Photovoltaics: Feed into the Grid or Use It Yourself?
2025-04-17
If you're generating solar power with a photovoltaic system, you essentially have two options: feed the electricity into the public grid and receive compensation, or use it directly in your own home. Both approaches have their advantages and trade-offs. This article outlines the key considerations to help you decide which strategy best fits your household or investment goals.
What is Self-Consumption?
Photovoltaic (PV) systems convert sunlight into electricity. Homeowners with a PV installation generate their own solar power — typically from the rooftop. This energy can be used immediately for household needs such as lighting, appliances, or heating. Any surplus electricity can be fed into the grid, a process commonly referred to as "solar feed-in."
Historically, the focus was on feeding as much solar energy into the grid as possible, taking advantage of government feed-in tariffs. However, as energy market dynamics shift, maximising self-consumption is now the more profitable option in most scenarios.
With self-consumption, you save the difference between the retail electricity price and your cost of producing solar power — which makes a significant financial impact, especially as grid prices continue to rise. Although the updated Renewable Energy Act (EEG 2023) introduces new incentives for full feed-in, self-consumption generally remains more beneficial.
Why Prioritise Self-Consumption?
Two main reasons:
Feed-in tariffs have decreased steadily in recent years. Although EEG 2023 temporarily halts this trend, self-consumption is still more cost-effective in most cases.
Grid electricity prices are rising – increasing the savings from every kilowatt-hour you use yourself.
Self-Consumption vs. Grid Feed-In: What Pays Off More?
For most residential PV systems, the more electricity you consume on-site, the better your return on investment. Every kWh you don’t have to purchase from your utility saves you money — in Germany, that was around €0.46/kWh in the first half of 2023.
That said, larger rooftop systems can still benefit from partial or full feed-in, especially if installation costs scale efficiently.
Note: Residential systems up to 30 kWp benefit from simplified regulations.
How Much Power Can You Feed into the Grid?
Previously, systems were capped at feeding in 70% of their output. This restriction no longer applies to new installations (as of 2023), meaning full feed-in is now permitted. Older systems must be retrofitted with a smart meter for expanded feed-in options, though systems under 7 kWp are generally exempt from this limitation.
How Much Solar Power Can I Use Myself?
You can use all the solar electricity you produce. There's no cap on self-consumption. The more solar energy you consume directly, the less you rely on grid electricity — significantly reducing your overall energy costs.
Adding a battery storage system greatly improves the effectiveness of self-consumption. Batteries allow you to store surplus solar power for later use — such as in the evening or during cloudy periods. This boosts your energy independence and enables charging electric vehicles or powering heat pumps with clean energy from your own roof.
Feed-in Tariff: Secure Income for 20 Years
Feed-in tariffs are fixed payments for solar power exported to the grid, introduced under the EEG 2000 law to promote clean energy expansion. In addition to the tariffs, grid operators are required by law to accept your solar electricity — ensuring the system’s output is utilized.
As of 2023, the compensation rates for new PV installations are as follows:
8.2 cents/kWh for systems up to 10 kWp
7.1 cents/kWh for systems up to 40 kWp
5.8 cents/kWh for systems up to 100 kWp
If you install a 20 kWp system, the first 10 kWp earns 8.2 cents, and the rest earns 7.1 cents per kilowatt-hour fed into the grid.
✅ Tip: Feed-in tariffs are guaranteed for 20 years. However, tariffs are expected to fall after 2024 — so it pays to act quickly. Still, the greatest financial benefit lies in self-consumption, not feed-in.
Self-Consumption With and Without Battery Storage
Without Storage Only about 10–15% of your solar power can be consumed directly — especially if you're away during the day when the system is producing the most. Morning and evening are typically peak demand times for households.
With Storage Modern batteries allow you to store excess solar energy for later use. If sized correctly, up to 80% of your solar power can be self-consumed, according to energy consultant Klaus Mons of Stadtwerke Esslingen.
Electric vehicle (EV) charging and using a heat pump further increase self-consumption — allowing you to use more of your clean energy in-house.
Conclusion
Wherever possible, it's smart to use your solar energy directly at home. Adding a storage battery significantly increases your savings, and smart applications like EV charging and electric heating further optimize usage. While feeding into the grid remains necessary — especially for surplus energy — the highest financial and environmental return comes from maximising your self-consumption.
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