komuw/price_of_solar_panel.py

## price_of_solar_panel.py
# How many units of KPLC do you use per month?
# Go to https://www.stimatracker.com/, click on `prepaid`, then enter amount in KES you use per month.
# Click `calculate`, it will give you your consumption in kwh. Mine is KES 5000, which give ~150kwh

monthly_kplc_cost = 5000 # KES
yearly_kplc_cost = monthly_kplc_cost * 12 # KES
consumption_per_month = 150 # kWh
consumption_per_month = 150 * 1000 # watt-hours

monthly_energy_production_of_solar_panel = (solar_panel_rating_in_watts * number_of_hrs_of_sunlight * solar_panel_efficiency_factor) * 30
solar_panel_rating_in_watts = 120 # Watts.  eg; https://copia.co.ke/product/ubbink-solar-panel-120w/
number_of_hrs_of_sunlight = 5 #hours.
# for number_of_hrs_of_sunlight, various meteorological orgs can give you the exact value. But you can also just approximate based on you having lived in the region.
# It is important to use the average number of hours for a bad month(like july) in this calculation. ie, use worst case scenario.
# It is also important to note that sio jua kali pekee. Solar panels will also generate power when there's light but no sun.
# You can use https://footprinthero.com/peak-sun-hours-calculator to calculate number of sunlight hours.
# For example, that website says that for `sarit center in westlands`, peak solar is 6hrs in February and lowest is 4hrs in July.
solar_panel_efficiency_factor = 15/100 # ie, 15%. Most residential panels are in between 13% to 22%. Check specification before buying.

monthly_energy_production_of_solar_panel = (120 * 5 * (15/100)) * 30 # watt-hours
assert monthly_energy_production_of_solar_panel == 2700 # watt-hours

number_of_solar_panels_required = int(consumption_per_month/monthly_energy_production_of_solar_panel) + 1 # plus one to roundup
assert number_of_solar_panels_required == 56

price_per_panel = 11000 # KES,  eg; https://copia.co.ke/product/ubbink-solar-panel-120w/
total_price_of_solar_panels  = number_of_solar_panels_required * price_per_panel # KES 616,000
# Remember to add price of inverter, labour, cables, etc. But the price of solar panels is the main one.

number_of_years_to_break_even = int(total_price_of_solar_panels/yearly_kplc_cost)
assert number_of_years_to_break_even == 10
	# How many units of KPLC do you use per month?
	# Go to https://www.stimatracker.com/, click on `prepaid`, then enter amount in KES you use per month.
	# Click `calculate`, it will give you your consumption in kwh. Mine is KES 5000, which give ~150kwh

	monthly_kplc_cost = 5000 # KES
	yearly_kplc_cost = monthly_kplc_cost * 12 # KES
	consumption_per_month = 150 # kWh
	consumption_per_month = 150 * 1000 # watt-hours

	monthly_energy_production_of_solar_panel = (solar_panel_rating_in_watts * number_of_hrs_of_sunlight * solar_panel_efficiency_factor) * 30
	solar_panel_rating_in_watts = 120 # Watts. eg; https://copia.co.ke/product/ubbink-solar-panel-120w/
	number_of_hrs_of_sunlight = 5 #hours.
	# for number_of_hrs_of_sunlight, various meteorological orgs can give you the exact value. But you can also just approximate based on you having lived in the region.
	# It is important to use the average number of hours for a bad month(like july) in this calculation. ie, use worst case scenario.
	# It is also important to note that sio jua kali pekee. Solar panels will also generate power when there's light but no sun.
	# You can use https://footprinthero.com/peak-sun-hours-calculator to calculate number of sunlight hours.
	# For example, that website says that for `sarit center in westlands`, peak solar is 6hrs in February and lowest is 4hrs in July.
	solar_panel_efficiency_factor = 15/100 # ie, 15%. Most residential panels are in between 13% to 22%. Check specification before buying.

	monthly_energy_production_of_solar_panel = (120 * 5 * (15/100)) * 30 # watt-hours
	assert monthly_energy_production_of_solar_panel == 2700 # watt-hours

	number_of_solar_panels_required = int(consumption_per_month/monthly_energy_production_of_solar_panel) + 1 # plus one to roundup
	assert number_of_solar_panels_required == 56

	price_per_panel = 11000 # KES, eg; https://copia.co.ke/product/ubbink-solar-panel-120w/
	total_price_of_solar_panels = number_of_solar_panels_required * price_per_panel # KES 616,000
	# Remember to add price of inverter, labour, cables, etc. But the price of solar panels is the main one.

	number_of_years_to_break_even = int(total_price_of_solar_panels/yearly_kplc_cost)
	assert number_of_years_to_break_even == 10