Electrical capacity: induction, heat pump and EV charging in one home

What power does a home with induction, a heat pump and an EV charger need?

A flat with induction, a heat pump and a home charger needs, in practice, 15 to 20 kW installed, with real simultaneous demand of about 10 to 12 kW, well above the 5 to 9 kW of an older flat. Power is sized before design: it decides cable sections, the board, the supply type and the timeline.

The test is what runs together in the heaviest hour. In the evening that is induction, oven, dishwasher, air conditioning and the car charging. That is why, in a luxury renovation, the conversation about power starts with the first sketch of the kitchen and the plant room, not when the site manager opens the board and finds an old 25 A double-pole breaker.

How do you work out the power you need before renovating?

List the appliances with their power and apply a diversity factor. Appliance power comes from the data sheet, and the designer chooses the factor: for cooking it is lower than for lighting. Practical guides: an induction hob up to 7 kW at peak, an oven 2 to 3 kW, dishwasher and washing machine around 2 kW each, air conditioning 1 to 1.5 kW per split, an electric water heater 1.5 to 2 kW.

Endesa, in its guide to power, gives typical figures: a home EV charger draws about 7.4 kW, a heat pump can exceed 5 kW on start-up, and the deciding factor is not the size of the house but which appliances run at once. You cannot simply add every figure: you get 25 kW on paper that never happens together. Nor can you undersize: the main breaker would trip at every dinner party. The low-voltage regulations set minimums for housing of roughly 5.75 kW for basic and 9.2 kW for elevated electrification. A luxury home normally plans above the elevated level.

Is three-phase supply possible in a flat?

It is possible, but not always. A single-phase supply to a dwelling tops out at about 14.5 kW (14,490 W at 230 V). If you need more, you move to three-phase. But the connection of a flat is not up to you, it depends on the building: you need a three-phase riser (columna montante), the comunidad's consent to run or replace the line, and technical conditions from the distributor.

In old Eixample buildings the riser is often single-phase with a small cable section. Replacing it in an occupied building means opening up the stairwell and approving it at an owners' meeting. So the first step is to ask the distributor (in Barcelona, usually e-distribución) and the building administrator what is at the entrance and what maximum you can get. If three-phase is not feasible, the load management described below helps. A villa is simpler: the supply is its own, and a three-phase connection of 20 to 25 kW for a house with a pool and two electric cars is almost normal.

How long does it take to increase the power?

From a few days, if only the contract and the breaker change, to several months if work on the network is needed: new cable, a transformer upgrade, permits. No exact figure is possible: the timeline is set by the distributor, not by the contractor or the electricity retailer.

To avoid losing time, the application goes in at the start of the project, not before handover. The installing electrician signs it after the boletín eléctrico (CIE). Equipment is ordered while approval is pending. If the power is raised at the end of the works but the board and lines were already sized for it, move-in is not delayed; if the board was built for the old supply, walls will have to be opened. During the works a temporary connection of lower power is often enough.

What should the electrical board look like, and what should it keep in reserve?

The board is built with 25 to 30% spare modules and separate lines for the big loads: induction, oven, heat pump, charger, pool and air conditioning. Each line has its own breaker and residual-current protection, and the cable section is calculated from length and power. For induction a 6 mm² cable is typical, and the charger gets its own line from the board.

Add surge protection and, in a villa, a sub-board in the plant room or beside the pool. The board sits somewhere accessible, clearly labelled and in view, so a line can be cut quickly. In a flat with home automation the controller is installed next to the board and manages the loads, so its space is reserved from the start.

What is load balancing and why do you need it?

It is a system that watches total consumption and cuts power to secondary loads when the supply nears its limit. A current clamp on the incoming line passes data to the charger or controller. The induction hob, oven and kettle switch on, and the car charger lowers its current by itself without tripping the breaker. When the peak passes, it returns to full power.

For the home it is a saving: you can keep the contracted power below the sum of all appliances and not pay for a peak that rarely happens. Set priorities: kitchen and climate first, then charging and pool heating. Peaks are smoothed with no human involvement. The one catch is that it has to be configured and tested, by switching on two or three loads manually and watching how the system reacts.

How does BCN YARD build power sizing into a renovation?

We calculate the load at the sketch stage, starting from the equipment list, heat pump data, number of cars and plans for a pool and climate control. From that we prepare the board diagram, the application to the distributor and the sequence of works. We run the project in Russian and Spanish, with one person responsible. If you need an estimate, send us the floor plan and the equipment list and we will answer within an hour.