The municipality of Gjorche Petrov will install photovoltaic systems on the roofs of all seven of its primary schools. The project is being delivered through a public-private partnership and, as Mayor Aleksandar Stojkoski puts it, is the first of its kind in Macedonia.

The key part of the arrangement: the municipality is not putting in any of its own money. The project carries no additional financial burden for the municipal budget, and Gjorche Petrov will receive 18 percent of the revenue generated from electricity production.

Eighteen percent - who does this split favour?

This is the part that deserves attention, and in the press releases it appears only as a positive-sounding number. The municipality provides the roofs of seven public buildings, built with citizens' money, and in return receives just under a fifth of the revenue. The private partner carries the risk and the investment, and keeps the rest.

Is 18 percent a good deal? The answer depends on things that have not been published: how many years the concession runs, who pays for the electricity the schools themselves consume, what happens to the equipment when the contract expires. Without those details, a percentage is just a percentage.

Stojkoski defends the model like this: "With this project we are putting school roofs to use, producing clean and renewable energy, creating more sustainable and energy-efficient schools, and securing a new source of revenue that will be reinvested into projects in the interest of citizens."

The idea is sound. The roofs of public buildings sitting empty under the Skopje sun are an obvious resource, and schools are ideal - they draw power at exactly the hours when the panels produce the most. If the model works, other municipalities will copy it, and that is the whole point of a pilot.

But when a municipality signs a contract that outlasts a single mayoral term, the full documentation should be public before it is signed, not after. That is not suspicion aimed at this project - it is the minimum standard for any public-private partnership.