Two of the six units in Bay

d’Espoir powerhouse No 1 have the ability to supply station service when they are running.

In a black plant condition, these units would be started first using power supplied by the

diesel generator.



2 PROJECT DESCRIPTION

This project will replace the emergency diesel generator, control panel and associated

auxiliary equipment in Powerhouse No. 1 at the Bay d’Espoir Generating Station. Due to

space limitations of the existing diesel room and the required increase in genset capacity, a

containerized module unit will be purchased and installed on a concrete pad directly

outside the powerhouse beyond the transformers. The single module will include the

genset, switchgear, fuel system and auxiliary equipment all housed inside a weather proof

enclosure suitable for the location.



3 EXISTING SYSTEM

This project is required to replace failing equipment in the Hydro system. The existing diesel

generator and associated equipment is original and was installed to support Stage 1 of the

powerhouse which was constructed in 1967. Stage 1 included four generating units but

since that time, under Stage 2 construction in 1970, the powerhouse has been expanded to

house another two generating units. The additional generating units and auxiliary

equipment added to the expanded powerhouse resulted in an increase in the essential

service load. This increase has resulted in the existing 200 kW diesel generator being

undersized for the task.

With the current capability if the Bay d’Espoir diesel generator, in the event it is called upon

to provide station service to a running plant (and prevent a black plant condition), the diesel

generator will trip because it is not capable of supplying all of the critical loads for the plant.

The operator then needs to turn off all breakers on the emergency panel before starting the

diesel. During this time, the operator is attending to a multitude of issues created by unit

auxiliaries shutting down that cause the units to trip off-line, all while in the dark. Before

the diesel can be started and be ready for load, all units in the plant will have tripped off-

line. The operator will then have to restore loads to critical equipment to begin the process

of starting one or two units to restore the plant.

Given that the Bay d’Espoir plant is the largest generating facility on the island of

Newfoundland, a black start condition in this plant would almost certainly result in

substantial service interruptions for the Island interconnected System. By ensuring that the

diesel generator is properly sized to fulfill its first purpose, the risk of a black plant condition

becomes much less likely.

The size of the new proposed unit will be 500 kW. In addition, the new unit will be

physically larger than the old one and can not be accommodated inside the small existing



diesel generating room. The current emergency genset can be seen below in Figure 2.

Figure 2 – Existing Powerhouse Emergency Diesel

The current diesel room is located on the west side of the powerhouse between two power

transformers. Due to its location inside the powerhouse building, and proximity to the

transformers outside, it is not possible to increase the size of the room to allow for the

larger emergency diesel generating unit.

3.1 Age of Equipment or System

The existing diesel generator and auxiliary equipment is original to the plant and was

installed in 1967.

3.2 Major Work and/or Upgrades

There has been one partial overhaul completed on this unit in 2003. A complete overhaul

was scheduled but due to replacement parts being unavailable only a portion of the

scheduled work was able to be completed. Parts were unavailable as the original equipment

manufacturer no longer supports this model of engine and was only able to provide parts



from its existing inventory.

3.3 Anticipated Useful life

Diesel generating units have an anticipated useful life of 25 years.

3.4 Maintenance History

The five-year maintenance history for the powerhouse emergency diesel generating unit is

shown in Table 1.

Table 1: Five-Year Maintenance History

Year

Preventive

Maintenance

($000)

Corrective

Maintenance

($000)

Total

Maintenance

($ 000)

2010 1.1 6.0 7.1

2009 1.3 1.7 3.0

2008 2.4 0.7 3.1

2007 1.3 2.3 3.6

2006 2.0 0.1 2.1

3.5 Outage Statistics

As the emergency diesel genset operates as a stand by unit detailed outage statistics are

not kept. However, the last time there was a black plant condition at Powerhouse 1, in

2003, the genset would not operate as designed. During the black plant condition the

genset failed to pick up load resulting in a several hour delay in bringing either of the station

service hydroelectric generating units back on-line. To overcome the issue with the genset,

a diesel mechanic had to manually operate the diesel engine governing unit to allow load to

be picked up to start critical equipment for a hydraulic generating unit. This is a procedure

that is not only unsafe for the diesel mechanic but it can lead to equipment damage, as the

output voltage from the generator is unstable, with a risk of exceeding designed voltage



and frequency tolerances.

Since 2003, Bay d’Espoir has not experienced a black start condition. However, if there is a

black start condition, the emergency diesel is in such a deteriorated condition that its

reliability cannot be counted on to maintain critical plant station service or to start a main

generating unit. During the 2003 overhaul, it was identified that a key part that allows the

governor to pick-up load was not working. A direct replacement part was not available.

The only available substitute part was very expensive and had a low probability of fixing the

problem. Since installing this part created the possibility of damaging other parts of the

diesel genset, that could not be sourced, it was decided not to install the substitute part.

Therefore, the diesel genset has to be manually loaded. Manually loading the genset places

people at unnecessary safety risks, while interacting with hot and moving parts of the diesel

genset at times with only a flashlight to help see what they are doing.

3.6 Industry Experience

Industry experience varies on the replacement of diesel gensets. For prime power

applications most utilities rebuild the engines based on the number of operating hours and

replace them at the end of their economic life. However for emergency back-up

applications, as in this case at Bay d’Espoir, gensets are normally replaced because of poor

reliability and obsolescence due to parts not being available.

3.7 Maintenance or Support Arrangements

Maintenance on the emergency diesel generator is performed by internal operations

personnel. Maintenance consists of scheduled preventive maintenance, such as oil and filter

changes, and required corrective maintenance to repair failed components or correct

operational problems that can be repaired.



3.8 Vendor Recommendations

There are no relevant vendor recommendations for this replacement.

3.9 Availability of Replacement Parts

The original equipment manufacturer no longer supports this model of genset and is only

able to provide replacement parts from its existing inventory. If a part is required and is not

part of the existing inventory it cannot be purchased. An example of this would be the

engine oil pump which was scheduled to be replaced during the 2003 overhaul. A

replacement pump could not be sourced so despite its deteriorated condition the existing

oil pump had to be reused. This is not an acceptable practice to achieve reliable operation.

3.10 Safety Performance

As noted in Section 3.5, manual operation of the diesel engine can cause a safety hazard.

Also, due to expansion of the powerhouse the essential service load has grown over the

years and the existing diesel generator is undersized by approximately 250 kW. This means

that in order to provide sufficient power to start one unit other essential loads such as

lighting, exciters, air compressors and governor pumps have to be manually tripped off until

the demand from the essential service system on the genset is reduced to a level low

enough to allow one hydroelectric generator to start. This practice is unsafe and exposes

operators to unnecessary risk.

3.11 Environmental Performance

There are no environmental performance issues related to this project.



3.12 Operating Regime

The emergency genset operates as a standby unit and is only required to perform when no

other power is available in the powerhouse. However as part of the standard operating

procedure for the diesel generating unit it is tested once a month by running it for a period

of one hour. Currently the diesel genset is not load tested. Load testing is a true test that

exercises the equipment similar to how it would normally function in an emergency

situation. Based on past black plant conditions, this diesel genset is not capable of operating

properly when in a loaded condition.



4 JUSTIFICATION

This project is justified based on the need to replace deteriorated and obsolete equipment

in order for Hydro to provide safe, least-cost, reliable electrical service to its customers.

4.1 Net Present Value

A cost benefit analysis was performed instead of a net present value calculation. See

Section 4.3

4.2 Levelized Cost of Energy

As this project does not involve new prime generation sources, a levelized cost of energy

analysis is not applicable.

4.3 Cost Benefit Analysis

A cost benefit analysis was completed on two alternatives. The study period for the cost

benefit analysis was 20 years.

Alternative 1 – Purchase Containerized Unit:

This alternative involves purchasing a diesel genset contained in an International Standards

Organization (ISO) approved sound attenuated container. The container will house all the

equipment required to operate the diesel engine including fuel, control, cooling, and

exhaust systems. This container will be mounted on a concrete pad on the transformer deck

in the vicinity of the existing diesel room. The Cumulative Present Worth (CPW) for

Alternative 1 is a cost of $863,503.



Alternative 2 – Construct New Building:

This alternative involves the construction of a steel building on the north end of the

transformer deck to house a skid mounted diesel genset. The site construction of a building

and installation of auxiliary mechanical and electrical systems will require an increase in

materials and labour cost compared to Alternative 1 and as a result the CPW for Alternative

2 is a cost of $1,200,954.

The analysis indicates that Alternative 1 is the least cost option. Table 2 shows the results of

the cost benefit analysis.

Table 2: Cost Benefit Analysis

4.4 Legislative or Regulatory Requirements

There are no legislative or regulatory requirements for this project.

4.5 Historical Information

Table 3 provides cost information for other diesel genset replacement projects completed

by Hydro over the last five years. One key difference between this project and those listed is

863,503 0

1,200,954 337,451

Cumulative Net Present Value

To The Year

2031

Alternatives

Containerized Unit

Construct Building

Least Cost AlternativeValue (CPW)

Alternative Comparison

BDE - Replace Powerhouse Emergency Diesel

CPW Difference between

Alternative and the

Cumulative

Net Present



that, with one exception, the building and most of the auxiliary equipment already existed.

The exception is the L'Anse au Loup project completed in 2010 whereby a mobile container

package was provided.

Table 3: Historical Information

Year

Capital

Budget

($000)

Actual

Expenditures

($000) Units

Cost per

unit

($000) Comments

2011 619

440

-

-

2

1

-

-

200 kW, 136 kW Francois

136 kW McCallum

2010 325

914

395

844

337

1,109

393

1,519

1

2

1

1

337

5551

393

1,519

50 kW Victoria Control

40, 70 Kw Norman Bay

35 kW Paradise River

2 MW L’Anse au Loup

2009 260

481

381

410

286

556

390

487

1

1

1

1

286

556

390

487

60 kW Burnt Dam

600 kW Cartwright

300 kW Black Tickle

50 kW Norman Bay

2008 290 310 1 310 80 kW William’s Hr.

2007 410 423 1 423 450 kW Rigolet

2006 331

382

321

357

1

1

321

357

250 kW Black Tickle

450 kW St. Lewis

4.6 Forecast Customer Growth

Forecast customer load does not affect this project.

4.7 Energy Efficiency Benefits

There are no anticipated energy efficiency benefits from this project.

1 This project also involved upgrades to the plant that are not typical of a normal genset replacement.



4.8 Losses during Construction

No losses during construction will be incurred.

4.9 Status Quo

The status quo is unacceptable. The existing diesel genset is original to the plant and is over

40 years old, and beyond the accepted standard service life of 20 years. Additionally, as

spare parts are no longer available for this unit, a failure could lead to an extended period

with no stand by diesel for backup power in the event of a black start condition.

4.10 Alternatives

Two alternatives were considered as discussed in the Cost Benefit Analysis under Section

4.3. The CBA indicates that the alternative providing for a containerized unit is the least cost

option.



5 CONCLUSION

This project is required to replace deteriorated obsolete equipment in order for Hydro to

provide safe, least-cost, reliable electrical service to its customers. The existing genset is

over 40 years old, undersized for present day needs, and spare parts are no longer

available. For these reasons this unit needs to be replaced.

5.1 Budget Estimate

The budget estimate is shown in Table 4.

Table 4: Budget Estimate

Project Cost:($ x1,000) 2012 2013 Beyond Total

Material Supply 377.5 100.0 0.0 477.5

Labour 162.4 29.6 0.0 192.0

Consultant 10.8 7.9 0.0 18.7

Contract Work 0.0 0.0 0.0 0.0

Other Direct Costs 29.9 4.2 0.0 34.1

Interest and Escalation 30.9 68.8 0.0 99.7

Contingency 0.0 72.2 0.0 72.2

TOTAL 611.4 282.7 0.0 894.1



5.2 Project Schedule

The anticipated project schedule is shown in Table 5.

Table 5: Project Schedule

Activity Start Date End Date

Planning Open project

Develop Design Transmittal

January 2012

January 2012

January 2012

February 2012

Design Finalize size and output

requirements of new unit

Complete electrical design

Complete P&C design

February 2012

June 2012

June 2012

February 2012

July 2012

July 2012

Procurement Order Genset

Order Switchgear

February 2012

February 2012

September 2012

September 2012

Construction Disconnect and remove U2037

Install new genset

September 2012

November 2012

September 2012

December 2012

Commissioning Commission genset January 2013 January 2013

Closeout Project closet out January 2013 February 2013

Documents

REPLACE POWERHOUSE ONE EMERGENCY DIESEL GENERATOR · diesel generator is properly sized to fulfill its first purpose, the risk of a black plant condition becomes much less likely