East-West Roof: Profitable for Solar in Luxembourg in 2026?

Why East-West Orientation Interests Homeowners in Luxembourg

In Luxembourg, most houses have a gable roof, often oriented east-west. For a long time, south-facing photovoltaic installations were favored, considered the most profitable. But with changing electricity prices and public subsidies, east-west orientation has become a serious option, sometimes even more advantageous. In this article, we analyze the profitability of an east-west roof for solar in Luxembourg, based on climatic data and current subsidies.

Production of an East-West Roof Compared to a South Roof

A solar panel facing due south with a 35° inclination produces the maximum annual energy. But an east-west roof (two slopes, one east, one west) produces about 85-90% of that maximum. This might seem like a loss, but consider the production distribution. A south roof peaks at noon, while an east-west roof produces earlier in the morning (east side) and later in the afternoon (west side). This distribution matches typical household consumption, which peaks in the morning and evening. Thus, self-consumption can be higher with an east-west installation, improving overall profitability.

Financial Aid in Luxembourg: Klimabonus Wunnen 2026

Since January 2022, the Klimabonus Wunnen program has replaced the former PRIME House. Managed by the Klima-Agence, it offers subsidies for energy renovation works, including photovoltaics. For a solar installation, the subsidy can reach 10,000 EUR, with a maximum of 8,300 EUR for 10 kWp, and the maximum is reached from 15 kWp. There is no penalty for east-west orientation. Additionally, if you install a home battery, you can get an extra 2,250 EUR. These aids make the investment more attractive regardless of orientation.

Economic Profitability of an East-West Installation

To assess profitability, let's take a typical example: a house in Luxembourg with an east-west roof, a 6 kWp installation (3 kWp on each slope). Installation cost is about 12,000 EUR. With the Klimabonus subsidy (around 6,000 EUR for 6 kWp), the net cost drops to 6,000 EUR. Annual production is about 5,400 kWh (90% of 6,000 kWh). If the household consumes 40% of this production (self-consumption), they save about 1,080 EUR per year (at 0.20 EUR/kWh). The surplus is sold to the grid at a feed-in tariff of about 0.05 EUR/kWh, yielding 162 EUR per year. Total income is about 1,242 EUR per year, giving a return on investment of about 4.8 years. Without subsidy, the return would be about 9.7 years. With a battery, self-consumption can rise to 60%, further improving profitability.

Optimizing Self-Consumption with a Battery

An east-west installation pairs well with a home battery. Production is spread over the day, allowing you to charge the battery in the morning with the east side and recharge in the afternoon with the west side. This way, you can store energy for the evening and night. In Luxembourg, the battery subsidy is 2,250 EUR, reducing the cost of a 10 kWh battery (about 8,000 EUR) to 5,750 EUR. With a battery, self-consumption can reach 70%, increasing savings and reducing payback time.

Practical and Aesthetic Advantages

Beyond profitability, an east-west roof offers practical benefits. It allows better production distribution, reducing grid dependence. Moreover, it's often easier to install panels on both slopes than on a single one, as the surface is divided. Aesthetically, some homeowners prefer the symmetrical look of panels on both sides. Finally, an east-west roof can be combined with other renovation works, like roof insulation, which also benefits from Klimabonus subsidies paid as a rate per square metre insulated, from 35 to 115 EUR/m2 depending on the insulant and the performance standard reached, and up to 140 EUR with the transitional increase, for insulation with R >= 6 in sarking or R >= 7 in attics.

Administrative and Technical Steps

To install solar panels in Luxembourg, you must follow certain steps. First, you need to apply for a subsidy from Klima-Agence before starting work. You must also inform the grid operator (Creos) for connection. If the installation exceeds a certain power, a building permit may be required. It's advisable to use a certified installer. For administrative aspects, the portal guichet.public.lu provides all necessary information. Finally, for data protection, the CNPD ensures that consumption data is processed securely.

Conclusion: East-West is a Profitable Choice in Luxembourg

In summary, an east-west oriented roof is quite profitable for solar in Luxembourg, especially with current subsidies. The slightly lower production compared to a south roof is offset by better alignment with consumption, increasing self-consumption. With Klimabonus Wunnen 2026, the investment is quickly recouped. If you're hesitant, remember that each installation is unique. It's recommended to get a personalized study from a professional to assess your roof's solar potential.

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