N, N-1 and ALO: The Letters in Your Grid Permit That Decide Your Revenue

When an investor opens the ATR (Aviz Tehnic de Racordare, the technical grid connection permit) of a Romanian project, the first number they look for is the approved capacity. It makes sense. But the capacity alone does not tell you how much energy you will actually sell. For that, you have to read the conditions, and three terms appear there again and again: N, N-1 and ALO.

N describes the normal state of the grid, with every line and transformer in service. When the ATR says the plant can export its full power "in N", it means that on a normal day, with the network intact, nothing stands between your plant and the market.

N-1 describes what happens when one element of the grid is out of service, for example a line under maintenance or a transformer that has tripped. Grid operators must keep the system safe in that situation, so the ATR may say that in N-1 your plant has to reduce its output to a lower value, or even stop. In other words, the full capacity is guaranteed only while the grid is complete.

ALO (Automatizare de Limitare Operațională, operational limitation automation) is the equipment that makes this work in practice. It is installed at the connection point, watches the state of the network, and automatically limits or disconnects the plant when a grid element is overloaded. Its purpose is positive: it allows projects to connect where the grid is tight, instead of waiting years for reinforcement works.

So is an N-1 limitation or an ALO condition a problem? Not necessarily. Many solid projects in Romania carry them, and in many cases the hours affected each year are limited. But "not necessarily" is not the same as "not at all", and this is where I see investors make two opposite mistakes. Some ignore these conditions and build a financial model on full export every hour of the year. Others see "N-1" in the permit and walk away from a perfectly good asset.

The right approach is to quantify. Before signing anything, I would want clear answers to a few questions. What is the exact limit in N-1, and does it apply to the full capacity or only above a certain level? Which grid elements trigger it, and how often are they typically out of service? Is the limitation permanent, or only until a planned reinforcement is completed? And for ALO, who pays for the equipment, and how fast does it act?

Storage changes this conversation in an interesting way. A BESS (Battery Energy Storage System) next to a solar or wind plant can absorb energy during a limitation instead of losing it, and release it once the grid is back to normal. A condition that costs a standalone plant revenue can become much less painful in a hybrid project.

At BRES ENERGY, every project we present comes with these conditions already read, explained and reflected in the financial model. An investor should never discover an N-1 limitation in the middle of due diligence. It should be on the table from the first conversation, with a number next to it.

Grid permits in Romania are not just administrative paper. They are the rules your revenue will live by for the next twenty-five years. Read the letters, not only the megawatts.