FAQ's

Calculate your total energy consumption and find out what percentage of this can be offset by the solar system. A degree of self-sufficiency of 60-70 % makes economic sense. Determining the energy requirement for a solar energy system is an important step in determining the optimum size and output of the system.

Here are some steps you can take:

1. Select location and technology:
   • Decide between Solar heat and Photovoltaics.
   • Take into account the number of residents in the house and the desired system.
2. Determine orientation and inclination:
   • Determine the orientation of the modules (e.g. south) and the angle of inclination of the roof.
3. Determine the size of the system:
   • Calculate the output on the roof (kWp) and the output on the façade (kWp).
   • Also think about a battery to store the electricity generated.
4. Estimate the proportion of self-consumption:
   • Think about how much of the electricity you generate you want to use yourself.
5. Costs and amortization period:
   • Calculate the costs for the turnkey system.
   • Estimate the amortization period, i.e. the period in which the investment will pay for itself.
6. Further settings:
   • Use a Solar calculatorto simulate the total electricity production, the share of self-consumption and the electricity output to the grid.

Clarify whether an additional storage tank makes sense for your solar system. Investing in a storage tank is often worthwhile as you can achieve higher self-consumption. A storage system also makes you a little more independent. An electricity storage unit for a solar system can offer various advantages:

1. Self-consumption optimization:
   • With a storage system, you can store the solar power you generate yourself and use it at a later time, e.g. in the evening or at night.
   • This will increase your self-consumption and reduce the amount of electricity you draw from the grid.
2. Independence from the power grid:
   • A storage system makes you less dependent on external power suppliers.
   • You can use the stored electricity if the grid fails.
3. Reduction of feed-in to the grid:
   • Surplus solar power normally has to be fed into the grid.
   • With a storage system, you can use this electricity yourself instead of giving it away.
4. Economic efficiency:
   • The amortization period of a storage system depends on the costs and usage.
   • Subsidies and falling storage prices make their use more economical.
5. Environmental friendliness:
   • By using your own solar power, you contribute to reducing CO₂-emissions.
6. Flexibility:
   • You can use the stored electricity flexibly over time, e.g. for electric cars or heat pumps.

Note: Nevertheless, it is important to consider the individual framework conditions and the costs for the storage system.

Invest in durable and efficient modules. The quality influences the long-term performance of the system. The most important factors here are:

1. Product and performance guarantee:
   • The product and performance guarantee should both be at least 30 years amount.
2. Observe equal warranty periods:
   • Note that product and performance guarantees should always be of equal length.
   • Otherwise, the shorter product guarantee could be used to legally undermine the longer performance guarantee.
3. Maximum degradation rate:
   • Ensure a maximum degradation rate of 0.25 % per year.
   • Degradation refers to the gradual decrease in the performance of solar modules over time.
   • The causes are ageing, moisture, temperature and UV radiation.
   • The higher the degradation, the lower the wattage that can be generated by the module in the long term.

Look for an experienced and reliable professional to install the system. Recognizing a reputable handyman company is crucial to getting quality services and avoiding scammers. Here are some tips on how to recognize a reputable tradesman:

1. Recognize reputable craft businesses:
   • Imprint and contact details:
     • Imprint: Check whether the website of the craft business contains an imprint. Reputable companies provide their contact details transparently.
     • Telephone number: Make sure that a local telephone number is given. 0800 or 032 numbers may indicate dubious providers.
   • Qualifications and experience:
     • Find out about the qualifications of the tradesmen. Reputable companies have experienced specialists.
     • References: Ask for references or look for customer reviews.
   • Transparency in costs:
     • A reputable craftsman's business will give you clear prices and break them down.
     • No cash payment: Be careful if a tradesman only accepts cash payment. Reputable companies offer various payment methods.
   • Contract and invoice:
     • Written contract: A reputable craftsman's business will offer a written contract that sets out all agreements.
     • Invoice: Ask for a proper invoice with all details.
   • Chamber of Crafts and Membership:
     • Check whether the company is registered in the register of craftsmen. You can find this out from the Chamber of Crafts.
     • Members of the Chamber of Skilled Crafts are generally reputable.
   • Gut feeling and social pressure:
     • Trust your gut feeling. If something seems strange, look for alternatives.
     • Regional companies are under social pressure because they risk their reputation if they do a poor job.

Set yourself a realistic budget for the purchase and installation of the solar system. Financial planning when building a solar system is an important step to ensure that your investment is profitable. Here are some aspects you should consider:

1. Economic planning of a solar system:
   • Determine your solar potential:
     • Roof surface: Calculate the available roof area for the solar system.
     • Alignment and inclination: Check the orientation and pitch of the roof to ensure optimum solar radiation.
   • Costs and subsidies:
     • Acquisition costs: Calculate the costs for the solar system, including the modules, inverter and installation.
     • Subsidies: Find out about funding programs at federal, cantonal and municipal level. These can significantly reduce costs.
   • Self-consumption and feed-in:
     • Own consumption: Estimate your own consumption share. The more you consume yourself, the more profitable the system becomes.
     • Feed-in: Clarify the feed-in tariff for surplus electricity into the grid with the grid operator.
   • Economic efficiency:
     • Calculate the return on investment of the solar system over its lifetime (usually 20-30 years).
     • Take into account inflation and the development of electricity prices.
   • Financing options:
     • Equity: Use existing equity for the purchase.
     • Credits: Explore the possibility of credit or loans.
   • Operating costs and maintenance:
     • Include the operating costs for maintenance, cleaning and any repairs.
   • Tax aspects:
     • Find out about the tax deductibility of the investment.
     • Note that local remuneration and individual framework conditions can have a strong influence on profitability.

Note: Professional advice can help you with your financial planning.

The size depends on the available roof area, the angle of inclination and the orientation of your roof. Make sure that no obstacles block more than 10 % of the area of a single system during peak production times. The size of the system also depends on your consumption. Bear in mind that if you purchase a heat pump, electric car, electric bicycle, etc., your energy consumption will increase. Your energy consumption will increase. The right size of your solar system depends on various factors. Here are some steps to determine the optimal size:

1. Determine power requirement:
   • Take a look at your electricity bills to find out your average annual consumption in kilowatt hours (kWh).
   • A rule of thumb says: 1 kWp (kilowatt peak) of installed capacity per 1,000 kWh of annual electricity consumption.
2. Take future consumption into account:
   • Plan for the next 30 years, as modern systems last that long.
   • Think of possible additional consumption such as electric cars or heat pumps.
3. Consult experts:
   • Talk to a solar expert to consider individual needs and special cases.
4. Standard sizes for detached houses:
   • For an average single-family home, 8 to 12 kWp of installed capacity is common.
   • This corresponds to a module area of around 56 to 84 m².
5. Observe individual framework conditions:
   • Remember that local conditions and support programs can influence the size.

Opt for high-quality solar modules and a powerful inverter. Here too, it is important not to save money at the wrong end.

1. PERC technology (Passivated Emitter and Rear Cell):
   • This technology is now obsolete, as the efficiency of the PERC cell has been exhausted. On average, these have a maximum efficiency of 21 %.
2. Heterojunction technology (HJT):
   • HJT solar modules are particularly suitable for warm and sunny conditions. Their low temperature coefficient ensures stable and efficient power generation, even at higher temperatures.
   • Unfortunately, the manufacturing costs are very high due to the raw materials and are not scalable in the long term.
3. n-Type TopCon - the technology of SwissWatt One AG modules:
   • These are characterized by high efficiency, durability, good low-light performance and better temperature resistance.
4. Bifacial modules - the Davos Diamond module from SwissWatt One AG with n-type technology:
   • These modules use both direct sunlight and reflected light from the rear.
   • They are particularly efficient and are suitable for various applications.
5. Tandem and perovskite solar cells:
   • Future technology: These technologies are still at the research stage, but are showing promising results. Market maturity in around 2 to 3 years.

Note: The choice of the most suitable technology depends on your individual requirements, the location and the costs. It is advisable to seek professional advice.

Find out about any permits or registrations required for the installation, among other things:

1. Regulatory and legal requirements:
   • Building permit: Check whether a permit is required for your region.
   • Registration with the Federal Network Agency: In Switzerland this is not applicable, in Germany it is mandatory (relevant for our customers in DE).
   • Registration with the grid operator: Before commissioning, the system must be registered with the local grid operator.
   • Registration with the trade office and tax office: This is required if electricity is fed into the grid and remunerated (e.g. in Germany as a small business).

Before installing a solar system, it is advisable to find out about the specific regulations in your country / federal state / canton and, if necessary, seek professional advice

Make sure that your roof is suitable for the installation. The roof surface should not be shaded and should have the optimum angle of inclination. It often makes sense to re-roof the roof in the course of installing a solar system.

Think about security measures to protect your system. Protecting your solar installation from theft and damage is vital to ensure long-term viability and functionality. Here are some measures you can take:

1. Theft and security protection for solar systems:
   • Mechanical fuses:
     • Use special screws and locking techniques to make access to the solar modules more difficult.
     • Markings and individual labels on the system components facilitate identification in the event of theft.
   • Electronic security systems:
     • Alarm systems: Install alarm systems that trigger an alarm in the event of unauthorized access.
     • Video surveillance: Use cameras to monitor suspicious activities.
     • GPS tracker: Use GPS trackers to track the location of the solar modules.
   • make access more difficult:
     • Access roads: Design the access roads to the solar installation so that they are difficult for thieves to access.
     • Avoid climbing aids: Remove ladders or other climbing aids.
   • Raising awareness among neighbors:
     • Inform your neighbors about the solar system and ask them to keep an eye out for suspicious activity.
   • Insurance and legal aspects:
     • Take out theft insurance for the solar system.
     • Clarify the legal aspects and register the system correctly.
     • Remember that a combination of mechanical and electronic security measures is most effective.

Note: This checklist can serve as a guide, but it is advisable to seek professional advice to take your individual circumstances into account.