Commercial solar depends on operating hours, load profile, roof or ground space and the cost of interruption. Start with the business solutions overview and build the enquiry around your numbers.
A small business solar project has to solve a business problem. That may be lost trading during outages, an electricity bill that keeps rising, diesel spend, or refrigeration and security loads that cannot be interrupted. Start there. The equipment comes later.
This guide is for owner-managed shops, restaurants, practices, guesthouses, workshops, offices and similar operations. If you are evaluating a larger site or need a formal investment case, begin with our commercial solar overview.
Key takeaways
Start with trading hours, electricity bills and the loads that cannot stop.
Separate bill savings, avoided downtime and tax effects. They are different parts of the business case.
A daytime-heavy business may get strong value from panels without buying a very large battery.
Compare funding by ownership, escalation, maintenance, exit terms and total paid, not only the first monthly amount.
A quote is still provisional until the provider has checked the load profile, site, supply and approval requirements.
Is your small business a good solar candidate?
Solar is worth investigating when at least one of these is true:
you use substantial electricity during daylight hours;
an outage stops sales, production, refrigeration, connectivity or security;
generator fuel and maintenance are becoming material costs;
you control the building or can obtain the owner's approval; or
the business expects to operate from the site long enough to recover the investment.
A high bill alone does not prove that a project will work. A bakery with early-morning ovens, a restaurant trading into the evening and an office open from 08:00 to 17:00 may have similar monthly bills but need very different systems.
Build the business case from three separate numbers
1. Electricity you can avoid buying
Panels generate during the day. The strongest savings usually come when the business can use that electricity as it is produced. Ask the provider to model monthly generation against your actual consumption pattern and tariff. Fixed network charges and other non-energy line items may remain even when grid consumption falls.
If you have interval data, use it. If not, provide 12 months of bills and explain your operating schedule, seasonal peaks, planned equipment and closure periods.
2. The cost of interruption
Bill savings do not capture lost card transactions, spoiled stock, cancelled appointments or idle staff. Estimate the contribution margin at risk during a typical interruption and the loads needed to keep trading. Do not add the full revenue number to the solar return. Use the margin or cost the system can reasonably protect.
Cash purchase, a business loan, asset finance and rent-to-own produce different cash-flow and ownership outcomes. Keep financing cost separate from electricity savings so the proposal can be tested when either assumption changes.
Use the commercial solar cost guide to build an installed budget from the site scope. The business solar finance comparison covers cash, bank finance, rent-to-own, leases and PPAs on the same ownership and total-cost basis. If the business is considering buying energy instead of owning the plant, the solar PPA guide explains the tariff, escalation, performance and exit clauses that need review.
Section 12B may also affect an ownership case. The current SARS guide to renewable-energy asset allowances says qualifying photovoltaic assets of 1 MW or less may be deducted at 100% of cost in the year they are first brought into use for the taxpayer's trade. Ownership, first use, qualifying cost and trade requirements matter. A rental or service arrangement may leave the allowance with the asset owner rather than your business.
The deduction reduces taxable income. It is not a cash rebate, and it does not rescue a weak project. Ask your tax practitioner to confirm eligibility and timing before the contract is signed.
Size the system around the operation
List the loads that must keep running
Separate loads into three groups:
Critical: refrigeration, tills, routers, alarms, access control or process equipment that cannot stop.
Useful: lighting, office plugs or selected appliances that support normal trading.
Deferrable: geysers, ovens, pumps or machinery that can be scheduled or isolated during an outage.
Record each item's running power, start-up surge and hours of use. Motors, compressors and pumps can demand much more power when they start than while they run.
Keep kW, kWh and kWp separate
Inverter power, measured in kW, limits how much equipment can run at once.
Battery energy, measured in kWh, affects how long the supported loads can run.
Panel capacity, measured in kWp, affects daytime generation.
A large inverter does not create longer battery runtime. A large battery does not guarantee enough inverter output for a motor start. A large panel array will not help during an outage if the design cannot operate safely when the grid is down.
Tell the provider about three-phase supply
Many commercial premises use three-phase power. Provide a recent bill, a photo of the main distribution board and details of any large motors or machinery. The provider must confirm phase balance, inverter arrangement and which circuits will receive backup.
What current commercial packages can tell you
Alumo currently publishes two commercial starting points on its business solar page:
Energy Efficiency: 50.05 kWp of panels and 120 kWh of battery storage, with the inverter sized in the proposal, from R18,000 per month on a seven-year rent-to-own route.
Business Powerhouse: 100.1 kWp of panels, a 125 kW inverter and 261 kWh of battery storage, from R34,000 per month on a seven-year rent-to-own route.
These figures were checked on 22 September 2026. They are provider-published starting points, not market averages or recommendations for every SME. Alumo's own calculator says its estimate is based on electricity usage and excludes pole fees and other additional costs. A smaller business may need a much smaller bespoke design.
18000R
34000R
Provider-published starting points checked 22 September 2026
Compare funding routes on the same page
Question
Cash or asset purchase
Business loan or asset finance
Rent-to-own
Who owns the system?
The business, subject to the purchase agreement
Confirm ownership and security terms
The provider or funder during the rental term
Upfront cash
Highest
Deposit and fees vary
Usually lower, but check initiation costs
Monthly commitment
None after purchase
Loan repayment
Rental payment, often with escalation
Maintenance
Business responsibility unless contracted
Usually business responsibility
May be included, subject to the agreement
Tax treatment
Ask the tax practitioner about the asset allowance
Depends on ownership and agreement
The asset owner may receive the allowance
Exit
The business can retain or sell the asset
Settlement terms apply
Buy-out, cancellation and end-of-term terms apply
Request the total paid under each route. Include escalation, fees, buy-out, insurance and maintenance. A low starting payment can still be the expensive option over seven years.
The electricity distributor sets the connection process. Municipal requirements are not identical, and an Eskom-supplied property follows Eskom's process. For example, the City of Cape Town requires authorisation for embedded generation in its electricity supply area and requires the relevant approval steps before the system is switched on.
Electrical work must also be properly certified. South Africa's Department of Employment and Labour advises customers to use legally registered electrical contractors and requires a valid Certificate of Compliance for an electrical installation. Confirm who will issue the certificate, who will submit the SSEG application and which documents you will receive at handover.
Tenants should obtain written landlord approval before spending money on design. The lease should also address roof rights, equipment ownership, reinstatement, access for maintenance and what happens when the tenancy ends.
Common mistakes
Buying from the monthly figure alone. Compare total paid, ownership, escalation and exit terms.
Sizing from the monthly bill alone. The bill does not show motor starts, trading hours or which circuits must survive an outage.
Treating avoided downtime as guaranteed savings. Use a defensible margin-at-risk estimate and record the assumptions.
Assuming the tax allowance belongs to the user. Ownership and agreement structure matter.
Leaving approvals until installation day. Ask for the connection and sign-off path in the proposal.
Choosing a battery before deciding what it must protect. Start with the critical-load list and required duration.
The practical next step
Prepare 12 months of bills, operating hours, critical loads, diesel spend, supply type and proof that you control the property. The commercial site assessment guide explains the interval data, electrical records, roof information and approval inputs to add. A provider can then screen the site and explain which information still needs logging or a technical visit.
The first proposal should make uncertainty visible. It should show what is measured, what is assumed and what will only be confirmed after assessment.
Frequently asked questions
How much does solar for a small business cost?
There is no reliable price from business type alone. Cost depends on the load profile, peak demand, panel area, battery requirement, supply configuration, switchgear, connection work and funding route. Use published packages as reference points only, then request a design based on the site.
Can a small business claim Section 12B?
Potentially. The SARS guide says qualifying photovoltaic assets of 1 MW or less may receive a 100% deduction in the year they are first brought into use for the taxpayer's trade. The business must satisfy the ownership, use and other requirements. Ask a tax practitioner to assess the proposed agreement before relying on the deduction.
Does a business always need a battery?
No. A daytime business focused on bill reduction may get better economics from grid-tied solar without a large battery. A battery becomes more important when continuity, peak management or evening operation is part of the job.
Do commercial solar systems need approval?
Grid-connected systems must follow the applicable distributor and municipal process. Requirements differ by supply area and system size. Put responsibility for applications, professional sign-off and handover documents into the contract.
Who supplies the quote through SolarGuide?
SolarGuide is an independent referral partner. Alumo provides its own assessment, design, finance terms, installation and warranties. Published prices are indicative and subject to site assessment, system design and credit approval.
SolarGuide is an independent referral partner. We help you compare options and arrange a free quote — Alumo supplies, installs, finances and warrants the systems. Pricing is indicative, sourced from Alumo’s published catalogue, and subject to a site assessment and credit approval.
