| PV system power (in kWp) | kWp | |
| Cost of PV system | ||
| PV system losses * | % | |
| Annual solar exposure ** | kWh/m2 | |
| Feed-in tariff per kWh | ||
| Annual PV electricity output | ||
| Annual feed-in income for electricity generated | ||
| Return on investment in PV system after | ||
| Month | electricity prod. in % | kWh | Income per month |
| January | |||
| February | |||
| March | |||
| April | |||
| May | |||
| June | |||
| July | |||
| August | |||
| September | |||
| October | |||
| November | |||
| December | |||
| In total: |
* losses in PV On-Grid systems amount to 15% (inverter, cable, temp. coefficient - performance ratio)
** in Central and North Europe between 1200-850 kWh/m2 in South Europe up to 2000 kWh/m2.
All financial data please define in the same currency, for every occurrence (system costs and feed-in tariff).
| PV System power (solar generator) | Wp | |
| PV system losses * | % | |
| Daily solar exposure ** | h | |
| System voltage | V | |
| Permissible battery discharge level *** | % | |
| Daily power generated | ||
| Daily current generated | ||
| Required battery capacity | ||
| Days with no current consumption (amount of charging cycles) | days | |
| Battery capacity for a several-day-long cycle | ||
* loses in PV Off-grid systems amount 20-25% (cable, charge controller, battery system)
** average daily solar exposure 5-6h (eg. summer 8h, winter 4h), depending on european location
*** in order to protect battery and avoid deep discharges (ref. 50% discharging considered as safe)
To optimize the system capacity:
1. Define whether the system will work: all year, only in summer or spring-summer-fall mode ? Please use the daily solar exposure (in hours) to define the working mode. Eg. for summer 8 hours or for all-year-system (incl. winter) 4 hours.
2. Major influences on optimal system design are: quality, technology, storage temperature and system-voltage.
| Battery(s) capacity | Ah | |
| PV system losses * | % | |
| Daily solar exposure ** | h | |
| System voltage | V | |
| Premissible battery discharge level *** | % | |
| Required PV power - for one day cycle (whole year average) | ||
| Days with no current consumption (amount of charging cycles) | days | |
| Required PV power - for several-day-long cycle | ||
* loses in PV Off-grid systems amount 20-25% (cable, charge controller, battery system)
** average daily solar exposure 5-6h (eg. summer 8h, winter 4h), depending on european location
*** in order to protect battery and avoid deep discharges (ref. 50% discharging considered as safe)
To optimize the system capacity:
1. Define whether the system will work: all year, only in summer or spring-summer-fall mode ? Please use the daily solar exposure (in hours) to define the working mode. Eg. for summer 8 hours or for all-year-system (incl. winter) 4 hours.
2. Major influences on optimal system design are: quality, technology, storage temperature and system-voltage.
| Appliances power demand | W | |
| Appliances running time | h | |
| PV system losses * | % | |
| Daily solar exposure ** | h | |
| System voltage | V | |
| Premissible battery discharge level *** | % | |
| Daily energy demand | ||
| Monthly energy demand | ||
| Required battery capacity | ||
| Required PV system power | ||
* loses in PV Off-grid systems amount 20-25% (cable, charge controller, battery system)
** average daily solar exposure 5-6h (eg. summer 8h, winter 4h), depending on european location
*** in order to protect battery and avoid deep discharges (ref. 50% discharging considered as safe)
To optimize the system capacity:
1. Define whether the system will work: all year, only in summer or spring-summer-fall mode ? Please use the daily solar exposure (in hours) to define the working mode. Eg. for summer 8 hours or for all-year-system (incl. winter) 4 hours.
2. Major influences on optimal system design are: quality, technology, storage temperature and system-voltage.