IngenEnergia

Every house is different: roof exposition, solar PV system size, induction hobsTo estimate the potential savings of an ESS system, it is required to consider several aspects:

Seasonal Solar Power Generation

Solar power generation significantly varies between summer and winter. In the winter, solar panels typically produce less electricity due to shorter days and lower sun angles.

• Winter Solar Generation: Assume winter generation is 50% of the average daily generation.
• Self-Consumption: Assume 30% of solar power is directly consumed by the home.

Daily Consumption

Every family has different habits and the houses different equipment.Therefore there is no unique numbers to estimate the daily consumption, but we are going to propose some realistic example for reference.

• Average Daily Consumption: 8 kWh/day, 12 kWh/day, 16 kWh/day

Self-Consumption

• Not all generated solar power goes into the battery; some is directly used by the home, reducing grid reliance. For most of the cases the self consumption is estimated around the 30%.

Calculations

Let's now calculate the potential savings by accounting for these factors and recommend suitable solar installation capacities for each battery size.

Given Data

• Average Cost per kWh: €0.31
• Feed-In Costs: €0.69/day

5 kWh Battery

• Daily Consumption Offset: 5 kWh
• Required Solar Capacity:     
• Annual Savings Calculation:
  • Summer Daily Generation: 
  • Winter Daily Generation: 
  • Average Daily Generation:    
  • Self-Consumption: ~30% of 5.36 kWh = 1.61 kWh
  • Battery Charging: ~70% of 5.36 kWh = 3.75 kWh
  • Adjusted Savings:
    • Grid Offset: 
    • Feed-In Cost Saving: 
    • 
    • Total Daily Savings:  €1.16 + €0.32 = €1.48/day 
    • Annual Savings:   €1.48 X 365 = €540.20 

10 kWh Battery

• Daily Consumption Offset: 8 kWh
• Required Solar Capacity: 

• Annual Savings Calculation:
  • Summer Daily Generation:
  • Winter Daily Generation: 
  • Average Daily Generation: 
  • Self-Consumption: ~30% of 8.59 kWh = 2.58 kWh
  • Battery Charging: ~70% of 8.59 kWh = 6.03 kWh
  • Adjusted Savings:
    • Grid Offset: 
    • Feed-In Cost Saving: 
    • Total Daily Savings:  €1.87 + €0.52 = €2.39/day
    • Annual Savings:  €2.39 ×\times× 365 = €872.35

15 kWh Battery

• Daily Consumption Offset: 12 kWh
• Required Solar Capacity: 
• Annual Savings Calculation:
  • Summer Daily Generation: 
  • Winter Daily Generation: 
  • Average Daily Generation: 
  • Self-Consumption: ~30% of 12.86 kWh = 3.86 kWh
  • Battery Charging: ~70% of 12.86 kWh = 9 kWh
  • Adjusted Savings:
    • Grid Offset: 
    • Feed-In Cost Saving:
    • Total Daily Savings: €2.79 + €0.52 = €3.31/day
    • Annual Savings: €3.31 X 365 = €1,208.15

20 kWh Battery

• Daily Consumption Offset: 16 kWh

• Required Solar Capacity: 

• Annual Savings Calculation:
  • Summer Daily Generation: 
  • Winter Daily Generation: 
  • Average Daily Generation: 
  • Self-Consumption: ~30% of 17.14 kWh = 5.14 kWh
  • Battery Charging: ~70% of 17.14 kWh = 12 kWh
  • Adjusted Savings:
    • Grid Offset: 
    • Feed-In Cost Saving: 
    • Total Daily Savings: €3.72 + €0.52 = €4.24/day
    • Annual Savings: €4.24 X 365 = €1,548.60

Estimated Savings

Hereafter is reported the result of our calculations: