The Rocky Mountain Institute (RMI) has been engaged by Saba Electric Company (SEC) as a Renewable Energy Client Engineering Consultant for the Saba Renewable Energy (RE) Phase 3 ground mount utility-scale solar + Battery Energy Storage System (BESS) Project, Giles Quarter, Saba.

Project Milestones 

• Request for Proposals Issuance – 1st August, 2024
• Deadline for submittal of “Questions” for Questions & Answers (Q&A) – 15th August 2024
• Proposal Submission Deadline [Electronic submission as per Section 9 – Submission Deadline] – 09:00 hrs. 26th August 2024
• Awards Contract to Successful Bidder – 6th September 2024
• Signing of EIA Agreement, issuing Notice to Proceed, and sharing relevant documents – 11th September, 2024
• Submittal of Draft Inception Report (Consultant) – TBD
• Submittal of Client Feedback to Draft Inception Report (SEC/RMI) – 5 Working Days after the submittal of the draft inception report
• Submittal of Draft Final Report – (Consultant) -TBD
• Submittal of Client Feedback to Draft Final Report (SEC/RMI) – 5 Working Days after the submittal of the draft report
• Submittal of Final Report – (Consultant) – 10th December 2024 latest.

Background
Saba Electric Company (SEC), in collaboration with the Public Entity (OLS), is seeking to increase its renewable energy (RE) fraction as part of its overall sustainable energy strategy to reach a 100% RE electricity generation target by 2025. SEC’s existing operational facilities consist of a 4.3MVA diesel generation plant and 2.1MWp of installed solar PV capacity plus 2.3MWh of battery storage from the Saba RE Projects Phases 1 & 2.

The proposed Phase 3 solar + BESS renewable energy plant will be located on a 34,530 square meter site at Giles Quarter. The solar + BESS plant will be interconnected to the Saba grid either by extending Feeder #3 by 1km or by a new 2-3km 12kV feeder from the SEC Power Station (Feeder #4).

Please reference Annexes 1, Figures 1 Site Location, Figure 2 Site Photograph, Figure 3 Site Boundary Survey, Figure 4 Topographic Map for site locations’ general features and Figure 5 for a Conceptual Site Plan showing a rendering of the proposed solar PV array, BESS Plant, Water Tank, and Driveway and Parking Areas.

Preliminary analysis has resulted in the selection of a 3MW solar PV plant and an 8MWh BESS (Saba RE Phase 3 Project) for the Giles Quarter site.

Goals and Objectives
This Request for Quotation aims to solicit consultancy services for the ground-mount utility-scale solar PV plus BESS connection studies and BESS optimization analysis for the island of Saba.
This Request for Quotation’s primary objective is the production of the following documents and reports:

• Inception Report / Data and Assumption Verification
• Draft Final Report
• Final Report

Saba Electric Company (SEC), the Government of Saba Public Entity (OLS), the Planning Bureau, and RMI will review the draft report. RMI will aggregate all feedback and share it with the consultant to inform changes in preparing the final report.

RMI is requesting quotations from Grid Connection Consultants for ground-mount utility-scale solar PV plus battery energy storage systems (BESS) connection studies and BESS optimization analysis for the island of Saba, as described below at Giles Quarters, Saba, as described in the scope of work section below.

Scope of Works / Statement of Work

TERMS OF REFERENCE
These Terms of Reference relate to consultancy services for PV and Battery Energy Storage System (BESS) connection studies and BESS optimization analysis for the island of Saba.

Objectives
The study will analyze the possible electrical system impacts of solar PV and BESS installation to the Saba grid. The consultant will also study the optimal parameters of connecting the battery energy storage system for the provision of renewable energy firming, frequency and voltage support, spinning reserve, and energy shifting when the solar PV and BESS are in isolated microgrid mode.

This interconnection study will provide detailed information regarding any limitations and mitigation actions including the use of battery storage as a grid resource and local solar PV firming solutions. These studies will be used to inform Saba Electric Company (SEC) of any grid enhancements that would be necessary in order to accommodate planned solar PV and BESS installations. They will also be used to inform potential bidders for the solar PV and BESS project of the requirement for interconnecting to the Saba grid.

SEC will share with the awarded consultant all relevant data from the existing power system on Saba.

SCOPE OF SERVICES
The scope of work includes the following analyses which are needed in order to study the impact of increased solar PV installations on the existing Saba power system in different solar penetration scenarios:

• Load flow calculations (Thermal ratings and voltage levels to be verified)
• N-1 contingency calculation
• Short circuit calculations
• Transient stability
• Harmonic analysis
• The transformer(s)/cables energization and current in-rush study
• Facility Cost Estimates (new transformers, conductors, regulators etc.)

The scope of work encompasses the following scenarios. These reflect various operational conditions of the grid. Once the operation of the grid is understood with these conditions, informed design considerations can be included in the scope for grid upgrades.

In addition to performing the analysis and recommendations, the models developed under this scope of work shall also be provided to SEC.

Table 1.Example Scenarios for power flow assessments

Scenario Description	Scenario	Existing Utility Scale Solar PV and DERs	Additional Utility Scale Solar PV (MW)	BESS (MW/MWh)
Normal operating conditions; all thermal generation, all feeders on Saba operating	1	All existing utility scale solar PV and DERs	3MW (current SEC expansion plan)	Optimal for Reserves and Smoothing of three solar plants
Normal operating conditions; all thermal generation, all feeders on Saba operating	2	All existing utility scale solar PV and DERs plus 100kW DER uptake over 5-year period after 3MW project (X20kW uptake each year)	3.3MW of utility scale over 5-year period after 3MW project	Optimal for Reserves and Smoothing of all utility scale Solar Farms and additional DERs
Islanded conditions. The solar, BESS and substation are isolated from the rest of the grid and providing capacity and energy to the new seaport	3	Current and projected DERs within the microgrid.	3MW connected to a new substation near Giles Quarter solar PV and BESS plant	BESS for microgrid capability connected to a new substation near the Giles Quarter solar PV and BESS plant

POWER SYSTEM & PV PLANT REPRESENTATION
The main purpose of these analyses is to study the impact of potential PV and BESS plants on the power system and to provide equipment verification. The system models generated in this scope and provided to SEC must be accurately developed and updated based on provided data. The proposed PV plants must be represented with all inverters, step up transformers, protection and reactive compensation equipment.

The quality and the level of details within provided data will directly reflect on study output, therefore special attention shall be given to model development and data verification with SEC staff.

LOAD FLOW STUDIES
A load flow (power flow) study of the network is required to ensure that all elements in the system (principally generators, overhead lines, cables, switchgear, and transformers) remain within their steady state thermal limits and that the voltage regulation across the network remains within acceptable limits for all network contingent scenarios considered.

Load flow studies shall be undertaken to assess the steady state performance of the system for various combinations of demand, generation, and reactive power support conditions to check voltage conditions and thermal ratings. At least four load conditions shall be analyzed for each PV scenario.

Load flow studies shall be done for all scenarios for the following loading conditions for the year 2026 when the proposed solar and batteries are operational and the 5-year period thereafter.

• Evening peak loading conditions
• Daily peak loading conditions (16h)
• Daily solar maximum loading conditions (13h)
• Loading conditions at 10:00am on a typical weekday

Load flow results should be presented in single line diagram and tabular form for all case studies. The minimum and maximum voltages at all network buses shall be tabulated in the summary report. Equipment ratings (if exceeded) shall be highlighted in tabulated report form. Any deviations from the agreed limits would be highlighted and appropriate remedial action recommended.

CONTINGENCY ANALYSIS
An investigation of the power system security shall be performed through contingency analysis for all three scenarios. Dynamic stability analyses shall be performed for single element outages in the distribution grid on Saba.

Types of outages that will be analyzed are:
— N-1 single outage of distribution/transmission lines and transformers. This will be performed for additional elements
— Loss of thermal plant
— Loss of two largest generators (n-2)
— Loss of largest load feeder
— Loss of feeder serving the Phases 1 & 2 PV plant
— Loss of feeder serving the Phase 3 PV plant

The results of this analysis will be used to determine strategies to protect the network in disturbed state.

SHORT CIRCUIT CALCULATION STUDIES
Fault level studies should be carried out using the system model for each PV scenario and compared with the grid without the proposed PV plants to determine the change in fault levels. Three-phase and single-phase fault levels will be calculated at the point of connection and in adjacent buses, and results will be included in the report.

The methodology which will be used for the calculation of short circuit currents should be in accordance with the latest IEC 60909 standard. Three-phase and single-phase fault levels should be calculated with a voltage factor c = 1.1 in order to simulate maximum pre-fault voltage conditions. Initial symmetrical short circuit current will be calculated and the obtained values should be presented in tabular form.

If it is found that three-phase or single-phase fault currents are exceeding relevant operational and security limits, conceptual design solutions should be proposed in terms of selection of adequate additional equipment, grid sectionalizing or insertion of earthing resistors.

TRANSIENT STABILITY STUDY
The consultant should perform dynamic analyses with the aim of assessing SEC power system stability for disturbances in the power system. It is important to study PV plant stability for external faults on the network to which it is connected. It is assumed that the faults to be studied will be of a worst case three-phase zero impedance type and will be electrically close to the point of common coupling or within the main export path.

The dynamic model of the plants should be based on standard dynamic library models only, with additional augmentations if necessary. The duration of simulations will be minimum 20s and adjusted according to grid characteristic (system inertia).

Results of simulations will be presented in the form of time domain diagrams of critical quantities (bus voltages, system frequency, active/reactive power flows, generator rotor angle etc.).

All dynamic studies will include, at a minimum the following:

• Simulate 3ph faults at main substations and calculate critical clearance time for night peak, daily peak and minimum loading conditions
• Outage of the two largest generators for night peak, daily peak and minimum loading conditions
• Cloud coverage for PV solar plant

For all these cases, the consultant shall show responses of the largest generators or response of the BESS in cases where no generators are running.

The consultant shall also fully analyze the responses when a potential microgrid is operating in islanded mode.

HARMONIC ANALYSIS
The system should be carried out in general compliance with the standards of SEC, and the best international practice applying IEC and IEEE standards (IEC 61000-4-7,61000-3-2, 50160, IEEE-519, etc.).

The impact of PV plants on external electrical system will be carried out based on:

— Current and voltage harmonic injected at the point of connection

— Current and voltage harmonic injected from PV plant and background harmonic distortion (if provided) at the point of connection and neighboring system nodes.

THE TRANSFORMERS/CABLES ENERGISATION AND CURRENT IN-RUSH STUDY
In order to carry out transformer energizations studies, the consultant should use a high frequency computer model of the power station equipment and adjacent feeders using the Alternative Transients Program (ATP) version of the universally accepted Electromagnetic Transients Program (EMTP) or PSCAD. Using this model switching/energization/inrush current and lightning phenomena can be examined with a view to ascertaining the maximum over-voltages likely to occur in operation of the plant. Peak over-voltages will be compared with relevant equipment ratings as specified in the IEC insulation coordination standards, IEC 60071-1 & 60071-2.

Specifically, the studies consider the following:

• Voltage depression due to the energization of transformers.
• Voltage increase due to the energization of any reactive power compensation equipment.
  The above analysis should be performed under maximum and minimum fault level conditions in order to fully assess the dynamic stability. Should any part of the PV plant or the power system experience voltage in excess of its BIL, then the addition of surge arresters or other measures will be investigated in order to achieve compliance with insulation requirements. Specifically, if surge protection measures are necessary to protect substation equipment then relevant studies will be repeated for the worst scenarios to prove that adequate protective margin exists with respect to the BIL of equipment.

BATTERY OPTIMIZATION STUDY
The BESS optimization study should start with a review of the current generation plan and demand forecast for the Saba power system. The consultant will review spinning and non-spinning reserve policy in terms of integration of solar PV. The Consultant shall develop a grid dispatch model for the SEC generation fleet for the next 5 years in PLEXOS. This shall serve as a basis for justification of PV penetration, feasibility of BESS and its sizing as well as provide battery optimization (usage, charging/discharging cycle, etc.).

To reach that objective, it is expected that consultant shall assess two energy storage alternatives:

1. The first consists of the battery storage equipment integrated with the synchronous reserve strategy and capable of covering or compensating for all intermittent renewable energy systems;
2. The second scenario is a battery storage system connected to solar power plants and a dedicated substation (or gen bus at the power plant) serving to support the firming of the solar PV and support a microgrid in islanded mode.

The consultants shall study the following:

• Analyze the history of the demand, of solar generation, as well as meteorological data, including the temperature, to determine the level of solar variations to be compensated by battery systems.
• Feasibility for SEC to optimize all of the solar and sell the energy at another moment in time (energy time shift)
• Present the advantages/disadvantages of SEC using solar and energy storage for generation purposes.
• Perform a technical-economic analysis of various battery BESS capacities to be considered by SEC including performance and cost estimates in USD $ MW/MWh.
• Perform a techno-economic analysis comparing the use of battery storage to thermal generation for synchronous reserve purposes
• Optimize the sizing of the battery in terms of Ah, the required MW of power and its charge/discharge category.
• More specifically, in the context of contribution to the synchronous reserve following a unit loss event, it is also important to:
• Size the battery by taking into account the global synchronous reserve strategy in the short and medium term and by checking the duration of the battery discharge cycle required according to the other generation sources available. Check the amount, the duration and the availability of the other generation sources that must intervene before the batteries are fully discharged to maintain the network stability criteria. The time of discharge of the battery shall be specified and the response time as well.
• Determine the discharge time of the BESS so that its contribution is optimized with the load. Then, determine the costs for different BESS discharge times to support the decision process.

With regard to the contribution of batteries during the peak period, it is important to determine the energy mix present at the peak of usage and their power levels. Study the contributions of the various sources and analyze the possibility of adding the energy of batteries during the peak period, but also identify other strategic moments where they would represent an advantage.

More generally:

• Recommend a power management system suitable in the context of renewable energy integration and estimate the cost benefits of such a management system.
• Estimate the full costs of the storage system, the connection to the substation and all related works necessary for the implementation of this system in relation to the location of the identified battery solution.

The estimation should consider recent and prospective cost data and electrical demand forecast data.

This study should consider the:

1. Maximization of PV penetration
2. Optimization of battery life and of the charge/discharge cycles
3. Cost of the investment (Capex)
4. Cost of the operation (Opex)

Recommendations and Justification
For the proposed ground mount solar PV sites, provide any required network reinforcements (above and beyond a direct express circuit), and optimum level of solar PV on Saba in relation to the BESS. For the proposed BESS, provide recommended sizing in power (MW) and energy (MWh) and use cases for the applications considered. Relevant justification shall be provided for the proposed conclusions on location, sizing of the BESS, including findings from the power systems analysis, cost-benefit analyses, business cases, etc. that demonstrate various value streams for the power system.

THE FACILITY COST ESTIMATES
Whether new equipment is required would be informed by the results of the studies and how this relates to the relevant grid code. The results from the studies performed would be used to inform a series of recommendations and conceptual design that outlines what upgrades to the solar farm substation and distribution system are required.

The consultant will develop a conceptual design of the new interconnection facilities and obtain vendor price quotes for required major equipment items including new circuit(s), transformers, capacitor banks, SVCs and STATCOMS. Balance of system equipment and installation costs will also be estimated using regional industry standard assumptions and local fully burdened labor costs and information provided by SEC.

Should network and other facility upgrades be required for interconnection, the above referenced power system studies will be re-modeled to include such upgrades and to demonstrate that the proposed upgrades remediate any of the identified issues.

Should network and other facility upgrades be required for interconnection, the above referenced power system studies will be re-modeled to include such upgrades and to demonstrate that the proposed upgrades remediate any of the identified issues.

Supporting details for the studies contained in this scope:

Impact Studies – Conduct studies and/or adhere to Codes and Standards as noted:

1. Analyzing power flow, short-circuit analyses, protection device coordination, power stability, steady-state and dynamic stability, electro-magnetic transients and spinning reserve to properly evaluate grid stability impacts of the proposed ground mount solar PV system on the grid.
2. The following standards will be applied to studies related to this project, including the ongoing SEC studies:
   a. IEEE Std 1547-2018, IEEE 1547a-2020, IEEE 1547.7-2013 Guide for Conducting Distribution impact studies for Distributed Energy Resource (DR) Interconnection.
   b. IEC 61727: Photovoltaic Systems – Characteristics of Utility Interface.
   c. IEC 62116: Utility-interconnected photovoltaic inverters – Test procedure of islanding prevention measures
   d. Safety of power converters for use in photovoltaic power systems – Part 2: Particular requirements for inverters
3. Islanding Studies:
   a. Evaluate bi-directional power flow and ensure voltage regulation is maintained; bidirectional sensing may be needed for all anticipated fault conditions.
   b. Evaluate that feeder conductor sizing is acceptable to reverse power flow condition (as applicable / express circuit conclusion).
   c. Determine what is needed for parallel operation for connection or restoration to the normal distribution grid (e.g. synch-check, reverse power flow, automatic islanding control, etc.)
4. Fault studies:
   1.Check for relay desensitization, report findings.
   2. Check/change relay settings as needed, report findings.
   3. Check for additional relay protection required, report findings.
5. Stability studies:
   1. Check generator-generator-load to assure islanding will be stable, report findings.
   2. Demonstrate that islanded systems can deliver power to within parameters established in IEEE Std 1547 (and related IEEE Standards and ANSI C84.1).
   3. Demonstrate voltage regulation capabilities of the distributed energy resources (DR).
   4. Demonstrate frequency regulation capabilities of the DR.
   5. Upon blending of generation sources, demonstrate the voltage and frequencies remain within acceptable limits.
6. Demonstrate switching and other transients are within acceptable limits.

TIMELINE
The consultant should be prepared to deliver all reports, models and results within 90-day period from the time of award.

KEY DELIVERABLES
During the execution of the study, consultant will prepare the following documents and reports:

• Inception Report / Data and Assumption Verification
• Draft Final Report
• Final Report

The Study reports will be submitted in electronic form (.pdf) and computer model files handed over to SEC.

Final Report will be produced in English and will include:

• Documentation of all input data
• Calculation results (plots, tables)
• Analysis of the results
• Final recommendations

RFQ Submission Requirements

Responses to this RFQ must include the following at a minimum:

• Appendix 2—The Declaration of Bidder Form MUST be completed, signed, and returned as part of the bidder submission. “Bidders are required to fill in Appendix 2 regarding grounds of exclusion. SEC can exclude a bidder from participation if, following the declaration, there are grounds of exclusion.” For a Word file of Appendix 2 – Declaration by Bidder, email [email protected]; include “Saba Grid Studies & Battery Optimization Study Consultancy Services RFQ Appendix 2 Word” in the subject line.
• The names of the project team members who will be responsible for carrying out the work and their respective roles. Details of relevant qualifications and experience for each member of the proposed project team (CVs) are mandatory.
• A description of the methodology that will be used to carry out the proposed work. This methodology will be in accordance with the requirements mentioned in the scope of the Work and with the current state of science.
• A work schedule for the completion of the work, indicating task durations, task sequences, task relationships, and total project duration. Note: The Final Report MUST be submitted on or before 10th December 2024.
• The quotation is on a Firm-Fixed-Fee basis. As per Appendix 1—Financial Pricing Schedule, a cost breakdown table with standard rates and prices for each line item and the total quotation cost shall be provided in an Excel file and PDF formats. Any transportation and accommodation costs (where relevant) should be reflected as separate line items in the cost breakdown table referred to above. Completed Appendix 1 – Financial Pricing Schedule in Excel and PDF formats MUST be submitted.
  For an Excel file of Appendix 1 – Financial Pricing Schedule, email [email protected]; include “Saba Grid Studies & Battery Optimization Study Consultancy Services RFQ Appendix 1 Excel” in the subject line.
• A proposed payment schedule aligned with the work schedule.
• An indication of when the consultant can begin working on this project if selected.
• The final deliverable shall be submitted by December 10th, 2024, at the latest.

Selection Criteria
The following combined scoring method will be adopted in selecting the best offer:

Criteria Weighting

• Technical Component (Qualifications, Experience, Methodology, Work Schedule):                      60%
• Cost Component:                                                                                                                                            40%

Question and Answer (Q&A) Log
RMI will manage a Q&A log for the benefit of bidders. Please submit questions to [email protected] and [email protected]; include “Saba Grid & Battery Optimization Studies Consultancy Services RFQ Q&A” in the subject line.

Responses to questions will be periodically sent to all bidders who have confirmed their interest in this RFQ by emailing [email protected] and [email protected], including “Saba Grid & Battery Optimization Studies Consultancy Services RFQ Interested Bidders” in the subject line. Shared responses shall be anonymous of the entity that posed the question(s).

Responses shall not be construed as in any way amending, modifying, or altering the meaning and intent of this RFQ unless the RFQ is amended via an addendum.

The Q&A submission deadline is 15th August 2024.

Submission Deadline
The deadline for submission of responses to this RFQ is August 26, 2024.

All responses or questions should be emailed to [email protected] and [email protected] with the subject: Saba RE Project Phase 3 Grid Studies & Battery Optimization Study Consultancy Services RFQ.

Validity of Quotations/Proposal
The proposal (including cost quotations) must be valid for 90 days.

Quotations submitted in response to this RFQ shall constitute binding offers and must be signed by a duly authorized representative of the Bidder.

Bidders are solely responsible for their own costs in preparing responses and for subsequent negotiations with RMI, if any. RMI will not be liable to any bidder for any claims, whether for costs or damages incurred by the bidder in preparing the response, loss of anticipated profit related to any final contract, or any other matter whatsoever.

List of appendices

• Appendix 1 – Financial Pricing Schedule. For an Excel file of Appendix 1 – Financial Pricing Schedule, email [email protected]; include “Saba Grid Studies & Battery Optimization Study Consultancy Services RFQ Appendix 1 Excel” in the subject line.
• Appendix 2 – Declaration by Bidder. For a Word file of Appendix 2 – Declaration by Bidder, email [email protected]; include “Saba Grid Studies & Battery Optimization Study Consultancy Services RFQ Appendix 2 Word” in the subject line.

Appendix 2 – Declaration by Bidder

Grounds of Exclusion

Date: [insert day, month, and year]
Reference RFQ: Saba RE Phase 3 Grid Studies and Battery Optimization Study
To: [insert full name of Employer]

We, the undersigned, apply to be selected for the referenced Request for Quotation (RFQ) and declare that:

• (a) No reservations: We have examined and have no reservations to the RFQ Document, including Addendum(s) No(s).: [insert the number and issuing date of each addendum].
• (b) No conflict of interest: We have no conflict of interest related to any Saba Electric Company (SEC) and or RMI personals.
• (c) Grounds relating to criminal convictions: Has the bibber itself or any person who is a member of its administrative, management or supervisory body or has powers of representation, decision or control therein been the subject of a conviction by final judgment for participation in a criminal organization, corruption, fraud, terrorist offences or offenses linked to terrorist activities, money laundering or terrorist financing, child labor and other forms of trafficking in human beings, by a conviction rendered at the most five years ago.
   Yes  No
• (d) Grounds relating to the payment of taxes and social security contributions: Has the bidder breached its obligations relating to the payment of taxes and social security contributions, both in the country in which it is established and the contracting entity if other than the country of establishment?
   Yes  No
• (e) Grounds relating to professional misconduct: Has the bidder, to its knowledge, breached its obligations in the field of environmental law, social law, or labor law?
   Yes  No
• (f) Grounds relating to insolvency: Is the economic operator bankrupt or the subject of insolvency or winding-up or in arrangement with creditors?
   Yes  No
  (i) True and correct: All information, statements and description contained in the Application are in all respect true, correct and complete to the best of our knowledge and belief.

Historical Contract Non-Performance, Pending Litigation, and Litigation History
[The table shall be filled in for the bidder]
Bidder’s Name: [insert full name]
Date: [insert day, month, year]

Table and images in page 18 of the attachment 

Saba Grid Studies & Battery Optimization Study Services RFQ – Final

Appendix 1 – Financial Pricing Schedules – Grid & Battery Optimization Studies Saba RE Phase 3 Project

Appendix 2 – Declaration by Bidder Grid & battery Optimization Studies – Final