Photovoltaic (PV) solar power

Photovoltaic (PV) solar energy directly converts sunlight into electricity using the cells in the modules. In buildings, it helps reduce grid purchases through self-consumption, potentially allowing for the sale of surplus energy and, in some cases, securing certain energy needs with storage. PV is not simply a "roof with panels": it's a DC/AC chain (modules → inverter → control panels) that must be sized according to the load profile, integrated into the building structure without compromising its integrity, and managed to maximize usable kWh at the right time.

Photovoltaics: operational definition

A PV array consists of modules (wired in DC strings), inverters (string, micro-inverters, or optimizers), protection devices (surge protectors, DC disconnectors, circuit breakers), and the AC connection to the distribution board. Production depends on irradiance, orientation/tilt, temperature (cells lose efficiency in hot weather), and shading (chimneys, parapets, trees, etc.; a mismatch in one cell can negatively impact the entire string). Production is measured in kWp (peak power) and kWh; the PR (Performance Ratio) indicates the quality of the installation.

In terms of integration, several solutions are available: surface mounting (rails/ballast), flat roofs (sloping frames), carports/shade structures, facades, and BIPV (integrated photovoltaics). An EMS/BMS can control loads (domestic hot water, cooling, HVAC) and storage (batteries) to increase self-consumption rates and limit unused energy injection. Network interfaces require decoupling protection, a fire department shutdown system, robust grounding, and lockout/tagout procedures for maintenance.

Advantages, limitations and points of attention of photovoltaic solar energy

Interests

• Reduction in network purchases and partial stabilization of the bill.
• Visible decarbonization and contribution to the site's renewable energy objectives.
• Real estate enhancement (active roofs, shade structures useful for comfort).
• Possible coupling with storage and control to smooth profiles.

Boundaries

• Weather variability (daytime and seasonal production) → need for arbitration between sizing, storage and demand response.
• CAPEX (modules, inverters, structure, connection) + OPEX for maintenance.
• Network constraints (injection power, possible clipping depending on context).
• Sensitivity to shading and over-temperature (yield losses).

Points to consider

• Structure & waterproofing: loads, wind stresses, controlled penetrations.
• Electrical quality: DC sections, surge arresters, AFCI/arc detection, selectivity.
• Inverter choices: string (simple & robust) vs micro/optimizers (better shading management, granular supervision).
• Thermal management of inverters (ventilation, technical room).
• Supervision: telemetry, fault alert, PR tracking and targeted cleaning.
• Life cycle: module/inverter warranties, end-of-life recycling, compliant documentation.

Anecdote — “The parking lot that lights up the cash register”

A supermarket in Vitrolles had installed solar panels on its roof, but its peak usage (refrigeration and air conditioning) sometimes put a strain on the grid during the summer. Solutions included adding solar canopies in the parking lot, installing power optimizers on partially shaded rows, and adjusting the domestic hot water system and shifting some defrost cycles to midday. The result: a significantly higher self-consumption rate, reduced grid peaks, improved customer comfort (cars in the shade), and delighted management: "Our parking spaces generate kWh... and smiles." Proof that the best location for solar panels isn't always... on the roof.