Photovoltaics: understanding self-consumption and injection

How to reduce your electricity bill when you have photovoltaic panels? How is electricity injected into the network paid for, and how does this vary? Is it normal to receive a bill for the electricity injected? In this article, we answer all your questions and help you maximise your savings.

Installing photovoltaic panels on the roof of your home offers many advantages. Most of all, producing electricity from solar energy allows you to reduce your electricity bill. The energy produced from your panels can be consumed directly to meet the needs of your home. Any surplus electricity produced will then be reinjected into the network for a fee.

As a result, many customers ask us how electricity injection rates are set. There are a few key details you need to know. In this article, we explain how pricing works and, above all, how to reduce your electricity bill as much as possible.

Investment aid and injection rates

In Luxembourg, homeowners can benefit from grants for the installation of photovoltaic panels on their homes. These investment aids have also largely contributed to the development of domestic electricity production systems in recent years.

It is important to clarify that the level of aid depends on a choice made from the outset by the person opting to install the panels. There are two options to choose from:

20% investment aid and injection rate guaranteed by the State

If you opt for aid limited to 20% of the investment in the system, you can benefit from an injection rate guaranteed by the State for 15 years for the electricity injected into the network. In 2025, this rate will be between 0.1374 euro/kWh and 0.1291 euro/kWh, depending on the power of the domestic system.

50% investment aid and variable injection rate

If you wish to benefit from a 50% investment aid, you must then waive the guaranteed injection rate and enter into a purchase agreement with a supplier for the electricity fed into the network. In this case, the injection rate is variable and will depend on developments in the electricity market.

Enovos offers you two variable injection rate options, based on the market price: dynamic solar and MW Solar. These rates are multiplied by a correction factor which takes into account the risks linked to forecasts and balanced energy costs. Fixed fees set by the supplier are also applied to your monthly bill.

Table of historical values ​​of the variable injection rate (0.8 X MW Solar)

To reduce your bills as much as possible, choose self-consumption

By installing photovoltaic panels, it is therefore in your interest to consume as much of the energy produced by your panels as possible directly within your home. 

You can also share the energy you produce by joining an energy community as a producer member. This way, members of the same community will be able to benefit from the energy you don’t consume at an attractive rate, and you will be able to maximise the value of your production.

It is worth remembering that photovoltaic panels only produce electricity during sunlight hours – the clearer the sky, the greater the production.

Run your appliances while your panels are producing

In order to maximise the consumption of energy produced by your panels, it is recommended to run your appliances, such as your washing machine, dryer or dishwasher, when the sun is shining. Where possible, people should also try to recharge their electric car during the day.

Choose a domestic battery for electricity storage

Installing a battery is an interesting solution. This allows you to store the energy produced by the photovoltaic panels during the day and redistribute it when you need it.

Why am I sometimes charged a fee for the energy injected?

Some customers may be surprised to occasionally receive bills to pay for the injection of energy into the network – this is easily explained.

At certain times of the year, photovoltaic panels produce less due to gloomy weather conditions. Under these conditions, it occurs that the remuneration linked to low electricity production does not cover the fixed costs associated with injection. This is all the more common if the owner has sought to maximise self-consumption, intending to minimise the volume of electricity injected into the network.

An attractive solution overall

While it may be surprising to find yourself being charged for the electricity injected, it should not be forgotten that self-consumption has allowed you to make substantial savings on the energy consumed from the network. As an owner of photovoltaic panels, this therefore remains a significant advantage.