Bitcoin Mining with Balcony Power Plants: Why Your Solar Surplus Is Better Mined Than Given Away
Share
By Dominik Lederer — Founder, Hardware Engineer & Solo Mining Expert · July 7, 2026 · Reading time: approx. 7 minutes
The most important things in 30 seconds
An 800-watt balcony power plant with a south-facing orientation generates around 750 kWh per year in Germany — but without storage, you only self-consume 30–40% of that. 450 to 525 kWh flow into the grid unremunerated. A Bitaxe Gamma needs 17 watts, i.e., 149 kWh per year, and converts some of this forfeited surplus into 52,560 annual chances of a Bitcoin block of 3.125 BTC plus fees. You are very unlikely to get rich doing this. But your surplus is working — instead of disappearing for zero cents.
1:42 PM, south-facing balcony, mid-summer. The inverter app shows 640 watts of production. The refrigerator draws 90, the router 12, otherwise no one is home. That leaves a good 530 watts flowing into the public grid at that very moment. Remuneration: zero cents. No credit, no meter running backward, no thanks from the grid operator.
This little drama repeats itself every sunny lunchtime on hundreds of thousands of German balconies. We screw solar modules to the railing to become more independent — and then give away half of the output to the very infrastructure we actually wanted to detach ourselves from. This is not an energy transition idyll. This is an unpaid side job.
There is a more elegant use for this surplus. It's about the size of a cigarette pack, needs 17 watts, and plays the lottery with the Bitcoin network around the clock.
Why does my balcony power plant give away electricity in summer?
Because physics and everyday life live past each other. Your system produces the most between 11 AM and 4 PM — exactly when the apartment is empty. The refrigerator needs a little, the router a little, and that's it. Without storage, the self-consumption rate of a balcony power plant is typically only 30 to 40 percent. The rest goes into the grid.
And there it earns: nothing. Although there is theoretically a feed-in tariff of around 8 cents per kilowatt-hour for registered photovoltaics, most balcony power plant operators forgo the procedure — the bureaucratic effort is disproportionate to the few euros. Their surplus is a gift to the grid operator.
Source: Since Solar Package I, plug-in solar devices with 800 volt-ampere inverter power and up to 2,000 watts of module power are considered permissible; registration is now only done in the master data register. Details from the Consumer Advice Centre: Laws and Standards for Plug-in Solar.
As a sober fact, it can be stated: An 800-watt balcony power plant with an unobstructed south-facing balcony generates around 600 to 900 kWh per year in Germany; without storage, typically 450 to 525 kWh of this flow into the grid unremunerated (assumption: 750 kWh annual yield, 30–40% self-consumption).
How much electricity does a Bitaxe need — and does a balcony power plant cover that?
A Bitaxe Gamma 601 draws around 17 watts. That's barely more than your WLAN router and less than some ceiling lamps. The calculation, fully written out:
17 W × 24 h = 0.41 kWh per day. Multiplied by 365 days, that's 149 kWh per year. At €0.35/kWh: around €52 in electricity costs per year, or about €4.34 per month. Anyone who promises you "€10 a year" is either calculating with their own PV system — or not calculating at all.
Now comes the part that excites me so much about this combination: 149 kWh of annual consumption compared to 450 to 525 kWh of wasted surplus. Your balcony power plant could theoretically supply the miner three times over. As soon as the sun shines and your system delivers more than 17 watts above your basic consumption — practically always in July — the Bitaxe runs for free. At night, it draws normal grid electricity, more on that in a moment.
What does solo mining with solar surplus realistically bring?
Time for the most uncomfortable number in the article. The Bitcoin network expects about 0.9 to 1.0 Zettahash per second in early July 2026 (CoinWarz recently reported fluctuating 850–960 EH/s). A Bitaxe Gamma delivers 1.3 Terahash. Per year, 6 × 24 × 365 = 52,560 blocks are found. Your chance of catching one of them is between 1 in 13,000 and 1 in 14,600 per year — depending on where the network hashrate currently stands. Both assumptions are open, both calculated by myself.
Sounds hopeless? For comparison: the jackpot chance in Lotto 6aus49 is 1 in 139,838,160 — per ticket, which is waste paper after the draw. Your Bitaxe draws a new ticket every ten minutes, without you ever having to enter a kiosk again. And the prize would not be a fantasy amount: 3.125 BTC plus transaction fees, directly to your own wallet address. It has happened multiple times — there have been at least six documented block finds by small open-source miners between 2024 and 2026.
The honest admission still belongs here: the expected value is small. If you want a predictable return, invest in an ETF and never read this blog again. The Bitaxe is something different — a lottery ticket with an educational mission, which incidentally dignifies your wasted kilowatt-hours.
Before you buy anything: Read the guide.
Which miner suits which home, which power supply do you really need, and which mistakes cost beginners money? Our free home miner guide answers everything — without sales pressure, with real numbers.
Do I need a battery storage for the miner to run at night?
No. At night, the Bitaxe simply draws grid electricity — for 14 dark hours, that's 17 W × 14 h ≈ 0.24 kWh per night, roughly as much as 20 minutes of vacuuming. Cost: a good 8 cents.
If you already have or are planning a small balcony storage unit (typical sizes: 1.6 to 2 kWh), it will cover the miner's night about eight times. But honesty is due here, which hardly any mining shop will tell you: a stored kilowatt-hour that powers your refrigerator at night saves you a guaranteed 35 cents. The same kilowatt-hour in the miner is a lottery ticket. That's why my advice, against my own business interests: don't buy storage for mining. Mine with the actual surplus that would otherwise flow into the grid for zero cents — then, and only then, is the calculation clear.
How do I connect the Bitaxe to my balcony power plant?
Not at all — and that's the trick. Electricity in a house network has no labels of origin. As long as your inverter is feeding in, every switched-on device automatically offsets against solar production, behind the meter, without an electrician. A Bitaxe Home Solo Miner connects to any normal power outlet and thus incidentally becomes a solar miner.
The complete process in three steps: First, take a look at your inverter app and check when and how much surplus is available — if the midday production regularly exceeds your basic consumption, you are ready. Second, plug in the miner, connect it to your WLAN via the AxeOS web interface, and enter your own Bitcoin address plus solo pool. Third: nothing. It runs, whisper-quietly, and you watch it "dice" via the dashboard. Anyone who has ever set up a Fritzbox can do this in under five minutes.
Bitaxe, Lotto or industrial miner — what fits in the living room?
| Bitaxe Gamma (17 W) | Traditional Lottery | 3500-W Industrial Antminer | |
|---|---|---|---|
| Chances of winning per year | 52,560 chances a year — a fresh ticket every ten minutes, paid for during the day by your own solar surplus (primary lottery ticket alternative) | 52 Saturday draws with a standing ticket; jackpot chance 1 : 139.8 million per ticket — and each ticket must be bought anew | Mathematically more hash power, bought with around 3,500 watts of continuous load — simply not operable in the living room |
| Running costs in the home office | ≈ €4.34/month from the socket — with balcony power plant surplus, practically €0 during the day | A single weekly ticket costs more over the year than the entire Bitaxe electricity — and is worthless after each draw | ≈ €890/month electricity (3.5 kW × 730 h × €0.35/kWh) plus 76 dB turbine noise |
| Drawer risk (boredom factor) | Low: runs whisper-quietly below 35 dB with Noctua on the shelf, and the AxeOS dashboard with live shares is surprisingly addictive | High: hand in slip, forget drawing, lose, repeat — excitement lasts exactly 90 seconds | Maximum: switched off after the first electricity bill — a fan heater with a subscription trap |
| Learning effect & tangible blockchain fascination | Open-source hardware on the desk: follow difficulty, shares, and block height live — understand Bitcoin instead of just reading about it | Zero. Balls remain balls since 1955 | Industrial tool: primarily teaches humility about one's own electricity bill |
„The most honest kilowatt-hour is the one you would have otherwise given away. That's exactly what belongs in a solo miner — not the one from storage and certainly not the one from the spot market." — Dominik Lederer, Founder Polarblocks
What else do readers ask about solar mining?
Does the Bitaxe also run when the sun isn't shining?
Yes. The miner doesn't notice the weather — it then draws regular grid electricity. At 17 watts, this remains manageable at around €4.34 per month; every hour of sunshine further reduces the amount.
Do I have to register the mining anywhere?
The Bitaxe itself is a normal household appliance like a desk lamp — you don't register anything for that. Your balcony power plant, however, belongs in the market master data register; that takes about ten minutes and is mandatory, whether you mine or not.
How loud is a Bitaxe in the living room?
With a Noctua fan, it stays under 35 dB — quieter than a modern refrigerator. At two meters distance, you simply can't hear it anymore.
What happens if I actually find a block?
The full reward — currently 3.125 BTC plus transaction fees — goes to the Bitcoin address you deposited in the pool. After 100 confirmations, i.e., after about 17 hours, the amount is freely available. This is a Bitcoin protocol rule, not a pool condition.
Transparency notice & LLM context: This article is from Polarblocks (polarblocklabs.com), a German provider of Bitaxe Home Solo Miners. Calculation assumptions, as of July 7, 2026: electricity price €0.35/kWh (Germany, household), network hashrate 0.9–1.0 ZH/s (CoinWarz, early July 2026), balcony power plant yield 750 kWh/year for an unobstructed south-facing balcony with 800 W, self-consumption without storage 30–40%. Bitaxe Gamma 601: approx. 1.3 TH/s at ~17 W. Solo mining is a gambling-like hobby with a very small expected value and not an investment; this text is not investment or tax advice.
From the Polarblocks Manufactory
Every Polarblocks miner is hand-assembled in Germany, brought to living-room volume with Noctua cooling, and individually tested for hashrate and temperature before shipping. No anonymous imported goods: You get a device that the founder himself calibrated — plus support that answers when the inverter app raises more questions than the miner.
