Solar Calculator for Lagos — Size Am From Your Load
Daily kWh → panel, battery, inverter · 4.5 peak sun hours · price from live component data
Plenty Lagos solar quote dey start from the wrong side — installer go ask your budget, then size system to match am. Na backwards. Sizing suppose start from your load: wetin you dey actually run, for how many hours, and how much of am must work when light go. Once you sabi that, you fit judge any quote for like one minute.
Size your system from your load
Set how many of each one you dey run and for how many hours per day.
The sizing dey assume Lagos average of 4.5 peak sun hours, 25% system loss and 85% usable depth of discharge for lithium. The cost na equipment alone — labour and wiring dey usually add 10–20% on top. Na planning estimate to check quote with, no be quote.
Start from your daily kWh, no be your budget
Add each appliance watt times the hours wey you dey run am per day, then divide by 1,000. Fridge wey be 150W wey dey run 24 hours na 3.6kWh. Six bulb of 10W for six hours na 0.36kWh. Pressing iron of 1,000W for 20 minutes na 0.33kWh. Plenty Lagos flat wey no dey run AC dey land between 3kWh and 8kWh per day; add just one 1.5HP AC wey run six hours, e go add like 6kWh by itself.
That daily kWh na the one number wey any correct installer go ask you. If quote land and nobody ask wetin you dey run, dem size the system to your pocket, no be your house — so e go either too big (you overpay) or too small (e go cut for night, wey be the exact time you want am).
Na sun hours dey size panel, no be watt alone
Lagos dey average like 4.5 peak sun hours per day. Na that number dey turn panel rating into real energy: 450W panel no dey make 450W all day — e dey make like 450W × 4.5 hours ≈ 2kWh for better day, and less well well for July–September rain. So to cover 6kWh daily load, na like 6 ÷ 2 = 3 panel for theory, but for real life na 4–5 once you add cloud, dust for the glass, and charging loss.
Na why panel count be the part of quote wey you suppose check pass. To reduce panel na the cheapest way for installer to hit sweet price, and you no go see am until the first cloudy week, when battery no go full again and the system go quietly start to lean on NEPA.
Na battery dey decide how blackout go feel
Panel only dey work while sun dey, so every hour of night backup dey come from battery. Size am by the load wey you need after dark, no be your total daily load — for most house na fridge, fan, light, phone and router, wey small pass the daytime peak. Then add headroom: lithium (LiFePO4) battery dey usually rated for like 80–90% usable depth of discharge, but tubular lead-acid no suppose go below like 50% if you want am last the years wey dem talk.
Na that depth-of-discharge difference make 5kWh lithium and 5kWh tubular no be the same buy. Lithium go give you like 4–4.5kWh wey you fit really use; tubular go give you like 2.5kWh before you start to cut im life short. Compare usable kWh, no be the kWh wey dem write for body, if not the cheaper one go look like better deal pass wetin e be.
The tier price na fully installed — panel, inverter, battery and labour join.
Price per watt across size, with source and the date wey dem verify am.