The verdict in three sentences
An EPC installing 150 rooftop PV systems a year in Singapore and coordinating on WhatsApp loses quotes, misses inspections and lets O&M contracts lapse. Custom industry software covering sizing, quoting, crew scheduling and inverter monitoring costs between USD 60,000 and 140,000, delivered in 4 months. The fastest gain comes from maintenance contracts, up 30% thanks to renewal reminders and production alerts.
What WhatsApp cannot do
WhatsApp groups work for coordinating a crew on an industrial roof in Tuas. They fail when you need the invoice for an inverter installed 18 months ago, a list of clients whose contract expires next quarter, or proof of expected yield for a client questioning their SP Group bill.
| Process | WhatsApp and spreadsheets | With industry software |
|---|---|---|
| System sizing | manual, 1 to 2 h | wizard in 15 minutes from utility bills and roof data |
| Time to send a quote | 3 to 5 days | under 24 h |
| Project tracking | scattered photos | job file, checklists, handover certificate |
| Panel and inverter warranties | hard to find | serial numbers and dates per client |
| Contract renewals | often forgotten | automatic reminder at D-45 |
| Faults detected | when the client calls | monitoring alert within 24 h |
Scope and budget (2026 order of magnitude)
| Module | Scope | Estimated budget |
|---|---|---|
| Sizing and quoting | load, irradiance, storage, margin, EMA licensing data | USD 15,000 to 32,000 |
| CRM and sales pipeline | leads, follow-ups, PayNow and card payments | USD 8,000 to 18,000 |
| Scheduling and projects | crews, equipment, photos, handover, height-work permits | USD 12,000 to 28,000 |
| Inventory and warranties | panels, inverters, batteries, serial numbers | USD 8,000 to 20,000 |
| O&M and monitoring | contracts, visits, Huawei, SMA, SolarEdge APIs | USD 17,000 to 42,000 |
| Total | USD 60,000 to 140,000 |
Hosting and application maintenance run USD 1,000 to 2,500 a month. Monitoring relies on inverter vendor portals when they expose an API, avoiding extra hardware. For reference, the same scope for an installer in Dakar costs 7,000,000 to 18,000,000 FCFA.
Timeline and maintenance offers
| Step | Duration | Outcome |
|---|---|---|
| Scoping with the technical director | 2 weeks | sizing and pricing rules |
| Mobile mockups for technicians | 2 weeks | field-validated screens |
| Development | 9 weeks | modules in batches |
| Migration of 400 existing clients | 2 weeks | installed base referenced |
| Training and go-live | 2 weeks | autonomous crews |
The software makes it easy to sell clear O&M tiers, for example: Basic at SGD 600 a year (one visit, cleaning), Standard at SGD 1,200 (two visits, monitoring) and Premium at SGD 2,000 (monitoring, 48 h response, monthly report).
Mini case study
Wei Ming, director of a solar EPC in Singapore, has 400 installed clients and 80 active O&M contracts averaging SGD 1,500, or SGD 120,000 a year. With automatic reminders and production alerts he gains 30% more contracts: 24 contracts and SGD 36,000 of extra recurring revenue. His sales team sends quotes in 24 h instead of 4 days and wins 10 more projects a year at SGD 60,000 with a 20% margin, or SGD 120,000. Estimated annual gain: SGD 156,000 (about USD 116,000), for a USD 95,000 project paid back in under 10 months.
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FAQ
Does the field app work without connectivity?
Yes, the technician app works offline and syncs photos and handover forms once the network returns. This is part of the projects module, USD 12,000 to 28,000.
Can clients pay deposits by PayNow?
Yes, a PayNow QR or card payment link is generated with each quote. Card fees typically sit around 2.5 to 3.4% per transaction.
Which inverters support remote monitoring?
Common brands in Singapore (Huawei, SMA, SolarEdge, Sungrow) expose APIs or exports. Each additional brand costs USD 3,000 to 7,000 to integrate.
Do we need to build everything at once?
No. A first batch covering quoting and projects, around USD 30,000, ships in 8 weeks.
Does it handle C&I and solar leasing projects?
Yes, with multi-site quotes, PPA billing and per-site production tracking, which puts the budget at the top of the range, around USD 120,000 to 140,000.
Let's scope your project. Tell us your installation volume, installed base and inverter brands, and we will price your software between USD 60,000 and 140,000 with a 4-month plan. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
