Size your system

Start with the load.

List what you want running when the grid is off, and for how long. The inverter, the battery and the panels follow from that.

Step one

Typical appliance loads

Find each appliance, then add the watts of everything you want on at once.

Appliance	Typical watts	Hours a day	Needs at least
LED bulbs (ten)	100	6	Every system
Ceiling fan	75	8	Every system
TV and decoder	150	5	Every system
Fridge	150	24 (cycling)	3kVA and up
Chest freezer	200	24 (cycling)	3kVA and up
Washing machine	500	1	5kVA and up
Pumping machine 1HP	750	Half an hour	5kVA and up
Air conditioner 1HP (inverter type)	900	6	5kVA and up
Air conditioner 1.5HP	1300	6	8kVA and up
Electric iron	1200	Half an hour	5kVA and up; by day only

Typical figures; our survey measures yours.

Step two

Fitted prices in naira, including installation.

System	Inverter	Battery	Panels	Runs	From (naira)
Starter	1.5kVA	2.5kWh	Four 450W	Lights, fans, TV and phones	1,650,000
Flat	3kVA	5kWh	Six 450W	The starter load plus a fridge	3,200,000
Family	5kVA	10kWh	Ten 550W	Adds a pump and one 1HP air conditioner	5,600,000
Duplex	8kVA	15kWh	Fourteen 550W	Two air conditioners in turn and a borehole	8,900,000
Large home	10kVA	20kWh	Eighteen 550W	Three air conditioners in turn	11,800,000
Estate home	12kVA	25kWh	Twenty-two 550W	Generator off most days	14,500,000