Solar thermal in Neuchâtel: A comprehensive guide for homeowners

With an altitude of 434 meters and a global irradiation of 1320 kWh/m²/year, Neuchâtel offers favorable conditions for utilizing solar energy.

The 51 frost days per year highlight the importance of having a high-performance hot water system that effectively complements your main heating installation.

Undertaking these works is particularly relevant when you are planning a comprehensive renovation of your heat generation system or when replacing an aging water heater.

The local situation, marked by 2866 heating degree days per year, underscores the necessity of reducing dependence on fossil fuels. By investing in solar thermal, you stabilize your energy costs while benefiting from the city's 'Cité de l'énergie Gold' status.

The best time to act remains when your boiler reaches the end of its life or during roof refurbishment, which allows for limiting labor costs by consolidating technical interventions.

Sizing is the crucial step. Solar thermal collectors generally cover a large part of the summer hot water needs, thus drastically reducing the strain on your boiler during the mild months.

It is essential to choose between flat plate collectors, which are robust and economical, or vacuum tube collectors, which are more efficient in cold weather or low sunlight, although more expensive.

These options must be adapted to your actual household consumption.

Another technical dimension involves combining your solar collectors with a heat pump. This requires a rigorous sizing study carried out by a qualified professional to ensure optimal synergy between the technologies.

The integration into your building's management system must be designed to maximize the self-consumption of the produced energy.

Finally, the choice of the storage tank must take into account the space available in your basement and your peak consumption needs to avoid any shortage of hot water.

In Neuchâtel, the real estate stock is varied, ranging from historic buildings to more recent constructions.

If your building dates from before 1990, particular attention must be paid to the potential presence of asbestos in old insulation or coatings, especially when fixing structures on the roof.

A preliminary analysis by an expert is recommended before any drilling, especially if heavy roofing work is required to support the weight of the panels.

The quality of your home's insulation also influences the overall efficiency of the system. A well-insulated building better retains the solar energy captured in its distribution network.

For older houses, it is common for piping networks to require upgrading to limit heat loss between the collectors and the storage.

Also, check the condition of your roof structure : solar thermal installations add a structural load that an engineer or roofer must validate to ensure the durability of your roof against local weather conditions.

You must submit a notification to the competent communal or cantonal authority about twenty days before the scheduled start of works. This step is essential to validate the compliance of your project.

Be careful, however : if your building is located outside the building zone or if it is a protected object (historic monument or protected site), the simple notification procedure is not always sufficient.

It is imperative to contact your municipality's urban planning department beforehand to obtain written confirmation. This preventive check avoids costly administrative blockages and ensures that your project respects local heritage requirements.

Do not start any work before receiving formal approval or passing the required notification period.

These aids aim to encourage the replacement of energy-intensive systems and support your initial investment.

Tax-wise, investments intended to save energy are deductible from your taxable income. If your costs exceed your net income, you can carry forward this deduction to the next two tax years.

Note that if you opt for a flat-rate deduction for the maintenance of your property, you will not be able to deduct these actual costs separately.

It is therefore recommended to calculate each year, for each building, the most advantageous option between the flat rate and actual costs. The tax authority can provide you with details on the carry-forward amounts after full declaration of your invoices.

The project takes place in several key phases. Everything begins with planning and submitting the subsidy application. Once approval is received, work generally begins with securing the roof, then installing the mounting system.

The actual installation of the collectors follows, then comes the phase of hydraulic connection to the storage tank and the installation of the control system. Commissioning and pressure tests finalize the intervention.

It is wise to schedule work outside periods of heavy frost, as 51 days per year present risks for workers at height and can complicate the laying of heat transfer fluids.

Intermediate seasons such as spring or early autumn often offer milder weather conditions, facilitating precision work on the roof.

A good craftsman will know how to coordinate the steps to minimize the duration during which your heating or hot water system must be interrupted, thus ensuring your comfort.

The most common error is to underestimate the sizing of the system, which limits performance over the year. Never neglect the technical feasibility study.

Before requesting quotes, ensure you have the following : check the age and condition of your roof to support the panels, check the compatibility with your existing heating system, and request written confirmation from urban planning regarding authorization.

Ensure the quote details the type of collectors and the warranties offered.

Do not sign any commitment before receiving feedback on your cantonal subsidy application. Also avoid choosing a provider solely on price without comparing the quality of the components.

Finally, verify that the chosen company has proven local experience, particularly to respect installation rules on old or protected buildings in Neuchâtel.

A simple checklist : is the subsidy application submitted, is the urban planning department notified, and has the roof been inspected?