Yes, not only can you generate your own electricity, but it is even encouraged, as long as it is generated from renewable sources.
However, this should be done under certain conditions which are explained below.
For photovoltaic power installations to be installed on the roof of a residential house, there are generally no particular constraints. However, a building permit or permission from the municipality may be required. Check with your local authority before starting your project. Restrictions may apply to listed buildings (cultural or historical heritage).
Other types of power installations are also possible (e.g. mini wind turbines), but are subject to more restrictive conditions due to possible harmful effects.
Generally, from a technical and economic point of view, it is not feasible to install a power installation on a house that will meet consumption needs throughout the year. Therefore, it is better to connect the installation to the power supply network so that you can inject electricity into the network when you are producing surplus electricity and withdraw electricity when there is insufficient production to cover your consumption.
Firstly, the network operator should be contacted to find out about any capacity restrictions in its electricity network. Contact your network operator, either yourself or through your electrician, to find out about available capacity. Note that the network operator must not refuse to connect a renewable electricity generation facility, but in cases where the network needs to be reinforced, you may be charged for the costs involved and the work may take time and delay your project.
Note also that injecting electricity into the network is only possible with a feed-in contract with the network operator or a purchasing agreement with a supplier of your choice. If there is no contract, you will not be authorised to inject electricity into the network. Indeed, any injection must be associated with a balance perimeter administered by a Balance Responsible Party (which is generally an electricity supplier).
You should therefore conclude:
- a) either a feed-in contract with the network operator, whereby the remuneration is guaranteed on the basis of a regulated price for 15 years from the first injection. For more information on investment subsidies and regulated feed-in tariffs, please consult the Klima-Agence web pages (https://www.klima-agence.lu/fr/avantages-production-electricite)
- b) or an electricity take-back contract which suppliers are free to offer. This is a traditional commercial contract whereby the supplier buys the electricity produced directly from the producer at a price freely discussed between the parties.
Option a) is only available for newly built power plants if they have not benefited from the 50% investment aid scheme introduced by the Grand-Ducal Regulation of 7 April 2022; while option b) is, in principle, always possible (i.e. also for existing power plants).
Option a) must be selected before the plant is commissioned. It is not possible to select this option after the plant has been commissioned or to return after having left it.
When installing a generation plant, you can opt for full injection or self-consumption. Self-consumption is always possible, regardless of the type of contract concluded.
In the case of self-consumption, the network operator will calculate the net values (corrected after deduction of self-consumed quantities) of injection and withdrawal from the public network for each quarter hour. Your supplier will therefore not bill you on the basis of your total consumption, but will use the “corrected” withdrawal data and the “corrected” injection data for billing.
Therefore the electricity that is consumed remains “local” and is not charged; it is not subject to any network charges, fees or taxes.
In general, but even more so in times of high energy market prices, in most cases it makes financial sense to install a PV plant and to shift your consumption to the production hours of the plant as much as possible, i.e. when the sun is shining.
In order to increase the share of self-consumed electricity, it is possible to add a local battery to store the excess energy produced, thereby increasing autonomy by storing the energy produced for later consumption, instead of feeding it into the network.
However, in order to become completely independent in the event of a power failure, one would need to install a high capacity battery that is able to cover power requirements for the envisaged period. This does not preclude the possibility for a system that can continue to meet needs even in the event of a power cut, within the limits of the quantities stored using the battery. However, the economic profitability of this type of installation must be assessed on a case-by-case basis. For more information on financial aid and subsidy schemes, visit the “Klima Agence” website www.klima-agence.lu.
The network operators’ technical connection conditions provide connection diagrams, as well as the necessary protective devices for the different cases. Technically, the connection is done in the same way, whether for total injection or for self-consumption.