How to legalize your solar system with the grid operator

A grid-connected system interacts with your operator's infrastructure. That is why the connection has to be authorised: it guarantees the safety of people and of the grid, the quality of the energy and that surplus is measured correctly.

There is a concrete safety reason behind it. If the grid goes down and a system keeps injecting energy, it can energise sections that technicians believe to be disconnected while working on them. Grid-tied inverters include a protection — known as anti-islanding — that shuts them down automatically during an outage, and verifying that this protection exists and works is one of the reasons the process exists.

Without this process you cannot export surplus or benefit from the net metering regulated by CREG Resolution 174 of 2021. Operating a connected system without legalizing it, besides denying you those benefits, can lead to safety and contractual problems with your operator.

The Colombian regulatory framework distinguishes different categories according to who generates, how much capacity they have and what they do with the energy. The one that applies to a home, a shop or a company installing panels for their own consumption is that of the small-scale self-generator, known by its Spanish acronym AGPE.

A self-generator produces energy mainly to cover its own consumption. It can export to the grid the energy it has spare at any given moment — the surplus — and receive an offset on its bill in return. That distinguishes it from a commercial generator, whose business is selling energy.

CREG Resolution 174 of 2021 is the regulation governing the connection and operation of these self-generators. It replaced CREG Resolution 030 of 2018, which many out-of-date pages on the internet still cite. The regulation sets capacity ranges with different requirements and procedures; which one applies to your project is determined by the design, and it is one of the first things the installer defines.

In practice, a serious installer handles or supports the whole process as part of their service: they prepare the technical documentation, file the application and coordinate the bidirectional meter installation with the operator.

So it is worth confirming, before signing, that the proposal explicitly includes legalization. It is one of the most common causes of cost surprises and delays when it turns out it 'was not included'.

Even when the installer handles it, you are the party to the process, because the service contract with the operator is in your name. That means you will have to sign documents and it is worth understanding where the process stands at any moment. Ask them to share the filing reference and the operator's correspondence with you.

The process combines technical documentation, review by the operator and the installation of a special meter. Broadly speaking, what comes into play is the system's electrical design, the protections that guarantee safe disconnection during faults, the equipment datasheets and evidence that the installation complies with electrical regulations.

That last point deserves attention. Every electrical installation in Colombia must comply with the Technical Regulation for Electrical Installations (RETIE), and the photovoltaic part is no exception. The corresponding certificate of conformity is one of the documents supporting the application, and obtaining it requires the installation to be well executed, not just well designed.

The specific grid operator defines the exact forms and requirements, which can vary from one company to another within the common regulatory framework. An installer with experience in your area knows those forms, and it shows in the total time the process takes.

A conventional meter counts the energy coming into your home. When you install a solar system that exports surplus, you need equipment capable of recording both directions separately: what you draw from the grid and what you send to it.

That is the bidirectional meter. The grid operator installs or enables it, and its reading is the basis on which the offset is settled on your bill. Without it there is no way of evidencing how much energy you exported.

The equipment and its installation may carry a cost, which varies by operator and by whether your current meter can be reprogrammed or has to be replaced. It is one of the items worth clarifying explicitly in the quote, because it sometimes falls outside the installer's scope and shows up later as an operator charge.

Net metering is not a cheque: it is an offsetting mechanism within your bill. During the day, when your system produces more than you consume, the difference is exported to the grid. At night, or during periods of low generation, you draw energy from the grid. At the end of the period the two amounts are netted off.

The regulation sets how the exported energy is valued, and that value need not match the tariff you pay to consume. It also treats surplus differently according to its size relative to your own consumption, which in practice penalises oversizing the system well above what you actually use.

The practical consequence is twofold. First, direct self-consumption — using the energy at the moment it is produced — is usually more valuable than exporting it, so shifting loads to daylight hours improves the economics. Second, sizing well above your own consumption gives diminishing returns. The specific offsetting terms are set by the regulation in force and are worth verifying with your installer and your operator before deciding the size.

Legalization is the stage of the project with the most variability. It depends on the operator's workload and on the documentation arriving complete and correct from the outset.

The most common delays come from incomplete documentation, designs that need adjusting after review, or the operator's scheduling for installing the meter. Every return restarts part of the clock, which is why an application well prepared on the first attempt saves weeks.

It is worth building this stage into the schedule from the start and not assuming the project ends when the panels are on the roof. An appreciable amount of time can pass between the physical installation and formal commissioning, during which the system should not be exporting energy to the grid.

An unlegalized system can technically work for self-consumption, but it leaves on the table the part of the benefit that depends on the grid and adds risks worth knowing about.

There is no surplus offsetting: all the energy you produce and do not consume at that instant is lost, because neither the meter nor the agreement that would evidence it exists. On a system sized to cover a good share of consumption, that loss is significant.

Moreover, exporting energy to the grid without authorisation poses a safety risk to the staff who operate the grid and can have contractual consequences with your operator. And if at some point you want to access the tax benefits of Laws 1715 of 2014 and 2099 of 2021, the formality of the project is part of what is assessed.

Before signing, these questions prevent most of the surprises at this stage.