Tutorial 3 – Solar PV (WS 2024/25)

Greek Island Solar PV System

A Greek island has 5,000 households. Average household electricity consumption is 4,000 kWh/year. The island is to be powered entirely by solar PV with battery storage.

PV Module specs:

• Rated power: 400 Wp
• Efficiency at STC: 20%
• Active area: 2 m²
• Temperature coefficient: −0.4 %/°C
• STC temperature: 25 °C, Operating temperature: 45 °C

Battery specs:

• Capacity: 10 kWh/unit
• Depth of discharge (DoD): 80%
• Round-trip efficiency: 90%

Peak sun hours: 5 h/day

LCOE inputs:

• Specific investment: €1,200/kWp
• Lifetime: 25 years
• Discount rate: 5%
• O&M: 1% of investment/year
• Annual degradation: 0.5%

Task 1: Calculate the total annual electricity demand of the island [kWh/year].

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Or enter your answer (±1% tolerance)

Task 2: What is the PV module efficiency at the operating temperature of 45 °C?

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Or enter your answer (±5% tolerance)

Task 3: How many battery units are needed to cover exactly 1 day of island-wide demand? (round up to nearest whole number)

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Or enter your answer (±2% tolerance)

Task 4: How many PV modules are needed to meet the daily demand in the available peak sun hours, using the operating efficiency? (round up)

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Or enter your answer (±2% tolerance)

Task 5: Calculate the Levelised Cost of Energy (LCOE) [€/kWh]. Use the annuity method for capital costs.

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Or enter your answer (±10% tolerance)