First solar setup: Sizing and Scaling | DIY Solar Power Forum

Hi Guys. First post over here.
I am planning to setup a 3kw solar array to start with. This will be a ground mount setup. A 10kw roof mount setup will follow and probably replace the ground mount setup. Is it ok to get a 5kw victron multiplus 2 inverter to start with the 3kw setup in order to make the move less expensive for the 10kw roof setup in case I decide to remove the gound mount setup? Or do I have to go with a 3kw version for the gound setup and buy a beefier inverter for the 10kw setup later?
I plan on using the solar setup in a ups mode with a 16kw lfp battery pack. #1 - how to decide battery voltage and also figure how many panels you need.


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Plug and play kit - shed

Hi anyone have recommendations for a mostly plug and play kit - for a shed. to support the normal ....... lighting / low amp led but mostly power tools ...... direct and chargers for battery chargers. So its possible to have 2x 15A circuits dedicated on at a time plus lights. (eg Fan and...

Question was how do I decide battery voltage - I also answered on how to determine solar panels needed.


The main decision on battery voltage comes down to how many amps are drawn from the battery - Most of us are of the opinion that w is the highest practical wattage for a 12v system. w for a 24v system. Then 48v for anything beyond.


Watts drawn by your tools/etc multiplied by the number of hours in a day you... GOAL
I am building a 48v 10kW Solar System for my Duplex. I want the system to be tied to the grid so that I can sell excess power SCE. I want the versatility to power either one of the (2) apartments or both.

LOAD
Each Apartment is Identical 2bed 2bath. Avg around kWh a month
- 1.1 Over Range Microwave w
- Dishwasher 2,400w
- 30" Induction Cooktop 240v 3kW
- Electric Oven w
- 23cf Refrigerator 674kWh/yr
- Washer w
- Dryer w
- Mini/Split 115v 12,000btu
- Electric Tankless Water Heater w (though I have 2-Solar Hot Water Heaters)
- Then typical fair (5w lights, Security Cameras, TV, WIFI, Laptop, Rumba)
- Don't have an EV (but will one day)


LOCATION
I live in California 33.9 / 119 coordinates. My computer model says I will have no cast shadows year-round.
5 miles from the water, south-facing view, 34deg slope, composite shingles, with no obstructions.

COMPONENTS
I just purchased (15) NEW Trina 700w Vertex N Solar Panels, total 10,500w
What do you recommend for
- Mount?
- Inverters?
- Batteries?
- Setup?

Any help or recommendation would be greatly appreciated.

Attachments

• cat-Solar700w-b.jpg

GOAL
I am building a 48v 10kW Solar System for my Duplex. I want the system to be tied to the grid so that I can sell excess power SCE. I want the versatility to power either one of the (2) apartments or both.

LOAD
Each Apartment is Identical 2bed 2bath. Avg around kWh a month
- 1.1 Over Range Microwave w
- Dishwasher 2,400w
- 30" Induction Cooktop 240v 3kW
- Electric Oven w
- 23cf Refrigerator 674kWh/yr
- Washer w
- Dryer w
- Mini/Split 115v 12,000btu
- Electric Tankless Water Heater w (though I have 2-Solar Hot Water Heaters)
- Then typical fair (5w lights, Security Cameras, TV, WIFI, Laptop, Rumba)
- Don't have an EV (but will one day)


LOCATION
I live in California 33.9 / 119 coordinates. My computer model says I will have no cast shadows year-round.
5 miles from the water, south-facing view, 34deg slope, composite shingles, with no obstructions.

COMPONENTS
I just purchased (15) NEW Trina 700w Vertex N Solar Panels, total 10,500w
What do you recommend for
- Mount?
- Inverters?
- Batteries?
- Setup?

Any help or recommendation would be greatly appreciated.

Please post your question as a new thread please verse hijacking someone else.... You should ask simple questions that don't derail the thread into your own issues until the OP is answered and completely done.

Looks like I’ll be going for an all in one inverter. I wanted to get separate victron components but I will need three inverters for my three phase power supply if I want to do it right. Going with one inverter seems doable but not optimum. What do you guys think?

3 phase power can be accomplished a couple of ways -- @Hedges is a good person to talk about them.... I would do 3 inverters if that is what you need and you are starting/running heavy machinery -- but there are converters if you just need a bit here and there What are your 3-phase loads?
Operating current, and starting current (LRA) which is probably 5x as high as operating?

Sometimes a VFD is nice, gives you variable speed and soft startup.
Smaller ones can run from single phase input. I have 1.5kVA VFD feeding 2 HP pool pump. Larger ones usually want 3 phase input for less ripple after rectification.

I use SMA Sunny Island, which like Victron, Schneider, Midnight, Outback, and some AIO can have multiple connected for 3-phase.
Some (most) AIO would have weak surge current, can't start big motors. Sunny Boy Smart Energy for instance can only surge to 1.25x rated power while traditional LF inverters usually 2x. Some HF can too.

There are several brands of AIO that take 3 phase. Some require HV batteries (and BMS communications) while those that are 48V are easier to DIY and can be open loop whether Lithium or lead-acid. Hi Hedges ! I don't have any special needs. I bought the house with this setup. I don't run any heavy loads. Usual home appliances. I plan on getting an electric car in the future. I also plan on getting a heat pump for the house and will be adding a swimming pool later. My current grid plan is 6KVA. Breaker is 30a. So this makes it 10a per phase.
So initial setup is a 3KW ground setup then a 12 KW roof setup. I will probably remove the ground setup when the root setup is finished. Gound setup is 6x500W panels. I am also getting a 16kw battery pack (custom). Initial thought was getting a single phase inverter and wiring it to the critical phase but then everybody is recommending a three phase inverter for a three phase system...
So my options are:
1. Use a three phase inverter AIO with a battery pack and have the three phases backed up in case of power outages.
1. Use 3 single phase inverters with a battery pack and have the three phases backed up in case of power outages. This option is going to be costly.
2. Use a single phase inverter and an mmpt with a battery pack to power a chosen (critical) phase and have that phase backed up in case of power outages.
Battery storage is an important part of this setup
I would like to get an inverter to use with the 3KW now and keep it when I upgrade to the 12KW. So I think it's better to go with a beefy one right now. I might even keep the 3KW. Not sure a single AIO will be enough for both installs.
Can you give some more info on your setup please. I am going to look into SMA inverters. I am in Europe so they should be easy to get. I was thinking of getting a Fronius inverter. 30A breaker 3 poles? That would be 30A per phase. I assume your voltage is 230V, 50 Hz?
So 6.6kW per phase, 20kW total.

In the US we might have 120/208Y for 3-phase. 120/240V if single (split) phase.
Single phase inverter between L1 and L2, either 208V or 240V.

In your case, 230/400Y so inverter L1/N, single phase is 230V and 3 phase also L1/N, 3 inverters in Y configuration.

SMA makes a 10kW 3-phase hybrid inverter for Europe that can backfeed the grid and provide 3-phase backup for loads. It would use BYD batteries, difficult to DIY (but some people have code to take EV packs with BMS and emulate BYD and others, for HV battery inverters.)


Other brands will support 48V include lead-acid settings, which can work with any brand or DIY lithium battery.

Sunny Island would be a robust but expensive solution, 3x $ for battery inverter plus more for PV inverter.
We're using them (120V model) in the US because DC Solar bankruptcy dumped a bunch on the market cheap.


There are several similar Sunny Island models for European market. Some have internal relay to pass through grid, some use external. Be sure of what configuration it supports before buying

SMA may be retreating from the residential and small business market, competition from low-cost brands.
Both SMA an Fronius were very high quality PV inverters. I haven't looked into what battery inverters Fronius might have.

Some people here bought Deye as lower cost alternative to SolArk. You should be able to get Deye. I think 3x 48V inverters could be wired as 3-phase. Probably have HV battery 3-phase model.

Three phase solar inverters help turn sunlight into usable AC power. This power can be utilized in homes and businesses. These systems are very efficient, often converting over 98% of energy. In the best conditions, three phase solar inverters can reach up to 99%. They work better than single-phase inverters, using energy more effectively.

If you want to learn more, please visit our website Sunplus.

When paired with a battery, three phase solar inverters store extra energy. Batteries save energy generated during the day for later use, which is helpful when there is no sunlight. This setup keeps power steady and operates even during blackouts. Together, the three phase solar inverter and battery provide a smooth energy flow. They help save energy and support the environment.

Key Takeaways

• Three-phase solar inverters turn sunlight into AC power efficiently. They often convert over 98% of the energy.

• When used with batteries, they save extra energy for later. This ensures power is available even during blackouts.

• Picking the right battery and inverter is important. Choose ones that are efficient and work well together to save energy.

• Watching how much energy you use helps improve the system. Use stored energy when electricity costs the most.

• Buying a three-phase solar system can save money over time. It also helps support clean and green energy.

Understanding Three-Phase Solar Inverters

What is a three-phase solar inverter?

A three-phase solar inverter changes DC power from solar panels into AC power. This AC power can be used in homes, businesses, and factories. Unlike single-phase inverters, it creates three AC waveforms that work together. This setup gives a steady and smooth power supply.

Three-phase inverters work in two steps. First, the DC-DC conversion adjusts the solar panel’s DC voltage to a fixed level. It also uses Maximum Power Point Tracking (MPPT) to get the most energy. Second, the DC-AC conversion changes DC power into AC power for the grid. This design makes three-phase inverters very efficient and dependable, especially for big solar systems.

The global demand for three-phase inverters shows their value in solar systems. They are key to matching solar DC power with the grid’s AC needs.

Key differences between three-phase and single-phase systems

Three-phase and single-phase systems are used for different purposes. Single-phase systems are common in homes, while three-phase systems are better for businesses and factories. Here’s a simple comparison:

Three-phase systems give more power and work more efficiently. They are great for places with high energy needs. They also lose less energy during transmission, which is important for factories.

Why 3-phase solar inverters are ideal for larger energy demands

Three-phase solar inverters are perfect for handling large energy needs. They spread power across three phases, keeping energy flow balanced. This reduces stress on the system and ensures reliable power, which is important for factories.

These inverters also help with advanced grid tasks like peak shaving and load balancing. They save energy, cut costs, and keep power steady. Their use in systems over 30KW shows they are great for big operations. Whether for a factory or a large building, a three-phase inverter works well to meet energy needs.

Components of 3-Phase Solar Systems

Solar panels and their role in energy generation

Solar panels are the first part of a 3-phase system. They take sunlight and turn it into direct current (DC) electricity. This happens through photovoltaic (PV) cells, which make up the panels. These cells use sunlight to create power, making them very important.

In three-phase systems, solar panels work very efficiently. They can produce power from a few kilowatts to many megawatts. This makes them great for big places like factories or offices. Their design reduces energy loss and keeps power quality high, which is key for good energy production.

Did you know? PV cells use Maximum Power Point Tracking (MPPT) to get the most energy from sunlight. This helps the system work at its best.

The three-phase inverter and its functionality

The three-phase inverter is the main part of a 3-phase system. It changes DC electricity from the panels into alternating current (AC). AC power is what your home, business, or grid uses. The inverter makes three AC waveforms, keeping power steady and balanced.

Modern inverters have smart features. Some can run tests to check if they work well during emergencies. They also give a smooth sine wave output for steady power. These inverters can provide emergency power from 4.8kVA to 50kVA. This makes them useful for many needs.

Batteries and their integration with inverters

Batteries store extra energy made by solar panels. When used with a three-phase inverter, they keep power steady even during blackouts. Special inverters control energy flow between panels, batteries, and the grid. This setup stores energy well and uses it when needed.

Some systems use lithium-ion batteries, which work in tough conditions. For example, these systems can handle temperatures from -120°C to 80°C. This makes them reliable in different places. Also, three-phase systems share power evenly, protecting devices and improving efficiency.

Tip: Pick a battery that stores energy from all three phases. This will help you save more and store more energy.

How Three-Phase Solar Inverters Work with Batteries

Turning sunlight into usable AC power

A three-phase inverter changes sunlight into electricity for use. Solar panels collect sunlight and make direct current (DC) power. The inverter then turns this DC power into alternating current (AC) power. AC power is what homes, businesses, and factories use. This process makes solar energy work with the grid and devices.

Three-phase inverters are great at this job. They create three AC waveforms that work together. This keeps power steady and balanced, which is perfect for high energy needs. Studies show how well this works. For example:

This smart technology helps solar systems work better. It makes sure you get the most energy from the sun.

Storing and using battery energy wisely

Batteries are important in solar systems because they save extra energy. This energy can be used later when needed. A three-phase inverter controls how energy moves between solar panels, batteries, and the grid. It makes sure batteries charge and discharge efficiently.

You can check how well your battery works by tracking:

• State of Charge (SOC): Shows how much energy is left in the battery.

• Depth of Discharge (DOD): Tells how much energy has been used.

• Input/Output Power: Tracks energy going in or out of the battery.

• Overall Battery Efficiency: Measures how well the battery uses solar energy.

By managing these factors, three-phase inverters keep batteries working their best. This helps batteries last longer and improves the whole solar system.

Controlling energy between panels, batteries, and the grid

Managing energy flow is key for three-phase solar systems. The inverter acts like a manager, sending energy where it’s needed. During the day, it powers your home or business first. Extra energy charges the batteries. At night or on cloudy days, stored energy powers your needs.

Some systems use bidirectional inverters for better control. These inverters let energy move to and from the grid. This helps with saving costs and using energy wisely. For example, a project at UTFPR showed how a 10.72 kWp PV system and bidirectional inverters cut energy costs and supported sustainability.

By managing energy well, three-phase inverters make solar systems more useful. They provide steady power, reduce grid use, and save money.

Benefits of Using Batteries with Three-Phase Inverters

Storing energy for later use

Batteries with a three-phase solar inverter save extra energy. Solar panels make electricity during the day, often more than needed. Instead of wasting this energy, it gets stored in the battery. You can use this stored energy at night or on cloudy days.

This setup lowers your need for grid power. Using stored energy during busy times avoids high electricity costs. For example, if your home or business runs at night, the battery provides steady power. This makes solar and battery systems a smart and eco-friendly way to manage energy.

Tip: Check your battery’s charge level and use it during expensive electricity hours.

The company is the world’s best single phase hybrid inverter supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

Keeping power steady and balanced

Batteries help keep power stable in 3-phase solar systems. A three-phase inverter spreads energy evenly across all three phases. This prevents problems that could harm devices or waste energy. Adding batteries makes the system even better at balancing power.

For example, when energy demand changes quickly, the battery adds power to keep things steady. This ensures your devices get consistent electricity, even during spikes. By smoothing out these changes, solar and battery systems protect equipment and work more efficiently.

Did you know? Balancing power also helps batteries last longer by reducing strain.

Reliable power during blackouts

Batteries with a three-phase inverter are very helpful during blackouts. If the grid fails, the system switches to battery power. This keeps your home or business running without interruptions. It’s especially important for places like hospitals or data centers where power loss is critical.

With solar and battery systems, you don’t have to worry about outages. The inverter handles the switch smoothly, giving steady power from the battery. This ensures important devices like lights, fridges, or medical tools keep working.

Note: Pick a battery big enough to power your needs during long outages.

Saving Money with Better Energy Use

Using a three-phase solar inverter and batteries can cut energy costs. This system uses stored solar energy during expensive electricity times. It helps you depend less on the grid and saves money.

A cost-benefit analysis (CBA) shows how this setup saves money. It compares the upfront costs with long-term savings. While installing solar and batteries costs money at first, lower bills make it worth it. You also get other benefits like less pollution and better efficiency.

Here’s a simple look at cost savings:

To save more, watch how much energy you use. Use stored energy when electricity is most expensive. This keeps costs low and power steady for your home or business.

Tip: Check your battery’s charge level often. This keeps it working well and lasting longer.

By combining a three-phase solar inverter with batteries, you balance energy use and storage. This reduces waste and boosts efficiency, saving you a lot of money over time.

Choosing the Right 3-Phase Solar Inverter and Battery System

Understanding your energy needs

Knowing how much energy you use is very important. Look at your daily and seasonal energy patterns. This helps you decide the size of your solar panels and batteries. For example, if you use more energy at night, you’ll need a battery that stores enough power from the day.

Pick equipment that is efficient and affordable. High-efficiency solar panels and inverters give you more energy from sunlight. Use monitoring tools to check how much energy you make and use. This helps you improve how your system works.

Picking the right battery and inverter

Choose a battery that can handle your energy needs. Look for batteries with good depth of discharge (DOD) and state of charge (SOC). Lithium-ion batteries are a great option because they last long and work well.

Inverters should also be efficient. A good inverter reduces energy loss when converting power. Check the inverter’s specs to ensure it fits your needs. A well-matched battery and inverter will make your solar system work better.

Making sure your system works with the grid

Your solar system must follow local grid rules to work properly. These rules ensure your system runs safely and supports the grid. For example, international standards like IEC focus on battery safety and performance.

Key factors include voltage, frequency, and power quality. In North America, the NERC suggests grid-forming features for large systems. Other countries like Australia also have strict grid rules. Following these standards ensures your system is safe and efficient.

Tip: Ask an expert to check if your system meets all local rules and grid standards.

Tips for picking a system that grows with your needs

Choosing the right solar system helps it last and work well. Here are simple tips to pick a setup that fits your future energy needs:

1. Plan for more energy use later
   Think about how your energy needs might grow. If you plan to add devices or expand your space, pick a system that can handle more power. Scalable systems let you add panels or batteries without replacing everything.

2. Check the inverter’s power limit
   Choose an inverter that can handle bigger energy loads. A three-phase inverter with high capacity keeps energy steady as your needs grow. Always check the inverter’s details to match your current and future power use.

3. Pick strong and efficient batteries
   Batteries store energy for later use. Choose ones that last long and work well. Lithium-ion batteries are a great choice because they need little care and work reliably. Make sure the battery works well with your inverter.

4. Focus on quality and warranties
   Buy parts from trusted brands. Good systems often come with long warranties for peace of mind. Check the warranty for both the inverter and batteries to ensure support for years.

5. Get advice from experts
   Talk to certified solar installers or energy experts. They can check your energy needs and suggest the best system. Experts also make sure your system follows local rules and grid standards.

Tip: Check your system often to spot problems early. This keeps it working well and saves energy.

By using these tips, you can build a solar system that grows with you and provides steady power for a long time.

Three-phase solar inverters and batteries work together to save energy. They turn solar power into usable electricity and store extra energy for later. This setup keeps power steady, lowers grid use, and supports eco-friendly energy.

More people want hybrid systems because they mix batteries with three-phase inverters. These systems are very efficient, often above 95%. They also help create energy locally. By using this technology, you can save money, get reliable power, and help the planet. Start using three-phase solar systems now to manage your energy and live sustainably.