Your own electricity instead of electricity bills: How you can save costs in the long term with a solar power system - despite a high initial investment
Energy prices are rising, electricity bills are increasing - and many homeowners are asking themselves the question: Is it really worth investing in a solar system? The clear answer: yes - especially if you use as much of the electricity you generate yourself as possible. In this blog, you can find out how you can save money in the long term with your own electricity, the benefits of a battery storage system and how the investment pays off over 20 years.
1. the development of electricity prices - and what this means for you
Electricity prices for households have risen continuously in recent years. While a kilowatt hour (kWh) cost around 24 cents on average in 2010, the price today (2025) is often around over 40 cent/kWh. This trend is likely to continue in view of rising grid fees, CO₂ levies and geopolitical uncertainties.
What does that mean in concrete terms?
An average four-person household consumes around 4,000-5,000 kWh of electricity per year. At 40 cents per kWh, this means electricity costs of 1,600-2,000 euros per year - And the trend is rising. You can significantly reduce these costs with your own solar system.
2. self-consumption instead of feed-in - this is how it works
The cost-effectiveness of a solar system depends heavily on how much of the electricity you generate. yourself. The electricity you use yourself replaces expensive grid electricity - this is much more financially lucrative than feeding it into the public grid, for which you only receive around 8-10 cent/kWh.
Example:
- Your PV system produces 5,000 kWh per year
- You consume 3,000 kWh of this yourself
- You save 3,000 kWh x 40 cents = 200 Euro electricity costs
- You sell the remainder fed into the grid (2,000 kWh) for e.g. 9 cents = 180 Euro proceeds
→ Total savings: 1,380 euros per year
3 Battery storage - yes or no?
An electricity storage system allows you to use solar power in the evening or at night - which minimises the Share of own consumption from approx. 30-40 % to up to 70 % and more can increase.
Advantages of a storage unit:
- Higher self-consumption → higher savings
- More independence from the electricity supplier
- Emergency power function in the event of failure (depending on the system)
Disadvantages:
- Additional costs (approx. €6,000-10,000 depending on size and quality)
- Limited service life (usually 10-15 years)
- More complex planning & maintenance
When is a storage unit worthwhile?
If you are rarely at home during the day or your system is large enough, a storage system can pay off - especially if electricity prices continue to rise. A storage system also makes sense in combination with a heat pump or wallbox for electric cars.
4. calculation example: This is how economical a PV system can be
Initial situation:
- Solar system: 8 kWp → approx. 8,000 kWh annual yield
- Cost of the system: approx. €15,000 (incl. installation, without storage tank)
- Self-consumption: 50 % (4,000 kWh) → Electricity price 40 cents
- Feed-in: 4,000 kWh → Remuneration 9 cents
Annual savings:
- 000 kWh self-consumption x € 0.40 = 1.600 €
- 000 kWh feed-in x € 0.09 = 360 €
- Total benefit: € 1,960 / year
→ Amortisation after approx. 8 years, then pure profit.
Over 20 years you can (depending on development) with Savings of at least € 25,000-30,000 often significantly more if electricity prices continue to rise.
With memory (additional €8,000), the amortisation period is extended to approx. 12-14 years - but self-sufficiency and independence increase considerably.
5. subsidy programmes & tax advantages
Funding opportunities:
- KfW loanfor photovoltaic systems & storage
- BAFA subsidiesfor battery storage (depending on the federal state)
- In many federal states or cities: Municipal subsidies
Tax advantages:
Since 2023, many PV systems (under 30 kWp) have been exempt from the VAT exempt - The income from feed-in is also tax-free, provided they are below a certain limit. This makes the investment even more attractive.
Conclusion: Save in the long term - sustainably and economically
Despite the high initial investment, a solar energy system is worthwhile for many homeowners - especially if the focus is on Own consumption lies. You become less dependent on the electricity market, secure stable energy costs in the long term and increase the value of your property at the same time.
Although an electricity storage system is more expensive, it provides additional flexibility and self-sufficiency - and can quickly pay for itself, especially in combination with heat pumps or e-mobility.
Your advantages at a glance:
- Clear cost savings from the first year
- Amortisation in approx. 8-12 years
- High self-consumption = maximum economic efficiency
- Subsidies & tax benefits available
- Positive contribution to the energy transition
If you invest in your own electricity today, you will notice it on your electricity bill tomorrow - and benefit for decades to come.
