Solar system calculator
Recommended inverter size:
Recommended battery size:
Recommended PV array:
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Disclaimer:
This calculator provides an estimated solar system size based solely on the user’s monthly electricity bill, selected tariff, phase type, and estimated night-time usage. Actual system requirements may vary depending on load profile, appliance types, peak demand, wiring layout, roof orientation, shading, seasonal variation, municipal supply limitations, and other site-specific conditions.
All results are for preliminary guidance only and do not constitute a formal design, engineering analysis, or installation quotation. Deltool recommends an on-site assessment and detailed load study before any purchasing or installation decision is made.
Explore our Solar products
Deltool brings you a complete range of trusted solar solutions — Tier-1 solar panels, reliable inverters, long-life batteries, and all the installation accessories needed for a clean, safe and efficient system. When you buy from Deltool, you’re choosing top-quality products backed by solid warranties and real after-sales support.
You also get direct access to guidance from a seasoned installer, backed by Herholdt’s premium partnership and AREP membership, ensuring your system is designed and installed to industry-leading standards.
Pro-Design
Custom Solar Energy Design & Proposal
At Deltool, we make going solar simple and precise. Using your address, the past 12 months of electricity bills, and your cost per kWh, our team will generate a custom OpenSolar design and proposal tailored to your energy needs.
What You’ll Get in Your Proposal
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A tailored solar system design based on your roof orientation, location, and energy usage.
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System performance estimates showing expected energy generation and savings over time.
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Environmental impact benefits, including CO₂ reductions and equivalent offsets (trees planted, km driven avoided, etc.).
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Detailed product specifications for panels, inverters, and batteries.
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Clear cost breakdown, including equipment, warranties, and payment milestones.
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DIY or turnkey options — whether you want to install it yourself or have our accredited installers handle everything.
The proposal will also give you a realistic view of your long-term return on investment, taking into account annual energy price increases.
Our Proposal Fee
A small fee is payable for creating your proposal — but here’s the good news:
This fee will be fully deducted from your purchase with Deltool, whether you choose to buy just the materials for a DIY project or opt for our complete turnkey service.
Pro-Analyze
Deltool Energy Logging Service
Deltool uses state-of-the-art energy metering equipment to capture real-time electricity usage, giving you clear insights into your energy consumption patterns. Our Energy Logging Service allows you to track peak power usage, understand your energy load profile, and monitor power quality—all crucial for optimizing efficiency and reducing costs.
The service includes:
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Energy Meter Rental for one week
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Raw Data Export in .csv format for detailed analysis
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Data Analysis and Visualization in Excel, providing clear, actionable insights
Please note: meter installation and removal by a qualified electrician are not included but can be quoted on separately.
With Deltool’s professional energy logging, you gain the knowledge you need to make informed decisions about your energy management.
Cost:
R2500 per week
R8000 refundable deposit.
Optional extra:
Installation and removal
Pro-Tender
Pro-Tender™ – Smart Tendering & Project Management for Solar and Energy Projects
When institutions like schools or municipalities go out on tender for solar or energy systems, they often face confusion — unclear specifications, poor tender structure, and unanswered questions from officials not empowered to make technical decisions. That’s where Deltool’s Pro-Tender™ service steps in.
With Deltool’s active involvement in the renewable energy sector, we help clients set up clear, compliant, and technically sound tenders. By asking the right questions and listening with the right ear, Deltool accurately captures the client’s true needs within legal and regulatory frameworks.
Our team assists from concept to completion, offering:
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Expert tender drafting and evaluation
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Project management oversight from planning to commissioning
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Guidance on financial models, including rental, term, and ownership options
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Objective candidate selection, ensuring the best partner is appointed
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Independence — Deltool refrains from installation when providing this service, ensuring total impartiality
💡 Typical professional fee: 2–4% of total project value (depending on scope and complexity), or a flat consulting rate starting from R8,500.
Pro-Install
Installation, Technical Authority & Commissioning
Deltool operates as a solar consulting, supply, and commissioning partner. We do not perform physical installations directly. This ensures clients have an experienced technical authority on their side, regardless of who performs the installation.
Deltool’s Role
Deltool provides:
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System design and technical consultation
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Optional electrical-use analysis
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Specification of approved equipment and a full Bill of Materials (BOM)
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A Project Scope Document defining system intent and requirements
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Technical guidance to the installer (Deltool-approved partner or client-appointed installer)
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System inspection, commissioning, and final verification
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Equipment registration, app setup, and client handover training
Roof-structure engineering certification and SSEG applications can be facilitated but remain the responsibility of the client to approve and obtain where required.
Installation Responsibility
The physical installation is performed by:
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A Deltool-approved partner installer, or
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An installer appointed directly by the client
The installer is contracted and paid separately by the client at fair and approved rates, including all labour and consumables.
The installer is fully responsible for:
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Workmanship and on-site safety
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Compliance with applicable electrical and safety standards
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Issuing a valid Certificate of Compliance (CoC) for all work performed
Warranty & Sign-Off
Deltool acts as the technical authority for supplied equipment.
Commissioning and warranty sign-off are conditional on:
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Receipt of a valid CoC from the installer
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Compliance with manufacturer requirements
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Compliance with Deltool technical specifications
Deltool reserves the right to withhold commissioning and warranty sign-off if discrepancies or non-compliance are identified.
Support & Aftercare
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The installer provides first-line technical support related to installation and workmanship.
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Deltool provides support related to supplied equipment, configuration, and manufacturer liaison.
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Optional post-installation check-ins and maintenance support can be arranged by agreement.
