Home grower claims to produce 70% of vegetables for €2-4 per month

Home grower claims to produce 70% of their food at home for €2-4 per month in electricity

A forum user claims that a family of four can cover up to 70% of their annual vegetable consumption by growing at home. It sounds like a weekend utopia, but the figure comes with a method: two gardens, one outdoors in planters and another indoors with artificial light, which take turns producing so there are lettuces in July and tomatoes in January. The fine print is demanding: years of trial and error, a meticulously managed electricity tariff, and a significant amount of domestic space sacrificed.

How much does it cost to set up an urban garden and how much do you save?

The start-up is not cheap. Setting up the whole rig cost about €2,000, although whoever did it from scratch claims it would cost them a quarter of that today, "or less," now that they know what to buy and where. From then on, the expense is electricity: between €2 and €4 per month, according to their own calculation, to maintain heating in winter and air conditioning in summer for the plants. The key is not in the contracted power, but in when it is consumed: lighting is concentrated in off-peak hours, taking advantage of the cheapest times.

Not everyone agrees with that calculation. Some point out that in a Spanish city the price of water makes self-consumption an expensive hobby, and others demand an external audit that accounts for construction, maintenance, electricity consumption, and the usable square meters of housing that are lost. These are three items that rarely appear in harvest photos.

The indoor garden: LEDs, lux, and a bill that can be tamed

The heart of the system is the LED bulbs. Anything else, it is argued, is a fortune in consumption and doesn't work better. There is a figure that throws off any beginner: below 700 lux of red light—equivalent to 1,400 lux of white light—nothing grows, and at a distance of 50 centimeters, a decent spotlight reaches 5,000 lux. This is why 36W lamps, which actually consume 14W, are more cost-effective than 12W ones.

Heating determines whether the invention lives or dies. A poorly adjusted system used to consume 3,250 W per day, "completely prohibitive." After successive tests, the same function is now covered with 419 W over four hours—around €0.78 per month in off-peak hours—and a cold winter day ended with 713 W. These are figures from the author's own consumption meter, whose external audit is demanded by some participants.

Why does homegrown tomato taste better than supermarket tomato?

According to their explanation, what reaches the store are varieties selected to last on the shelf and withstand transport, not to taste good, and a large part is picked green to ripen later in gas-filled chambers. An old variety tomato, peine on the vine, is, in their opinion, something else entirely. The same is noted by another participant regarding fresh herbs, which are not exactly cheap at the supermarket.

The problems that don't show up in the photos

The list of complications is long. As recommended, new plants should undergo a month-long quarantine before entering the house, to rule out whiteflies, red spiders, and substrate insects: a plant protection product applied indoors is breathed by the whole family and can be lethal to a cat. Pets are a risk in themselves; some have seen their garden destroyed by two two-month-old cats and ended up installing a tiny electric fence. And someone logically asks if so many plants at night aren't altering the CO2 in the adjacent room.

Added to this is the mundane: leaving for a week in August leaves the watering unresolved, and the garden does not forgive. The two-garden system specifically aims to cover these gaps, not eliminate them.

The author himself warns of the system's dependence: if the electricity bonus disappears, he would probably remove the specific heating for the garden, although he would maintain the house temperature. In the meantime, he claims to have tomatoes, lettuce, lamb's lettuce, and peppers 365 days a year.