Net metering and self-supply: how electricity is billed
Solar self-supply pays off when system size matches consumption and the billing rules. The biggest mistake is sizing the plant by roof area alone.
Quick answer
If you want a fast decision, start with annual consumption, the roof and the time of consumption. A solar plant is not best when it is largest, but when production matches the real daily life of the house.
What matters when choosing
Panels produce most during daytime and in summer, while a home often consumes in the evening and winter. So you need yearly data, not a single bill. Future loads matter too: a heat pump, EV, boiler or air conditioning.
A good solar project connects the roof, inverter, grid connection, optional storage and consumption habits. The goal is not just high production, but less unnecessary export, better self-use and a clear payback period.
Local example and price
A house consuming 8 MWh a year does not necessarily need the largest possible plant. If much energy is exported to the grid under poor terms, a smaller system, smart load control or a battery makes more sense.
For a house near Ljubljana the biggest challenge can be shading from neighbouring buildings, in Maribor the connection to a heat pump, in Koper cooling and humidity, and at a weekend house battery storage and remote monitoring.
Indicative pricing: the final price of a solar plant depends on size, roof, inverter, storage and connection. A 5-10 kWh battery can be a multi-thousand-euro item, so it should be budgeted separately. For subsidies and self-supply, always verify current conditions before ordering.
Prices are indicative and meant to speed up the decision before the site visit. For legal, subsidy or technical conditions, always check the current state before execution. In any offer it is useful to separate equipment, installation, app setup, additional licenses or subscriptions and future expansion. That way the client compares the whole result, not just the cheapest device.
When you compare two offers, compare the same line items: brand and equipment class, warranty, labour, materials, configuration, testing, post-installation support and future expansion. The cheapest offer is not necessarily bad, but it must be clear what is included and what will be charged extra.
Choice table and on-site visit
| Factor | Impact | What to do |
|---|---|---|
| Annual use | System size | Gather bills |
| Daily use | Self-use share | Shift loads |
| Shading | Losses | Roof survey |
| Battery | Evening / backup | Separate calc |
- power consumption for the last 12 months
- roof orientation and shading by season
- space for the inverter, protection and storage
- future loads such as a heat pump, EV or boiler
- current connection, netting and subsidy conditions
A site visit reveals the slope, orientation, shading, cable routing, inverter space and real connection limits. Without it, the calculation quickly becomes too optimistic.
Related solutions and sources
For solar plants see /solar, for smart consumption control /packages, and to protect a weekend house or carport also /cameras. Related topic: Solar power plant subsidies in Slovenia 2026.
- GOV.SI: renewable energy sources
- GOV.SI: solar energy in Slovenia 2026
- Borzen: subsidies for self-supply solar plants
Frequently asked questions
Is solar self-supply worth it?
It is worth it if the calculation shows a good ratio of consumption, roof, price and connection rules.
Do I need a battery?
Not always. A battery makes sense for evening consumption, backup or weaker conditions for exporting energy to the grid.
What should I check before ordering?
Annual consumption, roof, shading, inverter, connection and current subsidies.
Can I expand the system later?
Yes, if the architecture is chosen with spare capacity and compatible components.
Why is a site visit important?
Because real production and price only become clear after the roof, cables, shading and grid connection are checked.
Free on-site visit
To calculate the roof, system size and payback, book a free site visit: /contact.html.