Réduire sa facture d'électricité de 50% avec le solaire - Benjamin Barnathan

The current state of solar photovoltaic (PV) installations in France is highly profitable, despite the country's significant reliance on nuclear energy, which leads to considerable price volatility. The core advantage of solar power lies in its ability to mitigate these uncertainties. Mathieu Stéphanie, host of "La Martingale," and Benjamin Barnatan, co-founder of Solaroc, discuss the ins and outs of solar PV for both individuals and businesses. Barnatan, with a background in a large photovoltaic project in Corsica during a period of significant subsidies, highlights that the technology has matured considerably. He contrasts this with China's aggressive investment in green energy, positioning them as leaders. Barnatan emphasizes that France, while strong in savings, lags in investment in production capacity, advocating for a shift towards greater investment in this sector. Solaroc, Barnatan's company, operates as a vertically integrated installer, handling everything from design to maintenance for individuals and businesses. Their innovative model involves both in-house operations, particularly in the Île-de-France region, and a "business in a box" approach for existing installers. This means they provide branding, software, and back-office support to local partners, empowering them to offer Solaroc's services under their own brand. This model aims to address a common issue in installation trades: the disconnect between sales and after-sales service, ensuring local expertise and accountability. The French PV market is fragmented, with large energy providers, marketplaces, and around 7,000 to 8,000 small and medium-sized businesses (SMBs) involved. Solaroc differentiates itself by focusing on "local champions"—established local companies with a strong regional presence—and equipping them with their operational framework. The discussion delves into two key areas: the potential savings from PV installations and the investment opportunities within the sector. **Understanding Photovoltaics in 2026** Barnatan clarifies that photovoltaics, commonly known as solar panels, has evolved beyond just panels. The modern PV system integrates high-quality batteries and Energy Management Systems (EMS). The primary goal is to maximize self-consumption of the energy produced, thereby reducing reliance on the grid and lowering electricity bills. The core principle is that the more self-consumed energy, the less electricity needs to be purchased from the grid. PV systems involve panels installed on rooftops that generate electricity. This electricity is converted by inverters. The concept of self-consumption is central: the energy generated is used directly by the household or business. Any surplus energy can either be reinjected into the grid at a low rate (around 4 cents per kWh, compared to purchase prices of 19 cents) or stored in batteries. While residential rooftops are a significant area, Barnatan notes that PV also applies to ground installations, carports (ombrières), and larger commercial surfaces. Solaroc specializes in residential and small-to-medium enterprise (SME) installations, primarily on rooftops but also including ground-mounted systems. The connection to the grid and the rules for selling surplus energy differ based on the installation type. **Economic Viability and Savings** To illustrate potential savings, Barnatan uses an example of an average household consuming 7,500 kWh per year, costing approximately €1,500 annually. An installation of 8-10 panels, costing around €8,000-€10,000 (excluding tax), could reduce this bill by 50% to 70%. The payback period for such an investment is estimated to be around 10 years. Given that solar panels have a lifespan of at least 30 years, with potential for 40 years of operation, the period after the initial investment is recouped represents pure savings. Manufacturers typically guarantee 90% of production capacity over 30 years, with potential output around 80% after that. Despite concerns about lower sunlight levels in regions like Normandy compared to the south, Barnatan asserts that PV is profitable across all of France. He points out that European neighbors like Germany and Scandinavian countries have much higher solar penetration rates (20-25%) compared to France (5%), indicating a significant lag and room for growth. **The Role of Batteries and EMS** Without batteries, self-consumption typically ranges from 40% to 60%. Batteries play a crucial role by storing surplus energy generated during the day for use during peak consumption times, such as evenings. This increases self-consumption to 80-95%, further reducing electricity bills. However, the added cost of batteries extends the payback period. A 7 kWh battery, suitable for a household consuming around 15 kWh daily, costs between €3,000 and €5,500. A larger 15 kWh battery might cost around €10,000. While technically possible to achieve 100% energy autonomy by over-dimensioning installations and batteries, it is economically unfeasible and impractical due to seasonal variations in sunlight and consumption. Solaroc focuses on partial autonomy and energy independence, particularly for those concerned about grid stability and potential power outages. Their systems offer backup capabilities, ensuring essential equipment remains powered during grid disruptions. The idea of complete autonomy is presented as a "chimera" (illusion). While technically achievable, it's not economically sensible. The key is to optimize energy production and consumption. The diminishing value of selling surplus electricity back to the grid (currently at 4 cents per kWh) further reinforces the importance of self-consumption and storage. Barnatan explains that grid sales are expected to phase out as the grid's need for external supply diminishes. The grid operates on a delicate balance between production and consumption. Renewables, when managed effectively with systems like EMS, can actually stabilize the grid. Solaroc's vision includes creating decentralized energy production entities that can form a virtual power plant, contributing to energy flexibility. Regarding battery technology, Barnatan acknowledges past skepticism about their efficiency and cost. However, he highlights significant advancements in battery technology over the last two years, leading to price reductions and improved performance. Batteries now offer a lifespan of around 20 years, with 10,000 charge cycles. A 7 kWh battery can cost around €3,300 and significantly reduce electricity bills by 20-30%. The increasing adoption of batteries in new installations, even after subsidy reductions, signals their growing importance. The decision to install a battery depends on an individual's profile. Those who are home during the day and can directly use solar power may not benefit as much as those with typical work schedules or electric vehicles, where batteries can manage peak demand and charging. **Vehicle-to-Grid (V2G) Technology** The potential of using electric vehicle (EV) batteries for home energy storage (Vehicle-to-Grid, or V2G) is discussed. With EVs having much larger batteries (e.g., 70-80 kWh for a Tesla compared to 7 kWh for a home battery), they could theoretically power homes and even sell energy back to the grid. While this technology is in its early stages in France, it represents a massive future market. The current focus for optimizing EV charging involves smart charging to align with solar production and off-peak grid rates. EMS will play a crucial role in managing these complex energy flows, including weather forecasts and grid stability needs. **Energy Management Systems (EMS)** EMS are crucial for optimizing energy usage. While Solaroc is developing its own EMS, they currently utilize existing solutions. Basic EMS can optimize heating schedules based on peak and off-peak electricity rates and solar availability. The goal is to achieve intelligent, holistic energy management within the home. AI is expected to play a significant role in future EMS, integrating with various smart devices and optimizing energy consumption based on real-time data, weather, and grid conditions. EMS can effectively manage energy trading, deciding when to draw from the grid, use stored battery power, or charge batteries based on real-time electricity prices. **Installation Costs and Solaroc's Offer** A typical 5-6 kWp solar installation (10-12 panels of 500Wp) costs around €10,000 (excluding tax) and can reduce electricity bills by about 50%. The average cost has been increasing, with installations including batteries now reaching €15,000 (excluding tax). About half of Solaroc's installations now include batteries and EMS. The cost of a solar panel is around €500, making the material cost approximately 30% of the total installation price. The majority of the cost (around 70-80% for rooftop installations) is attributed to labor and service. Solaroc emphasizes the importance of professional installation due to the complexity and the need for certifications like RGE (Reconnu Garant de l'Environnement) for grid connection and insurance. DIY installations are strongly discouraged due to safety, warranty, and regulatory issues. Solaroc offers financing solutions, including leasing and loans, to make installations more accessible. For businesses, subscription-based models can align monthly payments with electricity bill savings. **Common Mistakes and Future Trends** The most common mistakes in solar installations include: 1. **Mismatched sizing:** Installing too many or too few panels, failing to accurately assess current and future electricity consumption (e.g., with planned EV charging or heat pumps). Solaroc uses data from smart meters (Linky) and predictive modeling for accurate sizing. 2. **Lack of pilotage and EMS:** Not implementing systems to manage energy production and consumption intelligently, leading to inefficient self-consumption. 3. **Trusting unqualified installers:** Opting for large sales organizations that subcontract installations, potentially leading to higher prices and lower quality. Choosing local, expert companies with high-quality equipment is recommended. EMS are not prohibitively expensive, costing a few hundred to €1,500, and can significantly improve payback periods by increasing self-consumption. EMS are most effective when paired with batteries or EVs, and when integrated with real-time electricity pricing. The future of energy involves grid connectivity and participation in energy flexibility markets. Regarding panel technology, Barnatan states that current panels have reached maturity with around 22% efficiency. Future innovations are expected to focus more on battery technology and EMS rather than incremental gains in panel efficiency. Solaroc installs panels from brands like DualSun and Voltec (French assemblers with Chinese cell sourcing) and Atmos for batteries and inverters, prioritizing European equipment where possible. **Investment and Personal Philosophy** Barnatan's personal investment strategy includes startups and scale-ups, though he acknowledges the risks involved. His "true Martingale," however, is the pursuit of experiences, inspired by the book "Die with Zero." He advocates for optimizing life around experiences rather than solely accumulating wealth, believing that living a rich life through diverse activities is the ultimate form of capital accumulation. **Promotional Offer** For listeners of "La Martingale," Solaroc offers a 10% discount on installations and a free profitability study. In conclusion, solar PV is presented as a mature, profitable, and increasingly essential technology for energy independence and cost savings in France. The integration of batteries and EMS is key to maximizing benefits, and professional installation is crucial for optimal performance and safety. The market is evolving towards greater intelligence and integration with the broader energy grid.