Virtual battery and solar self-consumption: what it is, how it works, and how it helps you save

Virtual photovoltaic batteries are here to stay! Currently, virtual batteries are making their way into the photovoltaic self-consumption market as a much more practical alternative with which to store the surplus energy produced by the solar panels at your house. Since they are virtual, they offer a wide range of advantages such as: no space is needed, a factor that can be decisive when considering the installation of storage batteries; save on maintenance costs, since they are virtual and you don't have to worry about any physical element; and they offer you total freedom to decide if they are the most appropriate service for the characteristics of your home.

What is a virtual battery?

A virtual battery is a service that converts the surplus solar energy you export to the grid into a financial balance that you can use to pay your electricity bills. It does not store physical energy as a traditional battery would; instead, it stores the monetary value of the energy you haven't consumed at the moment of generation.

In practice, it works like a digital pot where the value generated by your exports accumulates. This balance has no capacity limit, does not expire, and can be used on subsequent bills or whenever it suits you best, allowing you to use 100% of your solar production.

How the virtual battery works in a self-consumption installation

Although it may sound technical, the operation of a virtual battery is very intuitive. In fact, it follows the same journey your solar installation already takes but adds a final step that allows you to make much better use of your surplus energy. To understand it clearly, we can divide the process into four phases:

From solar generation to consumption and surplus

During daylight hours, your solar panels produce electricity continuously. The first thing your installation does is cover your home's immediate consumption: appliances, lighting, heating and cooling... everything running at that moment.

If at any instant your panels produce more energy than you are using, that difference becomes surplus. This is common when you are away from home, when consumption is low, or when solar production is particularly high.

From solar surplus to grid export and conversion into credit

In a self-consumption installation with surplus, that excess energy is automatically sent to the electricity grid. This is where the virtual battery comes into play.

Instead of limiting itself to compensating for those exports only until your monthly consumption is matched (as happens with traditional compensation), the virtual battery converts all exported energy into a financial balance, applying the applicable compensation price.

In practice:

• Every kWh you export is transformed into money.
• That amount is saved in your virtual pot.
• It doesn't matter if you have generated more than you consumed: everything is credited.

Applying the balance to your monthly bill

When your bill arrives, the virtual battery uses the accumulated balance to reduce the amount you have to pay.

If you have generated a significant amount during the sunniest months (spring and summer), that balance can help you offset the months when your installation produces less (autumn and winter). The result is a more stable and predictable bill throughout the year.

Furthermore, this process is completely automatic: you don't have to do anything. The balance is applied month by month until it is exhausted.

What happens if there is leftover balance (accumulation, limitations)

This is where the virtual battery makes a huge difference compared to traditional surplus compensation.

With classic compensation, you are only paid for exports up to the limit of your consumption for that month. If you produce more than you consume, that energy is simply lost.

With the virtual battery, exactly the opposite happens:

• The balance does not expire.
• There is no monthly compensation limit.
• You can accumulate it indefinitely.
• You can use it when it suits you best.

In summary, with the virtual battery, no surplus is lost, and everything is transformed into real savings.

How a virtual battery differs from a physical one

Although they share a name, a virtual battery and a physical battery fulfil very different functions within a self-consumption installation. A physical battery stores actual energy in your home using equipment installed alongside the solar panels. The virtual battery, conversely, does not store kWh, but the economic value of the exports to the grid, which you can later use to reduce your bills.

The key difference lies in where that surplus is kept and how you can take advantage of it:

Physical battery

• Stores energy in your home to use when there is no sun.
• Has a limited capacity (kWh), defined by the size of the equipment.
• Requires installation, space, and maintenance.
• Involves a high initial investment.
• Offers energy autonomy, but only until the available capacity runs out.

Virtual battery

• Stores value in currency, not in kWh. Converts your exports into a financial balance.
• Has no capacity limit: you can accumulate as much as your panels generate.
• Requires no installation or additional equipment.
• The balance does not expire and can be used on future bills.
• Allows you to use 100% of surplus energy, even that exceeding your monthly consumption.

In other words, the physical battery gives you energy autonomy, while the virtual battery gives you economic autonomy. Both can coexist and complement each other, but each responds to different needs within solar self-consumption.

Advantages of using a virtual battery

The virtual battery offers a simple and efficient way to make the most of your self-consumption installation. These are its main advantages:

• You use 100% of your solar energy. No surplus is lost: everything is transformed into a financial balance that you can use on your bills.
• You reduce your bills directly. The accumulated balance is automatically deducted month by month, helping you balance your energy spending throughout the year.
• Requires no installation or maintenance. It is a digital service: you do not need additional equipment, building works, or space in your home.
• Allows accumulating balance for months of higher consumption. What you generate in the sunniest months can help offset winter months or periods of higher demand.
• Ideal for second homes. If your holiday home generates surpluses when you are not there, that balance can be applied to the bills of your main residence.
• Compatible with physical batteries. Both solutions can coexist: the physical battery stores energy, and the virtual one captures the surpluses that exceed its capacity.
• No capacity limit or balance expiration. You can accumulate as much as your panels generate, for as long as you need.
• Credits exports even when they exceed your monthly consumption. Unlike traditional compensation, the virtual battery pays for all your exports, without limits.

Limitations or aspects to consider

The virtual battery offers many advantages, but it is also useful to know its limits to have realistic expectations and assess if it fits your consumption profile:

• It is not physical storage. It does not allow you to use solar energy at night as you would with a physical battery, because it does not store kWh, only their economic value.
• The balance cannot be withdrawn as cash. The accumulated amount can only be applied to reduce your electricity bills.
• There may be accumulation limits depending on the supplier. Although many virtual batteries have no expiry or cap, some suppliers may establish a maximum balance or specific usage conditions.
• Depends on your tariff. To work, you need a tariff compatible with self-consumption and export compensation.
• The balance only applies to your consumption. If you generate much more than you consume over long periods, part of the balance may take time to be applied, especially in homes with very low consumption.

How much can you save with a virtual battery?

The savings you can achieve with a virtual battery depend on how much you export and your monthly consumption, but in most cases, it represents a significant reduction in the bill. In correctly sized systems, many households manage to cover between 30% and 70% of the annual energy cost thanks to the accumulated balance.

Some common examples:

• Homes with good orientation and moderate consumption usually save between €150 and €300 per year.
• Households with high generation and low daytime demand can effectively offset almost all spring and summer bills.
• Second homes, where significant surplus is generated when the property is empty, can use that balance to cover a good part of the main home's expenses.

Ultimately, the virtual battery converts your solar exports into real, tangible savings, month after month.

In which cases is the virtual battery most worthwhile?

The virtual battery is particularly interesting for specific usage profiles and property types. These are the scenarios where you can get the most out of it:

• Homes that generate more energy than they consume during the day. If your installation habitually produces a surplus, the virtual battery allows you to use it 100%.
• Households with high nocturnal consumption. In these cases, a physical battery may not cover all sunless hours, while the virtual battery helps you offset that expense with the accumulated balance.
• Second homes. When the house is empty, significant surpluses are generated which can be used to reduce the bills of the main residence.
• Installations without a physical battery. If you don't have a storage system, the excess energy would be lost or compensated at a very low price. The virtual battery allows you to monetise it much better.
• Users looking to save without investing in additional equipment. It is a digital solution, without building works or maintenance, ideal for those who want to maximise the value of their installation without adding costs.

The virtual battery pays off especially when your installation produces more energy than you consume, and you want to transform that export into real savings without the need to install physical equipment.

Is it compatible with a physical battery?

Yes, the virtual battery is totally compatible with a physical battery. In fact, both solutions can complement each other to make the most of the energy your solar panels generate.

• The physical battery stores real energy to use when there is no sun, reducing the amount of electricity you need to buy from the grid.
• The virtual battery captures the surpluses that do not fit in the physical battery and converts them into a financial balance that you can apply to your bills.

This combination allows for almost total utilisation of the generated energy, especially in larger installations or homes with variable consumption throughout the day.

How to sign up for or activate a virtual battery

Activating a virtual battery is a simple process and requires no building works or the installation of any additional equipment. To start using it, you just need to follow these steps:

• Have a self-consumption installation that generates surpluses. It is essential that your system exports the energy you export at the moment to the grid.
• Have a tariff compatible with surplus compensation and virtual battery. This type of tariff allows you to transform your exports into a financial balance.
• Request service activation. You can do this from your customer area, the app, or through customer service.

Once activated, the virtual battery starts generating credit automatically every time your panels produce more energy than you consume. From that moment on, you will only have to consult your accumulated balance and see how it is applied to your bills month by month.

If you want to take the step and start making the most of your solar surplus, you can consult the complete Endesa Solar Plus with Virtual Battery solution.

Endesa Solar Plus with Virtual Battery is a self-consumption tariff that converts all your solar exports into a financial balance. That balance is applied directly to your bills, potentially leaving them at €0, without the need to install additional equipment. It is an option designed for those who generate significant surplus and want to maximise their savings simply.