Off the Grid, On the Mountain: How the Energy System Works
Photovoltaics on the roof, up to 60 kWh of batteries in the basement, and heat pumps instead of a boiler. How a 600+ m² house at 897 meters can run on sunlight it collects above the clouds.
Why Energy Independence Matters at 897 Meters
A large house needs a lot of energy. A large glass house on a mountain, where winters are real and the grid is not always reliable, needs a plan for that energy that goes beyond "connect it and hope."
At Vkushty we treated energy the way we treated the water line: as core infrastructure, designed in from the start rather than bolted on. The goal is a home that is cheap to run, comfortable in every season, and as independent from the grid as a permanently-occupied family house can reasonably be.
The Stack
Three systems do the work, and they're designed to work together:
- Photovoltaic panels on the roof. House #3's structure was deliberately over-engineered — additional structural reinforcement — specifically so the roof could carry a full photovoltaic array. That's a decision made in the foundations, not an afterthought on the shingles.
- Battery storage of up to 60 kWh. Solar power is only useful when you can keep it. A battery bank of this size stores the day's production so the house runs on its own sunlight into the evening and through the night.
- Samsung heat pumps driving underfloor heating on every level. A heat pump doesn't burn anything — it moves heat, delivering roughly three to four units of warmth for every unit of electricity. Pair that electricity with your own solar and battery, and heating cost falls dramatically.
There's no gas boiler at the heart of this house, and no radiators. Warmth comes up through the floors, quietly, from electricity the house would rather generate than buy.
A Winter Day and a Summer Day
In summer, the roof produces far more than the house needs during daylight. The battery fills, the pool pump and cooling run on sunshine, and the surplus is there for the evening. Long days and a high sun make this the easy season.
In winter — and this is the part unique to the location — the house sits above Sofia's smog inversion. On the many days when the city below is trapped under grey cloud, Vkushty is in direct sun. A rooftop array up here collects light that panels down in the valley simply don't see. Winter production is lower than summer everywhere, but at 897 meters it's meaningfully better than the smog line allows below.
The battery smooths the rest: store when the sun is up, draw down after dark, lean on the grid only when a run of bad weather demands it.
What It Costs to Run
The honest framing is this. A conventional 600+ m² house heated by gas or direct electricity, with a pool, is expensive to run — the kind of monthly bill that makes people hesitate about large homes at all. The Vkushty approach attacks that bill from three directions at once:
- Generate your own power from the roof.
- Store it so you actually use what you generate.
- Heat with pumps that turn one unit of energy into three or four of warmth, through floors fed by that stored solar power.
The upfront investment is real. The payoff is a large house whose running costs behave more like those of a well-built small one — and a home that keeps its lights, heat, and water working when the grid down the mountain has a bad night.
The Quiet Part
There's a lifestyle dividend that doesn't show up on a bill. No fuel deliveries. No boiler to service. No radiators taking up wall space under the windows. Just even, silent warmth underfoot, air handled by central ventilation with filtration, and a roof quietly turning the mountain sun into the energy that runs the house.
Energy independence at altitude isn't a gadget. It's the same idea as everything else at Vkushty: build the invisible parts properly, and the visible life on top of them gets easier.