Solar inverters

The solar inverter is the heart of any photovoltaic system: it converts the direct current generated by the panels into 230V alternating current, which is the type of electricity used by the appliances in your home, your van or your industrial unit. Choosing the right inverter determines the system’s performance, its reliability and, above all, how much you’ll be able to expand it in the future.

What is a solar inverter and how does it work?
The panels produce direct current at a voltage that varies with radiation and temperature. The inverter takes this current and converts it into a sinusoidal alternating current at 230V and 50 Hz. In a modern system, it also performs three further functions: it identifies the panels’ maximum power point using MPPT tracking, synchronises the output with the grid where one is available, and manages the charging and discharging of the batteries if the system has them.
That is why the rated power is not the only figure that matters. A 3000W inverter that cannot start a pump motor is worse than a 2000W one with good peak capacity. A pure sine wave, as opposed to a modified sine wave, is essential for electronics, motors and compressor-driven domestic appliances.

The three types of solar inverters
Grid-connected or self-consumption inverters: connected to the grid, without batteries. They supply the household’s electricity needs and feed the surplus into the grid. They are the most efficient and the most cost-effective per kW installed. We are Fronius System Partner and Official Service in Spain.
Off-grid inverters/chargers: for off-grid installations or those with an unstable mains supply. They incorporate an inverter, a charger and an automatic transfer switch. The Victron MultiPlus and Quattro ranges cover capacities from 500VA to 20,000VA in 12V, 24V y 48V, and they can be connected in parallel and in a three-phase configuration.
Hybrid inverters: They combine self-consumption with the grid and storage in a single unit. This is the cleanest option if you’re going to install batteries from the outset, as it avoids duplicating electronics.
If you’re simply looking to convert 12V to 220V in a van or on a boat, without solar panels or a charger, the category you’re looking for is 12V to 220V inverters, also available at 24V y 48V.

What inverter power rating do I need?
Power is calculated based on the maximum simultaneous consumption, not on the total of everything you have plugged in. Make a list of everything that might be running at the same time during the busiest part of the day and allow for start-up peaks.
As a practical guide: a 3000W inverter is suitable for a small home or a holiday home with basic appliances and no heavy loads. A 5000W inverter is the standard for a main residence with an induction hob or heat pump. From 10.000W We’re talking about large premises, three-phase systems or commercial use, where the issue is usually resolved by connecting several units in parallel rather than using a single unit.
The system voltage is linked to the power output: 12V up to around 2000W, 24V up to 3000W, and 48V above that. Increasing the voltage reduces the current and, with it, the cable cross-section and power losses – something you can check in our cable cross-section calculator.

Hybrid inverter or grid-connected inverter
If you’re certain you’re going to install batteries, a hybrid system works out cheaper and is neater than a grid-tied inverter to which you’d later have to add a storage system. If, for the time being, you just want to reduce your bill but haven’t ruled out batteries in a few years’ time, a high-quality grid-tied inverter with a MultiPlus-II Adding it later is a perfectly valid approach and allows you to scale without having to discard anything.
In both cases, you’ll need to keep track of what comes in and goes out of the house: that’s what the energy meters and the systems for monitoring such as the Cerbo GX, which also allow you to view the system remotely.

Which brand of solar inverter should I choose?
There is no single answer, but there are criteria that matter more than price: the availability of spare parts, the quality of the firmware, technical support in Spain and the ability to integrate with third-party batteries.
We work mainly with Victron Energy in the off-grid, campervan and boating sectors, where its ecosystem is hard to match in terms of flexibility and documentation, and with Fronius in grid-connected self-consumption, where the fact that they are manufactured in Europe and their service network make all the difference when something goes wrong. We have direct agreements with both manufacturers and hold stock, rather than simply acting as a distributor.

We’ll help you choose before you buy
We stock solar inverters for all voltages and power ratings, ranging from 12V to 220V inverters for a van to high-power three-phase systems for industrial use. If you’re unsure which model is right for your installation, or would like us to review a diagram before you make a purchase, our technical equipment We offer free advice. Items in stock with delivery within 24–48 hours.