Statement of Work.doc

Statement of Work & Concept Design

Phillip Burton Federal Building

San Franisco, CA

Cogeneration System

Solicitation GS-09P-08-KSC-0040

PART 1 ROJECT DESCRIPTION

The General Services Administration (GSA) requires a design-build installation of a cogeneration system at the Phillip Burton Federal Building, located at 450 Golden Gate Street, San Francisco, California, that meets all the requirements for both the BAAQMD permit and the PG&E Self-Generation Incentive Program (SGIP) incentive. Bid Item #1 cogeneration system size shall be between 200 and 260 kW, net electrical output, with an option for a larger system up to 500 kW. The cogeneration system shall be connected in parallel with the utility power. The goal is for a turnkey, design-build cogeneration system to be substantially complete within 12 months from notice to proceed, with minimal occupant disruption.

This solicitation provides a description of the project, design criteria and concept design narrative, which communicates the project intent and requirements to the Contractor, and forms the basis for the Contractor to provide a proposal and fixed-fee pricing for the design and installation of the requested cogeneration system.

Background and Description of Work

The Phillip Burton Federal Building is located at 450 Golden Gate Ave. in San Francisco. The building is a 20-story building with two basement levels and has an approximate floor area of 1,400,000 sq-ft. A detailed description of the building’s electrical and heating systems and load profiles is provided in Appendix 2.

This is a Design-Build project to install a natural gas fueled cogeneration system that produces electrical output to supplement electricity provided by PG&E, thereby reducing the electricity supplied by PG&E, and recovers thermal waste heat to supplement the heating hot water boiler system, thereby reducing fuel input to the boilers. The cogeneration system shall meet all the requirements for both the BAAQMD permit and the PG&E SGIP incentive.

Roles and Responsibilities

GSA - The GSA (or "the Government") shall be responsible for any asbestos abatement required for the installation of the cogeneration system. Specifically, abatement of the existing boiler exhaust duct in the main exhaust shaft on the 1st floor (accessed from the Fitness Center) will require abatement in order to connect the new cogeneration system exhaust duct(s) to the main boiler exhaust duct. The Contractor shall mark the location of the required area for abatement on the boiler exhaust duct, within 6 weeks after the project notice to proceed. The GSA anticipates that it will take approximately 16 weeks after the location is marked, for the abatement to be completed.

The Government shall be responsible for obtaining the Bay Area Air Quality Management District (BAAQMD) Permits and associated fees.

Contractor - The Contractor shall provide all resources and materials required to fulfill and complete this contract. The Contractor shall:

1. Be solely responsible for the complete design, scheduling and construction of this contract work.

2. Determine the techniques, means, method, and materials of installation to meet the requirements of this contract.

3. Ascertain site conditions that may affect required equipment clearances and the contract work. Include all costs required to complete this project.

4. Not be time relieved or compensated for failure to accomplish the contract work.

5. Provide GSA a complete operational, balanced, commissioned and warranted system as outlined in this Request for Offer.

6. The Contractor shall state whether their offer meets these specifications, and shall note exactly which parts of these specifications their offer doesn't meet.

7. The government building will be fully operational and occupied during construction. The Contractor shall stage all contract work to minimize the building electrical and heating system downtime. .

8. The Contractor shall be responsible for the PG&E interconnection application, permitting, and all associated permit/study fees. The Contractor shall complete and submit the interconnection application to PG&E. The Contractor shall be responsible for all Rule 21 inspections, testing (including any 3rd Party testing) and all parallel interconnection work to provide a final cogeneration system that can operate in parallel with utility power.

9. The Contractor shall be responsible for providing all new electric meters, including net output generation meters, and coordinating the installation of the meters with PG&E.

10. The Contractor shall be responsible for providing a new PG&E gas service and GSA-owned gas sub-meter to the cogeneration system and coordinating the installation of the meter with PG&E. The meter shall be in conformance with PG&E’s metering standards and be accessible to PG&E.

11. The Contractor shall be responsible for insulating the area that will be abated by the GSA for all new the cogeneration system exhaust duct connections.

12. The Contractor shall be responsible for providing all required cogeneration system documentation and information to obtain the SGIP incentive and BAAQMD permit.

13. The Contractor shall be responsible for all cogeneration system testing required to obtain the BAAQMD permit to operate.

14. Within 30 working days of contract award, Contractor shall register with the Contractor Performance System (CPS) at https://cpscontractor.nih.gov/cr.asp.

15. The contractor is responsible for meeting all regulatory requirements pertaining to the project, including but not limited to OSHA, air quality district requirements, water district requirements, and state and local waste disposal requirements.

PART 2 THE WORK

Summary of the Work

The Contractor shall provide a complete and fully functional cogeneration system, including the design and installation of all project components, commissioning, operator training, warranty and O&M, meeting the design intent, objectives and requirements outlined in the solicitation and supporting appendices. This shall include attending meetings with the GSA and GSA, securing security clearance and access to the building, coordinating the work with the GSA, examining the existing conditions, completing the final project design including all necessary drawings and submitting design documents to the GSA for approval, providing safe working conditions, providing all equipment, tools and apparatus to execute the work, demonstrating the successful operation of the cogeneration system, providing as-built documents, and providing training on the operation of the system.

The work shall include without limitation all materials, labor, supervision, tools, equipment, services, and all other expenses necessary to meet the requirements of this solicitation.

Design Criteria

The system design by the Contractor shall meet the specific design criteria listed below and contained in the applicable sections of the project specifications in Part 4, the written concept design narrative, and the concept design drawings. Where conflict is discovered between these items the Contractor shall obtain clarification from GSA before proceeding with work.

The intent of the following sections: design criteria, site constraints, the concept design narratives and project specifications, is to provide the necessary criteria to convey the system description, system functionality and operation including overall performance requirements, design criteria, design constraints, equipment specifications and requirements, points of connection, tie-in and routing to existing building systems, major equipment location, etc., for the planned cogeneration system, suitable for a design-build installation. Some design elements are left up to the Contractor. Some equipment selections may be required, as noted in the specific electric and mechanical system concept design narratives below. Other equipment selection may be made by the Contractor.

Where any portion of the concept design is neither covered by code nor by criteria in the project specifications as to the quality or standards, the Contractor shall propose criteria and call such attention of the GSA, and obtain the GSA’s approval before proceeding.

1. The cogeneration system equipment shall either be a natural gas-fired internal combustion reciprocating engine generator or a natural gas-fired micro-turbine generator. The system shall include only one of these technologies (no dual technologies). The generators can be an induction or synchronous type or use inverter technology.

2. The acceptable total system size shall range from 200 kW to 500 kW, full-load, net electrical output. Net electrical output is defined as gross, full-load electrical output of the generators in the system minus the full-load, electrical output of the auxiliary equipment installed as part of the new cogeneration system, except for the dump radiator fans, i.e., when the system is operating at full-load electrical output and full heat recovery, the net electrical output provided to the building. The net electrical output of the system shall be at ISO conditions (per the SGIP incentive requirements): 59°F ambient, seal-level. Also, the Contractor shall assume a hot water return temperature of 147°F for defining system size. Bid options are described in more detail below.

a. Bid Item #1 is for a single system in the size range of 200 to 260 kW, full-load, net electrical output. A system is defined as one (1) internal combustion reciprocating engine generator or one (1) micro-turbine generator or multiple (more than two) micro-turbine generators connected together, to provide a combined full-load, net output of 200 to 260 kW. The single system shall be connected in parallel to the 1109 Feeder.

b. Option #1 is for two cogeneration systems in the total system size range of 360 to 500 kW full-load, net electrical output. Each system shall provide a full-load, net electrical output of 180 to 250 kW. One system shall be connected in parallel to the 1109 Feeder and the other system shall be connected in parallel to the 1108 Feeder. Waste-heat shall be recovered from both systems (combined together) and used to supplement and preheat the boiler heating hot water system.

c. Option #2: To increase the potential waste heat recovery, this option is for the design and installation of water storage tank(s) to store hot water from the cogeneration system when the cogeneration system heat recovery is greater than the building heating load and to use the stored hot water when the building heating load is greater than the cogeneration heat recovery. This option is applicable for both system sizes (Bid Item #1 and Option #1). This option will be restricted by the available space within the boiler or chiller mechanical room. One potential location for the hot water storage tank is in the corner (columns D & 3) of the boiler mechanical room, across from the existing domestic hot water heaters and to the west of the back corner stairwell. This area is approximately: 154" long (from the stairs to the west wall) x 120" wide (from south wall to domestic hot water heater pad) x 127" high (to the fire pump exhaust duct). The Contractor’s proposal for this option shall include the design and installation of an approximate 5,000 gallon insulated tank (or larger if there is sufficient space) and associated piping and controls for storing excess recovered hot water and using it during higher hot water load periods. For this potential location, the tank shall be rectangular to fit the required space with the necessary clearances.

3. The cogeneration system shall be designed to operate continuously (24/7), unless down for maintenance or repair. The cogeneration system shall be designed to operate at full electrical output with all, part or none of the waste heat recovered, or in a thermal-load-following mode, in which the electrical load is varied in appropriate increments above a minimum output or generators are shut off, in order to best match the heating needs of the building, in order to minimize the amount of rejected waste heat. Based on the system size, equipment, efficiencies, and electric and gas rates, the GSA and Enovity will determine the preferred operating strategy and schedules, with the Contractor’s review and input.

4. It is desired that the proposed system minimum output in the thermal-load-following mode be between 110 and 250 kW, to meet the building base heating hot water loads and optimize the cogeneration system total efficiency.

a. During non-occupied or off-peak electrical hours, the system will likely operate at the proposed system minimum output in the thermal-load-following mode. During occupied or on/mid peak electrical hours, additional electrical load would be provided and/or generators staged on to operate the system at full electrical output and full heat recovery.

b. Any generator on-off staging would be based on a time of day schedule; it is anticipated that the system will only be started and stopped once per day.

c. The base loads of the two main electrical feeds are 400 kW for Feeder 1108 and 600 kW for Feeder 1109. The electrical output for the generators connected to Feeder 1108 should not exceed 360 kW and the electrical output for the generator(s) connected to Feeder 1109 should not exceed 540 kW.

5. The cogeneration system equipment shall not operate in facility only island mode or in emergency mode.

6. The new cogeneration system shall operate in parallel with the PG&E electric grid and meet PG&E Rule 21 interconnection and protection requirements.

7. The new cogeneration system design shall meet all Bay Area Air Quality Management District (BAAQMD) requirements, including specification of Best Available Control Technology (BACT) to meet emission requirements for a permit to construct and a permit to operate. The Contractor shall provide all necessary system information and documentation to receive the BAAQMD permits.

8. The new cogeneration system shall meet all applicable PG&E SGIP criteria and requirements necessary to receive an incentive in 2007. The PG&E SGIP website is http://www.pge.com/selfgen/

9. As required for the 2007 SGIP incentive, the internal combustion engine or micro-turbine NOx emissions levels shall not exceed a standard of 0.07 lbs per MW-hr, per California Air Resource Board (CARB) emission requirements. If the emissions are above this standard, the SGIP allows a waste heat utilization emissions credit, as defined in the SGIP Handbook and calculated in the SGIP Waste Heat, Minimum System Efficiency & Emissions Spreadsheet. If the Bidder cannot meet the NOx emissions of 0.07 lbs per MW-hr, the Government will complete the SGIP Waste Heat, Minimum System Efficiency & Emissions Spreadsheet, to determine if the Bidder’s system can meet the NOx emissions with the cogeneration waste heat utilization emissions credit.

a. Provided in Appendix 3, are the boiler heating hot water load data that will be used to determine the amount of waste heat that can be recovered and used to preheat the boiler hot water, for the SGIP incentive application and the waste heat utilization emissions credit calculation. This data was developed based on regressions of the monitored data presented in Appendix 2 (i.e., a regression of the HW load as a function of the OSA temperature, during different time periods). The heating hot water load data is provided in two formats:

i. Estimated average hourly HW load at various OSA temperature bins, with the monthly hours in each temperature bin. The bin load data is provided during different time periods: a) weekdays 5am to 5pm, b) weekdays 5pm to midnight, c) weekdays midnight to 5am, d) weekends all hours. Multiplying the average HW load by the number of bin hours for each month will provide the total Btu load during each month.

ii. Estimated weekday and weekend, daily (24 hour) average hourly load and OSA temperature, averaged over the entire year.

10. As a minimum, the cogeneration system efficiency, defined as the rated full-load, net electrical output plus the waste heat recovery rate at rated full-load output, divided by the fuel input (higher heating value), shall be greater than 60%.

11. Heat recovery shall meet Public Utilities Code 218.5, which states; when useful thermal energy follows power production, the useful annual power (i.e., net of auxiliary) output plus one-half the useful annual thermal energy output equals not less than 42.5 percent of the natural gas fuel input (based on the lower heating value of natural gas). Also, the useful thermal output shall be greater than 5% of the useful electrical output plus the useful thermal output.

12. Heat recovery system shall be designed and operated to maintain the heating hot water supply temperature out of the new Preheat HX, before it enters the boilers, at 180°F.

13. It is assumed that the maximum number of equipment operating at the same time, using the existing exhaust stack flue would be two (2) HW boilers, two (2) domestic hot water heaters, two (2) emergency generators (the main 1,000 kW and new 300 kW FBI generator), and one (1) 8.2 liter diesel engine for the fire pump.

14. Electrical equipment – all equipment shall be UL listed for the use intended.

15. All equipment to be installed shall be seismically secured to meet the California Building Code requirements.

16. The Contractor’s proposed design shall strive to provide attributes of reliability and continuity of operation.

17. All manufacturer clearance requirements shall be provided.

18. All systems shall be installed by appropriately licensed California contractors in accordance with the rules and regulations adopted by the State of California Contractors’ State Licensing Board.

Site Constraints

The site constraints are listed below. The Contractor is responsible for verifying all information provided below and in the drawings, including all space and access dimensions and requirements and for making sure their equipment can be safely moved into place.

1. The cogeneration system is to be installed in the boiler mechanical room located in the sub-basement of the building. The main cogeneration system equipment (generators) shall be located in the “hatched” space indicated in boiler room equipment layout Drawing MP-101. Additional auxiliary electrical and mechanical equipment can be located in adjacent areas as indicated in Drawing MP-101 and Drawing E1.01 for the auxiliary electrical equipment in the substation electrical room.

2. Any large cogeneration system equipment can be moved into the boiler room either through the main outside air shaft on the north side of the boiler room or from the sub-basement parking garage loading dock through the sub-basement hallway into the main chiller room entrance, adjacent to the boiler room. The double door leading from the sub-basement garage to the sub-basement hallway is approximately 5’ 10” wide and 6’ 8” tall (to be verified by the Contractor) and the double door into the chiller / boiler room is approximately 5’ wide and 6’ 8” tall (to be verified by the Contractor). The main outside air shaft is open to the street level, two basement levels below the street. The main outside air shaft is approximately 19’ and 12½’. There are some pipes and a small radiator on the edges that will reduce the open area available by a foot or two, in order to lower equipment into the bottom of the shaft. The top of the outside air shaft at the street level has on open steel grate and concrete panels on top of steel panels. These grate and panels can be removed to lower equipment into the bottom of the shaft. The outside air shaft has a large louver array that would need to be removed in order to move equipment from the bottom of the outside air shaft into the boiler room.

3. For a single cogeneration system (Bid Item #1), the generator(s) shall be installed in the area south of (behind) the stairwell and the existing main emergency generator fuel and expansion tanks. If one single generator is installed for this single system then it shall be installed length-wise east-to-west, so the existing main emergency generator fuel and expansion tanks do not have to be relocated.

4. If needed, the stairwell shown in the Drawing MP-101 and E1.01 can be removed by the Contractor, prior to the start of construction to make room for the cogeneration system equipment and if required this cost should be included in the Contractor’s price. The approximate distance from the back wall to the stairwell post is 157 inches (to be verified by the Contractor). The back concrete curb can be also removed.

5. For Option #1, the existing main emergency generator fuel and expansion tanks can be relocated by the Contractor, if needed to provide sufficient space for the equipment; this cost should be included in the Contractor’s price. The preferred orientation for multiple generators is length-wise north-to-south, side by side in the area indicated on drawing MP-101.

6. If the existing main building emergency generator fuel tank and expansion tank located under the stairwell need to be relocated, they will be relocated, reinstalled including all piping, and tested by the Contractor; this cost should be included in the Contractor’s price. The preferred relocation option is behind the FBI emergency generator exhaust fan.

7. The main building emergency generator city water radiator drain pipe is located in a trench that runs along the south-west corner of the boiler room. This pipe drains into another trench that is located in the proposed location of the new cogeneration system equipment, running east-west along the back of the boiler room. The piping in this trench is abandoned, but the trench serves as a drain for the emergency generator city water radiator. If a concrete pad is poured over the trench, the radiator drain may need to be relocated to a different active floor drain in the vicinity (there is one adjacent to the main generator). The Contractor shall make this determination; any additional costs should be included in the Contractor’s price.

8. There is an approximate 83 inch floor width gap (to be verified by Contractor) between the emergency generator switchgear and the main 1,000 kW emergency generator (Gen-1). The distance from the raised emergency generator electrical panel (behind the switchgear) and the 1,000 kW emergency generator is actually less, but the metal support arm from the raised panel to the floor can likely be temporarily removed and supported in another manner. The new cogeneration system equipment will need to be moved into place between this gap, as there is not an other viable path. The Contractor is responsible for verifying all space and access dimensions and requirements and for making sure their equipment can be safely moved into place and shall state so in their proposal. There may also be a height restriction from the floor to the raised electrical panel mentioned that will need to be verified by the Contractor. The Contractor will need to make sure their equipment fits below this panel or that the panel is temporarily removed, as approved by GSA.

9. Under a separate contract, the existing 250 kW FBI emergency generator shown in Drawing MP-101 will be removed and replaced by GSA with a 350 kW generator. The housekeeping pad size may increase from the existing pad size. The existing switchgear and load bank equipment for both emergency generators will likely remain in place or may be moved behind the FBI generator exhaust fan.

10. No equipment can be located in the outside air shaft on the north exterior wall of the boiler room. This shaft is used to move equipment in and out of the boiler and chiller room.

11. Electrical interconnection shall be made at the 480 volt Substation #2 located in the adjacent electrical room as shown on Drawing E1.01. The main 12 kV service (as shown in Drawing E1.01 and E6.01) shall be remotely monitored (if required) for the Rule 21 protection scheme requirements.

12. The generator shall only be interconnected to the 12 kV circuit / feeder. Should utility power be lost, the generator output cannot be transferred to the other 12KV circuit / feeder (i.e., the generator interconnected with Feeder 1108 cannot provide electricity through Feeder 1109 if utility power is lost on the 1108 Feeder and vice-versa).

13. The Contractor shall provide all appropriate equipment to sub-meter the gas consumption for this cogeneration system as required to meet and receive the PG&E cogeneration transportation and distribution gas rate. The main gas line for the building currently feeds the boilers only. In the boiler room, a new gas line and sub-meter (GSA-owned; not PG&E owned) shall be added from the existing line feeding the boilers to feed the new cogeneration system. The gas sub-meter shall be in conformance with PG&E’s metering standards and be accessible to PG&E.

Electrical System Concept Design Narrative

Provided below is a written narrative of the electrical system concept design for this cogeneration system. Unless otherwise stated, the following requirements are for each individual generator system. Should the dual cogeneration system option be selected, each requirement shall be duplicated for each generator system package.

The electrical system concept design drawings are listed below.

· Drawing E0.01 – Legend, General Notes and Abbreviations

· Drawing E1.01 – Partial Basement Level Floor Plan

· Drawing E6.01 – Electrical Single Line Diagram

· Drawing E6.01E –Emergency Power Single Line Diagram

· Drawings E6.02 to E6.03 – Electrical Three Line Diagrams

· Drawing E6.04 to E6.05 – Control Schematic Diagram

Provided in Drawing E1.01 is an equipment floor plan showing both existing electrical equipment and switchgear for the building and the new electrical equipment proposed for this project. And provided in Drawing E6.01 is a single line electrical diagram showing the conceptual design features of the proposed cogeneration system along with existing building electrical infrastructure, discussed in more detail below.

1. Interconnection – Electrical service to the Phillip Burton Federal Building is provided through two radial 12kV services (the building is not on the PG&E network). The generator(s) shall interconnect to the facility at the 480 volt Substation #2 located adjacent to the boiler room, on the west side of the basement. The generator(s) will provide power to the circuits feed from Substation #2 and also to additional areas in the building by back-feeding through the 12 kV to 480V transformers to other substations and/or to the main 12 kV bus. The interconnection shall be achieved by installing a new ABB K-Line Power Circuit Breaker in an available space on the 1109 side of the distribution switchboard (for the Bid Item #1 System) or a new ABB K-Line Power Circuit Breaker on each side (both the 1109 and 1108) of the Substation #2, distribution switchboard (for Option #1). There is space available (empty buckets) for a breaker on each side of the switchboard in Substation #2 to connect to the Feeder 1109 and 1108. The interconnect conductor shall be 600V rated, with a minimum current rating of 125% of the maximum generator system package output.

The main 12 kV service (as shown in Drawings E1.01 and E6.01) shall be remotely monitored for the Rule 21 protection scheme requirements. New wiring is required as shown in the drawings.

2. Rule 21 Protection – Two (2) Beckwith M-3520 relays shall be provided (1 primary, 1 backup) per generator. Input voltage and current source shall originate from the main 12kV service switchgear in which the generation is connected to. The Beckwith relays shall monitor voltage for under-voltage (27), over-voltage (59), under-frequency (81U) and over-frequency (81O). The relay shall monitor both voltage and current for the under power relay (32).

a. If the proposed system is a synchronous generator, synch check (25) and overcurrent protection (50, 51, 50N 51N) shall be required and shall meet PG&E’s interconnection requirements. The synch check shall monitor voltages on both sides of the generator circuit breaker. The overcurrent protection shall protect the PG&E system from fault contribution by the synchronous generator. The new CT circuit from the 12kV switchgear shall be utilized for current input for overcurrent protection.

b. The current input signal shall originate from the existing 800:5 CTs located in the corresponding 12kV switchgear. The voltage input signal (except for 25 device) shall originate from the existing 14,400:120V PTs located in the corresponding switchgear.

c. Any of the above targets shall initiate a DC shunt trip relay to open the corresponding generator main protection. The relay settings are determined by Rule 21 and the Contractor to protect their equipment. The GSA shall review the Contractor’s relay settings for coordination with the existing facility electrical system.

3. Relay Settings

a. Contractor shall provide fault and coordination study encompassing generator equipment, cabling and connection to existing facility equipment.

b. Contractor shall determine the relay settings required for the protection of their equipment and the facility electrical system. These settings shall be reviewed and approved by the GSA, as part of the 90% design drawings.

PG&E required relay settings for the redundant Beckwith M-3520 relays shall be dictated by the latest Rule 21 requirements.

4. Generator – Synchronous or Induction generator shall be 60Hz, 480V rated with integral output circuit breakers with shunt trip sized for the generator per NEC.

a. The generator package shall be provided with its own protection equipment to protect the generator during the following events:

i. Overcurrent

ii. Reverse power

iii. Over/under voltage

iv. Over/under frequency

v. Synchronizer and synch check (synchronous generator)

b. Start-up and connection to utility shall be automatic without the need to manually operate the circuit breaker or the generator control.

c. Micro-turbine utilizing inverter technology for interconnection to utility shall meet PG&E’s Rule 21 certification.

5. DC Control – The Rule 21 protection relays and generator shunt trip circuit breaker shall be supplied by the existing 125VDC battery system located in the 12KV switchgear room. A separate protected DC circuit shall be provided to meet the relay and shunt trip power requirements.

6. New Auxiliary Switchboard & Meter – A new auxiliary switchboard shall be provided, as shown in the Drawing E1.01 and in the single line diagram in Drawing E6.01. This equipment may be located in the boiler plant along the back wall labeled column D, however, this is a suggested location and the Contractor may propose an alternative location as needed. The new auxiliary switchboard shall include the following sections:

a. Non-fused 600V disconnect, lockable in the open position. Ampere rating of 125% of maximum generator output.

b. Metering cabinet for PG&E net generation metering. Cabinet to meet PG&E metering requirements with CT installation space and 13 jaw meter socket. The Contractor shall be responsible for providing any new PG&E owned electric meters (net output generation meter) for the cogeneration system and coordinating the installation of the meters with PG&E.

c. Motor control cabinet – MCC to provide auxiliary power for engine generator control and mechanical equipment for heat recovery system.

d. Protection Relay – Rule 21. Protection relay mounted in cabinet at auxiliary switchboard location.

7. Pre-parallel Inspection – prior to connection to PG&E, a Rule 21 pre-parallel inspection (PPI) shall be required, and pre-approved relay settings shall be programmed into the relays.

a. The following is required to complete the PPI. The Contractor shall:

i. Provide final relay setting and submit Form DG5 to PG&E for approval.

ii. Submit equipment commissioning report

iii. Schedule inspection by PG&E to witness equipment and relay function test.

iv. Provide final relay testing and setting documentation. The relays shall be bench tested by a third party testing company. A third party testing company shall be present when PG&E witnesses the function test.

b. At the completion of the PPI, PG&E shall submit a letter allowing for interconnection to the utility. All interconnection agreements and special agreements shall be submitted to PG&E prior to interconnection.

8. Building Automation System – The cogeneration system control package shall be compatible with the building automation system (BAS) to integrate the necessary points to the BAS for monitoring and remote start-stop and load control purposes. See the Mechanical System Concept Design Narrative (Part 2-E-15) for the requirements for BAS integration.

9. Cogeneration System Controls:

a. The generator shall operate in automatic mode to meet output requirements.

b. Start-up and connection to the PG&E utility power shall be automatic without the need for manual control of the circuit breaker or generator control.

c. The generator shall automatically shut down in an orderly and safe manner. The generator shall cool down in a manner that prevents damage to the unit. All shutdown sequences shall be automatic and appropriate for the event.

Mechanical System Concept Design Narrative

The mechanical system concept design drawings are listed below.

· Drawing MP-001 – Symbols Legend, Abbreviations, General Notes and Map

· Drawing MP-101 – Boiler Room Mechanical Floor Plan

· Drawing MP-102 – Partial Sub-Basement Mechanical Floor Plan

· Drawing MP-601, 602 & 603 – Heat Recovery System Single Line Diagrams

Provided below is a written narrative of the mechanical system concept design for this cogeneration system.

1. Exhaust Stack / Flue - 1The building has an existing 42-inch diameter exhaust stack flue which serves the boilers, emergency generators, and a diesel engine driven fire pump. The insulation of the exhaust flue has asbestos (inside the main exhaust shaft). The GSA will abate the asbestos required for connecting the cogeneration system exhaust to the main exhaust flue. (See Part 1-B for roles and responsibilities and Part 3-H for hazardous materials). The boiler exhaust duct (42” x 36”) does not have asbestos insulation. The boiler exhaust duct connects to the main exhaust stack flue inside the main exhaust shaft that runs up to the building roof. The new cogeneration system exhaust duct(s) shall connect to the main exhaust duct inside the main shaft, not to the boiler exhaust duct inside the boiler room (due to back pressure concerns), as shown conceptually in Drawing MP-101 and in a similar fashion as the two existing emergency generator exhaust duct connections.

a. The equipment assumed to be operating simultaneously with this new cogeneration system are noted in the Design Criteria, Part 2-B. Preliminary calculations show that the 42 inch diameter flue will be sufficient to handle the output of existing equipment plus the new cogeneration system equipment (either one or two generator systems). This shall be verified by the Contractor.

b. The capacity of the existing stack is estimated at 35,000 ACFM. The flue gas contributors considered operating simultaneously only input approximately 12,000 ACFM. Where the exhaust from the cogeneration system will likely enter the main 42 inch diameter stack, it is anticipated that the pressure in the stack to be slightly below atmospheric pressure.

c. The Contractor shall design the new cogeneration system exhaust duct(s) to maintain the back-pressure requirements (maximum pressure drop from the generator exhaust to the main exhaust flue) as specified by the generator manufacturer for ensuring rated system performance.

d. Some provisions for dampering of the generator exhaust at the inlet to the flue stack may be required by the Contractor to optimize exhaust flow. Some adjustment of the boiler dampers may also be required and shall be included in the Contractor’s proposal.

e. The intent is that each generator will have its own exhaust duct that runs from the generator and ties into the main exhaust stack flue. This will allow for generators to be shut-down and not have exhaust flowing into a generator that is off and causing condensation. If the Contractor proposes to combine the exhaust from multiple generators into one common exhaust duct that is connected in the main exhaust stack flue, then the Contractor must be able to completely isolate any generator that is off and prevent exhaust air from any operating generator to enter any generator that is off and provide a guarantee that condensation will not occur. The Contractor’s proposed design must be approved by the GSA.

2. Heat Recovery - The cogeneration system shall include a reciprocating engine or a micro-turbine fueled by natural gas to drive an electrical generator. Using heat exchangers, useful heat energy shall be recovered from the micro-turbine exhaust (gas-to-water heat exchanger) or from the engine cooling jacket water (water-to-water heat exchanger), the engine exhaust (gas-to-water heat exchanger) and possibly from the engine intercooler (water-to-water heat exchanger).

a. The primary use of the recovered heat for the proposed cogeneration system at the Phillip Burton Federal Building is to supplement heat for the building heating water system, which is currently supplied by the three main hot water boilers (10,000 kBtu/hr capacity each). There is a continuous heating hot water load, even on the weekday night-time hours and weekends. The boilers are enabled 24 hours per day, 7 days per week, in order to maintain temperature in the heating hot water loop and to meet the minimal after-hours heating load. The boilers cycle on and off during these time periods and the load varies from 0 to 1,000 kBtu/hr. Thus, there is an average "base" heating hot water load of about 500 kBtu/hr. During the weekdays, the boiler heating hot water load from 5am to 5pm ranges from about 2,000 kBtu/hr to 10,000 kBtu/hr. There are periods in the winter where the peak load is as high as 16,000 kBtu/hr. The peak load has historically occurred during the morning hours.

b. A summary of the estimated average boiler hot water loads during different monthly outside air temperature bins calculated from the monitored heating load data is provided in Appendix 3. Also, provided are the estimate average weekday and weekend hourly hot water load, supply and return temperatures and flow rate. The 24/7 heating hot water load is believed to be sufficient for the dual cogeneration system to meet the required PURPA efficiency (1 system may operate 24/7 and the other system during the main hot water heating loads from 4am to 6pm).

c. Option #2 is to store excess heat using a heating water storage tank, rather than dumping the excess heat. This is optional for the Contractor to propose the additional cost of an approximate 5,000 gallon storage (or larger, if sufficient space) tank and system design features and operation.

3. Heat Recovery Configuration - The recovered heat from the cogeneration system will be used to pre-heat the building heating return water before entering the boilers using a water-to-water heat exchanger (HX), referred to as the “Preheat HX”. An intermediate heat recovery loop shall connect the Preheat HX to the generator heat exchangers. The concept design for the heat recovery system is supplemented by Drawings MP-601, 602 and 603, which contain single-line heat recovery flow diagrams for the various cogeneration system options (single engine generator, dual engine generators and single/multiple micro-turbine generators).

a. The specified heat recovery rates from the engine/micro-turbine driven generators shall be made available for recovery and if not used, their equipment will automatically reject the heat to maintain the system electrical output.

b. For a system with two or more generators, the generators shall be connected in parallel and the heat recovered from each of the generator heat exchangers shall be combined before going into the Preheat HX to preheat the return hot water to the boilers.

c. The system shall have the capability to reject all (100%) of the generator heat that is not used to preheat the heating hot water load, either through a dump radiator and/or dampers to divert exhaust around the exhaust-to-hot water heat exchanger. If a dump radiator is used, only one dump radiator shall be installed.

d. The single-line diagrams in drawings MP-601, 602 and 603 are conceptual in nature and do not depict the final piping, valves and instrumentation required for the cogeneration system heat recovery loop. For example, some of the ancillary mechanical components such as control and isolation valves, air separators, expansion tanks, etc., are shown on the conceptual design single line piping diagrams. Some components such as additional isolation valves, balance valves, check valves, temperature and pressure gauges, flow meters, pressure relief valves, pipe and pump fittings/flanges, etc., are not depicted and shall be designed by the Contractor.

e. Make-up water to the cogeneration system is available in the boiler room, from either a two-inch city water line or a four-inch pressurized domestic cold water line.

f. The Contractor shall design the piping for the intermediate heat recovery loop piping, determine pressure drop losses and shall properly select the pumps to meet both full-load and part-load operation. If there are two generators, then the design flow for both generators shall be provided by one pump with a VFD for flow control if only one of the two generators is operated. If there are more than two generators, the Contractor can either provide one or two pumps, with a VFD, sized to all generators, or a pump sized for each generator. In all cases, one redundant pump shall be provided. The system shall automatically adjust the flow rate based on the number of generators operating.

g. The intermediate heat recovery loop piping shall include any required flow balancing devices and field balancing work as well as installation of isolating valves and unions. These shall be included in the design drawings by the Contractor.

h. The preferred location of the Preheat HX is with the major generator equipment, thereby reducing pumping requirements in the intermediate heat recovery loop. If the Contractor chooses to locate the Preheat HX near the heating hot water return lines, they shall define so in their proposal.

i. As shown on drawings MP-601, 602 and 603, a bypass line and diverting valve (CV-4), either a two-way or three-way valve (to be determined by the Contractor in the final design), is recommended around the boiler Preheat HX on the heating hot water “cold” side to maintain the proper flow rate. Manual isolation valves shall be installed before and after the diverting valve. The Preheat HX shall be sized for a maximum flow rate (to be determined by the Contractor). The flow rate through the Preheat HX shall be controlled when the total boiler HW flow is greater than that which can be sent to the Preheat HX (i.e., the remaining water is diverted around the HX). This requirement is necessary because the waste heat from the cogeneration system is not sufficient to meet the entire load of the heating hot water loop. The waste heat can only provide a fraction of the total heating hot water load during peak usage periods. Only during the low load periods will the waste heat potentially be able to meet all of the hot water load requirements without requiring the boilers. This configuration will be able to control the flow rate through the Preheat HX to a value as specified by the Contractor. The recommended piping configuration and instrumentation for connecting the Preheat HX into the existing heating hot water return line is provided in Drawings MP-601, 602 and 603.

j. The Contractor shall include a bypass line around the diverting valve, with manual isolation valves on this valve bypass line, to allow the water to bypass the diverting valve incase the diverting valve were to fail or need to be replaced.

k. The Contractor may propose modifications to the piping in Drawings MP-101, 102, 601, 602 and 603 as long as they provide stable control and water balance, and are approved by the GSA.

l. The heating hot water supply temperature setpoint to the building is maintained at 180°F. The boiler hot water return temperature is typically 147°F on average, and will vary from a low of about 130°F, during peak load periods, up to about 165°F during the base load (after-hours) periods. The Contractor shall design and operate their system around these temperature requirements, to provide as much heat recovery to preheat the heating return water and to ensure that the heating supply water temperature out of the Preheat HX does not exceed 182°F.

m. The Contractor shall design the heat recovery system to handle the varying heating water return temperatures and delta-Ts. During the non-occupied periods, the return water temperature is higher than during occupied periods and the delta-T is much lower than during occupied periods.

n. The heating hot water flow varies from a minimum of about 250 gpm during the base load, after-hour periods (evening, weekends) to about 550 gpm at 10,000 kBtu/hr, and likely peaks at about 900 gpm at a peak load of 16,000 kBtu/hr.

o. The water pressure on the return side out of the boilers and into the suction side of the hot water pumps is about 145 to 150 psig. The boilers are rated up to a maximum pressure of 160 psig. The hot water system is high pressure because water is pumped from the sub-basement up to the 20th floor. The Preheat HX shall be designed to meet these pressure requirements.

p. If multiple generators are installed, the Contractor shall ensure that the Preheat HX can operate with reduced flow on the hot side of the HX if generators are staged off, i.e., ensuring that the specified minimum flow rate of the HX is below the flow rate if only one generator is operated. If not the Contractor shall state the minimum number of generators that can be operated to provide minimum flow rate through the Preheat HX.

q. The need for a dedicated pump to feed the heating hot water into the building/boiler Preheat HX is not recommended and likely not required. The pressure drop of the new piping and heat exchanger shall be designed by the Contractor to be small enough that it will not impact the system and the existing hot water pumps can likely overcome this additional pressure drop. The existing hot water pumps have sufficient capacity to overcome a small pressure drop increase due the new Preheat HX.

4. Heat Recovery Control - A key requirement for the cogeneration system will be automatic controls to regulate the amount of heat recovered from the generators based on the available load from the building heating hot water system to ensure the maximum amount of waste heat is recovered and that proper temperatures are maintained in the building heating hot water loop (particularly if there is little or no heating hot water load). The heating hot water temperature out of the Preheat HX (shown as T2 on Drawings MP-601, 602 and 603), before entering the boilers, shall be controlled by the cogeneration control system to 180°F and shall not exceed 182°F. When the heating hot water load to the Preheat HX is greater than the heat recovery rate of the cogeneration system, all of the cogeneration system waste heat shall be recovered and used to heat the heating hot water so no cogeneration waste heat is dumped; in this mode, the building heating hot water temperature (T2) out of the Preheat HX may vary below 180°F. When the heating hot water load to the Preheat HX is less than the heat recovery rate of the cogeneration system, all of the heating hot water load should be preheated with the remaining excess heat dumped; in this mode, the cogeneration control system shall control the amount of heat being delivered from the cogeneration system in order to maintain a heating hot water temperature (T2) out of the Preheat HX that does not exceed 182°F.

a. The Contractor shall decide if the amount of cogeneration system heating water delivered to preheat the building heating hot water system will need to be regulated with a three-way control valve (CV-1 in the single line diagrams in MP-601, 602 and 603) for proper temperature control on both the cold (boiler) and hot (generator) side of the Preheat HX.

b. The cogeneration system controls will control the applicable heat recovery valves, dampers, and radiator fans, on the intermediate heat recovery loop “hot” side to maintain the required temperatures into the generator heat exchangers.

c. Control of the boiler Preheat HX two-way or three-way diverting valve (CV-4) will be through the BAS to maintain the required flow rate through the Preheat HX as specified by the Contractor.

5. Cogeneration Heat Recovery Equipment Package - At a minimum, all of the heat recovery equipment and controls except for the Preheat HX and three-way or two-way diverting valve (shown as CV-4 in Drawings MP-601, 602 and 603) shall be supplied by the Contractor, as a “packaged” system.

6. Spool Piece Tie-in to HW Return for Preheating:

a. There are three boiler HW return lines, as shown on Drawing MP-101. Two 4-inch lines from the east and west sides of the basements and a 6-inch line from the 20th floor. Each return line has an isolation valve just before connection to the main return header into the boilers.

b. There are approximately 4-feet between the last return line (20th floor) into the return header and the first boiler, i.e., 4-feet of “common” return pipe.

c. As shown on Drawing MP-101, this approximate 4 foot common return pipe shall be replaced with a new spool pipe piece, pre-fabricated and installed in one heating hot water system shut-down. See Drawings MP-601, 602 and 603 for the piping and instrument requirements.