How to Choose a Solar Power System for Your Home

You size a solar power system around your home’s annual electricity consumption: as a rough rule of thumb, you need about 1 kW of installed capacity for every 1,000 kWh you use per year. From there, you decide on the inverter type (grid-tie or hybrid) and whether you need a storage battery. Mounting position and orientation are best assessed with a specialist, since they determine how much the system actually produces.

Where to Start: Consumption and Power Output

Start by checking your electricity bills and finding your annual consumption in kilowatt-hours (kWh). That’s the single most important number for planning a system.

As a general rule for Lithuanian conditions: 1 kW of solar modules produces roughly 900–1,000 kWh per year. So if you use around 5,000 kWh a year, you’re looking at a system of roughly 5 kW. Most households need a system in the 5–10 kW range.

It’s worth factoring in future needs too. If you’re planning to buy an electric vehicle, install a heat pump, or add air conditioning, your consumption will rise — size the system with a margin if any of that is on the horizon.

Choosing an Inverter

The inverter converts the DC power your modules produce into the AC power your home’s appliances use. There are two main types:

• Grid-tie inverter — simpler and cheaper. Surplus energy goes to the grid, and you draw it back when you need it. Suitable if you’re not planning to add a battery.
• Hybrid inverter — works with both the grid and a storage battery. It costs more, but gives you flexibility, and is the logical choice if you want a battery now or later.

When choosing a brand (Deye, for example), look at whether its power rating matches your module output, the warranty terms, and how easy it is to get support in Lithuania.

Do You Need a Storage Battery?

A battery lets you use energy generated during the day in the evening or at night, and gives you backup power if the grid goes down (provided your inverter supports it). It does significantly increase the overall investment, though.

A battery pays off fastest if:

• a large share of your consumption happens in the evening, once the sun is down;
• you value having backup during short power cuts;
• your terms for exporting surplus to the grid make direct self-consumption more valuable than exporting it.

If most of your electricity use is during the day, or keeping the initial investment as low as possible matters most, it’s fine to skip the battery at first and choose a hybrid inverter that leaves you the option to add one later.

Installation and Position

System output depends heavily on roof orientation and pitch. The best output comes from south-facing roofs that aren’t shaded. East–west orientation also works, just with slightly lower annual output.

Shading matters too: even partial shade from trees or neighbouring buildings can meaningfully cut output. Modules can be mounted on a pitched or flat roof, or on the ground if you have the space.

Before installation, make sure your roof structure and covering are in good condition — modules are meant to run for decades, so it’s worth doing any roof repairs beforehand.

What to Choose: The Short Version

We don’t sell solar modules — you’ll buy those elsewhere. What we do stock is everything else the system is made of: the inverter, the storage battery, the controllers. And we’ll match an inverter to your modules’ output and wiring no matter where the panels came from.

• No battery, grid only — the grid-tie inverter Deye SUN-6K-G06P3-EU-BM2-P1, 6 kW, 599 €. The simplest and cheapest route when your surplus goes to the grid. For a smaller system there’s also the 4 kW version at 599 €.
• A battery now or later — the hybrid inverter Deye SUN-5K-SG05LP1-EU-AM2-PLUS, 999 €. It runs on the grid from day one and lets you connect storage whenever you decide to. The batteries themselves are in our storage section.
• An awkward or shaded roof — the microinverter Deye SUN800G3-EU-230, 249 €. Each module works on its own, so one panel in the shade doesn’t drag the whole string down with it. There’s also the SUN600G3-EU-230 at 209 €.

We currently have 44 hybrid inverters, 13 grid-tie inverters and 2 microinverters in stock, all Deye. If you’re not sure which one fits your consumption and your roof, send us your module output and your annual kWh figure and we’ll point you to a specific model.

Why buy from us: the price on the product page is the final price — we’re not VAT-registered, so no VAT is added on top. Delivery anywhere in Lithuania is free, within 14 days. Returns within 14 days, with the return shipping paid by us. Everything comes with the manufacturer’s warranty and CE conformity, and sizing advice before you buy is free.

Prices are current as of the day of publication.

Frequently Asked Questions

What size solar power system does a home need?

It depends on your annual consumption. A rough rule of thumb is 1 kW of capacity for every 1,000 kWh used per year. Most households need a system in the 5–10 kW range.

Do I have to buy a battery straight away?

No. With a hybrid inverter, you can add a battery later. If you use a lot of electricity in the evening, it pays off faster; if you mostly use power during the day, you can start without one.

How much does 1 kW of solar modules produce per year in Lithuania?

Roughly 900–1,000 kWh, depending on roof orientation, pitch and shading.