Solar energy for industry

In housing, average monthly consumption is enough to size a system. In industry that is insufficient and leads to expensive mistakes.

What determines the value of an industrial system is the overlap between the generation curve and the demand curve, hour by hour. A plant with three shifts, one with a single daytime shift and one with peaks concentrated first thing in the morning have very different returns with the same installed capacity.

That is why the first piece of a serious project is not a design but an analysis: an hourly consumption history, ideally covering a year, cross-referenced against the expected generation curve. That is what tells you which fraction is self-consumed, which is what is valued at the full tariff.

It is also worth looking at the demand-charge component of the bill, not only energy: for industrial users part of the cost depends on peak demand, and a solar system does not always reduce it if the peak falls outside daylight hours.

The Colombian framework distinguishes categories according to installed capacity and what is done with the energy. The small-scale self-generation that applies to a home or a shop is not necessarily the one that applies to a plant, and the threshold triggers different requirements, procedures and timelines.

Larger projects also bring in medium-voltage connection, the studies the grid operator requires and, depending on the case, coordination with the system operator. Determining which category applies is one of the first design tasks, and it shapes the entire schedule.

Do not extrapolate timelines or requirements from a residential project. Verify the framework in force for your capacity with the installer and with your operator before committing to commissioning dates.

Industrial scale usually enables an option that does not exist in housing: ground-mounted installation. Each alternative has its own balance.

The roof makes use of surface that is already occupied, does not consume productive land and shortens the electrical run to the point of consumption. In exchange it is constrained by structural capacity, by the remaining service life of the sheeting and by the difficulty of doing maintenance at that height.

The ground allows orientation and tilt to be optimised, makes maintenance easier and enables bifacial modules over a light-coloured surface, where they genuinely contribute. In exchange it consumes land, requires civil works, fencing and surveillance, and lengthens the electrical run.

The decision is rarely purely technical: it depends on whether the land has a valuable alternative use and on the remaining life of the existing roof.

An outright purchase maximises the return and gives full access to the income tax deduction and the accelerated depreciation of Laws 1715 of 2014 and 2099 of 2021, provided the company is in a position to use them.

Leasing turns the investment into an instalment and changes the accounting treatment, useful when financial policy prioritises not tying up capital in non-productive assets.

The power purchase agreement — PPA — is common at this scale: a third party finances, installs and operates, and the plant buys the energy at an agreed price over a long term. It removes the investment and the operational risk, in exchange for giving up the asset and the incentives. The critical points of the contract are the term, the price indexation formula, the availability guarantees, what happens during a prolonged plant shutdown, and the conditions for early termination or purchase of the asset.

On a residential system, maintenance is an annual inspection and the occasional clean. At industrial scale it is a function with its own budget.

It covers continuous monitoring with alarms, scheduled cleaning suited to the environment — a cement plant, an unpaved road or an agricultural setting soil panels far faster — thermography to detect hot spots in connections and modules, torque checks on the structure, and a stock of critical spares so a fault does not leave you waiting on import lead times.

It is worth agreeing indicators: minimum system availability, fault response time and expected performance ratio, with the calculation formula written down. Without that, the maintenance contract is an intention, not a commitment.

Before committing capital, an industrial project goes through a review that does not exist at smaller scales.

On the electrical side: load profile analysis, a study of the connection point, an assessment of harmonics and power quality if there are variable-speed drives or non-linear loads, and a review of protection devices and coordination. On the civil side: structural capacity, wind loads for the area and, on the ground, a geotechnical study.

And on the risk side: what happens to output if the plant stops for scheduled maintenance, how that affects the financial model, and what insurance cover protects the installation against hail, wind, fire or theft. These are questions worth resolving during the assessment and not after signing.