Solar panels, or solar electric modules, are typically installed on the roof. These solar panels convert sunlight into direct current (DC) power.

The DC power from the solar panels is sent to an inverter, where it is converted into alternating current (AC) power, or standard electrical current used by your home.

Control how and when to use your stored energy - even during a blackout. Choose the appliances you want to hook up to the battery and optimize your perpetual investment.

Solar storage batteries will increase your energy efficiency and reduce energy cost during the day. Your solar panels charge the battery each day. You will have stored energy you can use during peak hours as needed. Also, you can use your stored energy during blackouts.

Don't worry about batteries unless you are building a self-contained home or living compound. If you stay "on the grid" in a populated area, you will continue to get power at night from the local utility, just as you are doing today.

Allows you to monitor renewable energy production. If the monitoring gateway is connected to the internet, you will receive alerts in case production levels drop below normal.

AC power travels from the inverter to the electrical panel.

This power is now ready to use in your home.

The utility meter continually measures your electrical supply; when your solar electric system produces more power than you need, the meter literally spins backwards, accumulating credits with the utility company that will offset your next bill.

Your home remains connected to the utility grid to supply you with electricity when you need more power than your solar electric system has produced, such as at night.

A growing family will face growing energy needs, but if you are childless or have college-age kids ready to leave the nest, you can expect your energy costs to go down, and stay down. Get a solar installer to calculate your planned electricity demands.

Ideally, of course, solar systems should be on the southwest-facing area of your roof. Truth be told, the direction your panels face is not as important as you may think (or salesmen may insist).

Positioning the panels to face west or south will work, and even southeast, east and north-northwest give acceptable results, too.

In most European countries, adding a solar PV system will not cause a reassessment of your property tax.

After installation, contact your homeowner's insurance company and have your policy amended. You will face an increase on your property insurance of probably less than €9 a month, but protecting your system from fires or other damage is critical.

Learn about the two kinds of solar electric system warranties that are normally offered. The first one is the panel and inverter manufacturer warranty, which are usually 25 years on panels and up to 25 years on the inverters. The installers should also offer a warranty on the quality of their work, which means guaranteeing they made no holes in your roof likely to lead to leaks for a specified period, from two to 10 years, normally.

Generally speaking, a solar panel will last 30 ears or more and lose some ½ percent (0.5%) conversion efficiency annually.

Hosing the panels off a few times during the summer and keeping leaves off them in the fall is about the only maintenance required.

The panels will not harm your roof in any way when properly installed. Frankly, they protect the areas located directly beneath them from the ravages of weather, light, and heat. You may even find that the room(s) of your home directly beneath the panel installations will remain cooler in summer and warmer in winter, regardless of the other insulation.

The kind of roof you have makes a big difference in installation costs. It will definitely be costlier to install solar panels Spanish tile or shake than on plain old asphalt shingle roofs.

Both tile and shake are far more brittle than asphalt shingles...

Hence, additional time and intensive care is needed to ensure that attachment points penetrating the roof are completely and properly sealed..

Our family homes usually have 1 fase, mainly 1x35 A, which can meet our daily electrical appliances, such as lighting, refrigerators, laundry rooms, microwave ovens, hybrid heat pumps, and household solar panels.

But if you have more power needs, such as air conditioning, induction cookers for kitchens, and the popular charging piles, 3x 25A among the 3 fase is more suitable for you.

If your home has higher power needs, such as Jacuzzi, sauna, pure electric heat pump, etc., 3x35A is more suitable for you.

In recent years, solar inverter technology has made great strides, becoming a key player in converting solar energy into electricity that can power our homes and businesses. At its core, inverters take the direct current (DC) produced by solar panels and turn it into alternating current (AC), the type of electricity that runs our appliances and can be fed into the electrical grid. When it comes to inverters, there are mainly two types you’ll come across: string inverters and microinverters. Each serves a different purpose and is suited for specific situations.

Understanding how these inverters work is crucial for anyone looking to install solar panels. The decision to go with either a string inverter or a microinverter affects not just the efficiency and cost of your solar system, but also how much maintenance it might need. Choosing the right inverter is more than just about converting energy; it’s about getting the most out of your solar investment. It ensures that your setup is perfectly tailored to meet your energy needs and fits the specific conditions of your location.

WHAT ARE STRING INVERTERS?

How Do String Inverters Work?

String inverters are commonly used in solar power setups. They link a string of solar panels together, feeding their direct current electricity into a single inverter. This inverter then transforms the DC into alternating current (AC), the type of electricity used in homes and supplied to the power grid. The key role of a string inverter goes beyond simple conversion; it’s also about enhancing the energy yield from the connected panels. However, string inverters share a limitation: their performance hinges on the least efficient panel in the series. This means if even one panel is shaded or not working well, the energy production of the whole series drops.

Benefits of String Inverters for Solar Arrays

String inverters come with some great benefits, especially for specific types of solar projects:

1. Cost Savings: String inverters are known for being more wallet-friendly. They usually cost less up front than microinverters. To put it in numbers, string inverters can be about 30% less expensive than microinverters, making them a solid choice for big projects where keeping costs down is key.
2. Easier to Fix Problems: Dealing with issues in string inverters is generally simpler. They connect many panels to just one device, so if there’s a problem, it’s easier to find and fix than in systems with lots of microinverters. This means you can get things back to normal faster and usually with less expense for labor.
3. Simple to Install and Maintain: String inverters are straightforward, making them easy to like. They have fewer parts to set up than microinverter systems do, so putting them in place is faster and less complicated. Plus, looking after them is more straightforward, as you’re mainly dealing with one main unit instead of many, saving you time and hassle.
4. Best for Big, Open Spaces: If you’ve got a large space with no shade, string inverters are ideal. They work best when there’s a lot of open sky, making them perfect for big commercial solar projects or homes with lots of roof space.
5. Works with Many Setups: String inverters are pretty flexible. They work well with lots of different solar panels and setups. This flexibility makes them a good fit for all sorts of solar projects, whether it’s for a house or a business.

Common Downsides with String Inverters

String inverters bring several advantages to solar installations but also come with disadvantages, especially in certain conditions:

• Struggle with Shade: Their biggest issue is handling shaded areas. If just one panel in the array gets shaded, the performance of the entire string drops to that of the least effective panel unless power optimizers are added. This makes them less ideal for roofs that experience partial shading, where even a small shadow can significantly reduce energy output.
• Expansion Difficulties: It’s not easy to add more panels to a system with a string inverter. Unlike systems with microinverters, where you can easily add panels, expanding a string system might mean needing a new inverter or reconfiguring the existing setup, which can be both costly and complex.
• Shorter Lifespan: String inverters typically last about ten years, which is shorter than the 20 to 25 years lifespan of microinverters. This means you might face extra costs for replacement and possible breaks in power production over time.
• Safety Concerns with High DC Voltage: These inverters work at high DC voltage levels, raising safety risks during system failure or installation. The higher voltage can lead to arc faults, a serious fire hazard.
• Limited Monitoring Capabilities: With string inverters, monitoring the individual panel performance is tough because they consolidate the output. Spotting and fixing problems with specific panels can be challenging without extra monitoring tools.
• Risk of Complete System Failure: If the string inverter fails, the whole system stops producing power, leading to significant energy loss until the problem is fixed. This is different from microinverter systems, where a problem would only affect one panel.
• Need for Additional Equipment: Complying with safety standards like rapid shutdown rules might require more components for string systems, increasing the solar project’s cost and complexity.

WHAT ARE MICROINVERTERS?

How Do Microinverters Work?

Micro inverters are a newer technology in the solar industry. Unlike traditional string inverters that connect to an entire array of panels, microinverters are installed with each solar panel. This allows for the direct conversion of DC electricity from each panel into AC electricity on its own. This arrangement means that if one panel isn’t doing well, it won’t drag down the performance of the whole system. Microinverters are particularly great at boosting the efficiency of each panel, making them ideal for areas with inconsistent shading or different panel directions.

Advantages of Microinverters in Solar Installations

Microinverters offer several advantages for solar power setups, making them an excellent choice for a wide range of projects:

• Improved Performance in Shaded Areas: Microinverters excel in locations with variable shading. Since each solar panel has its own microinverter, shading on one panel doesn’t affect the whole system’s output. This setup ensures that your solar array maintains high energy production, even if some panels are shaded, leading to better overall performance.
• Monitoring for Each Panel: With micro inverters, you can monitor the performance of individual panels. This capability makes it easier to identify and address any issues promptly, leading to optimal performance and more efficient maintenance.
• Safer Operation: Microinverters convert DC power to AC power right at the panel, minimizing the risks associated with high voltage DC current. This feature makes your solar installation safer, reducing the risk of electrical fires in both residential and commercial settings.
• Easy Expansion: If you’re looking to expand your solar array, microinverters make it straightforward. Their scalability allows you to add more panels as your energy needs grow, without overhauling your existing setup.
• Long-Term Reliability: Many microinverters come with a 25-year extended warranty, highlighting their durability. This extended coverage offers long-term peace of mind and ensures a solid return on your investment throughout the life of the system.
• Versatility for Complex Roofs: Microinverters are particularly well-suited for roofs with unusual layouts or orientations. Their independent operation allows for a customized solar array that maximizes sun exposure and optimizes energy generation.
• Built-In Rapid Shutdown: Some models feature a rapid shutdown capability for added safety during emergencies. This function allows for immediate power disconnection, providing an additional safety layer for your installation.

Potential Drawbacks of Microinverters

Microinverters bring a lot of positives to solar power systems, but there are a few downsides to think about:

1. Upfront Costs: The biggest issue with microinverters is they cost more at the start. They might be 20-30% pricier than string inverters when setting up. This can be a hurdle for those watching their budget closely.
2. Installation Complexity: Installing microinverters is a bit more involved since each panel needs its own. This can make the setup process longer and possibly lead to higher costs for labor compared to the simpler string inverter setups.
3. Maintenance and Repair: Even though microinverters can boost how well your system works, fixing them can be harder. They’re up on the roof, attached to each panel, so finding and fixing issues can take more time and maybe cost more.

Yet, it’s worth noting that these issues can be balanced out by the benefits over time. The increased energy output, better safety features, and lower costs for maintenance in the long run can make up for the higher initial price. Also, being able to monitor each panel closely means problems can be spotted and sorted out faster, which might lower maintenance troubles down the line.

PERFORMANCE ANALYSIS: STRING INVERTERS VS MICRO INVERTERS

On bright, clear days, both string inverters and microinverters typically have similar outcomes in terms of energy generation, with only minor differences. In such ideal scenarios, string inverters might be the more cost-effective choice because of their lower upfront costs and simpler setup. Yet, Beny’s microinverters are reported to enhance energy output by up to 97.5%, a notable boost that might make them the better option even in perfect weather conditions. This improvement indicates that microinverters can convert sunlight into energy slightly more efficiently than string inverters, making the most of every bit of sunlight.

The true measure of an inverter’s performance, though, is seen when conditions are far from perfect, like when solar panels experience partial shading. In these situations, microinverters stand out significantly. Thanks to their independent operation, each panel with a microinverter keeps its efficiency up, regardless of how well other panels are doing. So, if one out of ten panels is shaded and its output drops by 50%, only that panel’s production is reduced. On the other hand, with a string inverter, if one panel’s output decreases, it could pull down the performance of the entire array. For example, if a single panel drops to producing 150 watts from 300 watts due to shade, instead of getting 2850 watts (with nine panels at full capacity and one underperforming), the total might fall to just 1500 watts for all ten panels. This demonstrates a significant drop in the system’s overall performance.

FINANCIAL CONSIDERATIONS BETWEEN STRING VS MICRO INVERTER

The financial implications of choosing between string inverters and microinverters are significant and multifaceted, encompassing initial costs, long-term benefits, and potential energy production efficiencies.

String Inverters: Generally, the cost for string inverters ranges from $0.10 to $0.20 per watt, making them a more budget-friendly option initially. For a typical residential solar system of 5 kW, the inverter might cost between $500 and $1,000. This affordability is particularly appealing for installations in consistent, unshaded environments, where the absence of shading means that performance between panels remains uniform, thus maximizing the system’s overall efficiency. For example, in a large-scale commercial setup with direct sunlight, the lower initial investment could translate into considerable savings, with minimal performance sacrifice compared to microinverters. However, the typically shorter warranty period, around 10 to 15 years, means potential additional costs down the line for replacement or repairs.

Microinverters: On the other hand, microinverters are priced around $0.30 to $0.40 per watt. For the same 5 kW system, this translates to an initial cost range of $1,500 to $2,000. While this is a steeper upfront expense, the long-term benefits can be substantial. Microinverters can increase energy production by up to 15-25% in partially shaded conditions compared to string inverters. If your solar array produces, on average, 7,000 kWh annually, a 20% increase in efficiency can equate to an additional 1,400 kWh per year. At an average electricity rate of $0.12 per kWh, this results in an extra $168 in energy savings annually. Over the 25-year warranty period of a microinverter, this can add up to $4,200, potentially offsetting the initial higher costs.

INSTALLATION AND SCALABILITY

The process of installing solar inverters and their scalability can significantly impact your solar project’s overall feasibility and growth potential. String inverters offer a straightforward installation process, typically requiring less time and fewer components than microinverter systems. This simplicity can lead to reduced labor costs, with average installation times ranging from a few hours to a full day for large residential systems. String inverters are particularly well-suited for projects with a large number of panels in areas without shading, as they can connect multiple panels — often up to 10 to 15 — in a single string. This ability makes them an ideal choice for expansive, uniform installations, where adding additional panels usually means expanding existing strings without the need for new inverters, provided the existing ones have adequate capacity.

On the other hand, microinverters, despite their higher initial cost and more complex installation process, excel in scalability and flexibility. Each solar panel operates with its own microinverter, which means adding new panels is as simple as installing them with their respective inverters without affecting the rest of the system. This modularity makes microinverters a perfect fit for smaller installations or systems that plan to expand incrementally over time. For instance, a homeowner starting with a small setup can easily add more panels as their energy needs increase or as their budget allows. While the initial setup might take longer and cost more compared to string inverters — with individual installations per panel increasing initial labor — the long-term benefits, such as the ability to expand the system one panel at a time without significant additional infrastructure, present a clear advantage for growing or evolving solar energy needs.

SUITABILITY BASED ON SOLAR ARRAY CONFIGURATION

Choosing the right inverter depends a lot on how your solar panels are set up. If your home or installation site has a lot of nooks and crannies — like different angles, directions, or spots that get shaded at various times — microinverters are probably your best bet. They let each panel work on its own, so if one panel is in the shade, it doesn’t drag down the whole system. This is really useful in residential areas where buildings or trees might block the sun at different times. For example, if your roof is broken up by things like chimneys, some parts might get less sun; microinverters make sure these shaded panels don’t affect the whole system’s output, making sure every panel is used to its fullest.

On the other hand, string inverters fit best with large, straightforward solar setups that don’t have to worry about shade, like on big commercial roofs or open fields. Here, you can line up lots of panels to catch sun in the same way, which is something string inverters are good at handling. They can manage many panels at once, which can make installing and maintaining them simpler and cheaper. Say a large commercial building has a big roof without anything blocking the sun; a string inverter could be a smart, cost-effective way to oversee all those panels together. But, remember, in setups like these, if even one panel gets less sun, it can lower the efficiency of the entire string. So, while string inverters are great for big, shade-free areas, they might not be ideal if the sunlight hitting the panels varies a lot due to shadows or other obstructions.

ENVIRONMENTAL AND SAFETY CONSIDERATIONS

When we talk about the environmental and safety impacts of solar inverters, it’s really important to grasp how different types of inverters, like string inverters and microinverters, work. Microinverters are known for working at a lower voltage, generally between 30 to 50 volts DC for each solar panel. This is quite a bit safer than the higher voltages, up to 600 volts or more, that string inverters deal with. Because of this, the chances of electrical fires and arc faults are much less with microinverters, making them a particularly good choice for homes where safety is the top priority.

On top of being safer, microinverters are also better for the environment. They get the most out of each solar panel, turning as much sunlight as they can into electricity. This not only cuts down on waste but also bumps up efficiency. So, if part of your solar panel setup is shaded or covered in debris, microinverters can still keep the other panels working at their best. But with string inverters, the output might drop a lot, leading to more wasted energy. That’s why setups with microinverters can squeeze more electricity out of the same sunlight compared to those with string inverters. This means they’re not just safer; they also have a lower environmental impact by making better use of solar energy.

MICROINVERTER VS STRING INVERTER: WHICH IS YOUR RIGHT SOLAR INVERTER SOLUTION?

When you’re picking an inverter for your solar panels, there are a few essential considerations. Look at how big your solar panel setup is, if there are shaded areas, how much money you can spend, and if you want to make your system bigger later. Knowing all this helps you and your installer choose the best inverter for your needs. This way, you make sure your solar energy system works really well and doesn’t cost too much.

Here’s a comparative analysis to help illustrate the differences:

FactorMicroinverterString InverterVoltage OperationTypically operates at 30-50 volts per panelCan operate up to 600-1000volts overallCostHigher upfront costLower upfront costShading ImpactMinimal impact; only affects shaded panelsCan affect entire string of panelsScalabilityHighly scalable; add panels individuallyLess flexible; may require new invertersMaintenanceIndividual panel monitoring; easier to pinpoint issuesWhole system monitoring; harder to isolate problemsSafetyLower DC voltage reduces electrical risksHigher DC voltage may increase risksInstallation ComplexityMore components, potentially more complex installationSimpler, faster installation for large arraysLifespanGenerally longer, often up to 25 yearsTypically around 10-15 yearsIdeal Use CaseComplex roofs, partial shading, expansion plansLarge, unshaded areas, fixed installations

How to Choose?

• If your home deals with a lot of shade or has a complicated roof design, microinverters might be the way to go. They excel in optimizing the output of each solar panel individually.
• For those eyeing large, sun-soaked projects, especially in the commercial sector, string inverters could be a smarter, more budget-friendly pick. They’re generally easier to set up for vast, even spaces.
• In case you need to watch your spending now but are thinking about adding more panels later, starting off with a string inverter might look attractive due to its lower upfront cost. However, keep in mind the future of your setup. Microinverters, though more costly at first, offer greater adaptability and might generate more power down the road.
• Homeowners prioritizing safety and keen on keeping tabs on each panel might find microinverters to be a better match. They operate at lower voltages and allow for detailed monitoring of each panel, offering an extra layer of safety and control.

After installing solar panels, will the energy company charge additional management fees?
Yes, most energy companies have started to charge this part of the fee.
 
Is it expensive? How much is the specific fee?
After consulting several mainstream energy companies, I found that each company has a different calculation method.
* Some charge according to the interval, for example, Figure 1: Annual power production minus annual usage, if it is between 5-1000 kWh, a monthly fee of 4 euros is charged, 48 euros a year.
 
* There are also charges based on per kWh, as shown in Figure 2, according to the annual settlement, the extra electricity returned is calculated at 5.5 cents per kWh. 1000 kWh is 55 euros
 
Will my family return so much electricity?
Usually not. Because we will give you the most reasonable installation suggestions based on your actual usage + future plans: install as much as you use, and a little surplus is best.
 
In the future-in the days when you have solar panels, arrange the use of electrical appliances at home reasonably, and gradually replace the use of natural gas with electricity to achieve a double harvest of environmental protection and economy!