Installing solar panels on a 150m2 house is a big step towards energy independence and doing something for the planet. With energy bills rising and the climate changing, more and more homeowners are turning to solar. It helps reduce expenses and carbon footprint. We will see how to estimate the price of solar panels for a 150m2 house and what aid is available.

Key Points to Remember

• The price of solar panels for a 150m2 house depends on several things, such as the power of the panels and the type of installation.
• For a 150m2 house, you need to carefully calculate your energy consumption to choose the right panel power.
• There are financial aids, such as the self-consumption premium or reduced VAT, which can lower the price of solar panels for a 150m2 house.
• A solar project is an investment that becomes profitable over time, thanks to savings on bills.
• Choosing an RGE certified installer is important to have guarantees and benefit from aid.

Understanding the price of a solar panel installation for a 150m2 house

Investing in solar panels is a bit like buying a car: there’s the base price, but also the options, the brand, and the installation. For a 150m2 house, you need to understand what makes the total cost vary. It’s a significant investment, but one that can pay off handsomely in the long term, especially with the available aid.

Factors influencing the cost of solar panels

Several elements come into play. First, the type of panels: photovoltaic (for electricity) or thermal (for hot water). Then, their power, their efficiency, and their brand. A high-end panel will cost more, but will produce more electricity. The inverter, which converts direct current into alternating current, is also a significant expense. Not to mention the installation, which can vary depending on the complexity of your roof. The cost of the solar panels themselves is a determining factor.

• Type of panels (photovoltaic, thermal, hybrid)
• Power and efficiency of the panels
• Brand and quality of components

The installation price can also vary depending on the region where you live. Installer rates, climatic conditions (which can make installation more complex), and local aid can influence the final cost.

Average price estimate for 150m2

For a 150m2 house, it is estimated that an installation of about 12 kWp is needed to cover energy needs. This represents a certain number of panels, and therefore a certain cost. In general, we are talking about a price range from 8,000 to 15,000 euros, including installation. But be careful, this is only an estimate! The best thing to do is to ask for several quotes to get a precise idea. For a 100m² house, the number of solar panels is about 7 units.

Installation options and their costs

There are several ways to install solar panels: on-roof (this is the most common), in-roof (more aesthetic, but more expensive), or ground-mounted (if you have space in your garden). Each option has its advantages and disadvantages, and its own cost. On-roof installation on the roof is often the most economical. In-roof integration, on the other hand, requires more work and therefore a larger budget.

Calculating energy needs for a 150m2 house

Annual consumption assessment

For a 150m2 house, it is crucial to accurately assess annual energy consumption. This step is essential for correctly sizing your solar installation. In general, a house of this size can have a fairly significant annual electricity consumption, especially if heating is electric.

• Average consumption: A 150m2 house consumes on average between 11,000 and 15,000 kWh per year.
• Influencing factors: Insulation, type of heating, consumption habits and number of occupants play an important role.
• Importance of energy audit: An energy audit can help you identify weaknesses in your insulation and optimise your consumption.

It is important to note that these figures are averages. Your actual consumption may vary considerably depending on your habits and the characteristics of your home. A precise assessment is therefore essential.

Determining the necessary power in kWp

Once the annual consumption has been assessed, it is necessary to determine the required power of your solar installation, expressed in kilowatt-peak (kWp). This power represents the maximum production capacity of your solar panels under optimal conditions. For a well-insulated house, the annual consumption can vary considerably.

• Power calculation: For a consumption of 15,000 kWh, and considering that 1 kWp produces approximately 1200 kWh per year, an installation of approximately 12 kWp would be needed (15,000 / 1200 = 12.5).
• Factors to consider: The orientation and inclination of the roof, as well as the sunshine in your region, influence the actual production of your panels.
• Self-consumption: If you are aiming for self-consumption, it is important to adapt the power of the installation to your actual needs to avoid producing too much electricity that you will not be able to consume.

Average efficiency of solar panels

The efficiency of solar panels is a key factor to consider. It indicates the panel’s ability to convert sunlight into electricity. Modern solar panels generally have an efficiency ranging from 16% to 22%. Higher efficiency means greater electricity production for a given surface area.

• Types of panels: Monocrystalline panels generally have higher efficiency than polycrystalline panels.
• Degradation: Panel efficiency decreases slightly over time (degradation). Manufacturers generally guarantee at least 80% production after 25 years.
• Optimal conditions: Efficiency is maximised when panels are clean, well-oriented, and not shaded.

Financial aid to reduce the price of solar panels

The initial investment in solar panels may seem substantial, but fortunately, various financial aids are available to lighten this burden. These schemes aim to encourage the adoption of solar energy and make this technology more accessible to individuals. Let’s explore the main aids available in 2025.

Self-consumption premium and its conditions

The self-consumption premium is financial aid paid to individuals who choose to install solar panels and consume part of the electricity produced. This premium is paid during the first five years of the installation’s operation. To be eligible, you generally need to opt for a system with self-consumption with sale of surplus. The amount of the premium depends on the power of the installation, expressed in kilowatt-peak (kWp). In 2025, the amounts are as follows (for information only, check updated figures):

• Less than or equal to 3 kWp: Amount X €/kWp
• Between 3 and 9 kWp: Amount Y €/kWp
• Between 9 and 36 kWp: Amount Z €/kWp

It is important to note that eligibility conditions and premium amounts may vary. It is therefore essential to inquire with the relevant organisations or your RGE installer for precise and up-to-date information.

EDF OA purchase tariffs for surplus sales

If you choose to sell the surplus electricity you don’t consume, you can benefit from EDF Obligation d’Achat (OA) purchase tariffs. EDF OA commits to buying your electricity at a fixed price for a period of 20 years. This scheme ensures you a stable and predictable income in the long term. Purchase tariffs vary depending on the power of your installation and the connection date. Currently, tariffs are around €0.04/kWh for low-power installations. For more information, you can consult the EDF OA purchase tariffs in force.

Reduced VAT and other local subsidies

In some cases, you can benefit from a reduced VAT rate of 10% instead of the normal rate of 20% for the installation of your solar panels. This reduced VAT generally applies to low-power installations (less than or equal to 3 kWp) and energy renovation works. In addition, some regions, departments or municipalities offer local subsidies to encourage the installation of solar panels. These aids can take the form of premiums, interest-free loans or tax exemptions. Do not hesitate to inquire with your town hall or your regional council to find out about the aids available in your area. For example, MaPrimeRénov’ is an important financial aid to consider. Here are some examples of local aids:

• Regional aids
• Departmental aids
• Communal aids

Amortisation and profitability of a photovoltaic installation

Average return on investment period

Acquiring solar panels represents a significant investment, and it is natural to wonder about its profitability. In general, the return on investment (ROI) of a photovoltaic installation is between 10 and 15 years. Several factors influence this duration, including the initial cost of the installation, the amount of energy produced, the price of electricity, and any financial aid received.

It is important to note that this duration is an average. In some particularly sunny regions, or with optimal installation conditions, the ROI can be faster. Conversely, in areas less favoured in terms of sunshine, or with higher installation costs, the return on investment can be longer.

Optimising amortisation through self-consumption

Self-consumption plays a crucial role in optimising the amortisation of a photovoltaic installation. By directly consuming the electricity produced by your panels, you reduce your dependence on the electricity grid and lower your electricity bills. Moreover, if you produce more electricity than you consume, you can sell the surplus to EDF, thus generating additional income. To calculate the profitability of your installation, you must take into account the sunshine.

Here are some tips to maximise your self-consumption:

• Schedule the use of your electrical appliances (washing machine, dishwasher, etc.) during daylight hours.
• Install an energy management system to optimise consumption based on production.
• Consider storing the electricity produced using batteries, so you can use it even when the sun is not shining.

Calculating long-term savings

To assess potential long-term savings, it is essential to consider several elements:

• The annual electricity production of your installation, which depends on its power and the sunshine in your region.
• The current price of electricity, as well as its foreseeable evolution in the coming years.
• Income generated by selling surplus electricity.
• Maintenance costs of the installation (cleaning panels, replacing the inverter, etc.).

In France, solar panels reach their photovoltaic profitability in 10 to 15 years, with an annual return of 8% to 12%.

By carrying out a rigorous financial analysis, you will be able to accurately determine the savings you can expect to make thanks to your photovoltaic installation, and thus assess its long-term profitability.

Choosing the right type of solar panels for your home

It is essential to choose the right type of solar panels for your home. This decision directly influences the efficiency of your installation, its cost, and its durability. Several options are available to you, each with its advantages and disadvantages. It is important to carefully assess your energy needs and the characteristics of your home before making your choice. A solar advisor can help you see things more clearly.

Photovoltaic panels for electricity

Photovoltaic panels are the most common. They convert sunlight into electricity. There are mainly two types of photovoltaic panels: monocrystalline and polycrystalline. Monocrystalline panels are generally more efficient and have a longer lifespan, but they are also more expensive. Polycrystalline panels are a more economical option, but their efficiency is slightly lower. The choice will depend on your budget and the available space on your roof. You need to carefully assess the available surface area.

Thermal panels for hot water

Thermal panels, on the other hand, are used to heat water. They capture heat from the sun and transfer it to a heat transfer fluid, which then heats the water in your tank. This is an interesting solution if you have significant domestic hot water needs, for example, for a large family. They can be a good complement to photovoltaic panels, helping to cover part of your energy needs.

Hybrid solutions and their advantages

Hybrid solutions combine both technologies: photovoltaic and thermal. They allow you to produce both electricity and hot water. These systems are more complex and more expensive to install, but they offer a complete solution for energy autonomy. They can be particularly interesting if you want to maximise your independence from the electricity grid.

Choosing the right type of solar panel is an important step. You need to consider your needs, your budget, and the characteristics of your home. Do not hesitate to ask a professional for advice to make the best choice.

Here is a simplified comparative table:

It is important to determine the number of solar panels to install on your property for an installation perfectly suited to the household’s electricity consumption.

The importance of the RGE installer for your solar project

Choosing the right installer is as important as choosing the right solar panels. An RGE (Recognised Guarantor of the Environment) certified installer is a guarantee of quality and seriousness for your project. It is important not to rush and to carefully evaluate the available options.

Selection criteria for a qualified professional

Several criteria must be taken into account when choosing your installer. It is important to check that the company has the RGE certification, but also to ensure its experience and references. Do not hesitate to ask for examples of achievements and to contact former clients to gather their opinions. A good installer must be able to advise you on the sizing of your installation, the choice of equipment and administrative procedures.

Here are some points to check:

• The company’s RGE certification
• The installer’s seniority and experience
• References and customer reviews
• Clarity and precision of the quote
• Quality of the proposed material

Guarantees and certifications offered

An RGE installer must be able to provide you with guarantees on their work and on the installed equipment. The ten-year warranty covers damage that could affect the solidity of the work for 10 years. It is also important to check the duration of the warranty for solar panels and the inverter. A ten-year insurance is a guarantee of security for your investment.

It is important to note that using a non-RGE certified installer may deprive you of financial aid from the State and local authorities. Moreover, in case of a problem, you risk not being covered by insurance.

Advantages of using an RGE expert

Using an RGE expert offers many advantages. First, it allows you to benefit from financial aid from the State, such as the self-consumption premium or the guaranteed purchase tariff for the sale of your surplus electricity. Then, it ensures an installation carried out according to the rules of the art, with quality equipment and a ten-year warranty. Finally, an RGE expert is able to advise and support you throughout your project, from design to commissioning. It is important to be wary of solar panel scams and always ask for several quotes to compare prices and services. Opting for an RGE installer means ensuring a successful and profitable solar project in the long term.

The different solar panel installation configurations

The choice of your solar panel installation configuration is a decisive step in the success of your project. Several options are available to you, each with advantages and disadvantages in terms of cost, aesthetics, and performance. It is important to carefully assess your needs and the constraints of your home before making a decision.

On-roof installation

On-roof installation is the most common method. It involves fixing the solar panels above the existing roof covering, using specific rails and fixings. This is generally the most economical and simplest option to implement. The on-roof installation is quick and does not require significant modifications to the roof structure. Furthermore, it allows for good ventilation of the panels, which helps to optimise their efficiency.

In-roof integration for optimised aesthetics

In-roof integration (IAB) is a more aesthetic solution, but also more complex and costly. In this case, the solar panels directly replace part of the roof, ensuring both waterproofing and electricity production. This option offers a more discreet and harmonious appearance, but it can be more restrictive in terms of installation and maintenance. In addition, in-roof integration can sometimes lead to poorer ventilation of the panels, which can slightly reduce their efficiency. It is important to note that IAB can qualify for specific financial aid, but it must meet precise technical criteria.

Ground-mounted solutions and their specificities

Installing solar panels on the ground is an interesting alternative if your roof is not suitable for a solar installation (poor orientation, shading, etc.) or if you have a sufficiently large plot of land. The panels are then fixed on metal structures anchored to the ground. This solution offers great flexibility in terms of orientation and inclination, which optimises the efficiency of the panels. However, it requires a significant amount of space and may be subject to regulatory constraints (building permits, etc.). In addition, the installation of solar panels on the ground can be more vulnerable to bad weather and vandalism.

It is essential to carefully study the different installation options and to call on a qualified professional to advise you and carry out the work according to the rules of the art. An RGE (Recognised Guarantor of the Environment) installer will be able to guide you towards the solution best suited to your situation and help you benefit from the available financial aid.

Maintenance and durability of solar panels

It is essential to understand that the longevity and optimal performance of your solar installation depend on regular maintenance and particular attention to the durability of the equipment. A well-maintained installation will allow you to maximise your investment and fully enjoy the benefits of solar energy.

Regular maintenance for optimal performance

Maintaining solar panels is generally simple, but it should not be neglected. Here are some important points:

• Panel cleaning: Dust, leaves, and other debris can reduce panel efficiency. Regular cleaning, usually once or twice a year, is recommended. It is not necessary to clean after every rain, as the production difference is minimal.
• Visual inspection: Regularly check the condition of the panels, cables, and fixings. Look for signs of damage, corrosion, or degradation.
• Production monitoring: Carefully monitor the energy production of your installation. A sudden or gradual drop may indicate a problem.

Average lifespan of equipment

The lifespan of solar panels is an important factor to consider when investing. In general, solar panels are designed to last a long time. Solar panel installations have an estimated lifespan of 30 years, retaining at least 80% of their nominal power during this period nominal power. However, certain elements can influence this lifespan:

• Panel quality: Opt for panels from recognised brands known for their reliability and durability. Among the best solar panel brands are DualSun, Voltec Solar, and SunPower.
• Climatic conditions: Extreme climatic conditions (hail, high heat, snow) can affect the lifespan of the panels.
• Installation quality: An installation carried out by a qualified professional is essential to guarantee the durability of the equipment.

Manufacturer and installer warranties

The warranties offered by manufacturers and installers are an important element to consider. They protect you in case of manufacturing defects or installation problems. Make sure you fully understand the terms and conditions of these warranties.

It is important to note that most manufacturers offer a performance warranty of 25 to 30 years, ensuring that the panels will retain at least 80% of their initial power during this period. In addition, a warranty on equipment and labour is generally offered by the installer.

Environmental impact and energy autonomy

Reducing your household’s carbon footprint

Adopting solar panels represents a significant step for the planet. By using solar energy, you reduce your dependence on fossil fuels, major sources of greenhouse gas emissions. Every kilowatt-hour (kWh) produced by your solar panels helps reduce your household’s carbon footprint. It’s a concrete step towards a more sustainable future.

Contribution to the energy transition

By opting for solar energy, you actively participate in the energy transition. This transition aims to replace polluting energy sources with renewable and clean alternatives. Solar panels, by producing electricity without emitting pollutants, play an essential role in this collective effort. Investing in solar installation is an investment in the future of our planet.

Achieving greater electrical autonomy

One of the major advantages of solar panels is the possibility of achieving greater electrical autonomy. By producing your own electricity, you are less dependent on the traditional electricity grid and fluctuations in energy prices.

Here are some points to consider to maximise your autonomy:

• Correctly size your installation according to your energy needs.
• Optimise your consumption by using energy-efficient appliances.
• Consider storing the energy produced using batteries.

Energy autonomy does not necessarily mean total independence from the grid, but rather a significant reduction in your dependence and greater control over your consumption. Self-consumption with sale of surplus remains an interesting option.

In conclusion, installing solar panels offers many advantages, both environmentally and economically. It reduces your carbon footprint, contributes to the energy transition, and achieves greater electrical autonomy. It is a wise investment for the future.

Financing your solar panel project

The initial investment in solar panels can seem substantial, but several financing options are available to lighten this burden. It is important to carefully examine these different possibilities to find the one that best suits your financial situation and your objectives.

Dedicated loan and financing options

Several banks offer loans specifically designed to finance solar panel installation projects. These loans can offer advantageous interest rates and repayment terms adapted to the lifespan of the equipment. It is also possible to turn to organisations specialising in financing renewable energies. They are familiar with the sector and can offer tailor-made solutions. Do not hesitate to compare offers to find the best interest rate.

Comparison of banking offers

It is essential to compare offers from different banks and credit institutions before making a decision. Here are some elements to consider:

• Nominal interest rate and APR (Annual Percentage Rate)
• Loan term
• Monthly payment amount
• Application fees and other ancillary fees
• Possibility of early repayment

It is recommended to request several quotes and simulate different financing scenarios to assess the impact of each option on your budget.

Tips for a suitable financing plan

To develop a financing plan adapted to your solar project, here are some tips:

1. Accurately assess your energy needs and the total cost of the installation. The quote amount is an important factor.
2. Take into account available financial aid, such as the Hydro-Québec subsidy, which can significantly reduce the amount to be financed.
3. Determine your repayment capacity based on your income and expenses.
4. Do not hesitate to seek advice from a financial advisor to support you in your approach. Tailor-made support can help you make the right decisions.

Conclusion

Ultimately, investing in solar panels for a 150 m² house is a decision that pays off. It’s true, the initial cost may seem a bit high. But with the various aids available, such as the self-consumption premium or reduced VAT, it immediately becomes more affordable. And then there are the savings on electricity bills, which are far from negligible. Not to mention the environmental aspect, which is increasingly important for many people. In short, it’s a sensible choice, both for the wallet and for the planet.

Frequently Asked Questions

How long does it take for solar panels to pay for themselves?

In general, a solar installation takes about 12 years to pay for itself. This period may vary depending on the size of the installation and the aid received.

What is the average cost to install solar panels on a 150 m² house?

For a 150 m² house, the price of a turnkey solar installation is approximately €12,250 including VAT. This amount may change depending on the options chosen and the type of panels.

Is there financial aid for installing solar panels?

Yes, there are several aids such as the self-consumption premium, electricity sales tariffs to EDF OA, and reduced VAT. These aids reduce the total cost of your solar project.

How can I make my solar installation more profitable?

To optimise profitability, it is advisable to consume as much of the electricity your panels produce as possible, especially during sunny hours. Selling unused surplus can also generate income.

Why choose an RGE installer?

An RGE (Recognised Guarantor of the Environment) installer is a certified professional who guarantees the quality of the installation and allows access to financial aid. It is a guarantee of seriousness for your project.

What makes the price of a solar installation vary?

Several elements influence the price, such as the power of the panels, the type of installation (on the roof or integrated), available aid, and included services (warranty, maintenance).

How many solar panels are needed for a 150 m² house?

For a 150 m² house consuming 15,000 kWh per year, approximately 12 to 13 solar panels are needed to cover the needs. This also depends on the sunshine in your region.

How can I finance the installation of my solar panels?

You can finance your project with specific bank loans or consumer credits. It is important to compare offers to find the solution best suited to your budget.