Solar thermal energy in Écublens: A comprehensive guide for homeowners

Ecublens, situated at 426 meters above sea level, has a significant energy demand of 2759 Kj/year. With a global annual irradiation of 1371 kWh/m², the potential for solar thermal energy is substantial.

Adopting this technology supports the goals of the Climate Plan, which aims for carbon neutrality by 2050 and a 35% reduction in GHG emissions by 2030.

The ideal time to install solar thermal collectors often coincides with the replacement of your domestic hot water system or a comprehensive roof renovation. Solar collectors typically cover a large portion of summer hot water demand, reducing the load on your main boiler during periods of low heating demand.

By integrating this work into an energy renovation, you optimize your investment and improve your building's energy rating while anticipating future municipal energy requirements.

The choice of equipment depends on the collector technology, primarily between flat-plate and vacuum tube collectors. Flat-plate collectors are robust and suitable for summer and spring use. Vacuum tube collectors offer better efficiency, especially on less sunny days.

It is advisable to accurately assess your actual hot water needs to correctly size the collector area. Incorrect sizing can limit system efficiency.

Furthermore, coupling with your existing heating system is crucial. Combining collectors and heat pumps requires a rigorous sizing study. You will need to choose a suitable storage tank capable of retaining the thermal energy produced during the day.

The choice between an in-roof integrated system or one mounted on supports is also a matter of aesthetics and budget. Remember to check the compatibility of your existing roof structure to support the additional weight of the collectors, especially if your roof is several decades old.

The municipality of Écublens has a diverse building stock, ranging from old farmhouses to houses built between 1960 and 1990. If your building was built before 1990, be vigilant about the possible presence of asbestos in insulation or roof components.

A technical inspection is recommended before any work begins to ensure site safety and the longevity of your solar installation. The building's thermal insulation also directly impacts the profitability of the solar system; a well-insulated roof limits heat loss during energy transfer to the tank.

Regarding networks, check the condition of your existing pipes. Installing solar collectors often requires adding piping between the roof and the boiler room. In older buildings, routing conduits can be complex.

It is sometimes necessary to create new conduits or modernize the heat distribution network to optimize the circulation of the heat transfer fluid.

An analysis of the existing situation by a professional helps avoid budget surprises and ensures that your new solar installation works in perfect harmony with the existing central heating system.

In the canton of Vaud, the procedure for installing solar thermal collectors is simplified. For most projects, you benefit from a simplified procedure or a building permit exemption. However, this rule is subject to verification, especially if your building is listed or located in a protected area.

It is highly recommended to contact the technical services of the municipality of Écublens before starting work to confirm whether your project falls under the simplified procedure or requires more in-depth steps.

If your installation significantly changes the exterior appearance or the roof height, the competent authorities – the municipality or the prefect – will be able to specify the local constraints for you.

Although there are no specific guidelines for Écublens regarding heritage protection zones, caution remains advised in old neighborhoods. Ensure you have a clear written response from the authorities before ordering equipment or signing a final quote with a company to avoid any subsequent administrative opposition.

The Buildings Program (VD) supports homeowners with subsidies for solar thermal installations, in the form of a flat fee or calculated per square meter of collectors. This aid aims to encourage the production of domestic hot water and heating support.

It is imperative to submit your subsidy application before starting work; no aid will be granted for projects already completed. The official portal link allows you to check updated amounts and technical requirements for eligibility.

Regarding taxation, investments intended to save energy are fully deductible from taxable income. Expenses incurred to replace obsolete installations or add renewable building elements benefit from a 100% deduction rate.

If your costs exceed your income, you have the possibility to carry over the balance to the two following tax periods. Note that if you receive a public subsidy, only the portion you personally pay is tax-deductible.

This smart tax management helps to significantly reduce the actual cost of your solar project in Écublens.

The flow of a solar thermal project follows a rigorous logic. The first phase consists of conducting a feasibility study and applying for financial aid before signing any quotes. Once the grant agreement is received and any administrative permits are obtained, the equipment can be ordered.

The site itself often begins with preparing the roof and installing the collector fixing system, followed by installing the panels and the hydraulic connection to the storage tank.

the best season to undertake this work is spring or summer, to avoid weather-related issues. In Écublens, with an average of 48 frost days per year, it is essential to schedule the work outside these periods to ensure optimal commissioning without the risk of freezing fluids.

Indoor connection work can be carried out during the cooler months. A final commissioning allows checking the tightness of the circuits and the proper functioning of the thermal regulator, thus ensuring your installation is ready to produce energy from the first day of sun.

The most frequent error is underestimating the thermal storage need, which limits the use of solar energy. It is imperative to check the general condition of the roof, as installing solar collectors on a roof at the end of its life is not recommended.

Another error is omitting to apply for subsidies before signing contracts. Finally, ensure the chosen company has proven experience in solar thermal energy.

Before requesting quotes, follow this checklist : check the age and condition of your roof; have an assessment of your current hot water consumption carried out; ensure the compatibility of your central heating; confirm your building's zone with the municipality; submit your subsidy application to the Buildings Program; demand a precise sizing plan including the tank; compare several detailed offers on equipment and installation.

By following these steps, you minimize risks and ensure the success of your project.