Business Confidential - Willdan
Water Department
1000 Buena Vista
Solar PV & Battery Storage Project
September 18, 2026
Final IGA Report Version 2
Business Confidential - Willdan
Table of Contents
Final Project IGA Deliverable
Page # Report Section
3 - 9 Project Background & Goals
11 - 18 Scope of Work
20 - 25 Final Project Financials & Air-Quality Benefit
27 - 27 Implementation Planning
29 - 35 Appendix 1: Detailed Scope of Work
37 - 41 Appendix 2: Savings Calculations
43 - 46 Appendix 3: Performance Guarantee
48 - 48 Appendix 4: Savings Measurement & Verification
50 - 50 Appendix 5: PG&E Utility Rate Escalation
52 - 52 Appendix 6: Financial Disclosure
2 Business Confidential - Willdan
Project Background
and Goals
Business Confidential - Willdan
Project Goals
Fiscal Responsibility – Maximize electrical utility cost savings. ▪ Reallocate elsewhere in the Domestic Water Enterprise Fund operational budget. (minimum $414,000 per year)
▪ Hedge against future utility rate escalation.
(average ~10.2% increase each year over last 5-years)
Asset Ownership – Water Dept retains ownership of assets. Realizes full benefit of the savings rather than a PPA.
System Sizing and Optimal Generation – Offset as much electrical spend as possible. Avoid diminishing returns of selling power back to the grid.
Air-Quality Benefit – Cleaner air and reduced pollutants of City owned infrastructure and equipment for the Community.
Leverage All Available Funding Sources – Including federal, state, and regional grants, incentives, etc.
4 What are the project goals for 1000 Buena Vista?
1 2
3 4
5 Business Confidential - Willdan
Project CIP History
Municipal Water Enterprise Fund (MWF) already had this project programmed
▪ The Solar PV and BESS project has been a well-thought out and planned CIP Project for the Municipal Water Fund.
▪ It was incorporated in the 2025 Supplemental Rate Study for Rate Increase through Prop 218.
▪ Budget Authority was approved for the project through FY 2026 and FY 2027 Budget Process.
▪ CIP Dollars approved through the Rate Study are not changed, just reallocated as the Water Department has experienced cost savings from other CIP projects. ▪ No New Dollars are being requested at this time.
The Water Department believes in the economics of this project; that it will showcase fiscal responsibility by the MWF and benefit the ratepayers both in the near- and long-term. 5 Background on the Budget Authority Approved for the Project 1 Business Confidential - Willdan
Water Rate Payer Benefits
Annual budget savings and one-time Federal ITC tax credits will be reallocated for other uses; along with hedging against future utility cost escalation ▪ Annual dollar savings will be significant ($382K) and reallocated for other priority needs currently in the MWF budget.
▪ By implementing the project, the Water Department will be saving guaranteed units (kWh).
▪ There will also be a rate tariff shift to a more favorable rate structure. ▪ Regular PG&E utility increases will continue to exacerbate the MWF overall operational budget – having to find funds elsewhere and eventually build into future water rate increases to accommodate for rising utility costs (~$3M increase city-wide in last 2 years).
This is an area of the Municipal Water Fund budget the Water Department has the ability to control and will be one contributor – of many being explored by the Domestic Water Fund – to help reduce the impact of future rate increases. Along with obtaining $3.5M in free Federal tax credits that are going away. 6 How Will this Project Help Ease Future Rate Burdens?
2 Business Confidential - Willdan
Project Updates
Removed EV Chargers and Infrastructure Scope
▪ While the EV Project will need to be implemented in the near future at this location, it has been fully removed from this project.
▪ This also included a measurable amount of site work costs taken out as well.
▪ Overall, reduced the first cost by over $1M dollars.
▪ Was also pulling down the overall ROI created by the Solar PV and Battery Project due to a higher payback period.
Want to focus on the core goal of the project which is the economic benefit by implementing the Solar PV and Battery technologies at the site.
7 What Updates Have Been Made to the Project and Why?
3 Business Confidential - Willdan
Contracting Clarification
The City is Utilizing Energy Savings Performance Contracting (ESPC) to leverage energy savings and Guaranteed Maximum Price Contracting (GMAX) to Avoid Change-Orders ▪ SB 4217 enables ESPC for cities and other public agencies as an alternative contracting delivery method to help reduce energy-related operational costs and to also control construction costs, providing a more reliable project outcome.
▪ This was a stated goal of this Council back in 2024 when the City solicited RFPs to select a DesignBuild/Energy Services parter. ▪ In that RFP, it was very clearly written the requirement for a GMAX contract; meaning no changeorders from the contractor. ▪ Willdan provides a GMAX price to the City – it contractually means it will be the maximum price for the City – unless change orders are requested by the City. Not Willdan. ▪ Thus, the amount of City “Allowances” and “Contingency” built into this contract.
The City controls the use of these funds over the course of the construction. They will be reconciled with the project accounting – not come to the City Council as change-orders to increase the project cost. Any unused funds will be returned to the City at the completion of construction.
8 Addressing the Expressed Concerns Regarding Change-Orders 4 Business Confidential - Willdan
“Doing Nothing Scenario”
Immediate Utility Savings – Year 1 dollar savings for the Interface Facility and Water Resources Office Building is $382,732 which is 56% savings from baseline costs.
Hedge Against Future Utility Rate Escalation – Protect the Water Department budget in upcoming years by hedging against future utility rate escalation.
Project Showcases Fiscal Responsibility in this Economic Climate– Will contribute significantly to helping reduce future water rate increases and overall rate-payer burden in the future.
9 Fundamental Economic Reasons to Implement this Project 1 2
3 “Do Nothing Scenario” – How much will utilities cost at 1000 Buena Vista in 10-Years if the Water Department does not implement this project?
By using 8% escalation which is already being proposed
by PG&E for 2027 (and less than the 10.2% average over
the last 5-years) the Water Department can expect utility costs to increase from Current FY 2027 $682,300 to
$1,473,035 in FY 2037 which is a 216% increase.
Interface Pumping Facility Expansion
▪ Planning expansion of system in next 5-10
years including adding more pumps to the
location
▪ Will increase the load at the location
significantly
▪ This will increase the importance of hedging
against future utility rate increases
▪ Exploring Resiliency through a microgrid to
protect the Water System and adding more
Solar PV will make sense at that time
Business Confidential - Willdan
Scope of Work
Business Confidential - Willdan
Solar PV and BESS
Carport Canopy Solar PV
▪ Goal: Match the necessary load without
unnecessary exporting to PG&E.
▪ Seven carports
▪ Total system size = 511 kWdc
▪ 465.4 kWdc serving Interface Pumping
Station
▪ 45.8 kWdc to serve the office building
Battery Energy Storage System (BESS)
▪ Goal: Substantial peak demand shaving in
peak and off-hours and self-consumption of
PV generation.
▪ System size = Tesla Megapack 2XL - 612 kW
/ 2448 kWh
11 Business Confidential - Willdan
Solar PV and BESS
Interface Pumping Station System
Solar PV System
▪ Estimated production 734,000 kWh/yr
▪ 44% offset of annual electricity usage
▪ 14% exported to grid
BESS
▪ Dispatch Strategy - Stacking Demand Charge Management & Energy Arbitrage
▪ Import Only from PG&E, charge from grid or PV
Modeling Assumptions:
▪ Rate switch from B19 to B19 Option S
▪ Option S rate reserved until 9/10/27 (confirmed by PG&E on 3/10/26)
▪ PG&E Rates Effective 9/1/25
Water Resources Office Building System
Solar PV System
▪ Estimated production 70,800 kWh/yr
▪ 78% offset of annual electricity usage
▪ 37% exported to grid
Example Summer Day
Example Winter Day
12 Business Confidential
- Willdan
Civil Work
Parking Lot Redesign ▪ Goal: Expand parking, provide paved stalls for new EVCS (from Fleet EV
Project), and provide an additional
access point from parking lot to work
area.
▪ Civil Engineering will be finalized by
Willdan following geotechnical soils
study.
▪ Installation can be completed by
Willdan as part of the project as well
and coordinated with all other
scopes.
BESS Foundation and Pad ▪ Goal: Include a BESS foundation with turndown beams in lieu of a retaining
wall. Soils and GeoTech testing will
be necessary to finalize this design.
13 Business Confidential - Willdan
Benefits of Solar PV Parking Canopies
Solar Carports Turn Parking Areas into Dual-Use
Infrastructure
They do not require new land and convert existing paved and gravel surfaces into power generating assets.
1) Generate electricity and reduce building and
infrastructure electrical demand
2) Shade vehicles
3) Reduce heat on asphalt
4) Protect vehicles from the sun, rain, and other weather 5) Support EV charging
6) Improve employee satisfaction
7) Increase the value of the City-owned property
14 Business Confidential - Willdan
Electrical
Surge Protection Devices (SPDs)
▪ Goal: Ensure protection of critical Interface Facility pumping equipment and domestic water infrastructure.
▪ SPDs will be installed at all DER distribution equipment including the PV AC combiner panels, and at the existing main switchboards for both the Interface Pump Station and the Water Resources Office.
▪ The multiple SPDs and isolation transformer in combination with advanced DER energy meters and software monitoring package are included.
▪ Power Quality: Power quality testing will be conducted preand post- project installation to establish a baseline and identify if any impacts arise as a result of DER system installation.
15 Business Confidential - Willdan
Solar PV & BESS Renderings
Canopies 1-5 Serve Interface Terminal, 6-7 Serve Resources Office 16 Battery
Storage
System
Location
1 3 2
4 5
6 7
Business Confidential - Willdan
BESS Rendering
17 BESS Enclosure, DER Panel & Concrete Pad/Bollards
Business Confidential - Willdan
Solar PV Canopy Clearances Renderings
18 Heavy Duty Equipment Approach to Yard from Buena Vista Rd 24’
17.7’ 14’
Business Confidential - Willdan
Final Project
Financials & AirQuality Benefit
Business Confidential - Willdan
Overview & Updates | Turnkey Costs, Grants & Incentives 20 Solar PV & BESS
▪ Solar PV ITC: With the decision by the City to not Safe Harbor the Solar Modules by July 3, 2026, the only other option to obtain all, or some, of the ITC tax credit will be to have full PG&E PTO (“permission to operate”) and system energized by December 31, 2027. This will be challenging, but the Willdan team is working diligently on a Project Schedule and ways to fast-track the equipment deliveries and expedite the interconnection agreement with PG&E. ▪ BESS Down Payment Reconciliation: The cost to Safe-Harbor the Tesla Battery is included in the overall cost of the total BESS solution. Once construction commences and invoicing happens on a monthly basis, Willdan will credit the Water Department back the full down payment amount of $344,240 itemized on the first or second invoice when all other equipment and materials are being ordered.
▪ Self Generation Incentive Program (SGIP): SGIP Application for BESS submitted in October to Waitlist, however the SGIP program closed as of 1/1/26, and all project applications still on waitlists were cancelled. Willdan will monitor in case of future program re-funding.
Parking Lot Upgrades (Civil)
▪ Civil Scope of Work: The 1000 Buena Vista Civil SOW has been bid and is a final turnkey price in the project financials.
▪ The Civil SOW Allowance in the current final pricing will be trued up via change order once the project is contracted and Schedule of Values / Invoicing process has begun.
Business Confidential - Willdan
Overview & Updates | Turnkey Costs, Grants & Incentives 21 Turnkey GMAX Project Costs Include: Engineering/design, program management, PG&E coordination and interconnection, grant and incentive applications and processing, procurement, fixed-price GMAX contract, subcontractor materials and labor, construction management, commissioning, training, close out, warranty, performance guarantees, M&V, and support services.
Expected Useful Life (EUL) of Equipment & Infrastructure:
▪ Solar Photovoltaic Modules: 25-30 year EUL.
▪ Solar PV Inverters: String Inverters. 10-year warranty. 10-15 year EUL.
Replacement included in cash flows in 2042.
▪ Battery Energy Storage System: Tesla Megapack 20-year extended warranty included, requires ongoing O&M past Year 1 (included in cash flow). 18-20 year EUL.
▪ Electrical Switchgear: 25+ years.
▪ Electrical Infrastructure: 30+ years.
▪ “Average Weighted-EUL” of all components of the scope of work exceeds 25-year Expected Useful Life (“EUL”).
Focused on Addressing Council Members Concerns Regarding the Simple Payback and ROI of the PV and Battery
▪ Energy Projects/Equipment is now broken out from General Construction scopes to better depict simple payback and return on investment relative to to the equipment’s useful life.
Important Variables Included in Cash
Flows:
▪ Electricity Rate Escalation: 5%
▪ Inflation Rate: 3%
▪ O&M Escalation Rate: 3%
▪ PV Degradation Rate: 0.5%
▪ BESS Degradation Rate: 3%
▪ Inverters (7) Replacement: 2042
Business Confidential - Willdan
Solar and Battery Project
22 FINANCIAL NOTES:
▪ Reduced First Cost from Original Project: $1,222,437
▪ Range of ITC Incentives: $3.5M - $1.5M
▪ Net Cost to Municipal Water Fund: $4.48M - $6.44M
▪ Range of Energy Projects Payback: 9.54 - 14.65 years
Financial Tables Overview & Reorganization: Full Solar PV, BESS, and associated Parking Lot Upgrades are included. EV scope has been completely removed. Project will utilize budget funds already programmed in the CIP for FY 2026 and FY 2027. Due to the risk of not obtaining the Solar PV ITC, Best- and Worst- Scenarios are provided. The Energy Projects and General Construction Scopes have been separated. It is unfair to penalize the payback and ROI of the Solar PV and BESS with non-ROI Parking Lot and Civil Upgrades.
Category Project GMAX Turnkey Cost Incentives Water Dept Net Cost Utility Savings Payback Energy Projects Carport Solar PV Systems & Interface BESS $7,153,670 $3,503,415 $3,650,255 $382,732 9.54 General Construction Parking Lot Upgrades, City Contingency (2.5%) & Const. Allowances (3.8%) $836,518 $836,518 Project Totals $7,990,188 $4,486,773
Category Project GMAX Turnkey Cost Incentives Water Dept Net Cost Utility Savings Payback Energy Projects Carport Solar PV Systems & Interface BESS $7,153,670 $1,545,941 $5,607,729 $382,732 14.65 General Construction Parking Lot Upgrades, City Contingency (2.5%) & Const. Allowances (3.8%) $836,518 $836,518 Project Totals $7,990,188 $6,444,247
Updated Project - Worst Case Scenario
Updated Project - Best Case Scenario
PROJECT BENEFITS:
▪ Begin reallocating $382K per year of net positive cash flow in OPEX budget for other uses. ▪ Utilize $3.5 – 1.5M in tax credits for other priority CIP projects. ▪ One of many similar projects that the Water Department can implement to help reduce future rate-payer burdens and hedge against future utility rate escalation.
Business Confidential - Willdan
Solar and Battery Project
*Note: Willdan Performance Engineering is not acting as a Financial Advisor. Project Financial Scenarios are provided as illustrative and for example purposes only. 23 ▪ Projected Federal Investment Tax
Credit (ITC): $3,503,415
▪ Minimum Net Total OPEX Savings
Over Project Duration:
$10,685,289
▪ Net Program Benefit
(NPV positive cash flow):
$6,198,516
▪ Return on Investment
(Simple ROI): 77.6%
▪ Return on Investment
(IRR): 7.6%
Total Project Cost: $7,990,188
Replace Inverters (7): 2042
Utility Escalation Rate: 5.0%
O&M Escalation Rate: 3.0%
Inflation Rate: 3.0%
PV Degradation Rate: 0.5%
BESS Degradation Rate: 3.0%
Cash Flow Assumptions
Year
PV Electrical
Savings
BESS Electrical
Savings PV O&M Costs
BESS O&M
Costs CIP Funds
PV ITC
Tax Credit
(Estimate)
BESS ITC
Tax Credit
Net Annual
Cash Flow
Const. $0 $0 $0 $0 ($7,990,188) $0 $0 ($7,990,188)
2028 $104,632 $278,100 Included Included $0 $1,957,474 $1,545,941 $3,886,147 2029 $109,340 $283,662 Included ($9,476) $0 $0 $0 $383,526 2030 $114,261 $289,335 Included ($9,760) $0 $0 $0 $393,836 2031 $119,402 $295,122 ($14,378) ($10,053) $0 $0 $0 $390,093 2032 $124,776 $301,024 ($14,810) ($10,355) $0 $0 $0 $400,636 2033 $130,391 $307,045 ($15,254) ($10,665) $0 $0 $0 $411,516 2034 $136,258 $313,186 ($15,712) ($10,985) $0 $0 $0 $422,747 2035 $142,390 $319,449 ($16,183) ($11,315) $0 $0 $0 $434,341 2036 $148,797 $325,838 ($16,668) ($11,654) $0 $0 $0 $446,313 2037 $155,493 $332,355 ($17,169) ($12,004) $0 $0 $0 $458,676 2038 $162,490 $339,002 ($17,684) ($12,364) $0 $0 $0 $471,445 2039 $169,802 $345,782 ($18,214) ($12,735) $0 $0 $0 $484,636 2040 $177,443 $352,698 ($18,761) ($13,117) $0 $0 $0 $498,264 2041 $185,428 $359,752 ($19,323) ($13,511) $0 $0 $0 $512,347 2042 $193,773 $366,947 ($77,583) ($13,916) $0 $0 $0 $469,221 2043 $202,492 $374,286 ($20,500) ($14,333) $0 $0 $0 $541,945 2044 $211,605 $381,772 ($21,115) ($14,763) $0 $0 $0 $557,498 2045 $221,127 $389,407 ($21,749) ($15,206) $0 $0 $0 $573,579 2046 $231,078 $397,195 ($22,401) ($15,662) $0 $0 $0 $590,209 2047 $241,476 $405,139 ($23,073) ($16,132) $0 $0 $0 $607,410 2048 $252,342 $0 ($23,765) $0 $0 $0 $0 $228,577
2049 $263,698 $0 ($24,478) $0 $0 $0 $0 $239,220
2050 $275,564 $0 ($25,213) $0 $0 $0 $0 $250,352
2051 $287,965 $0 ($25,969) $0 $0 $0 $0 $261,996
2052 $300,923 $0 ($26,748) $0 $0 $0 $0 $274,175
$4,662,947 $6,757,099 ($496,749) ($238,007) ($7,990,188) $1,957,474 $1,545,941 $6,198,516 Financial Benefits
Business Confidential - Willdan
Air Quality Benefits
Combined Air Quality and City of Bakersfield
Environmental Annual Benefit from the Solar PV
Project is:
These are annual amounts projected for the project:
Solar PV Systems = 406 Metric Tons of CO2e
This is the equivalent to carbon sequestered by
planting 6,713 trees in Bakersfield
All conversions & equivalencies calculated using the EPA’s “Greenhouse Gas Equivalencies Calculator”:
https://www.epa.gov/energy/greenhouse-gas-equivalenciescalculator 24 Business Confidential - Willdan
Implementation
Planning
Business Confidential - Willdan
Construction Planning
26 Long Lead Time Equipment
▪ BESS
▪ Tesla will not agree to a delivery date until NTP, and engineering approvals are provided. ▪ Willdan provided Tesla engineering documentation in mid-January 2026, still awaiting feedback.
Current delivery time is projected to be ~Q2 2027. Looking into fast-ship options. ▪ Solar PV
▪ Electrical infrastructure (xfmrs, switchgear, etc) are still experiencing moderate lead times of 5- 10 months.
▪ Domestic Content PV modules are in high demand, so that will be priority to secure order.
Pre-Construction Planning Meetings
▪ Upon full execution of the ESPC construction contract with the City, Willdan Construction Team will immediately work to get subcontracts executed and initiating submittal process. ▪ Will continue to keep our regular meetings which will shift to being led by the Construction Team. ▪ Detailed Construction Schedule will be completed.
▪ Schedule of Values, billing and invoicing agreed upon. ▪ Permitting process completed.
▪ Numerous onsite planning activities will commence.
▪ Formal Construction Kickoff Meeting conducted prior to onsite work.
Project Schedule & Schedule of Values
▪ The Willdan Construction Team cannot accurately create a preliminary Construction Schedule or Schedule of Values until the contract is executed with the City and subcontracts, completed and lead times confirmed.
Business Confidential - Willdan
Appendix 1: Detailed
Scope of Work
Business Confidential - Willdan 28
▪ This Project includes the complete design, engineering, procurement, installation, testing, commissioning, and placement into operation of Solar Photovoltaic (PV) Systems and a Battery Energy Storage System (BESS). ▪ All systems will be fully integrated, code-compliant, utility-interconnected, and operational in accordance with the ESPC Documents, including Drawings and Specifications.
1) Solar PV Systems:
▪ Carport Canopy Solar PV System - 465.43 kWdc.
▪ Carport Canopy Solar PV System - 45.75 kWdc
▪ Work includes:
▪ Design and construction of solar canopy structures over designated parking areas. ▪ Installation of photovoltaic modules mounted to structural steel canopy systems. ▪ Installation of inverters, combiner panels, disconnect switches, and related balance-of-system components. ▪ DC and AC wiring, conduit systems, overcurrent protection devices, and interconnection equipment. ▪ Integration into the existing facility electrical distribution system. ▪ Installation of energy production metering and monitoring equipment. ▪ LED canopy lighting integrated into the existing lighting control system (as applicable). ▪ Utility interconnection and coordination to achieve Permission to Operate (PTO). ▪ Scope of Work includes the same elements as above, scaled appropriately for system size and site conditions.
Solar PV Systems & Battery Energy Storage
Business Confidential - Willdan 29
2) Battery Energy Storage System (BESS)
▪ Tesla Megapack 2XL - 612 kW / 2,448 kWh.
▪ Work includes:
▪ Design and installation of manufacturer-compliant foundation system. ▪ Delivery and placement of Tesla Megapack 2XL unit.
▪ Integration with facility electrical infrastructure.
▪ Installation of required switch gear, protection relays, and power control systems. ▪ Compliance with NFPA 855, California Fire Code, PG&E Rule 21, UL 3141, UL 1741 SA/SB, and IEEE 1547. ▪ Fire Alarm System upgrade for Water Resources Office. ▪ Installation of required fire safety clearances and access pathways. ▪ Metering, monitoring, and control integration.
▪ Commissioning in coordination with manufacturer and City. ▪ Submission of all manufacturer documentation and testing records. ▪ The BESS will be fully operational and capable of performing demand management, energy arbitrage, and applicable incentive program participation functions.
Solar PV Systems & Battery Energy Storage
Business Confidential - Willdan 30
The scope of work includes civil, structural, and electrical engineering required to design, permit, and construct the systems. ▪ Electrical Engineering
▪ Stamped electrical plans and calculations.
▪ Single-line diagrams and protection coordination.
▪ Arc flash analysis.
▪ Verification of interconnection feasibility.
▪ Utility coordination drawings.
▪ Electrical as-built documentation.
▪ Civil Engineering
▪ Site layout modifications for parking expansion and
curb/ramp adjustments (shown in drawings).
▪ Trenching layouts.
▪ Drainage considerations within designated work areas. ▪ Preparation of permit-ready parking civil plans.
▪ Incorporation of redlines into final as-built drawings. ▪ Structural Engineering
▪ Structural calculations and stamped engineering
drawings.
▪ Foundation design based on assumed 14-foot
caisson depth minimum for all canopy column
foundation.
▪ Column concrete abutments 30” above-grade.
▪ Evaluation of existing soils conditions to determine
best method for solar canopy structures
foundations.
▪ Design of solar canopy structures.
▪ Evaluation of existing structural interfaces.
▪ Concrete scanning where required.
▪ Minimum canopy clearance of 14’-6”.
▪ Galvanized structural steel systems.
Design & Engineering Services
Business Confidential - Willdan 31
The scope of work includes all labor, materials, equipment, and supervision necessary to complete the systems described.
Construction Activities
▪ Site preparation within designated work areas.
▪ Excavation and foundation installation.
▪ Installation of canopy steel structures.
▪ Solar module mounting and wiring.
▪ BESS placement and electrical integration.
▪ Conduit trenching or directional boring.
▪ Grounding and surge protection systems.
▪ Required labeling and code-compliant placards.
▪ Restoration of disturbed asphalt, concrete, landscaping, irrigation, and striping within work limits.
▪ All work will be performed during normal business hours 7am-4pm.
▪ Single mobilization for construction.
Construction & Installation
Construction Management
▪ Willdan Prime Contractor.
▪ Regional Director, Sr. Construction Manager, Site
Superintendents, Field Engineers.
▪ Present onsite throughout the construction.
▪ Manage Client and subcontractor meetings.
▪ Schedule, 3-Week Look-Ahead, Meeting Minutes,
Progress Reports, etc.
▪ Close coordination with Water Dept. throughout
entire implementation.
▪ Manage Schedule of Values and invoicing.
▪ Manage training.
▪ Punch lists.
▪ O&M Manuals and project documents delivery.
▪ Warranties.
▪ Closeout.
▪ Transition to M&V and Support Services Team.
Business Confidential - Willdan 32
Functional Testing of PV, BESS, and EV Systems
▪ Verification of system performance.
▪ Utility witness testing (if required).
▪ Sixteen (16) hours of formal training sessions covering operation and maintenance.
▪ Delivery of digital O&M manuals.
▪ Delivery of warranty documentation.
▪ Permit closeout and utility PTO documentation.
Warranties and Services
Solar PV
▪ 1-year workmanship warranty.
▪ 12-year module product warranty.
▪ 25-year module performance warranty.
▪ 10-year inverter warranty (minimum).
▪ 25-year mounting system warranty.
▪ Three (3) years O&M services.
▪ Routine maintenance adjustments, replacements, and
cleaning.
▪ Documentation of maintenance and warranty items.
▪ Three (3) years of monitoring services.
Warranties and Services
BESS
▪ 20-year manufacturer warranty.
▪ One (1) year workmanship warranty.
▪ One (1) year preventative maintenance services. Each
year following will require an annual O&M payment
directly with Tesla to keep the manufacturer warranty.
This is included in the cash flows.
▪ Performance reporting support.
Commissioning, Training, Warranties & Support
Business Confidential - Willdan 33
Solar Monitoring
▪ Revenue-grade production metering.
▪ Minimum 15-minute interval data recording.
▪ Remote access capability for City.
▪ Ethernet or cellular communication.
BESS Monitoring
▪ Manufacturer-integrated monitoring platform.
▪ Performance reporting compatible with SGIP (if becomes applicable). ▪ Remote software update capability.
Monitoring & Controls
Business Confidential - Willdan 34
The following are excluded unless specifically amended:
▪ Hazardous material abatement.
▪ ADA upgrades not shown in ESPC documents.
▪ Improvements outside defined scope of work areas.
▪ Major subsurface remediation due to unknown soil conditions. ▪ Rock excavation requiring specialized mechanical pulverizing. ▪ Third-party testing beyond standard Authority Having Jurisdiction Inspections. ▪ Preventative maintenance for BESS beyond Year 1.
▪ City IT infrastructure upgrades beyond designated system connection points. ▪ Expedited procurement unless separately authorized.
▪ Additional fire protection measures required by the Authority Having Jurisdiction beyond those identified in the ESPC documents. ▪ Relocation of existing underground utilities not shown in City-owned provided documents and not reasonably discoverable through standard utility locating procedures.
▪ Responsibility for City network modifications.
▪ Responsibility for cybersecurity compliance beyond equipment standards. ▪ Compliance with Domestic Content requirements is based on manufacturer certifications available at time of procurement.
Contractor does not guarantee final IRS determination.
▪ SOW is based upon visual observations and available record documents. Concealed or unknown conditions that materially differ from those reasonably anticipated will be addressed through a Change Order. ▪ Utility interconnection approval is subject to utility review and requirements. Costs resulting from unforeseen utility-required upgrades beyond those shown in the ESPC documents will constitute a Change Order.
Work Exclusions
Business Confidential - Willdan
Appendix 2: Savings
Calculations
Business Confidential - Willdan
Solar PV & BESS Savings Calculations
36 Summary
▪ Baseline Utility Bill Calculation: Utility bills are calculated using 15min interval data and the applicable PG&E rate tariffs for each meter.
▪ Resources Bldg: B-10 Secondary
▪ Interface Terminal: B-19 Secondary
▪ Solar PV: Hourly simulation profiles are created in Helioscope to model Year 1 solar PV generation and then fed into the interval data analysis to apply the avoided cost for offset electricity usage as well as estimated credits for exports to the grid. ▪ BESS: Battery storage charging and discharging patterns are modeled using the energy management software (EMS) that will be installed along with the system. Energy Toolbase (EMS provider) provides the charging/discharging algorithm used to maximize dollar savings at the site.
▪ Rate Switch: For the Interface Terminal, a rate switch to Option S was modeled, as it yields the highest overall savings. ▪ Option S is a pilot program for select PG&E rate tariffs where customers install battery storage. It adjusts the demand charge calculation to be set on a daily basis rather than a monthly basis. This way, if there is higher than expected site demand, it only affects the charges for the single day, instead of an entire month. ▪ Time of Use (TOU) Analysis: The following slides illustrate the output tables of the Energy Toolbase utility rate analysis, showing the projected utility spend:
▪ Baseline scenario: No solar PV or BESS installed
▪ DER Savings & Rate Switch: PV + BESS installed and applicable rate switch modeled Business Confidential - Willdan
Interface Terminal: Baseline
37 Start Date End Date Season On Peak Part Peak Off Peak Super Off
Peak
NC / Max On Peak Part Peak Other NBC Energy Demand Total 1/1/2024 2/1/2024 W1 20,107 74,903 244 244 $1,849 $2,699 $10,507 $10,350 $25,405 2/1/2024 3/1/2024 W1 17,789 67,607 154 154 $1,729 $2,426 $9,427 $6,533 $20,115 3/1/2024 4/1/2024 W2 21,117 60,473 21,500 307 232 $1,849 $2,929 $9,694 $12,783 $27,254 4/1/2024 5/1/2024 W2 20,274 59,423 18,979 418 331 $1,789 $2,803 $9,406 $17,453 $31,452 5/1/2024 6/1/2024 W2 26,591 83,463 19,844 588 448 $1,849 $3,690 $12,775 $24,495 $42,809 6/1/2024 7/1/2024 S 35,320 31,399 101,604 738 595 577 $1,789 $4,782 $21,016 $67,955 $95,542 7/1/2024 8/1/2024 S 44,794 37,865 131,948 733 571 612 $1,849 $6,097 $26,690 $66,870 $101,506 8/1/2024 9/1/2024 S 44,726 35,934 132,457 732 551 552 $1,849 $6,055 $26,464 $65,043 $99,410 9/1/2024 10/1/2024 S 41,034 32,842 114,992 660 481 547 $1,789 $5,366 $23,619 $58,368 $89,142 10/1/2024 11/1/2024 W1 40,726 129,464 608 443 $1,849 $4,835 $19,093 $25,263 $51,040 11/1/2024 12/1/2024 W1 26,421 83,265 455 367 $1,789 $3,116 $12,315 $19,020 $36,240 12/1/2024 1/1/2025 W1 21,583 73,343 258 238 $1,849 $2,697 $10,584 $10,880 $26,010 Total 360,482 138,040 1,112,942 60,323 $21,826 $47,495 $191,588 $385,014 $645,924 Bill Date Ranges Energy Before PV/ESS (kWh) Max Demand Before PV/ESS (kW) Charges Before PV/ESS ($) Other: Fixed Utility
Customer Charges
NBC: Non-Bypassable
Charges (cannot be offset via
PV exports to grid)
Business Confidential - Willdan
PV & BESS Installed with Rate Switch to Option S
38 Start Date End Date Season NC / Max On Peak Part Peak Other NBC Energy Demand Total 1/1/2024 2/1/2024 W1 140 140 $1,849 $1,884 $8,796 $3,452 $15,981 2/1/2024 3/1/2024 W1 127 126 $1,729 $1,481 $6,776 $2,406 $12,392 3/1/2024 4/1/2024 W2 253 96 $1,849 $1,568 $6,415 $4,576 $14,407 4/1/2024 5/1/2024 W2 181 0 $1,789 $957 $3,637 $3,117 $9,500 5/1/2024 6/1/2024 W2 235 73 $1,849 $1,924 $7,676 $4,136 $15,584 6/1/2024 7/1/2024 S 337 0 0 $1,789 $2,569 $16,170 $5,803 $26,331 7/1/2024 8/1/2024 S 645 0 391 $1,849 $4,297 $26,441 $11,138 $43,725 8/1/2024 9/1/2024 S 478 0 478 $1,849 $4,066 $25,691 $8,269 $39,874 9/1/2024 10/1/2024 S 415 0 0 $1,789 $3,825 $24,347 $7,146 $37,108 10/1/2024 11/1/2024 W1 352 0 $1,849 $3,623 $16,515 $6,061 $28,048 11/1/2024 12/1/2024 W1 287 0 $1,789 $2,316 $10,420 $4,942 $19,467 12/1/2024 1/1/2025 W1 166 138 $1,849 $2,006 $9,217 $3,028 $16,100 Total $21,826 $30,514 $162,101 $64,075 $278,517
Bill Date Ranges Max Demand After PV/ESS Charges After PV/ESS ($) Total Simulated Y1 Utility Bill Savings:
$645,924 - $278,517 = $367,407
Interface Terminal
Business Confidential - Willdan
Resources Building: Baseline
39 Max
Demand
Before PV
(kW)
Start Date End Date Season On Peak Part Peak Off Peak
Super Off
Peak
NC / Max Other NBC Energy Demand Total
1/1/2024 2/1/2024 W1 899 4,350 18 $361 $149 $1,201 $399 $2,110 2/1/2024 3/1/2024 W1 768 3,720 17 $338 $128 $1,027 $377 $1,869 3/1/2024 4/1/2024 W2 800 2,860 1,281 19 $361 $141 $1,082 $421 $2,005 4/1/2024 5/1/2024 W2 1,023 3,063 1,438 23 $350 $157 $1,214 $510 $2,231 5/1/2024 6/1/2024 W2 1,672 3,575 1,939 28 $361 $205 $1,589 $620 $2,776 6/1/2024 7/1/2024 S 2,304 2,102 6,135 37 $350 $300 $2,817 $820 $4,287 7/1/2024 8/1/2024 S 3,308 2,851 8,178 44 $361 $408 $3,848 $975 $5,593 8/1/2024 9/1/2024 S 2,514 2,348 6,872 38 $361 $334 $3,132 $842 $4,669 9/1/2024 10/1/2024 S 2,298 1,940 5,409 38 $350 $275 $2,597 $842 $4,063 10/1/2024 11/1/2024 W1 1,640 5,900 36 $361 $215 $1,737 $798 $3,111 11/1/2024 12/1/2024 W1 846 3,427 13 $350 $122 $982 $288 $1,741 12/1/2024 1/1/2025 W1 934 3,903 16 $361 $138 $1,110 $355 $1,964 Total 19,006 9,241 57,392 4,658 $4,265 $2,572 $22,336 $7,246 $36,419 Bill Date Ranges Energy Before PV/ESS (kWh) Charges Before PV ($) Business Confidential - Willdan
Resources Building: Utility Bill After PV Installed
40 Total Simulated Y1 Utility Bill Savings:
$36,419 - $21,094 = $15,325
Max Demand After
PV (kW)
Start Date End Date Season On Peak Part Peak Off Peak Super Off Peak
On Peak Part Peak Off Peak Super Off
Peak
NC / Max Other NBC Energy Demand Total
1/1/2024 2/1/2024 W1 832 1,659 68 2,691 17 $361 $103 $769 $377 $1,610 2/1/2024 3/1/2024 W1 569 204 199 3,516 14 $338 $75 $540 $310 $1,264 3/1/2024 4/1/2024 W2 212 1,411 (1,878) 588 1,449 3,159 15 $361 $77 $580 $332 $1,351 4/1/2024 5/1/2024 W2 50 953 (2,639) 972 2,110 4,077 17 $350 $72 $552 $377 $1,351 5/1/2024 6/1/2024 W2 410 937 (2,910) 1,262 2,639 4,849 15 $361 $80 $585 $332 $1,358 6/1/2024 7/1/2024 S 951 327 543 1,353 1,776 5,592 23 $350 $123 $1,087 $510 $2,068 7/1/2024 8/1/2024 S 1,929 1,054 2,612 1,379 1,797 5,566 27 $361 $194 $1,803 $598 $2,957 8/1/2024 9/1/2024 S 1,370 630 1,760 1,144 1,718 5,112 22 $361 $153 $1,363 $488 $2,365 9/1/2024 10/1/2024 S 1,588 526 1,111 710 1,414 4,297 21 $350 $139 $1,281 $465 $2,235 10/1/2024 11/1/2024 W1 1,209 1,204 431 4,696 21 $361 $116 $880 $465 $1,822 11/1/2024 12/1/2024 W1 785 (83) 60 3,510 13 $350 $78 $545 $288 $1,260 12/1/2024 1/1/2025 W1 900 1,227 34 2,676 13 $361 $94 $710 $288 $1,453 Total 10,805 2,537 13,538 (7,427) 8,200 6,705 43,854 12,085 $4,265 $1,303 $10,695 $4,831 $21,094 Bill Date Ranges Energy After PV (kWh) PV Generation (kWh) Charges After PV ($) Business Confidential - Willdan
Appendix 3:
Performance
Guarantee
Business Confidential - Willdan
Guarantee Phase Contract Sum
42 Summary
▪ City will pay Willdan annual payments for Guarantee Phase services in the amounts listed below, subject to Schedule B and any other applicable terms of this Energy Savings Guarantee:
▪ City may cancel the Guarantee Phase services on any anniversary of the commencement of Guarantee Services, or at the end of City’s fiscal year. If City cancels these services, Willdan reserves the right to cancel the Energy Savings Guarantee as outlined in the ESPC Contract.
Solar PV Electricity Guarantee
Year One through Three: $0.00 (included in Construction Phase Contract Sum)
Year Four and Beyond: Determined upon request for CITY
Business Confidential - Willdan
Guaranteed Energy Savings
43 Solar Photovoltaic Savings Guarantee
▪ Willdan guarantees that the City will produce [706,913] kWh in Year 1. The Solar PV generation is expected to degrade by 2.0% in the first year of operation, and then 0.5% per year after that. The total guaranteed production accounting for this degradation is shown below:
▪ International Performance Measurement and Verification Protocol Option B - Fully Measured Retrofit Isolation will be utilized to verify annual electric production of [706,913] kWh from the Solar PV measure following the completion of the scope of work in Year 1. This guarantee comprises 90% of the total estimated generation from the PV measure, as well as a 2.0% degradation rate for the module’s first year. The guaranteed savings for subsequent years will be derated by 0.5% annually to account for normal degradation of the PV system.
Post installation energy consumption will be compared to baseline energy consumption.
PV Production Guarantee - Full Portfolio
M&V Year Guarantee Solar PV Production
(kWh)
Year 1 706,913
Year 2 703,378
Year 3 699,861
Total 2,110,152
PV Production Guarantee by Site Guaranteed Production
PREMISES Site
Simulated
Annual
Production
Year 1 Year 2 Year 3 Total
Interface Pumping
Facility - Base Design 732,598 644,687 641,463 638,256 1,924,406 Water Dept Resources
Building Base Design 70,711 62,226 61,915 61,605 185,746 Total 803,310 706,913 703,378 699,861 2,110,152
Business Confidential - Willdan
Guaranteed Energy Savings
44 Battery Energy Storage System Guarantee
▪ Willdan and City agree that an additional energy savings of $278,100 annually is achieved as guaranteed at the Water Department Interface Facility from Battery Energy Storage System installation. No further tracking or monitoring of these savings will take place.
Why Stipulated Savings are Appropriate for BESS
▪ Unlike Solar PV – where energy production is driven by a well-understood, measurable input (irradiance) and decades of degradation data – the financial performance of a Battery Energy Storage System depends on variables that are largely outside the control of the system owner or installer, and that change unpredictably over the life of the contract. ▪ The core issue is that BESS value is market- and tariff-dependent, not asset-dependent. A solar panel's output can be guaranteed because it is a function of the equipment itself. A BESS's savings, by contrast, are a function of how the system is dispatched against a rate structure and load profile, both of which shift over time. Specifically:
▪ Utility rate changes. Demand charges, time-of-use differentials, and rate structures are revised by the utility periodically, sometimes in ways that significantly increase or decrease the arbitrage opportunity. A rate restructuring could compress or eliminate the spread the BESS was designed to capture - or expand it.
▪ Load profile variability. The customer's own electricity consumption patterns drive how much demand can realistically be shaved or shifted. Changes in operations, occupancy, equipment, or on-site generation all alter the savings envelope in ways no vendor can predict or control. ▪ Dispatch optimization is probabilistic, not deterministic. The Energy Management System uses forecasting algorithms to make real-time decisions about when to charge and discharge. These algorithms are sophisticated, but they are optimizing against uncertain future conditions (next-day load, weather, rate periods). Guaranteeing the output of a probabilistic optimization engine to a fixed dollar figure would require the EMS provider to accept risk for factors entirely outside the system - which no credible vendor in this market does, for good reason. ▪ Industry practice reflects this reality. Performance guarantees for BESS in behind-the-meter applications are not standard in the market today. Where they exist, they typically guarantee only equipment-level metrics (round-trip efficiency, availability, capacity retention) rather than dollar savings. We are proposing the same approach: guaranteeing that the hardware will perform to its rated specifications, while using stipulated savings to model the expected economic benefit.
Business Confidential - Willdan
Guaranteed Energy Savings
45 Battery Energy Storage System Guarantee
What Willdan is Guaranteeing – and Why It Protects the City ▪ We are standing behind the things within our control: system availability, roundtrip efficiency, capacity, and degradation within manufacturer specifications. The Tesla Megapack 2XL carries robust manufacturer warranties on these parameters. If the equipment underperforms its rated specs, that is on us. ▪ What we are not guaranteeing is a specific dollar outcome from the interaction of a properly functioning system with external conditions no party controls. The stipulated savings in the contract represent a reasonable, conservative projection based on your current rate structure and load profile, and they give both parties a clear, agreed-upon economic framework without forcing either side to absorb risk for utility rate decisions or operational changes. ▪ We believe this structure is the most honest and bankable approach - it avoids embedding hidden risk premiums that would inflate the project cost, and it reflects how the BESS market actually prices behind-the-meter projects today. :
Business Confidential - Willdan
Appendix 4: Savings
Measurement &
Verification
Business Confidential - Willdan
Savings Measurement & Verification
47 Solar PV Savings Measurement – IPMVP Option B
▪ International Performance Measurement and Verification Protocol Option B verification techniques measure savings at a system level where key performance factors load and hours of use are directly measured. ▪ The solar production will be tracked utilizing the system portal. Production data cost impacts will be analyzed using the outlined blended rate.
Determination of Dollars Saved for Solar PV
Total Annual $ Savings = ∑ (Energy/Demand Savings x Contractual Energy/Demand Rates) Where: Contractual Energy Rates = Utility rates defined in this table:
PREMISES Site Avoided Cost Rates ($/kWh)
Year 1 Year 2 Year 3
Interface Pumping
Facility - Base Design $0.1220 $0.1269 $0.1320
Water Dept
Resources Building
Base Design
$0.2160 $0.2246 $0.2336
Business Confidential - Willdan
Appendix 5: PG&E Utility
Rate Escalation
Business Confidential - Willdan
Historical Electrical Utility Rate Escalation
49 PG&E Utility Cost Increases for Bakersfield
3.96%
11.36%
-1.50%
0.65%
3.88% 3.95%
7.86%
2.16%
7.44%
1.29%
3.11%
10.83%
15.26%
10.16%
11.91%
-4.00%
-2.00%
0.00%
2.00%
4.00%
6.00%
8.00%
10.00%
12.00%
14.00%
16.00%
18.00%
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 Historical Electricity
escalation based on example
PG&E rate for large
commercial customers
(compound annual growth rate)
15-year 6.05%
10-year 7.31%
5-year 10.18%
Projected Rate Adjustments
(PG&E has already requested an 8%
increase for 2027 with the CPUC)
2027 8.00%+
2028 - 2030 6.10%+ Pacific Gas and Electric (PG&E) commercial electricity rates in Bakersfield, California, have grown by roughly 6% on average annually over the past 15 years, significantly outpacing standard inflation.
Business Confidential - Willdan
Appendix 7: Financial
Disclosure
Business Confidential - Willdan
Disclosure
Willdan Financial Services (“Willdan”) is registered as a "municipal advisor" pursuant to Section 15B of the Securities Exchange Act and rules and regulations adopted by the United States Securities and Exchange Commission ("SEC") and the Municipal Securities Rulemaking Board ("MSRB"). The MSRB has made available on its website (www.msrb.org) a municipal advisory client brochure that describes the protections that may be provided by MSRB rules and how to file a complaint with the appropriate regulatory authority. As part of its SEC registration Willdan is required to disclose to the SEC information regarding criminal actions, regulatory actions, investigations, terminations, judgments, liens, civil judicial actions, customer complaints, arbitrations and civil litigation involving Willdan. Pursuant to MSRB Rule G-42, Willdan is required to disclose any legal or disciplinary event that is material to Client's evaluation of Willdan or the integrity of its management or advisory personnel. Willdan has determined that no such event exists. Copies of Willdan’s filings with the United States Securities and Exchange Commission can currently be found by accessing the SEC's EDGAR system Company Search Page which is currently available at: https://www.sec.gov/edgar/searchedgar/companysearch.html and searching for either Willdan Financial Services or for our CIK number which is 0001782739.
For the avoidance of doubt and without limiting the foregoing, in connection with any revenue projections, cash-flow analyses, feasibility studies and/or other analyses Willdan may provide the municipality with respect to financial, economic or other matters relating to a prospective, new or existing issuance of municipal securities of the municipality, (A) any such projections, studies and analyses shall be based upon assumptions, opinions or views (including, without limitation, any assumptions related to revenue growth) established by the municipality, in conjunction with such of its municipal, financial, legal and other advisers as it deems appropriate; and (B) under no circumstances shall Willdan be asked to provide, nor shall it provide, any advice or recommendations or subjective assumptions, opinions or views with respect to the actual or proposed structure, terms, timing, pricing or other similar matters with respect to any municipal financial products or municipal securities issuances, unless formally engaged to provide such information.