How My Solar Plan works
My Solar Plan is Red Energy's public planning tool for commercial and industrial solar in South Africa. You start with a property; it fits panels to the roof, estimates production, and builds an indicative energy, backup and savings plan you can save and refine with Red Energy. This page sets out exactly what it uses and what it does not.
What My Solar Plan does
- Finds the property and its roof. Enter an address. Where Google Solar covers the building, its measured roof planes are proposed as roof sections; otherwise you trace the roof yourself on aerial imagery. You choose which sections to use, and can also draw a ground-mount area.
- Lays out panels. Red Energy's layout engine packs its installed panel onto each section and reports the panel count and capacity.
- Estimates production for each section from its own pitch and direction.
- Asks how the business uses electricity and what it needs from the system — savings, backup, or both.
- Recommends a system size and battery and shows an indicative saving.
- Saves the plan. Verify your email to save it, resume it later, and continue with Red Energy, who confirm the design on site and prepare a priced proposal.
Where each number comes from
| Part of the plan | You provide | Defaults and rules | External data |
|---|---|---|---|
| Roof sections | Address; which sections to use; a traced outline where no measurement exists | South-facing pitched faces excluded; faces of 10° or less treated as flat | Google Solar roof measurements; aerial imagery |
| Panel layout | — | Jinko Tiger Neo 625 W (2382 × 1134 mm), portrait on roofs; 0.3 m edge clearance, 20 mm panel gap, 300 mm access gap after at most three rows | — |
| Ground mount | The area outline | 15° tilt facing north; blocks of two or three rows; 3.5 m between blocks; incomplete blocks dropped | — |
| Production | — | 7% system-loss allowance on PVGIS-modelled surfaces, which are modelled as free-standing (open-rack) mounting; no degradation; no local shading from nearby buildings or roof fittings | Google Solar per-face measurement where available; otherwise PVGIS (SARAH-3, including the distant terrain horizon) for the face's pitch and direction |
| Consumption | Average monthly kWh, or monthly spend with a rate; daytime share; expected growth | 70% daytime share if not changed; no growth | Load-logger interval data, when Red Energy measures the site |
| Tariff | An average rate per kWh, or tariff structure | Per-kWh charges only (the energy charge, plus a per-kWh surcharge where it is established to vary with consumption); VAT-exclusive rates | Red Energy's verified catalogue of 2026/27 supplier tariffs, applied when you continue with Red Energy |
| Backup battery | Hours of backup; operating level or known backup load; normal site load | 90% usable depth of discharge; 95% charge and discharge efficiency | — |
How the system is sized
The recommendation sizes solar to the electricity used while the sun is up: average daytime consumption divided by what one kilowatt-peak produces on an average day, plus the energy a battery needs to recharge, capped at what physically fits on the selected roof and ground-mount areas. A backup battery is sized as backup power × hours of autonomy, then increased for depth of discharge and efficiency. On a time-of-use tariff a battery can instead be sized to cover Peak-period use. See the system sizing example.
How the saving is calculated
Solar is valued only where it actually replaces grid electricity: generation used by the daytime load, and surplus solar a battery stores and delivers in the evening. Anything else is not counted, because no export-credit model is applied. On a flat or blended rate, the saving is the electricity replaced multiplied by that rate. On a time-of-use tariff, solar used directly is valued at the Standard rate, up to the daytime load, and a battery serving Peak periods is valued net of the cost of charging it. See the warehouse savings example.
What is not included
- Any saving on maximum-demand or notified-demand charges, capacity charges, fixed, basic or service charges, reactive-energy charges, or connection, metering and administration charges.
- Tariff escalation, panel degradation, finance and tax.
- Day-of-week patterns: the model uses one average day across the year, so it does not reduce the saving for weekends or holidays when a site is closed, and for such a site the indicative saving is overstated. Seasonal variation in use is recorded but not modelled month by month.
- Export or feed-in credits.
- A price or payback period: both follow Red Energy's priced proposal.
What needs a site inspection and engineering
My Solar Plan's layout is indicative. Before anything is installed, Red Energy's site inspection and design confirm: shading from nearby buildings, parapets and plant; skylights, vents and other roof fittings; fire-access routes; the roof's structure and condition; the electrical supply phase, distribution board and cable routes; and equipment locations. The final design is then matched to an approved Red Energy equipment configuration and priced. Information you supply is kept as your answer until it is verified on site.
Worked examples
The commercial solar buyer's guide answers common questions and walks through three examples produced by this engine: a factory roof, a warehouse's savings and sizing a system with backup.
Frequently asked questions
Is My Solar Plan a quote?
No. It produces an indicative plan you can save. A formal quotation follows a site inspection and Red Energy's priced equipment configuration.
Do I need to create an account first?
No. You can start with a property anonymously. You verify an email address only when you want to save or resume a plan.
Does it work for commercial and industrial sites?
Yes. The journey supports large and multiple roofs, ground-mounted arrays, business usage patterns, commercial tariffs and backup requirements typical of commercial and industrial properties in South Africa.
Are the savings guaranteed?
No. Figures are indicative and depend on the information you enter, future tariffs, actual usage and how the installed system performs.
Where does the solar production estimate come from?
From Google Solar's measurement of a roof face where one exists. Otherwise it comes from PVGIS, the European Commission's solar radiation model, for that face's own pitch and direction with a 7% system-loss allowance; PVGIS includes the distant terrain horizon but not shading from nearby buildings or roof fittings. A surface with neither is given no production rather than a guess.
Build an indicative plan for your own site
My Solar Plan runs the same engine on your property: start with the address, confirm the roof, describe how the business uses electricity, then save the plan privately and refine it with Red Energy.
Start with my propertyLast reviewed 2026-10-13.