Watti

Detached houses & holiday homes

Store cheap electricity, save every day.

A home battery stores solar power or electricity from the cheapest spot-price hours for use when electricity is expensive. A home battery system improves your home's self-sufficiency and security of supply. With a backup power solution, you have electricity even during power cuts.

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Emaldo Power Core home battery

Four reasons

Why a home battery pays off

Lower electricity bills

Consumption shifts automatically from the most expensive hours to the cheapest. You don't change your daily routine; the system handles the timing.

Backup power during blackouts

The separately sold Backup Power unit switches the battery to supply electricity to selected household appliances during an outage. The backup power solution is ordered separately.

Make the most of solar panels

Surplus daytime production is stored for evening and morning consumption instead of being sold to the grid for pennies.

Reserve markets

The opportunity to earn monthly returns by selling electricity stored in your battery system.

Savings calculator

Calculate your savings

Estimated savings, reserve market earnings and payback period.

18 000 kWh

You can find this figure on your electricity bill or in your energy supplier’s online portal.

I already have solar panels

Solar panels already installed.

Is the property heated with electricity?

Heat pump, storage heating or direct electric heating.

Do you charge an electric vehicle at home?

Charging your car using your home’s electricity supply.

The guaranteed return depends on your electricity supplier.

Savings and returns estimate

Example calculation

Adjust your answers to see your personalised estimate.

TOTAL BENEFIT

1 834 € / year

Electricity bill savings

708 € / year

Reserve market earnings

1 126 € / year

Payback period

approx. 5,6 years

Our recommendation for your home

Emaldo Power Store

Connects to your existing solar PV system.

Recommended battery capacity 20,48 kWh

Request a quote based on your estimate

Savings are based on the average electricity price; guaranteed returns are based on the latest figures from Emaldo's Grid Rewards calculator (3 years, at least 3 batteries). A detailed calculation will be provided during the assessment.

November promotion

To celebrate the Watti.com relaunch, everyone who requests a home battery quote between 15.10 - 30.11. will be entered into a prize draw to win an ABOK Elux 1 portable power station, worth 595€ incl VAT.

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Watti.com's own installers fitting a home battery

  • Omat asentajat
  • Kotimainen asiakaspalvelu

Finance

From 160 €/month

Finance your home battery with instalment payments or lease your energy storage system, so you start saving immediately without tying up capital. Finance partners: Grenke Rahoitus Oy, Siemens Financial Services.

  • Hire purchase
  • Leasing
  • Commercial financing
Request a finance calculation

Omavarainen koti

All systems store solar power or cheap spot-price electricity for self-consumption during high-price hours.

Varavoima tarvittaessa

An optional Backup Power unit switches the battery to feed power to household devices during a power cut. Backup power is not included in the base package.

Simple to use

The battery decides for you: charging and discharging automatically whenever it is most cost-effective. Manage everything straight from the app.

Questions about home batteries?

Find answers to frequently asked questions about returns, backup power, installation and use.

Frequently asked questions

Three ways to get started

Choose the right Emaldo for your home

All models store solar energy or low-cost spot-price electricity for use during expensive hours. The right model depends on your home and energy needs.

Energy for your home, on your terms.

Emaldo Power Core home battery
Emaldo Power Core home battery

All in one package

Power Core

For homes that do not yet have solar panels

Power Core combines battery storage, inverter, solar PV connection, and EV charging into one sleek unit. A single installation visit, no extra cabling, and no separate charging station. Perfect for detached houses with a garden or carport.

  • Built-in EV charging — no separate charging station
  • Also works with an existing solar PV system
  • Effortless SlideOn installation and concealed cabling
  • Earning potential with the Grid Rewards programme
Request a quoteDownload brochure
Emaldo Power Store home battery

Most popular choice

Power Store

For homes that already have solar panels and an inverter

Power Store is an expandable home battery that connects to both new and existing solar PV systems. Smart control stores daytime solar power and uses it when electricity is at its most expensive.

  • Compatible with existing solar systems
  • Built-in safety and effortless SlideOn installation
  • Earning potential with the Grid Rewards programme
Request a quoteDownload brochure
Emaldo Power Sense home battery

Most powerful model

Power Sense

For homes seeking maximum power and the best earnings potential

Power Sense is Emaldo's newest and most powerful system. Power of up to 15 kW delivers the product family's best Grid Rewards earnings potential. It can be installed with an existing or new solar system — or completely without solar panels. Quiet operation and concealed cabling provide a sleek look and enhanced safety.

  • Backup power readiness with a separate backup unit and built-in DC switch
  • Compatible with existing systems
  • Effortless SlideOn installation, concealed cabling
Request a quoteDownload brochure
Emaldo Power Core home batteryPower Core expansion unit and additional batteries in the manufacturer's image

Room to grow

Battery capacity expandable up to 143,36 kWh

Start with a system that suits your home. Emaldo Power Core capacity can be expanded with additional batteries as your energy needs change. Additional batteries are sold separately.

Energenie AI

The battery makes decisions for you

The control system combines electricity prices, weather forecasts, your own generation and household consumption. The battery charges and discharges automatically when it delivers the greatest benefit.

Control via the app

Monitor generation, consumption and battery charge in real time.

Grows with your needs

Modular battery capacity can be expanded as your home's needs change.

Energenie app on a phone: solar, battery, grid and household consumption in real time
Energenie AI control unit

Energenie AI control unit

Smart battery control is part of the Emaldo system — decisions are based on your home's energy use and generation.

What does the solution include?

Save every day. Add more as needed.

Emaldo KeepON backup power unit

The Emaldo KeepON backup power unit is available as an optional addition to the system.

Core function

Every system stores solar electricity or low-cost spot-price electricity for use when electricity is expensive.

Backup power

Backup during power cuts requires a separately sold Backup Power unit. It switches the battery system to supply power to your home appliances. Backup power is not included in the basic package.

Internet connection

Internet access for the devices is ensured during installation. We recommend a separate wireless router. Watti can manage router maintenance and monitor the entire installation as a monthly subscription service.

Installed in homes

Part of your home and garden

The home battery can be installed indoors, for example in a garage, or outdoors beside a wall, such as on a terrace — installation is carried out by Watti.com's own installers or an installation partner.

Personalised quote

Request a quote for a home battery solution

Share your contact details and estimated electricity consumption. We will size an Emaldo system to suit your needs, calculate your savings and send you a quote — we will respond within a day.

18 000 kWh
1 000 kWh80 000 kWh
Property details

We only use your details to prepare your quote.

The basics

What is a home battery?

A home battery is a battery energy storage system installed in a detached house or holiday home that stores electricity from the grid or solar panels. It charges during cheap hours and discharges into the home during the most expensive ones, and with the Emaldo Grid Rewards programme, it also earns guaranteed income for three years – up to €90/month depending on the electricity supplier.

When is a home battery worthwhile?

  • You have a spot-price electricity contract or want to capitalise on hourly price fluctuations.
  • The property has electric heating, ground-source heat, an air-source heat pump or an electric vehicle.
  • The home has solar panels whose surplus is currently sold cheaply to the grid – or a home battery is installed without solar panels.
  • You want to prepare for power cuts with a backup power unit.

Sizing

What size home battery is needed for a detached house?

One Emaldo battery module is 5.12 kWh. A standard starting point is a three-battery package (15.36 kWh), which also qualifies for guaranteed Grid Rewards income. The savings calculator suggests a size based on your consumption.

  1. 1Annual consumption and heating method
  2. 2Electricity contract and supplier (affects Grid Rewards income)
  3. 3Solar panel capacity and current inverter
  4. 4EV charging and other heavy loads
  5. 5Need for backup power during a power cut

Price by tailored quote

The price of a home battery depends on the model, number of batteries and installation. The savings calculator shows the overall benefit, and you can get an exact price with a free quote request. Financing is available.

Frequently asked questions

Questions about energy storage

Is a home battery worthwhile without solar panels?

It can be. Spot-price price arbitrage and Grid Rewards income are also achieved without solar panels. Panels can always be added later.

Does a home battery work with spot-price electricity?

Yes. The system tracks hourly spot prices and automatically charges the battery during the cheapest hours.

How much does a home battery cost?

The price depends on the model, number of batteries and installation. Request a free quote to get a price and savings calculation for your home.

What is Emaldo Grid Rewards?

An agreement between Emaldo and electricity suppliers where you are paid a guaranteed return for your battery's flexibility over three years, up to €90/month. The guaranteed return requires at least a three-battery system.

Does a home battery work during a power cut?

Yes, when a backup power unit is added to the system. This keeps your home running when the grid is down.

Sources and updates

Content reviewed 28.10.2026. Market terms, tariffs and technical suitability are always checked for each site.

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