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Request for Proposal

Proposals are kindly requested from parties that are willing and able to undertake the services as specified in the detailed TOR in Annex A.

INSTRUCTIONS TO THE OFFERORS

(a) The Quotation must cover all the objectives, outputs and activities as specified in the TOR;

(b) The Quotation must clearly include the costs for the mission to Niue and all related travels; 

(c) US$ only must be used in the Quotation;

(d) The Quotation must include:

(i) An updated CV of the individual(s) who will contribute to the consultancy and as part hereof a summary of recent work in the areas to be covered in this consultancy (including client and work produced);

(ii) Information on availability;

(iii) Total person days proposed for the work on the consultancy and daily rate in US$ for each person;

(iv) A preliminary work plan presented as a breakdown of major activities (specified in the TOR) into a timeline; and

(v) A draft output / report structure and its estimated length.

(e) The offer must be in the English language only; 

(f) The above-mentioned documents, information and requirements are mandatory and as such are required to form a complete tender. An offer will be rejected unless it is substantially responsive;

(g)The consultancy will include a data gathering mission to Niue to meet with the General Manager and staff of the Niue Power Corporation (NPC), Premier’s Office and relevant representatives from both government and non-government agencies.  And a visit to demonstrate the deliverable tools.

(h) The consultancy is expected to be undertaken in the period October – December 2008  with the mission to take place in within this time frame;

(i) The exact number of working days for the consultancy will be determined subsequently between the successful Contractor, SPREP and NPC;

(j) The final working plan for the consultancy will be determined subsequently between the successful Contractor, SPREP and NPC; 

(k) The final report structure and all outputs will be determined subsequently between the successful Contractor, SPREP and NPC; 

(l) Travel expenses for the country mission will be provided / reimbursed from SPREP based on an agreed-to itinerary;

(m) If a Quotation is received prior to the closing date corrections/modifications can be made up to that date; 

(n) The Quotation must be submitted in electronic format only (Word and PDF-format) by e-mail to the e-mail addresses specified below.

(o) Receipt of offers will be acknowledged by e-mail;  

(p) Successful as well as unsuccessful offerors will be informed by e-mail as soon as possible after the submission date. Unsuccessful offerors will not be debriefed; and

(q) For more information on PIGGAREP please visit the following homepage: http://www.sprep.org.ws/climate_change/piggarep.htm

EVALUATION CRITERIA
The following evaluation criteria will be applied when selecting the successful Contractor:

(a) Price (20%)
(b) Methodology/Work Plan (30%)
(c) CV’s of personnel employed (20%)
(d) Relevant experience of firm in small isolated power utilities (20%)
(e) Experience in the Pacific Region or tropical areas (10%)

QUALIFICATIONS AND EXPERIENCE
The person/company is expected to have all or most of the following qualifications and experience:

1. Relevant human resource management, energy and engineering or other relevant qualifications;
2. Years of experience with remote area power utilities;   
3. Significant working experience with renewable energy and energy efficiency preferably in very small Pacific and/or other Small Island Developing States (SIDS); 
4. Excellent working knowledge of English; and
5. Cross–cultural communication skills.

CONTRACT – FORMAT AND CONDITIONS
The contract for the consultancy will be between the successful Contractor and SPREP.

SUBMISSION DATE
Proposals in hard copy or electronic (in Word) should be addressed to the General Manager, Niue Power Corporation, Alofi, Niue and on Email: gm.npc@niue.nu

A copy should also be forwarded to the Director, SPREP, Box 240, Apia, Samoa on Email: sprep@sprep.org

Deadline for the submission of proposals is 3rd October 2008 Niue time.

CONTACT INFORMATION

Annex A

Terms of Reference
Consultancy Study to do a Network and System Modelling of the Niue Power Corporation’s Power System

1. BACKGROUND

 1.1. PIGGAREP

The PIGGAREP is a continuation of the close collaboration between SPREP, UNDP and the GEF to build the capacity of the PICs to deal with the challenges of Climate Change. The global environment and development goal of PIGGAREP is the reduction of the growth rate of GHG emissions from fossil fuel use in the Pacific Island Countries (PICs) through the removal of the barriers to the widespread and cost effective use of feasible renewable energy (RE) technologies. The specific objective of the project is the promotion of the productive use of RE to reduce GHG emission by removing the major barriers to the widespread and cost-effective use of commercially viable RE technologies (RETs). PIGGAREP consists of various activities whose outputs will contribute to the removal of the major barriers to the widespread utilization of RE technologies (RETs). The project is expected to bring about in the PICs: (1) Increased number of successful commercial RE applications; (2) Expanded market for RET applications; (3) Enhanced institutional capacity to design, implement and monitor RE projects; (4) Availability and accessibility of financing to existing and new RE projects; (5) Strengthened legal and regulatory structures in the energy and environmental sectors; and, (6) Increased awareness and knowledge on RE and RETs among key stakeholders.

Niue is one of the participating PICs in the PIGGAREP and one of its activities for 2008 is a Technical Modeling of the Niue Power Grid System to assist with the introduction of renewable energy into the grid.

1.2 Niue

Niue is a self Governing State situated 19S, 169W.  Being geographically isolated, Niue is vulnerable to interruptions in fuel supplies, for which it is 100% depending on for its commercial energy needs.  This combined with the ever-increasing cost of fuel has made Niue embrace a 100% renewable energy goal for the future.

Niue has a newly commissioned powerhouse comprising state of the art digitally controlled Caterpillar C18 engines.  There is also an European Union-funded program to install 50 kW of grid-connected PV arrays as an initial step towards Niue’s 100% renewable energy goal.  There will be follow-on programs to install more renewable energy systems.
Dynamic load testing has proven the new generators’ ability to handle 50% load steps providing some confidence that at least 50% renewable energy can be achieved without the use of energy storage.  In order to confirm and go beyond the 50% renewable, modeling of the network stability is required to determine system options when renewables are increased towards the 100% goal. The modelling should be based on a 20% of the peak penetration and increasing by multiples of 10%.

1.3 Niue’s Power System

(a) Niue  has a base load diesel powered  power generation systems comprising four caterpillar C18  generators.  The C18 includes  a digital voltage regulator operating in a proportional integral closed loop  control system (block diagram is  in Appendix A)  and cross  current compensation to equalize  VAR  sharing.  The engine speed governor is a digital integral/proportional  control Woodward Easygen 3000. 

(b) A typical load profile for Niue has  a main peak load in the evening of some 50% increase from base load.  A program to replace electric cooking with gas should  flatten this peak.  Appendix B shows a typical daily load profile.

(c) The Regulatory environment of Niue is governed by the Electric Power Act.   There are currently no subordinate  regulations to this Act however there are draft Renewable Energy Regulations and a  Draft Grid connect  regulation.    Niue follows the  ASNZS3000 wiring rules.  The proposed National voltage  limits are 230V +/- 10% and 50Hz +/- 3Hz . This relatively wide frequency and voltage  tolerance  takes into account the isolation of the Network and also to allow for greater flexibility in introduction of renewable energy systems.  These limits should be  considered to be  average values.

(d) Generator characteristics for single generator :  508kW power rating @ 0.8 lag pf, 600kVA, 410V nominal and [1.2%] droop.  Total number of generators is four, but for modeling can assume up to three in parallel.  Generator impedances are shown in Appendix A. Generator  buss bar characteristics has a 2500A rating, generator cables comprise three 150mmsq Cu in trefoil for average length of 10m ( ie nine conductors  total  per generator). 

(e) Main 415/11,000 DYN11 distribution transformers rated  at 750kVA, .  One transformer for each of north(Z=4.99%) and south feeders (Z=4.36). 

(f) Generator will trip for  under frequency (after 60Sec) of <40Hz, overfrequency ( instant trip) of >57Hz,  overcurrent of 150% for >30Sec, reverse power for >10sec of 8% .  Under and over volts trip  >[20v ] from nominal 410volts, reverse kVAR for >4 sec exceeding 0.05pf.

(g) The Niue network comprises mainly of three single core, XLPE insulated 6350/11kV Al cable of 35mmsq.  There are some overhead lines and there are some three core XLPE cables. Cable network lengths are shown in Appendix C.

(h) Network distribution transformers are YD11 11,000 /415 for three phase circuits and single 10 or 25kVA for single phase distribution in villages.  Transformers are generally 3.5 to 4% impedance. Appendix C provides transformer details, including current maximum demand. 

(i) Typical demand cycle shows minor load peaks in morning and midday (especially on hot days when air-conditioners are running).  Evening peak is about 50% of the average demand of 400kW.  The load presents a leading power factor of about 0.9

(j) Appendix D shows measured frequency and voltage transient response to 50% step load.

(k) Environmental data for Niue can be found from NASA LARC wind and insolation tables.

1.4 Future Renewable Energy Developments in Niue

Niue is currently installing some 50kW of three phase PV Grid connected renewable systems distributed over three sites.

There will be more renewable power systems planned under national projects to be funded by the Italian government and the European Union or from private individual renewable energy systems.  Renewable energy systems could be wind or solar: the power utility is considering the installation of Redox Flow batteries on the main powerhouse generator bus.

2.   OBJECTIVES

2.1 General

The general objective of this study is to identify technical opportunities, requirements and constraints in the Niue electric generation and distributions systems for the progressive introduction of renewable energy and other generation sources.

2.2 Specific

The specific objective of the study is to conduct engineering studies to model the Niue electric generation and distribution system and development of an engineering decision support tool to predict system performance as various renewable energy / generation systems are placed on the grid. The tool shall be based on user friendly and widely available softwares and shall be designed to operate on widely available computing hardwares.

The grid baseline model shall include provision to include all previously added renewable energy systems so that the baseline can reflect the actual installed system architectures.
The tool shall provide a go/no-go heuristic or objective decision aide to provide guidance on technical acceptability of any given renewable energy proposal.  The user shall also be able to select/ view/ edit all input and output data from the model and store acceptable output as an update to the baseline model.

3. OUTPUTS

The anticipated outputs from this study will be the following:

3.1 Inception note

• Desk Study and review relevant background materials,
• Identity key stakeholders for the study; and 
• Write-up an inception note comprising the Consultant’s understanding of the consultancy and associated tasks; identification of issues crucial to the successful completion of the consultancy; and comments on this TOR. Subsequently, if required and approved by NPC and SPREP the activities can be elaborated, modified, etc.

3.2 Debriefing note

• Prepare debriefing note, based on the desk study, preliminary findings, conclusions and recommendations from the field mission to Niue; and
• Discuss the debriefing note with the General Manager and staff of NPC and the Premier’s Office.
• 3.3 Comprehensive Report. 

The consultancy report shall include, but not be restricted to the following:

• Discuss NPC’s current generation and distribution system and future estimates
• Prepare a comprehensive set of technical and engineering recommendations for the NPC in its future effort to introduce renewable energy and other generation technologies into the grid. 
• Provide a decision making  / modelling tool
• A report shall be prepared that explains in detail all models, algorithms and heuristics used.
• Operating instructions to allow editing, alteration, addition deletion of components of the models,
• A library of generic standard units say gensets, flow battery, windmill, solar inverter systems, loads, etc that can be used in the model.
• Run time licence, or licence free/ royalty free software used as part of the simulation including operating system, simulation software and data files.
• An operator manual for the staff of NPC and suggestions of any required training on the use of the manual

4.   ACTIVITIES

The scope of work for the consultancy will include, but not necessarily be limited to, the following activities:

(a) Documentation review/desk study.

(b) Mission to Niue

(c) Interviews and Consultations.

(d) Modelling:

 

(i) Modelling & Simulation Parameters:

Shall include calculation of at least the following: volts, amps, kW, kVar, number of diesel on line, time, for up to [four] feeders

(ii) It is recognized that finite modeling accuracy and technical assumptions will create risk that a go recommendation may in fact be “no-go”.   The required modeling accuracy shall contain this risk to probability of less than 0.1/(number of 10kW units added or subtracted by the model). Where the model cannot produce output within this risk level it shall still produce outputs and shall include a suitable warning that risk level may be exceeded.

(iii) Heuristic advisor on go/no-go plus detailed presentation of results

(iv) Ability to add extra nodes/ units/ generators/ lines cables, reactors, transformers, Wind, solar, diesel, flow battery, flywheel, resistive loads, motors, generic power source.

(v) Ability to user modify all data and load profile scenarios, include adding new loads generator on any network nodes

(vi)Modeling of HV cable /OH wires network

(vii)The modelling will consider the following parameters:

• REP-5 50 kW PV
• EDF-10 Renewables
• Wind power systems
• Distributed renewables

5.   REPORTING REQUIREMENTS

6. OTHERS

The following data and information provided in the attached data appendices are baseline information. Clarifications and additional information requests will be provided to the contractor where available within two weeks of the request.

Appendix A:  Niue Generator characteristics

1. Voltage regulator

2. Generator winding pitch is 0.66

3. Generator Impedances (Ohms) are as follows:

(a) SUBTRANSIENT - DIRECT AXIS X''d   0.0316

(b) SUBTRANSIENT - QUADRATURE AXIS X''q  0.0363

(c) TRANSIENT - SATURATED X'd  0.0396

(d) SYNCHRONOUS - DIRECT AXIS Xd  0.8080

(e) SYNCHRONOUS - QUADRATURE AXIS Xq  0.4850

(f) NEGATIVE SEQUENCE X2  0.0340

(g) ZERO SEQUENCE X0  0.002

4. Generator Time Constants (Seconds)

(h) OPEN CIRCUIT TRANSIENT - DIRECT AXIS T'd0  2.0390

(i) SHORT CIRCUIT TRANSIENT - DIRECT AXIS T'd  0.1000

(j) OPEN CIRCUIT SUBSTRANSIENT - DIRECT AXIS T''d0  0.0130

(k) SHORT CIRCUIT SUBSTRANSIENT - DIRECT AXIS T''d  0.0100

(l) OPEN CIRCUIT SUBSTRANSIENT - QUADRATURE AXIS T''q0  0.1330

(m) SHORT CIRCUIT SUBSTRANSIENT - QUADRATURE AXIS T''q  0.0100

(n) EXCITER TIME CONSTANT Te  0.0300

(o) ARMATURE SHORT CIRCUIT Ta  0.0150

 

Appendix B: Typical Demand Cycle

Appendix  C:  11 KV Cable lengths

1.  Niue has some 11kV  7/080  Cu overhead lines on its Southern feeder as shown below:

Distances in km are distances from the Powerhouse.  The overhead lines branch out to the underground 11kV cable  network( see underground cable table on next page) as follows:

(i) Kaimiti – New hospital  200kVA Tx

(ii) Kaimiti RMU/ABS to New  bore 30kVA Tx

(iii) Porrite road to Airport 100kVA Tx

(iv) Porrite  Road to Fualahi 200kVA Tx

(v) Porrite Road to New Industry Park 100kVA Tx

(vi) Fonuakula (RMU3) to  High Com 30kVATx and

(vii) Fonuakula (RMU3) to HuiHui  100kVA Tx

2. 11kV Underground cables and associated transformers are shown in the table below:

Note: 10 & 25kVA Transformers are single phase, all others are three  phase

Appendix D: Single generator response to 200 kW step load increase.

The picture  shows the dynamic response of the NPC generator to a  nominal  200kW (50%) step increase in load. The display shows generator harmonics  that emphasis in more detail the speed  changes  caused by the  step load.