Short answer: small-business solar should be designed around downtime cost as well as electricity cost. Keeping POS, card machines, Wi-Fi, CCTV, servers, fridges, lights and key equipment operating can protect revenue even when the grid fails. The system should then use daytime solar to reduce purchased electricity where the load profile supports it.
Which business loads should be backed up first?
| Business type | Critical loads | Secondary loads |
|---|---|---|
| Retail shop | POS, lighting, Wi-Fi, CCTV, alarms | Air conditioning, display loads |
| Office | Internet, laptops/desktops, server/network, lighting | Aircon, kitchen appliances |
| Butchery / food retail | Refrigeration, tills, security | Non-critical comfort loads |
| Salon | POS, lighting, selected tools | High-power heaters/dryers depending on design |
| Restaurant / takeaway | POS, refrigeration, extraction controls, lights | Large cooking equipment often needs separate planning |
| Warehouse | Security, office, selected lighting | Large motors and plant equipment |
Start with business continuity
Ask what stops the business from trading if power disappears for four hours. Those loads define the first backup layer. Then look at high-energy daytime loads that solar can offset economically.
Why solar is attractive for daytime businesses
Retail and office loads often overlap with daylight hours, so solar energy can be consumed directly instead of being stored and discharged later. This can improve the value of PV relative to a home that uses most energy after sunset.
Tariff pressure still matters even without load shedding
Eskom's 2026/27 average direct-customer tariff increase is 8.76%, while municipal bulk tariffs average 9.01%. Actual business tariffs vary by supply and municipality, but electricity remains a material operating cost. See Eskom's tariff notice.
Do not put refrigeration on an undersized inverter
Compressors can have starting current above normal running power. Use manufacturer data or measurements and leave enough inverter surge capacity. The same applies to pumps, workshop motors and some commercial appliances.
What about growth?
A business may add tills, refrigeration, air conditioning or another workstation next year. Choose an inverter/battery architecture with realistic expansion rather than sizing so tightly that every new appliance becomes a problem.
Current Whitehouse options
For smaller commercial loads, products such as the Luxpower SNA5000 5kVA Inverter + Wi-Fi can form part of a tailored design. Larger requirements may use platforms such as the Deye 8kW Hybrid Inverter or products sourced specifically for the business.
What should a business quote include?
- Trading hours and critical processes.
- List of equipment that cannot switch off.
- Motor/compressor startup loads.
- Monthly electricity bills and tariff.
- DB and supply phase.
- Roof/parking area available for PV.
- Required backup duration.
- Existing generator/UPS.
- Future expansion.
Three business continuity tiers
{tbl(["Tier","Typical backup","Commercial outcome"],[ ["Essential trading","POS, Wi-Fi, lights, CCTV, alarms","Keep taking payments and serving customers"], ["Operational","Above + selected refrigeration/IT/workstations","Continue normal core operations"], ["Full/near-full continuity","Above + cooling, machinery or high-power equipment","Higher capital requirement and detailed load study"] ])}Calculate downtime before calculating payback
If a shop loses R5,000 of gross margin during a four-hour outage, the value of backup is not captured by electricity savings alone. For a business, the economic case can include avoided lost sales, spoiled stock, idle staff and disrupted customer service. These values should be estimated conservatively but not ignored.
Use daytime load to your advantage
A business open from 08:00 to 17:00 often consumes electricity at the same time solar is producing. That can make additional PV attractive even if battery capacity is modest, because the energy is used directly instead of being stored first.
FAQ
Is solar only worthwhile when load shedding is active?
No. Businesses may value energy-cost reduction, resilience against local outages, power quality/continuity and predictable operating capability.
Can a business start with backup and add panels later?
Yes, if the selected inverter and installation are planned for future PV.
Can Whitehouse source larger commercial equipment?
Yes. Not every project product is kept online; larger systems can be sourced around the quote and design.
Get a tailored Whitehouse solar or backup-power quote
Whitehouse Lighting & Electrical can help you build a solution around your actual loads, budget, property and expansion plans. We do not rely only on the products shown online; where a project needs a different inverter size, battery bank, protection arrangement or commercial configuration, we can source around the brief.
We arrange solar and backup-power solutions for homes and businesses across South Africa, including Secunda, Ermelo, Mpumalanga, Mbombela/Nelspruit, Johannesburg, the East Rand, Pretoria, North West and Bloemfontein. Panels, batteries and other bulky equipment may need a dedicated delivery quotation depending on route and handling.
Important: this guide is for planning and buying decisions. Cable sizes, protection ratings, earthing, DB alterations, PV strings and final system settings must be confirmed for the actual installation by appropriately qualified persons and the relevant manufacturer documentation.
