PV System for On-Site Electricity Generation

Roof-integrated or elevated PV system for on-site generation, with inverter and optional storage.

How does a PV system for self-supply work?

A photovoltaic system converts sunlight into direct current, and an inverter turns this into grid-compliant alternating current for the building. The electricity generated first covers the current on-site demand; the surplus is fed into the grid or charged into a battery. Per kilowatt peak (kWp) of installed capacity, a system in Austria delivers around 950 to 1,150 kWh per year, on average 1,050 kWh/(kWp·a) with a south-facing orientation and 30° tilt, and from 850 with a flat east-west layout. The decisive figure is the self-consumption rate: the share of PV electricity used directly in the building. Without storage it is 25 to 40 %, with a battery 50 to 80 %. PV electricity can be generated for 4 to 8 ct/kWh, well below the purchase price, so grid parity has long since been reached.

Which buildings benefit from photovoltaics?

The prerequisites are a suitable roof facing south, east or west, adequate structural capacity and little shading. The system must be registered with the grid operator, and larger systems require a meter change. Typical properties are detached and multi-family houses, office buildings, industrial halls and carports. Commercial businesses are particularly well suited, because their consumption occurs during the day, so self-consumption rates of 60 % and more are achievable without storage. Exclusion criteria are permanently shaded roofs or roofs that are structurally inadequate.

What does a PV system actually deliver?

Depending on the load profile, 30 to 70 % electricity self-supply is possible. Economically, self-consumption is what counts: every kWh used on site saves the purchase price of €0.20 to €0.30/kWh for households and €0.12 to €0.20/kWh for businesses, while feed-in only earns around €0.07/kWh. A 10 kWp system generates around 10,500 kWh/a, avoids 1,638 kg CO2 and yields around €1,400/a. Investment is €1,300 to €1,800/kWp for a detached house and €800 to €1,200/kWp for commercial systems above 50 kWp. Payback is 8 to 14 years, with a service life of 25 years.

Energy carrier

Strom (Netzbezug) → Solar (Eigenverbrauch)

Savings potential

30-70 % Strom-Eigenversorgung möglich

Worked example

A 10 kWp PV system is installed on a residential house, facing south with a specific yield of 1,050 kWh per kWp per year. Generation is therefore 10 × 1,050 = 10,500 kWh/a. Without storage, 35 % is consumed directly in the house, i.e. 3,675 kWh; the remaining 6,825 kWh is fed into the grid. The electricity purchase price is €0.25/kWh, the feed-in tariff €0.07/kWh. For self-consumption, the difference between the two prices is saved: 3,675 × (0.25 − 0.07) = €661. The entire generation is additionally valued at the feed-in tariff: 10,500 × 0.07 = €735. Together, this gives an economic benefit of €1,396/a, rounded to €1,400/a. Since the entire PV generation replaces grid electricity at 0.156 kg CO2/kWh, 10,500 × 0.156 = 1,638 kg CO2 per year is avoided.

Investment & payback

EFH (5-12 kWp): 1.300-1.800 €/kWp; gewerblich >50 kWp: 800-1.200 €/kWp; Speicher: 600-1.000 €/kWh · Service life: 25 a · Payback: 8-14 a

Applicability

Requirements

Exclusion criteria

Typical buildings

Frequently asked questions

How much electricity does a PV system generate per kWp in Austria?

In Austria, a PV system generates 950 to 1,150 kWh per kWp per year depending on location and orientation. With a south-facing orientation at 30° tilt, an average of 1,050 kWh/(kWp·a) is realistic; with a flat east-west layout around 850; with an optimal southern aspect up to 1,200. A 10 kWp system therefore delivers around 10,500 kWh per year.

What is the self-consumption rate and why does it matter so much?

The self-consumption rate is the share of generated PV electricity that is consumed directly in the building. It is 25 to 40 % without storage and 50 to 80 % with a battery. It determines the economics: electricity used on site saves the purchase price of €0.20 to €0.30/kWh, whereas exported electricity earns only around €0.07/kWh. Self-consumption is therefore worth roughly three times as much as feed-in.

Is a PV system worth it for commercial businesses?

Commercial businesses are usually the best PV sites, because their electricity consumption occurs during the day when the system is producing. Self-consumption rates of 60 % and more are achievable without storage. With specific costs of €800 to €1,200/kWp for systems above 50 kWp and purchase prices of €0.12 to €0.20/kWh, payback is typically at the lower end of the 8 to 14 year range.

How much does a 10 kWp PV system cost?

A PV system for a detached house with 5 to 12 kWp costs €1,300 to €1,800 per kWp, so a 10 kWp system costs around €13,000 to €18,000 including inverter and installation. A battery adds €600 to €1,000 per kWh of usable capacity. With a yield of around €1,400/a, the system pays back in 8 to 14 years over a 25-year service life.

How much CO2 does a PV system save in Austria?

Every PV kilowatt-hour generated replaces grid electricity at around 0.156 kg CO2/kWh based on the Austrian electricity mix (Umweltbundesamt 2024). A 10 kWp system with 10,500 kWh/a thus avoids around 1,638 kg CO2 per year. The upstream chain of the PV modules themselves accounts for around 40 g CO2/kWh and is already taken into account in this assessment.

Related measures

Standards & sources

Metering points in the EDM Toolbox

Wechselrichter haben fast immer Modbus TCP / SunSpec - direkter Anschluss EDM Toolbox. Wichtige KPIs: PV-Erzeugung, Eigenverbrauch, Netzeinspeisung, Eigenverbrauchsquote, spezifischer Ertrag pro kWp. Perfekt zur Optimierung mit Lastverschiebung.

All measures