24-Hour Energy Flow Engineering Diagram
Professional engineering diagram showing energy generation, storage, and consumption patterns
24-Hour Energy Generation & Consumption Profile
Battery State of Charge (SOC) Profile
Solar Generation
2.75 kW
Peak @ Noon
Battery Capacity
10.24 kWh
9.22 kWh Usable
Daily Capacity
18.5 kWh
PV + Battery
Grid Connection
3 kW
Bidirectional
R50k System Overview
Total Investment
R49,893
Incl. VAT
PV Capacity
2.75 kW
5 × 550W Panels
Battery Storage
10.24 kWh
9.22 kWh Usable
Daily Capacity
18.5 kWh
PV + Battery
NRS097 Shared Transformer Network Design
Engineering diagram of 60A single-phase houses on shared feeder with ADMD calculations
Understanding ADMD (After Diversity Maximum Demand)
Definition: ADMD is the maximum power demand that a group of consumers will simultaneously place on the electrical network after considering diversity. It accounts for the statistical reality that not all consumers use their maximum demand at the same time.
Why ADMD Matters: If we sized transformers based on the sum of all individual maximum demands, the infrastructure would be vastly oversized and economically unviable. ADMD allows for realistic, cost-effective network planning.
ADMD Calculation Example:
- • Individual House Max Demand: 13.8 kVA (60A @ 230V)
- • Total Installed Demand (57 houses): 18 × 13.8 = 248.4 kVA
- • ADMD Factor (Residential): 0.35 - 0.45 (typically 0.4)
- • Actual Maximum Demand: 248.4 × 0.4 = 314.6 kVA
- • Transformer Size Required: 315 kVA ✓
Network Planning Application: Using ADMD factor of 0.4, a 315 kVA mini-sub transformer can reliably serve approximately 57 houses with 60A single-phase supply, even though their combined maximum demand would theoretically be 248.4 kVA.
Per House Specification
- Supply: 60A Single Phase (230V)
- Max Demand: 13.8 kVA
- Max Export: 3.68 kW (16A @ 230V)
- Nano-Grid: 2.75 kW PV + 10.24 kWh BESS
ADMD Calculations
- ADMD Factor: 0.35 - 0.45
- Avg per House: ~5.5 kVA (@ 0.4 ADMD)
- Mini-Sub Capacity: 315 kVA
- Houses per Mini-Sub: ~57 houses
NRS097 Export Limits
- Per Phase Export: Max 25% of supply
- 60A Supply: 15A export limit
- Max Export Power: 3.45 kW @ 230V
- System Compliance: 2.75 kW ✓
Network Topology Diagram
Network Configuration Summary
Transformer Specifications
- Transformer Rating: 315 kVA
- Voltage: 11kV / 400V-230V
- Houses Connected: 57 houses
- Total Installed Demand: 786.6 kVA (57 × 13.8 kVA)
- ADMD Demand (0.4 factor): 314.6 kVA
- Utilization Factor: 99.9%
Export Scenario Analysis
- Max Export per House: 2.75 kW (System Limited)
- Simultaneous Export (50%): 78.4 kW (29 houses)
- Peak Export (All Houses): 156.8 kW (57 houses)
- Transformer Reverse Flow: 49.8% of rating
- NRS097 Compliance: ✓ Compliant
- Grid Stability: ✓ Maintained
UtCS Mass Deployment Framework
Comprehensive framework for nano-grid mass deployment
Key Role Players
Program Owner
Municipality
Public sector oversight and governance
CAPEX Acquisition
Private Funders
Capital expenditure financing through Municipal Schedule 2 of the ERA-Compliant SSEG Program
Program Execution
UtCS
Design, execution, and oversight
UtCS Execution Framework: Three Pillars
PLACE
Installation Location
- • Drone-based rooftop assessments
- • Site evaluation & suitability
- • Location establishment
Warehouse Operations
- • Equipment inventory management
- • Deployment kits compilation
- • Kits dispatching
- • Post-dispatch management
Consumer Info Pods
- • Information centers
- • End-user support
- • Community engagement
PEOPLE
Consumers
- • In-person education
- • Contracting process
- • Post-commissioning activation
- • Monitoring & evaluation
Deployment Teams
- • UtCS training programs
- • Deployment operations
- • Maintenance services
- • Efficiency: 300 per R250k
EQUIPMENT
Core Systems
- • PV Solar Panels
- • Hybrid Inverters
- • BESS (Battery Storage)
Monitoring
- • Smart Meters (E460)
- • WiFi CCTV Cameras
- • WiFi Routers
Support Infrastructure
- • Mounting structures
- • Protection equipment
- • Cabling & peripherals
Implementation Phases
Assessment Phase
Drone-based rooftop assessments for site suitability
Logistics & Supply Chain
Warehouse management, kit compilation, and dispatching
Consumer Engagement
Education, contracting, and activation
Deployment & Maintenance
Installation and ongoing system support
Continuous Improvement
Monitoring, evaluation, and optimization
System Design Specifications
PV Array
- Capacity: 2.75 kW
- Panels: 5 × 550W
- Brand: JA Solar JAM72S30
- Type: Monocrystalline PERC
- Efficiency: 21.3%
- Warranty: 25 years
- Daily Gen: 9.28 kWh/day
Hybrid Inverter
- Model: Huawei SUN2000-3KTL-L1
- Capacity: 3 kW
- Type: Hybrid String
- Efficiency: 98.3%
- MPPT: 2 Trackers
- Phase: Single Phase
- Warranty: 10 years
Battery Storage
- Model: Huawei LUNA2000-5-S0
- Modules: 2 × 5.12 kWh
- Total: 10.24 kWh
- Usable: 9.22 kWh (90% DoD)
- Type: LiFePO4
- Cycles: 6000 @ 90% DoD
- Warranty: 10 years
Complete Bill of Quantities (BOQ)
Major Equipment (CAPEX)
| Item Description | Qty | Unit Price | Total |
|---|---|---|---|
| JA Solar JAM72S30 550W Monocrystalline PERC Panel | 5 | R 1,520 | R 7,600 |
| Huawei SUN2000-3KTL-L1 3kW Hybrid String Inverter | 1 | R 8,300 | R 8,300 |
| Huawei LUNA2000-5-S0 5.12kWh Battery Module (LiFePO4) | 2 | R 4,200 | R 8,400 |
| Landis+Gyr E460 4-Quadrant Bi-Directional Smart Meter | 1 | R 2,550 | R 2,550 |
| CAPEX Subtotal: | R 26,850 | ||
Support Equipment & Monitoring
| Item Description | Qty | Unit Price | Total |
|---|---|---|---|
| WiFi Router (Outdoor IP65 Rated) | 1 | R 620 | R 620 |
| WiFi CCTV Camera 2MP (Hikvision or equivalent) | 1 | R 880 | R 880 |
| Roof Mounting Structure (Aluminum, 5 panels) | 1 | R 1,650 | R 1,650 |
| AC/DC Protection & Isolator Package | 1 | R 1,650 | R 1,650 |
| Cabling (DC: 15m, AC: 12m, 4mm² & 6mm²) | 1 | R 945 | R 945 |
| MC4 Connectors & Cable Terminals | 1 | R 420 | R 420 |
| Earthing Kit (Rods, Clamps, Cable) | 1 | R 580 | R 580 |
| PVC Conduit & Trunking (10m) | 1 | R 260 | R 260 |
| Weatherproof Enclosure IP55 (for protection devices) | 1 | R 380 | R 380 |
| Support Equipment Subtotal: | R 7,385 | ||
Installation & Labor
| Item Description | Qty | Unit Price | Total |
|---|---|---|---|
| PV Panel Installation (Roof mounting, alignment) | 1 | R 1,250 | R 1,250 |
| Inverter & Battery Installation (Wall mounting, wiring) | 1 | R 1,500 | R 1,500 |
| Electrical Work & DB Board Modifications | 1 | R 1,800 | R 1,800 |
| Smart Meter Installation & Configuration | 1 | R 750 | R 750 |
| CCTV Camera Installation & WiFi Network Setup | 1 | R 520 | R 520 |
| WiFi Router Configuration & Network Integration | 1 | R 350 | R 350 |
| System Commissioning & User Training | 1 | R 850 | R 850 |
| Installation & Labor Subtotal: | R 7,020 | ||
Professional Services
| Item Description | Qty | Unit Price | Total |
|---|---|---|---|
| Electrical Design & Single-Line Diagram | 1 | R 1,000 | R 1,000 |
| Certificate of Compliance (CoC) | 1 | R 750 | R 750 |
| Documentation & User Manuals | 1 | R 380 | R 380 |
| Professional Services Subtotal: | R 2,130 | ||