SITER-Solar/v2-siter-solar-plan.md

SITER Solar Installation Project

2026 Renewable Energy Initiative - v2 Analysis

---

Executive Summary

This document outlines a solar energy installation project for SITER, designed to offset a portion of monthly electricity costs through solar generation. The system will utilize 16 solar panels across 8 custom-built ground-mount racks, paired with a Sol-Ark 5K hybrid inverter that integrates with the existing Base Power battery backup system.

Total Project Investment: $4,100.00 Estimated ROI Period: 9.1 years (based on updated billing analysis) Estimated Monthly Savings: $37.61 (14.2% bill offset)

Existing Infrastructure: SITER currently operates with a Base Power battery backup system and automatic transfer switch (ATS), installed in 2025, providing resilience and a fixed energy rate of $0.085/kWh through a 3-year contract (Oct 2025 - Oct 2028).

Updated Billing Data (15 months): Average monthly consumption of 1,885 kWh (~22,600 kWh/year) at average effective rate of $0.140/kWh.

NREL PVWatts Analysis: Based on location data for SITER, a 16-panel system (4.0 kW DC with 250W panels) is projected to produce ~6,000 kWh/year, offsetting approximately 14% of current consumption.

---

Table of Contents

1. Project Overview
2. Technical Specifications
3. Detailed Budget
4. Project Timeline
5. Risk Analysis
6. Return on Investment Analysis
7. Recommendations
8. Appendix

---

Project Overview

Objectives

• Reduce monthly electricity expenses through solar generation (~14% offset with current panels)
• Integrate with existing Base Power battery backup infrastructure
• Leverage Base Power's 4¢/kWh solar buyback program for excess production
• Complete installation with minimal upfront capital expenditure
• Achieve positive ROI within 10 years while gaining energy resilience

Scope

Component	Quantity	Description
Solar Panels	16	Existing inventory (250W each)
Ground-Mount Racks	8	Custom steel construction
Inverter	1	Sol-Ark 5K Hybrid
Wiring & Connectors	TBD	To be determined based on site layout

Current Status

• Phase: Initial procurement and rack construction
• Spend to Date: $360.95 (first solar rack completed)
• Next Milestone: Complete remaining 7 racks

Existing Infrastructure

SITER has the following energy infrastructure already in place:

Component	Details	Install Date
Base Power Battery System	Battery backup with automatic transfer switch	2024
Automatic Transfer Switch (ATS)	Seamless grid/battery switching	2024
Base Power Contract	3-year fixed rate at $0.085/kWh	2025-2028

Site Base Load: ~1,885 kWh/month (15-month average)

This existing infrastructure significantly de-risks the solar project:

• ATS already installed for grid switching
• Battery backup provides load smoothing and outage protection
• Fixed-rate contract provides predictable baseline costs

---

Technical Specifications

Inverter: Sol-Ark 5K-5kW-48V Single-Phase Hybrid

Specification	Value
Power Output	5kW
System Voltage	48V DC
Phase	Single Phase
Type	Hybrid (Grid-tied + Battery Backup)
Source	EcoDirect

Key Benefits:

• Grid-tied operation for net metering eligibility
• Integrates with existing Base Power battery system
• Hybrid functionality ensures power during grid outages
• High efficiency rating minimizes energy loss
• Compatible with existing ATS infrastructure

Existing Base Power System

Specification	Value
Contract Rate	$0.085/kWh (fixed through Oct 2028)
Solar Buyback Rate	$0.04/kWh (4¢/kWh)
Contract Term	3 years (Oct 2025 - Oct 2028)
Site Base Load	~1,885 kWh/month (actual 15-month average)
Backup Capability	Automatic transfer switch + battery
Installation Date	2024
Solar Integration	Seamless - no additional equipment needed

Source: Base Power Solar Integration

Solar Buyback Program Details

Base Power offers competitive solar buyback rates for excess production:

Feature	Details
Buyback Rate	4¢/kWh for all excess solar production
Credit Application	Applies to entire bill (not just energy charge)
Negative Balance	Rolls over to following month
Solar Tracking	Shown on monthly bill in "Solar Credits" section
Outage Protection	Base keeps solar panels producing during grid outages

Integration Strategy: Solar generation will first offset on-site consumption (reducing the $0.085/kWh charge), with excess production credited at $0.04/kWh. The existing Base Power battery system provides:

• Automatic solar integration without additional equipment
• Continued solar operation during grid outages
• Battery storage for excess daytime production

image-1-placeholder

Rack System: Ground-Mount Steel Construction

Each rack accommodates 2 solar panels using galvanized steel posts and adjustable mounting hardware.

Materials per Rack:

• 6x 8' steel posts (driven into ground)
• 14x 5/16" x 5-3/8" U-bolts (panel mounting)
• 3x 2-3/8" Galvanized Adjustable Clamps (structural support)

image-5-placeholder

---

Detailed Budget

Phase 1: Equipment & Materials

1.1 Panel Rack Construction

Line Item	Qty	Unit Cost	Subtotal	Notes
8' Steel Posts	48	$34.97	$1,678.56	6 posts per rack × 8 racks
5/16" x 5-3/8" U-bolts	112	$2.33	$260.96	14 per rack × 8 racks
2-3/8" Galv Adj. Clamps	24	$3.77	$90.48	3 per rack × 8 racks
Rack Materials Subtotal			$2,030.00

1.2 Tools & Equipment (One-Time)

Line Item	Qty	Unit Cost	Subtotal	Notes
Post Driver	1	$57.75	$57.75	Reusable for future projects
Tools Subtotal			$57.75

1.3 Electrical Components

Line Item	Est. Cost	Notes
Romex Wiring	$200.00	Gauge/length TBD based on site survey
Connectors & Junction Boxes	$112.25	MC4 connectors, conduit, etc.
Electrical Subtotal	$312.25	Conservative estimate

1.4 Inverter

Line Item	Qty	Unit Cost	Subtotal	Notes
Sol-Ark 5K Hybrid Inverter	1	$1,500.00	$1,500.00	Includes shipping
Inverter Subtotal			$1,500.00

---

Budget Summary

Category	Amount	% of Total
Rack Materials	$2,030.00	49.5%
Tools (One-Time)	$57.75	1.4%
Electrical Components	$312.25	7.6%
Inverter	$1,500.00	36.6%
Contingency Reserve (10%)	$200.00	4.9%
TOTAL PROJECT BUDGET	$4,100.00	100%

Spend to Date

Date	Item	Amount	Running Total
2026	First Solar Rack (materials)	$360.95	$360.95
	Remaining Budget	$3,739.05

---

Cost Comparison: Per-Rack Analysis

Cost Element	Per Rack	8 Racks Total
Steel Posts	$209.82	$1,678.56
U-bolts	$45.92	$367.36
Adjustable Clamps	$11.31	$90.48
Base Rack Cost	$267.05	$2,136.40
Wiring/Connectors (est.)	$32.95	$263.60
All-In Rack Cost	$301.08	$2,400.00

---

Project Timeline

Phase Overview

Week 1-2:  [████████] Procurement & Site Prep
Week 3-6:  [████████████████████████████████] Rack Construction
Week 7-8:  [████████████] Inverter Installation
Week 9:    [████] Electrical Wiring
Week 10:   [████] Testing & Commissioning

Detailed Schedule

Phase	Tasks	Duration	Dependencies
1. Procurement	Order inverter, purchase remaining steel posts, hardware, wiring	1-2 weeks	Budget approval
2. Site Preparation	Mark rack locations, clear vegetation if needed	1 week	Phase 1
3. Rack Construction	Build 7 remaining racks (1 already complete)	3-4 weeks	Phase 2
4. Panel Mounting	Install panels on completed racks	1 week	Phase 3
5. Inverter Installation	Mount inverter, connect to panel array	1 week	Phase 4
6. Electrical Integration	Run wiring, install disconnects, connect to building	1 week	Phase 5
7. Testing & Commissioning	System testing, safety inspection, energize	1 week	Phase 6

Estimated Total Duration: 8-10 weeks

Milestones

• M1: All materials procured
• M2: Site preparation complete
• M3: All 8 racks constructed
• M4: Panels mounted and secured
• M5: Inverter installed and connected
• M6: System commissioned and operational

---

Risk Analysis

Risk Register

ID	Risk Description	Probability	Impact	Risk Score	Mitigation Strategy
R1	Wiring costs exceed estimates	Medium	Medium	6	Obtain quotes from 2-3 suppliers; consider DIY installation
R2	Weather delays rack construction	Medium	Low	4	Build buffer into timeline; work during favorable seasons
R3	Inverter supply chain delays	Low	High	5	Order early; confirm stock before project start
R4	Structural issues with racks	Low	Medium	3	Follow engineering best practices; inspect posts regularly
R5	Utility interconnection delays	Low	Medium	3	Research local requirements early; submit paperwork promptly
R6	Permit requirements	Medium	Medium	6	Verify local building codes before construction
R7	Panel compatibility issues	Low	Low	2	Confirm panel specs match inverter requirements
R8	ROI takes longer than projected	Low	Medium	3	Conservative savings estimates; monitor actual output

Risk Matrix

                    IMPACT
              Low      Medium      High
         ┌─────────┬─────────┬─────────┐
    High │         │    R6   │         │
PROB     ├─────────┼─────────┼─────────┤
   Medium│    R2   │  R1,R8  │         │
         ├─────────┼─────────┼─────────┤
      Low│    R7   │  R4,R5  │  R3     │
         └─────────┴─────────┴─────────┘

Key Risk Mitigations

R1: Wiring Cost Overrun

• Current Status: Only rough estimates completed
• Action Items:
  • Conduct site survey to determine exact wire runs
  • Obtain quotes from multiple electrical suppliers
  • Consider aluminum conductors for long runs (cost savings)
  • Allocate $200 contingency specifically for electrical

R6: Permit Requirements

• Current Status: Unknown
• Action Items:
  • Contact local building department
  • Research setback requirements for ground-mount systems
  • Verify utility interconnection requirements
  • Factor permit fees into budget if required

---

Return on Investment Analysis

Updated Billing Analysis (15 Months of Data)

Based on actual Base Power billing data from October 2024 through January 2026:

Service Period	Consumption (kWh)	Bill Amount	Effective Rate
Oct 18 - Nov 19, 2024	1,368	$34.61	$0.025/kWh*
Nov 19 - Dec 18, 2024	863	$132.37	$0.153/kWh
Dec 18, 2024 - Jan 17, 2025	1,092	$160.33	$0.147/kWh
Jan 17 - Feb 19, 2025	1,434	$210.73	$0.147/kWh
Feb 19 - Mar 21, 2025	1,398	$199.35	$0.143/kWh
Mar 21 - Apr 22, 2025	1,472	$209.71	$0.143/kWh
Apr 22 - May 21, 2025	1,936	$277.13	$0.143/kWh
May 21 - Jun 20, 2025	2,713	$385.08	$0.142/kWh
Jun 20 - Jul 22, 2025	2,995	$423.56	$0.141/kWh
Jul 22 - Aug 20, 2025	3,015	$428.76	$0.142/kWh
Aug 20 - Sep 19, 2025	2,924	$440.35	$0.151/kWh
Sep 19 - Oct 20, 2025	2,486	$372.89	$0.150/kWh
Oct 20 - Nov 18, 2025	1,553	$235.81	$0.152/kWh
Nov 18 - Dec 18, 2025	1,469	$240.12	$0.163/kWh
Dec 18, 2025 - Jan 20, 2026	1,549	$216.25	$0.140/kWh
15-Month Average	1,885	$264.47	$0.140/kWh

*Note: Oct-Nov 2024 bill had credit applied from previous provider transition

Seasonal Consumption Patterns

Season	Months	Avg Consumption	Avg Bill
Summer Peak	Jun - Sep	2,912 kWh	$415.89
Winter Low	Nov - Feb	1,333 kWh	$175.56
Shoulder	Mar - May, Oct	1,777 kWh	$261.55

Key Insight: Summer consumption is 2.2× higher than winter, creating opportunity for solar to offset peak production months.

NREL PVWatts Production Estimate

Based on NREL PVWatts analysis for SITER:

Parameter	Value
System Capacity	4.0 kW DC (16 × 250W panels)
Array Type	Fixed Open Rack (Ground Mount)
Orientation	30° tilt, 180° azimuth (South)
Annual Production	6,004 kWh
Monthly Average	500 kWh
Daily Average	16 kWh
Capacity Factor	17.1%
Avg Solar Radiation	5.52 kWh/m²/day

Ground Mount Advantages at SITER

The ground-mount configuration at this site has significant advantages:

Advantage	Impact
Optimal Tilt (30°)	Matches latitude for maximum annual production
South-Facing (180°)	Optimal azimuth for Texas
No Trees/Shading	Minimal shading losses (typical: 3-5%, this site: <1%)
Open Rack	Better airflow = cooler panels = higher efficiency
Adjustable Orientation	Can fine-tune tilt seasonally if desired

Optimized Production Estimate (8% losses vs 14% standard):

Scenario	Losses	Annual kWh	Monthly $	Payback
Conservative (NREL default)	14%	6,004	$37.61	9.1 yrs
Optimized (no shade)	8%	~6,500	~$41	~8.3 yrs

The site's open exposure and ground-mount flexibility make it an ideal solar location.

Monthly Production Profile (NREL)

Month	AC Output (kWh)	Daily Avg	Solar Rad (kWh/m²/day)
Jan	450	15	4.58
Feb	453	15	5.15
Mar	492	16	5.23
Apr	508	17	5.61
May	534	18	5.87
Jun	514	17	5.94
Jul	555	18	6.31
Aug	571	19	6.57
Sep	514	17	6.01
Oct	516	17	5.62
Nov	469	15	4.99
Dec	429	14	4.39
Annual	6,004	16	5.52

image-2-placeholder

Investment Summary (Updated)

Metric	Value
Total Project Cost	$4,100.00
Average Monthly Bill (15-mo actual)	$264.47
Site Avg Consumption	1,885 kWh/month (22,614 kWh/year)
Solar Production (NREL)	6,004 kWh/year (500 kWh/month)
Self-Sufficiency	26.6%
Base Power Energy Rate	$0.085/kWh
Base Power Export Rate	$0.04/kWh

Financial Analysis (Updated)

Category	kWh/year	Rate	Annual Value
Self-Consumed (60%)	3,602	$0.085/kWh	$306.18
Exported to Grid (40%)	2,401	$0.04/kWh	$96.06
Total Annual Value	6,004		$402.24
Monthly Savings			$33.52

ROI Summary (Updated)

Metric	Value
Monthly Savings	$33.52
Bill Offset	12.7% (of $264.47 avg bill)
Payback Period	10.2 years (122 months)

System Size Scenarios (NREL Analysis)

System	kW	kWh/yr	$/mo	Offset	Payback
16 × 250W (current)	4.0	6,004	$33.52	12.7%	10.2 yrs
16 × 300W	4.8	7,204	$40.22	15.2%	8.5 yrs
16 × 350W	5.6	8,405	$46.93	17.8%	7.3 yrs
16 × 400W	6.4	9,606	$53.63	20.3%	6.4 yrs
16 × 450W	7.2	10,806	$60.34	22.8%	5.7 yrs
20 × 400W (expanded)	8.0	12,007	$67.04	25.4%	5.1 yrs
24 × 400W	9.6	14,409	$80.45	30.4%	4.2 yrs

image-4-placeholder

Note: To achieve 100% bill offset would require ~32 kW (80 panels @ 400W each).

10-Year Financial Projection (Current System: 16 × 250W)

Year	Cumulative Savings	Net Position
0	$0	-$4,100.00
1	$402.24	-$3,697.76
2	$804.48	-$3,295.52
3	$1,206.72	-$2,893.28
4	$1,608.97	-$2,491.03
5	$2,011.21	-$2,088.79
6	$2,413.45	-$1,686.55
7	$2,815.69	-$1,284.31
8	$3,217.93	-$882.07
9	$3,620.17	-$479.83
10	$4,022.41	-$77.59
11	$4,424.65	+$324.65

image-3-placeholder

Assumptions

• NREL PVWatts production estimates based on TMY (Typical Meteorological Year) data
• 60% self-consumption / 40% export split (conservative estimate)
• System losses of 14% (inverter, wiring, soiling, etc.)
• Electricity rates remain constant (conservative - rates typically increase 2-3% annually)
• No major maintenance required in first 10 years
• Base Power contract at $0.085/kWh remains in effect through Oct 2028
• Base Power solar buyback at $0.04/kWh continues
• Solar integration with Base Power system is technically feasible

Key Considerations

Production vs. Consumption Gap:

• Current consumption: ~22,600 kWh/year
• Solar production: ~6,000 kWh/year
• Gap: ~16,600 kWh/year (73% still from grid/Base Power)

Options to Improve Economics:

1. Upgrade to higher-wattage panels (400W+ panels reduce payback to ~6 years)
2. Expand system size (additional panels/racks)
3. Reduce consumption through efficiency measures
4. Add more panels when costs decrease

Value Adds Not Quantified

• Energy Independence: Already partially achieved via Base Power; solar adds generation capability
• Property Value: Solar installations typically increase property value
• Environmental Impact: Reduced carbon footprint
• Existing Battery Storage: Already in place via Base Power system
• Rate Hedge: Protection against future electricity rate increases post-2028
• Redundancy: Solar + Base Power + Grid provides triple-redundant power architecture

---

Recommendations

Immediate Actions

1. Approve Budget: Authorize $4,100 project expenditure
2. Order Inverter: Confirm Sol-Ark 5K availability and place order
3. Complete Site Survey: Determine exact wiring requirements and costs
4. Verify Permits: Contact local building department to confirm requirements

Panel Upgrade Consideration

Based on the updated analysis, upgrading from 250W to 400W panels would:

• Increase production from 6,004 to 9,606 kWh/year (+60%)
• Increase monthly savings from $33.52 to $53.63
• Reduce payback from 10.2 years to 6.4 years
• Increase bill offset from 12.7% to 20.3%

Recommendation: If budget allows, consider sourcing 400W panels instead of using existing 250W inventory.

Project Execution

1. Continue rack construction using proven design from Rack #1
2. Procure all remaining materials in single order for cost efficiency
3. Consider hiring licensed electrician for final grid connection
4. Document entire process for future reference/expansion

Future Considerations

• Base Power Contract Renewal (2028): Evaluate contract terms vs. solar-only operation
• Panel Expansion: Inverter can handle additional capacity if needed
• Monitoring: Add production monitoring system for performance tracking
• Grid Export: Explore net metering options for excess generation

---

Appendix

A. Vendor Information

Inverter Supplier:

• EcoDirect
• Product: Sol-Ark 5K-5kW-48V Single-Phase Hybrid Inverter
• URL: https://www.ecodirect.com/Sol-Ark-5K-5kW-48V-Single-Phase-Hybrid-Inverter-p/sol-ark-5k-1p-n.htm
• Price: $1,500.00

B. Bill of Materials

Item	Specification	Qty Needed	Unit Cost	Total
Steel Posts	8' galvanized	48	$34.97	$1,678.56
U-bolts	5/16" x 5-3/8"	112	$2.33	$260.96
Adjustable Clamps	2-3/8" galvanized	24	$3.77	$90.48
Post Driver	Manual	1	$57.75	$57.75
Hybrid Inverter	Sol-Ark 5K	1	$1,500.00	$1,500.00
Wiring/Connectors	TBD	-	-	$312.25
TOTAL				$3,900.00

Note: $200 contingency brings total to $4,100.00

C. Rack Construction Details

Standard Rack Assembly (Per Rack):

1. Drive 6 steel posts into ground in 2 rows of 3
2. Connect posts with horizontal rails using adjustable clamps
3. Secure panel mounting rails with U-bolts
4. Mount 2 solar panels per rack
5. Route wiring through protective conduit

Completed: 1 of 8 racks ($360.95 invested)

D. Base Power Billing Details

Contract Information:

• Contract #: SITER (renewed Oct 2025)
• Contract ID: SITER
• Provider: Base Power Company (PUCT License #10338)
• Address: 1606 Headway Cir, Ste 9333, Austin, TX 78754
• Support: 1-866-479-POWR (7697)

Rate Structure:

• Energy Charge: $0.085/kWh (Oct 2025 - Oct 2028)
• Previous Rate: $0.090/kWh (Oct 2024 - Oct 2025)
• Utility Delivery (Oncor): Pass-through charges (~$0.056/kWh equivalent)
• Base Subscription Fee: $10.00/month
• Taxes: ~3.7% (SITER rates)

Meter Data:

• Consumption Meter #: SITER
• Generation Meter #: SITER (dual-purpose)
• Reads: Actual (not estimated)
• Tracks both Generation (solar/battery) and Consumption

E. Base Power Integration Notes

Technical Considerations:

• Verify Sol-Ark 5K compatibility with existing Base Power ATS
• Confirm DC voltage alignment between solar array and Base Power battery system
• Determine optimal AC coupling configuration
• Review interconnection requirements with Base Power

Contract Considerations:

• Review Base Power contract for solar integration provisions
• Confirm no penalties for reduced consumption
• Plan for contract renewal negotiations in Oct 2028

Base Power Solar Economics

Consumption Offset vs. Export Credit:

Scenario	Rate	Benefit
Solar consumed on-site	$0.085/kWh avoided	Higher value - reduces energy charge
Solar exported to grid	$0.04/kWh credit	Lower value - but credits apply to entire bill

Optimal Strategy: Maximize self-consumption during peak production hours (run high-load appliances when solar is generating) to capture the $0.085/kWh value rather than exporting at $0.04/kWh.

Key Advantage: Unlike many providers that only credit against energy charges, Base applies solar credits to the entire bill including delivery fees, taxes, and the $10/month subscription fee.

F. Document History

Version	Date	Author	Changes
1.0	February 2026	SITER	Initial project documentation
1.1	February 2026	SITER	Added Base Power infrastructure details
1.2	February 2026	SITER	Updated with actual billing data (5 months)
2.0	February 2026	SITER	Updated with complete billing data (15 months), revised consumption averages, seasonal analysis

---

Document prepared for SITER Board Review Project Start Date: 2026 Target Completion: Q2 2026