Photovoltaics cuts electricity costs through a simple mechanism: every kilowatt-hour you produce and consume yourself replaces an expensively bought-in one. The effect has three stages – the system itself, shifting consumption into the sunlight hours, and coupling large consumers like a heat pump and an electric car. Anyone who uses all three turns their electricity bill into a fraction of what it was; anyone who only builds the system gives away half the potential. (As of: July 2026)
Key points in brief
- The core mechanism: self-consumed solar power replaces the full grid purchase price – it's worth a multiple of the feed-in tariff.
- Stage 1 is the system itself; its size determines the potential.
- Stage 2 costs nothing: shifting consumption into the sunlight hours.
- Stage 3 is coupling: a heat pump and electric car turn solar power into heating warmth and mobility.
- The electricity bill won't disappear entirely – anyone who promises you that is calculating dishonestly.
How does a solar system cut electricity costs in the first place?
Through the difference between two prices. Electricity from the grid typically costs you 25 to 35 Rappen per kilowatt-hour depending on the utility and tariff – with everything that belongs to it: energy, grid usage, levies. Electricity from your own roof costs a fraction of that to produce. Every kilowatt-hour that you produce yourself and consume yourself at the moment of production replaces an expensive bought-in one with a cheap one of your own.
The emphasis is on «consume yourself» – and that's the point many underestimate. What you don't use yourself goes into the grid as surplus and only brings the feed-in tariff of typically 6 to 14 Rappen. The complete logic of this two-price world is explained in the article Self-consumption or feed-in; for electricity costs, in short it means: the system lowers the bill exactly to the extent that its electricity stays in the house.
This gives the structure of this article: the system is the prerequisite – but how much electricity costs really fall is decided by the stages after that.
The three stages: system, shifting, coupling
Stage 1: the system – the foundation. No production, no effect; the system size determines the potential. The fundamental questions – what it costs, what it produces, whether it pays off – are covered by the cost guide and the worth-it assessment. For the electricity-cost perspective, the core statement is enough: an appropriately sized system produces, over the year, roughly what a household consumes – the only question is how much of that is used at the same time.
Stage 2: shifting – the free lever. Without a single extra franc of investment, self-consumption rises when consumption moves into the sunlight hours: the washing machine, dishwasher and dryer run at midday instead of in the evening, the water heater heats up around noon. That sounds mundane and is the most underestimated item in the whole calculation – the specific steps for system owners are gathered in the article Optimising self-consumption.
Stage 3: coupling – the big chunks. The biggest electricity-cost effects arise when the household's large energy items move onto solar power: the heat pump turns sun power into heating warmth and hot water, the electric car fills up on the midday surplus instead of grid electricity or petrol. Both are separate investment decisions with their own guides – but anyone planning them anyway multiplies the value of the system.
| Stage | Measure | Costs | Effect on electricity costs |
|---|---|---|---|
| 1 | Build the system | Investment | Foundation — replaces grid purchase to the extent of self-consumption |
| 2 | Shift consumption | nothing | noticeably raises the self-consumption share |
| 3 | Couple heat pump/electric car | separate investments | largest absolute effects |
| (4) | Consider storage | Investment | shifts surplus into the evening — a matter of profile |
Simplified overview, as of: July 2026. The effect depends on consumption profile, tariff and system size – guideline values, not guarantees.
And the storage battery? It's deliberately the bracketed stage: it raises self-consumption further, but costs its own money – whether its contribution carries the investment is a matter of profile with its own calculation, not a given.
What's realistic – and what's salesperson's math?
The honest expectation: the electricity bill falls significantly, but it doesn't disappear. Even with a large system, you draw grid electricity at night and in winter – the idea of complete independence is a myth we address in the fact check. Realistically, depending on profile and how many stages you use, a substantial reduction in grid purchase is achievable – and in the financial calculation, the feed-in remuneration for the surplus comes on top.
How to recognise dishonest promises: percentage figures with no reference to a profile («save 80 percent!»), calculations that ignore base fees and winter purchase, and mixing up the feeling of self-sufficiency with the financial calculation. The transparent method – four figures, traceable arithmetic – is shown in the article on the profitability calculation: there you can see, down to the franc, how self-consumption and feed-in turn into the annual benefit.
For the sake of completeness, there's a truth that solar installers rarely say out loud: the cheapest kilowatt-hour remains the one not consumed. Efficient appliances and switching off things that run constantly lower the bill before any investment – the solar system then makes the best of the remaining consumption. Both together are the complete answer to high electricity costs.
The aha moment in electricity-cost consultations is almost always the same – and it comes at stage 2. Everyone knows the system produces electricity; that running the washing machine at midday makes the difference between 30 and 10 Rappen per kilowatt-hour surprises many people. We like to show this using the utility's annual bill: there's the grid purchase price in black and white, and next to it we put the feed-in tariff. These two figures explain the whole topic better than any brochure. Families in the Zurich region who use all three stages – system, shifting, heat pump or electric car – then experience their electricity bill as a different item afterwards: not zero, but a fraction of what neighbours without a system pay.
Frequently asked questions
By how much do my electricity costs fall with a solar system?
That depends on system size, consumption profile and your tariff – there are no reputable blanket figures. The mechanism is clear: every kilowatt-hour you consume yourself replaces the full grid purchase price, the surplus brings the feed-in remuneration. Using the calculation method from our profitability guide, you can determine your own order of magnitude.
Can I live entirely without an electricity bill with photovoltaics?
No – at night and in winter you draw grid electricity, and base fees remain in any case. Complete independence is a myth for a grid-connected single-family home. What's realistic and achievable is: significantly less grid purchase, plus feed-in income – the bill shrinks, it doesn't disappear.
What brings more: a storage battery or coupling the heat pump?
Usually coupling – it turns solar power directly into a large useful item (heat), while the storage battery only shifts it and costs its own money. The proven sequence: shift first (free), then couple large consumers, then check the storage question against your own profile.
Are the stages worthwhile with a small system too?
Yes – especially there: the tighter the production, the more important it is that it stays in the house instead of flowing into the grid for a few Rappen. Shifting costs nothing and works with any system size. The coupling question then depends on whether the system delivers enough surplus for a heat pump or car.
Does the system also lower the utility bill in an apartment building?
In an apartment building the effect runs via the ZEV: the residents buy solar power from the roof more cheaply than grid electricity – the mechanism is the same, organised through the shared billing. For tenants and condominium owners, we've described the paths in separate articles.
Free initial consultation
What your electricity bill can really give up
We work through the three stages for your house – system, shifting potential, coupling with a heat pump or electric car – with the tariff at your address instead of brochure figures.
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Sources: Tariff publications of the regional grid operators (purchase/feed-in), guideline values from the linked guides, experience from ecoEn GmbH's consulting practice, Zurich region.
Last updated: 9 July 2026 · Author: ecoEn editorial team
