Is it better to use surplus solar myself or feed it into the grid?

Use it yourself. Self-consumed solar replaces electricity you'd otherwise buy at the full grid price (~35 ct/kWh), while feed-in only earns a low tariff (~8 ct/kWh). Storing or shifting the surplus is worth the difference on every kWh.

Do I need a battery to use surplus solar power?

No. You can raise self-consumption without one by shifting appliances, EV charging, and hot-water heating into sunny hours. A battery adds the biggest jump — from about 30% to 70%+ self-consumption — but it's an addition, not a requirement.

How much can a home battery increase my self-consumption?

For a typical household, a battery can lift self-consumption from around 30% to 70% or more and raise self-sufficiency toward ~65%, because it stores midday surplus for evening use. The exact gain depends on system size and your load profile.

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How to Use Surplus Solar Power Instead of Feeding It Back

Stromfee Redaktion · 5. Juli 2026

Surplus solar power is the electricity your panels make at midday but your home doesn't use right then. The goal is to shift that energy to when you need it — because using it yourself is worth far more than the small feed-in payment.

The core problem in one line

Without extra measures, a typical 10 kWp household uses only about 30% of its own solar power directly. The other 70% is fed into the grid for a low tariff (roughly 8 ct/kWh), while in the evening you buy it back at around 35 ct/kWh. Every kWh you use yourself instead of exporting is worth the difference.

1. Store it in a battery (biggest lever)

A home battery charges from your midday surplus and discharges in the evening. This is the single most effective step: it can raise self-consumption from ~30% to 70%+. A common pairing is a 10 kWp PV system with a 10 kWh battery, which can also push energy self-sufficiency toward ~65%.

2. Shift your loads to midday

Run high-draw appliances while the sun is up: washing machine (~2.2 kW), dryer (~2.5 kW), dishwasher. A timer or a simple energy monitor lets you start them during peak solar hours so the surplus is consumed on the spot — no battery required.

3. Turn surplus into hot water or heat

Divert excess PV into a hot-water tank (via a heating element or heat pump) or run a heat pump during sunny hours. This stores solar energy as heat, which is cheap thermal storage compared with a battery and directly offsets gas or grid heating costs.

4. Charge your EV on solar

An EV is a large, flexible battery. Surplus-charging (PV-surplus / "solar" charging mode) only draws power the panels are actually exporting, so you fuel the car with electricity that would otherwise leave at the low feed-in rate.

5. Feed the rest into the grid

Whatever you can't store, shift, or charge should still be exported rather than curtailed — you receive the feed-in tariff for it. Treat feed-in as the last option, after self-use, because its value per kWh is the lowest.

🎬 Der Energie-Zähler

How to Use Surplus Solar Power Instead of Feeding It Back

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