min

max

The panels

Efficiency of the solar panels η

0,18

0,12

Average day time power demand Pday

25

35

kW, for ten hours

Average night time power demand Pnight

10

15

kW, for 14 hours

Energy use per day W24h

390

560

kWh

Average insolation psun (Jan, Aug)

6,3

4,2

kWh/m2/day

required panel power Ppanels

39

56

kW, assuming 10 hour sun

Required panel area A

344

1111

m2

The batteries

 dark time energy consumption Wdark

140

210

kWh

Battery bank (6V) capacity C

23333

35000

Ah

Number of batteries

13

19

battery: 6V, 1800 Ah, 350kg, 0,14m3

weight of batteries

4537

6806

kg

Volume of batteries

1,8

2,7

m3

Prices

(34 panels of 240pW for $12000)

1,07 €

I do not quite understand the peak watts

Panels (1€/W – 2€/W)

39 000 €

112 000 €

Batteries

24 954 €

37 431 €

Inverter etc. (50 kW)

8 000 €

12 000 €

A small generator (20kW – 40kW)

4 000 €

8 000 €

75 954 €

169 431 €

A reference solar system (3kW, 5000€)

65 000 €

93 333 €

All the power from NEPA

not available in practise

power

0,0170 €

0,0960 €

€/kw

fixed cost

0 €

590 €

€/month

Annual cost

2 420 €

26 702 €

Power from the generators

Fuel