Complete Inverter System Design for a Real or Sample Home
The capstone project for Inverter & Battery Maintenance — a free Trades course. Pass it and you earn a certificate anyone can verify.
- Free
- 6 steps
- Pass mark 65%
- Graded within minutes
- Beginner-friendly
The project unlocks once you complete the lessons. The workbook is free to download now so you can see exactly what is expected.
What you will submit
A single shared link or document containing the load calculation, the system and battery sizing, the install plan with safety notes, and an itemised naira cost quote for one home.
What to do, step by step
- Choose a real home you can access or a clearly described sample one. Note how many rooms it has, the power situation (how reliable NEPA is there, whether they currently use a generator) and what the family most wants kept running during outages.
- Do a load calculation: list every appliance the client wants on backup with its wattage, work out the realistic evening PEAK load (everything likely on at once), and the AVERAGE load over the backup hours. Show your arithmetic clearly.
- Size the system from your numbers: state the inverter kVA you recommend (peak load plus headroom, using the ~0.8 VA-to-watts factor) and the battery bank you recommend (battery type, Ah, quantity and bank voltage) to deliver the backup hours wanted, leaving safe depth-of-discharge headroom for lead-acid.
- Write an install plan: where the inverter and batteries will be mounted (ventilation, safety, reach), the cabling and protection (battery cable size, fuse/DC breaker, AC breakers, earthing) and the changeover arrangement — and flag the key safety points in your own words.
- Build an itemised naira cost breakdown with realistic 2026 figures: every item (inverter, each battery, changeover, cables/lugs, breakers/fuses, rack, trunking) with prices and your markup, a separate labour figure, transport, deposit terms, warranty and a clear grand total.
- Combine the load calculation, sizing, install plan and costed quote into ONE shareable document or link (Google Doc, PDF or clear image set) that you could genuinely hand to a paying client.
Files to work with
Project workbook (fill in, then submit)The whole brief, an evidence checklist, the grading rubric as a self-check and the link-sharing steps in one file. Opens in Word, Google Docs or WPS.Word · 6 KBHow it is graded
| Criterion | Weight |
|---|---|
| Load calculation: a complete appliance-by-appliance list with wattages and a clear, correct peak-and-average calculation with the arithmetic shown | 25% |
| Sizing: inverter kVA justified from peak load plus headroom, and a battery bank correctly sized from average load × backup hours with safe depth-of-discharge headroom and a stated bank voltage | 25% |
| Install plan and safety: sensible placement/ventilation, correctly-rated battery cable, fusing/breakers/earthing and a proper changeover, with the key electrical and battery-acid safety points clearly explained | 25% |
| Itemised naira quote: realistic 2026 prices, equipment with markup plus separate labour, logistics, deposit, warranty and a correct grand total | 15% |
| Clarity and professionalism: realistic Nigerian context (NEPA/generator/data realities) and a neat, well-organised document genuinely presentable to a paying client | 10% |
You need 65% overall to pass. A failed submission comes back with feedback and can be revised and resubmitted.
Before you submit: make your link public
If your work lives in Google Drive or Google Docs, open Share → General access and change “Restricted” to “Anyone with the link” (Viewer). Then paste the link into a private browser window: if it opens without sign-in, you are ready. A private link cannot be graded — it is the single most common reason a good project fails.
Frequently asked questions
Do I have to finish Inverter & Battery Maintenance before submitting the project?
Yes. The submission screen opens once every lesson in Inverter & Battery Maintenance is marked complete. The lessons are where the methods, the Nigerian context and the worked examples the project depends on are taught.
How is the project graded?
An examiner scores each rubric criterion from 0 to 100 and weights them as shown on this page; you need 65% overall to pass. Most submissions are graded within minutes and you get written feedback on what was strong and what to improve.
Can I resubmit if I fail?
Yes. A failed project comes back with feedback; revise the weak parts and resubmit. A passed project is final — the certificate is issued and cannot be re-rolled.
What do I actually submit?
A write-up of what you did (under 5,000 characters) plus a public link to your work — a Google Drive folder, Google Doc, spreadsheet, GitHub repository or video. The link must open without sign-in; a private link cannot be graded. The free project workbook on this page walks you through all 6 steps.
Is the certificate real?
Yes. Passing this project issues a certificate with a unique verification code. Anyone — an employer, a client, a school — can open the verification page and see that the certificate is genuine and which project earned it.
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Ready to earn this certificate?
Inverter & Battery Maintenance is free and self-paced. Finish the lessons, complete this project, and the certificate is yours to share.
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