Photovoltaics & smart grid

It follows from your actual consumption, not from a rule of thumb. The study starts with your bills and, where possible, a load-curve measurement over several days: it shows at which hours you consume, and that decides how much solar can cover.

Two sites with the same annual consumption do not call for the same installation. Daytime activity lends itself to direct self-consumption and needs little storage; continuous or night-time activity shifts the sizing towards batteries.

Without a battery, the installation produces only during the day and stops when the grid does: that is the economical choice where your consumption is daytime and outages are tolerable.

A battery answers two distinct needs, best not confused: using in the evening what was produced in the afternoon, and riding through an outage. The second requires sizing against the outages you actually experience, and against only the equipment you want backed up.

Yes. Overcast skies reduce output, they do not cancel it: modules also work in diffuse light.

Sound sizing is in any case based on the least sunny month of the year, not the annual average — otherwise the installation holds for eleven months out of twelve and disappoints in the twelfth.

Few parts move, but three things matter. Cleaning the modules first: dry-season dust costs several points of output, and an array that cannot be reached never gets cleaned — access is planned from the layout stage.

Then checking connections and torque, which heat and humidity loosen. Finally, monitoring the inverter: most report their output, and an abnormal drop shows up before it becomes expensive.

Photovoltaic modules lose efficiency slowly rather than failing: their service life is counted in decades, and manufacturers publish a declining output warranty that states it.

The other components have shorter and differing horizons — the inverter and the batteries are replaced before the modules. Exact durations depend on the references selected, and are set out in the proposal.