PV Solar Savings

Detailed analysis of photovoltaic generation and cost savings

Key Metrics

Installed Capacity

0.961 MWp

0.70% of 137.61 MWp target

SSEG Producers

118

Registered generators

Cost Reduction

47%

vs Eskom weighted avg

Annual Savings

R 85.56M

R 7.13M per month

Monthly PV Generation & Savings

Generation (GWh) and corresponding savings (R millions)

Cost Comparison: Eskom vs SSEG

Tariff rates by TOU period (R/kWh)

TOU Period Distribution

PV generation occurs during Peak and Standard periods only

Peak (30%)

Standard (70%)

PV Savings Formula

S_PV = Σ E_PV(t) × [τ_Eskom(t) − τ_SSEG]

E_PV(t): PV energy generation during TOU period (kWh)

τ_Eskom(t): Eskom tariff during period (R/kWh)

τ_SSEG: Fixed SSEG purchase rate = R 1.25/kWh

Weighted Average Eskom Tariff:

0.30 × R4.20 (Peak) + 0.70 × R1.56 (Standard) = R 2.36/kWh

Monthly PV Generation Calculation

How each month's generation is calculated from system parameters

Generation Formula

E_month = P_installed × H_solar × D_month × PR

P_installed = 0.961 MWp (System Capacity)

H_solar = Peak Sun Hours (varies by month)

D_month = Days in month

PR = 0.85 (Performance Ratio)

Month	Days	Solar Hrs	Calculation	Generation
January	31	8.6	0.961 × 8.6 × 31 × 0.85	7,044 MWh
February	28	8.9	0.961 × 8.9 × 28 × 0.85	6,608 MWh
March	31	8.3	0.961 × 8.3 × 31 × 0.85	6,836 MWh
April	30	7.5	0.961 × 7.5 × 30 × 0.85	5,943 MWh
May	31	6.8	0.961 × 6.8 × 31 × 0.85	5,546 MWh
June	30	6.5	0.961 × 6.5 × 30 × 0.85	5,196 MWh
July	31	6.7	0.961 × 6.7 × 31 × 0.85	5,491 MWh
August	31	7.3	0.961 × 7.3 × 31 × 0.85	6,036 MWh
September	30	8.2	0.961 × 8.2 × 30 × 0.85	6,530 MWh
October	31	8.6	0.961 × 8.6 × 31 × 0.85	7,088 MWh
November	30	9.4	0.961 × 9.4 × 30 × 0.85	7,451 MWh
December	31	9.2	0.961 × 9.2 × 31 × 0.85	7,601 MWh
Annual Total				77,370 MWh

Example: January Calculation

E_Jan = P × H × D × PR

E_Jan = 0.961 MWp × 8.6 h/day × 31 days × 0.85

E_Jan = 0.961 × 8.6 × 31 × 0.85

E_Jan = 217.77 MWh/day × 31 days

E_Jan = 7,044 MWh

Peak Sun Hours vary seasonally for the Eastern Cape region. Summer months (Nov-Feb) average 8.6-9.4 hours, while winter months (May-Jul) average 6.5-6.8 hours, reflecting the Southern Hemisphere solar irradiance patterns.

Monthly Generation Running Totals

Cumulative generation building to 77,370 MWh annual total

Month	Generation (MWh)	Running Total (MWh)
January	7,044	7,044
February	6,608	13,652
March	6,836	20,488
April	5,943	26,431
May	5,546	31,977
June	5,196	37,173
July	5,491	42,664
August	6,036	48,700
September	6,530	55,230
October	7,088	62,318
November	7,451	69,769
December	7,601	77,370
Annual Total	77,370 MWh

Calculation:

7,044 + 6,608 + 6,836 + 5,943 + 5,546 + 5,196 + 5,491 + 6,036 + 6,530 + 7,088 + 7,451 + 7,601 = 77,370 MWh

Annual PV Savings Calculation

Step-by-step cost comparison between Eskom and SSEG rates

Annual PV Generation

E_PV = 77,370 MWh = 77,370,000 kWh

Eskom Cost Calculation

Weighted Average Eskom Tariff:

τ_Eskom = (0.30 × R4.20) + (0.70 × R1.56)

τ_Eskom = R1.26 + R1.092 = R 2.36/kWh

Total Eskom Cost:

C_Eskom = 77,370,000 kWh × R 2.36/kWh

C_Eskom = R 182,267,859

SSEG Cost Calculation

Fixed SSEG Purchase Rate:

τ_SSEG = R 1.25/kWh

Total SSEG Cost:

C_SSEG = 77,370,000 kWh × R 1.25/kWh

C_SSEG = R 96,712,500

Annual PV Savings

S_PV = C_Eskom − C_SSEG

S_PV = R 182,267,859 − R 96,712,500

S_PV = R 85,555,359

Savings Rate:47% cost reduction

Component	Value
Annual PV Generation	77,370 MWh
Eskom Cost (at weighted avg R2.36/kWh)	R 182,267,859
SSEG Cost (at R1.25/kWh)	R 96,712,500
Annual PV Savings	R 85,555,359