Energy savings

“How many kVA do I need to power my whole house?”

I get this WhatsApp message 20 times a week. Last week, a man in Trans Ekulu sent me his NEPA bill: ₦187,000 for May. He has 3 ACs, 2 freezers, pumping machine, and 7 bedrooms. An installer quoted him “10KVA solar will do”.

I went to his house. Did load test with clamp meter. Real need: 18KVA. If he bought 10KVA, his ACs would trip the system every afternoon and he’d call solar a scam.

After 47 full-house installs in Enugu, here’s the truth: “Entire house” means different things. 3-bedroom bungalow ≠ 5-bedroom duplex. Your installer must do math, not guess.

kVA = power at one moment. kWh = power over time.

Example: Your 1.5HP AC is 1.2kW. If it runs 8 hours = 9.6kWh/day.

10KVA inverter can RUN the AC. But if your battery is only 5kWh, the AC kills the battery in 30 mins.

June 2026 case: Client in New Haven bought 15KVA inverter + 5kWh battery because Facebook vendor said “it will power everything”. System shuts down 7pm daily. He can run AC, but not for long. ₦4.2M wasted.

I measured these 3 houses June 2026 with my clamp meter. Use them to estimate yours:

NEPA bill: ₦65k/month. Gen: ₦40k/month.

Appliance Watts Hours/Day kWh/Day

1.5HP AC x2 2400W 6h 14.4

Fridge + Freezer 400W 24h 9.6

Pumping Machine 1HP 750W 1h 0.75

Lights + Fans + TV 600W 8h 4.8

Total 29.55 kWh/day

Peak load if everything starts at once: 2400 + 400 + 750 + 600 = 4.15KW. Add 25% surge = 5.2KVA minimum inverter.

Battery math: 29.55 kWh x 1.3 = 38.4kWh. For 1 day backup = 40kWh battery bank.

Inverter 6KVA Growatt: ₦750k

Battery 40kWh Felicity: ₦8.8M

Panels 9KW Jinko: ₦1.65M

Installation: ₦550k

Total: ₦11.79M | Payback: 3.1 years vs ₦105k/month NEPA+gen

NEPA bill: ₦140k/month. Gen: ₦110k/month.

Appliance Watts Hours/Day kWh/Day

1.5HP AC x4 4800W 7h 33.6

2HP AC x1 1800W 5h 9.0

3 Freezers 600W 24h 14.4

Pumping 2HP 1500W 1.5h 2.25

Lights/Fans/TVs 1200W 10h 12.0

Total 71.25 kWh/day

Peak load: 4.8+1.8+0.6+1.5+1.2 = 9.9KW. Add 25% = 12.4KVA minimum. Use 15KVA inverter.

Battery: 71.25 x 1.3 = 92.6kWh. 100kWh battery for 1 day backup.

Inverter 15KVA Deye: ₦2.2M

Battery 100kWh Felicity: ₦22M

Panels 22KW Jinko: ₦4.03M

Installation: ₦1.1M

Total: ₦29.33M | Payback: 4.7 years vs ₦250k/month

NEPA bill: ₦28k/month. Gen: ₦22k/month.

Appliance Watts Hours/Day kWh/Day

1HP AC x1 900W 5h 4.5

Fridge 150W 24h 3.6

TV + Fans + Lights 400W 6h 2.4

Total 10.5 kWh/day

Peak: 0.9+0.15+0.4 = 1.45KW. Use 3KVA inverter minimum. 5KVA better for future.

Battery: 10.5 x 1.3 = 13.65kWh. 15kWh battery.

Inverter 5KVA Growatt: ₦650k

Battery 15kWh Blue Carbon: ₦2.94M

Panels 3.3KW Jinko: ₦605k

Installation: ₦300k

Total: ₦4.495M | Payback: 7.4 years. This house should maybe do “AC only” system for ₦2.8M instead.

I fixed these June 2026 alone:

“Vendor said 10KVA means 10 hours” → No. 10KVA with 5kWh battery = 30 mins if you load it to 10KVA. Client in Awkunanaw learned hard way.

Ignoring surge power → Fridge compressor start = 3x watts for 2 seconds. Pumping machine = 4x. If inverter is too small, it trips. Always +25% headroom.

No energy audit → Installer guesses. I use clamp meter on your DB for 24hrs. ₦15k service. Saves you ₦2M mistake.

“Use solar in day, NEPA at night” → NEPA is 90V at night in Enugu. Can’t charge battery. You need enough battery for full night. Half systems fail here.

Month Avg Sun Hours Enugu Can 1KW Panel Make Will You Use Gen?

Dec-Mar 5.5h 5.5kWh/day No. Best months

Apr-Jun 4.2h 4.2kWh/day Maybe 3 days/month

Jul-Sep 3.1h 3.1kWh/day Yes, 8 days/month if battery small

Oct-Nov 4.8h 4.8kWh/day No

My rule: If you want 100% off-grid, size battery for 2 rainy days. For House 2 above: 71kWh/day x 2 = 142kWh battery = ₦31M just for battery. Most clients do 1-day backup + keep gen for rainy week.

Real off-grid client: Dr. Eze, Independence Layout. 120kWh battery, 30KW panels. ₦41M system. Hasn’t used gen since Jan 2026. But he can afford it.

Package Runs What Inverter + Battery Panels Total June 2026

Essential 5KVA 1 AC, Fridge, Lights, TV 5KVA + 15kWh 3.3KW ₦4.5M

Family 10KVA 3 ACs, 2 Freezers, Pump 10KVA + 30kWh 6.6KW ₦9.8M

Duplex 15KVA 5 ACs, 3 Freezers, 2 Pumps 15KVA + 60kWh 13.2KW ₦19.2M

Mansion 30KVA Everything + Gate + Pool 30KVA + 120kWh 26.4KW ₦41M

What’s included: Growatt/Deye inverter, Felicity/Blue Carbon battery, Jinko panels, rails, DC SPD, installation, 2-year workmanship warranty.

Not included: Changeover switch ₦85k, additional DB ₦60k, transport outside Enugu.

Take photo of your NEPA bill + list all appliances. WhatsApp me 0803 XXX XXXX. I’ll tell you real kVA free in 10 mins.

Ask installer: “Show me your load calc sheet.” If he says “we’ll know when we start”, run.

Demand battery spec sheet: Cycles, DoD, warranty. Felicity gives 6000 cycles. If vendor can’t show, it’s fake.

Visit 1 old client site. If installer says “privacy”, he’s hiding something. My clients in G.R.A allow visits.

Whole house solar works. My own house in Trans Ekulu has been 100% solar since Nov 2024. ₦0 NEPA bill. But I sized it right.

Don’t let vendor size it wrong. You’ll blame solar. Solar doesn’t fail. Bad math fails.

About the Author: Ekeson Collins, CEO Ekeson Energy Solution. COREN http://R.Eng. Installed 47 full-house systems. Office: 12 Ogui Road, Enugu. My 15KVA home system is open for inspection.