For a small business, solar is not a hobby but a tool to cut energy costs. A good investment starts with knowing exactly when and how much electricity the company uses, because generation is only worth a lot if you consume it on site.
1. Load profile: the foundation
Ask your utility for quarter-hourly (profile) metering data covering at least one full year. It shows the daytime base load, any weekend consumption and the peaks. An office, a workshop and a cold store need very different sizing. If most consumption happens during the day, a system can reach 70-90 percent self-consumption, which is the single biggest factor in payback.
2. System size and grid conditions
The household-scale small power plant category (HMKE) applies below 50 kVA. Above that, the grid connection procedure is stricter, the permitting under MEKH, the utility and MAVIR rules takes longer, and connection fees differ. For many SMEs it is worth checking whether a well-sized system under 50 kW gives the best ratio. Since net metering ended, energy fed back to the grid is sold under gross settlement at a lower price, so overproduction is worth less than it used to be.
3. Choosing the inverter
For three-phase, larger systems, the Fronius Tauro and the Huawei SUN2000 50-100 KTL series are proven choices. The Tauro is robust and outdoor-rated, and grid services such as reactive power and power limiting are easy to handle. The Huawei is highly efficient, its multiple MPPT inputs suit complex roofs, and smart I-V curve diagnostics help with troubleshooting. With both, proper monitoring and grid-protection settings matter.
4. Payback, tax, grants
- Payback: with good self-consumption typically 4-7 years, depending on price, roof and load. Always ask for a sensitivity calculation on electricity prices.
- Tax: the investment can be depreciated; discuss details with your accountant, including the VAT treatment of business use.
- Grants: corporate energy and GINOP-type funds open from time to time. Do not sign a contract before applying, as a started investment can disqualify you.
5. Roof, structure, installation
The roof load capacity, the condition of the covering and fire-safety requirements must be checked. On flat roofs an east-west layout gives a flatter daily output curve, which suits many businesses better than a south-facing array. Do not install panels on an old roof that is due for renovation.
6. What to ask for in a quote
- A monthly production simulation that accounts for orientation and shading.
- Self-consumption and payback calculations using your actual profile.
- Product and performance warranties, plus the installer warranty period.
- Who handles the paperwork (connection request, commissioning) and how long it takes.
SolarBay engineers design from your profile data and handle the whole process, from permitting to commissioning.
Typical SME mistakes
The most common mistake is oversizing: the company fills the entire roof while daytime consumption absorbs less than half of production. Another is that quotes show only total generation, not self-consumption. Compare quotes using the same assumptions (electricity price, degradation, annual yield). Finally, do not skip the utility consultation: the capacity of the connection point and the transformer can cap system size, and this should surface at the very start of design.
