How Much Does a 10kW Solar Power System Cost? – 2021 Update

Before deciding to install a solar power system, people will normally ask a lot of questions. For sure, the most frequent one is this – how much does a solar power system cost?

For this example, we will consider a prevalent system size for residential or commercial installation. And that is an on-grid 10kW solar system. In this article, we will answer this exciting question in detail. We will demystify it as much as the solar salespeople don’t want you to know.

Basically, there are two common types of solar PV systems: on-grid and off-grid. If you want to know more about them, you may want to read our article about the differences between on-grid and off-grid solar power systems.

How much does a 10kW solar system cost?

So, how much money do you need to buy a 10kW solar power system? To directly answer this, a 10-kilowatt solar system of good quality can cost between US$9,800 to US$14,000.

This is the price range of a system of this size.  You will confirm it when you know the real costs of each component from the suppliers. Learn more about the cost breakdown, details, and information below.

What is a 10kW solar power system?

A 10kW solar power system has at least 25 to 40 solar panels. It can take up space between 55 to 70 square meters. However, the number of solar modules and space required depends on the module’s efficiency.

The system can generate up to 16,400 kWh of electrical energy every year or up to 45kWh daily. This depends on the tilt angle, orientation, and geographical position of the solar power system.

Time-lapse Video for Solar Power System Installation

What is in a 10kW solar power system?

To have an idea about the cost, we need to break down the whole system into its basic components. We will determine the bill of quantity or BOQ of the 10kW solar power system.

A solar power system consists of four basic components. These are the solar panels, the inverters, the mounting structures, and the balance of the system (BOS).

The quantity of each component will base on the total capacity of the system. This means as the kW increases, the number of materials for each component will also increase.

Considering a 10kW or 10,000-watt system, we can break it down into its basic parts as follows:

Solar Panels for a 10kW PV System

Solar panels’ cost usually falls between 45% to 60% of the total system spending. Now, for a 10,000-watt solar power system, you will need at least 25 solar modules. However, consider only the power capacity of solar modules available in the market. You can choose from 250-watt up to 410-watt module capacity.

Choose modules with high power capacity as much as possible. It reduces the number of solar panels that your system will require. By doing so, you will be able to optimize your budget in the long run.

Although the price of solar panels will be based on USD/watt, reducing the number of modules will benefit you. It’s because it reduces your cables’ length, number of racks or supports, and even maintenance costs.

Solar Panel Selection

For this system, the most effective option is to use a 400-watt solar module. What you need to do next is to divide the solar panel capacity’s total solar power. Then, you will determine the total number of modules to buy. You may also check what solar panels are made up of.

10,000-watt / 400-watt = 25 units

For a 10kW solar power system, you will need 25 units of 400-watt solar modules. You may want to check out our article about solar panels for homes to learn more about this.

Solar Inverters for a 10kW Solar System

For a 10kW solar power system, you will need at least one solar inverter unit. As for the cost percentage, this component will amount between 15% up to 25% of the total system cost.

We want to invite you to read our article about the best 10kW inverters today for you to have an idea of what your options are.

What is a solar inverter?

One of the major components of a solar power system is the inverter. It comes in different shapes and sizes. Sometimes, it is installed outdoors or in the field together with the solar arrays. But, most of the time, it can be found under the shade or even indoors.

The inverter is the heart of the solar power system. Its main purpose is to transform DC power from solar arrays into useful AC electricity. This will then be used for homes or other establishments.

What are the different types of solar inverters for a 10kw PV system?

There are many types of inverters that are available right now. We will just focus on the inverters, which will apply to a 10,000-watt solar power system. We can consider these two types:

Micro Inverters

A micro inverter is the type of inverter which is directly connected to a single solar panel. It is installed just underneath the solar module. It also means the number of modules will determine exactly how many micro-inverters you need.

Its output is AC power. In most cases, it has almost the same capacity as the panel it is connected to. Since the output is relatively small, you will need to have a combiner or collector. This will combine all the smaller AC outputs from the microinverters into an electrical panel. It will have an output power relatively closer to the total capacity of the system.

Advantages of Micro Inverter over String Inverter

Here is the list of advantages of micro inverters.

• By using microinverters, the effects of partial shading to the system will make less impact.
•  If the solar panels are facing different tilt angles, microinverters will be of great use.
• Micro-inverters will let you monitor the performance of each solar panel.

Disadvantages of Micro Inverter over String Inverter

Here is the list of disadvantages of micro-inverters.

• The system will be costlier with micro inverters.
• Operation and maintenance will be more complicated.

String Inverters

A string inverter is a device that requires several solar panels connected in series as an input. When you connect about 5 to 18 solar panels in series, it is already called a solar string. Thus, the name of the inverter comes from that concept.

Most string inverters convert DC power from the solar strings into AC using MPPT or maximum power point tracking.

MPPT is an algorithm that string inverters use to sample the output power from the solar panel strings. It then applies the proper resistance (load) to get maximum power. This allows the string inverter to maximize the extraction of power from the solar modules. Thus, making them convert sunlight into useful electricity efficiently.

Advantages of String Inverter over Micro Inverter

Here is the list of advantages of string inverters.

• Most of the time, you will only use 1 string inverter for small to medium size installation.
• String inverters are cheaper compared to buying multiple micro-inverters.
• The operation and maintenance of the string inverter is simple.
• Installation of a string inverter is quicker and easier.

Disadvantages of String Inverter over Micro Inverter

Here is the list of disadvantages of string inverters.

• There will be no individual solar panel monitoring.
• There could be some string mismatch when there is partial shading or a difference in solar panels’ inclination angle.

Why choose string inverters

Considering a 10kw solar system, it will be best to use a string inverter. Why? It’s because the cost-effectiveness of a string inverter outweighs the advantages that micro inverters have. Besides, not everyone needs to monitor each solar panel.

Additionally, one string inverter will be enough for a 10,000-watt system. Thus, it will help in optimizing the budget.

String Inverter Oversizing

Sizing the inverter is not as difficult as it sounds. Once you have the system’s total size (in kilowatt peak), choosing inverter size will be straightforward.

However, one thing you need to know is that string inverters can be oversized. It is a practice recommended by solar designers and consultants. Why? It’s because it significantly lowers the cost of the system. Additionally, it maximizes the inverter efficiency, considering the peak capacity of solar panels won’t be reached all the time.

Inverter oversizing means you can choose an inverter with a lower output power capacity than the solar panels. However, you should always refer to the inverter’s datasheet to know the limitations.

In general, the recommended oversizing ratio is up to 130% (DC to AC ratio). To simplify, DC to AC ratio refers to the total solar power (DC) over the inverter output power (AC).

How to choose string inverter for 10kW solar power system

• Check all the available string inverters in the market with a rating that will satisfy up to 120% DC to AC ratio.
• Considering a 10,000-watt solar array, an inverter rating from 7.7kW to 9kW will be the best choice.
• Get the datasheet for each inverter and read them carefully. Always check how much power it can take as input.
•  Since we consider 25 nos. 400-watt solar panels, choose a string inverter with at least 2 MPPT inputs.

Solar Panel Mounting Structures

Mounting structures are the supporting structures that hold the solar panels to the roof or ground. This can be made out of GI steel or aluminum materials. Usually, it has a combination of railings, end clamps, mid-clamps, mounting brackets, and other supporting structures. Its application ranges from ground mount, flat roofs, sloped roofs, tiled roofs, and others.

In general, the component amounts between 8% to 15% of the total solar power system cost. The cost will vary depending on the application of the solar mounting structure.

For a 10kW solar power system, we will consider a common sloped roof installation. This system will require 5 sets of 1×5 mounting structures for this type of application.

Balance-of-System (BOS) for a 10kW Solar System

Balance-of-system for a solar power plant includes cables, wiring accessories, metering equipment, breakers, and switches. It usually sums up to 10-20% of the system’s total cost.

AC Power Cables

It is recommended for a 10kW solar power system to use an AC cable with at least 10sq.mm. in size. This is the case when we decide to use a string inverter. The cable should be a  4-core copper armored cable that will connect the inverter to the 3-phase main distribution board.

DC Cables

You have to consider a DC cable with at least 4sq.mm. in size for this system. This should be a single-core copper solar cable that will connect the solar strings to the inverter.

Breakers and Switches

Proper sizing of the breakers to be installed on the AC Main distribution board is very important. Always check the maximum output current of the inverter. From there, you can determine the size of the breaker you will need.

Usually, for a 10kW solar power system, you need to use between 32A 3-phase breaker.

Metering Panel

The metering panel is the enclosure where you or your electric utility will install the solar meter. Its main purpose is to measure how much your system has generated in kWh or kilowatt-hour.

BOQ for a 10kW solar power system

BOQ (or bill of quantities) is a document used to itemize the materials you will use in constructing a project. Here, we will show you what a 10kW solar power system BOQ will look like.

Cost Breakdown of a 10kW solar power system

Now, here is the cost breakdown of the system. This will base on the actual average cost from direct suppliers. However, brands will not be mentioned here.

From the table above, you will see the materials cost will be around $10,000 only. If you hire a contractor to build your system, additional labor charges, permit fees, and others are expected. On top of that, they might also add their margin for the materials. The final cost might go up to $20,000 or even more.

However, always look for professional solar contractors to do the job. This way, you will avoid headaches and delays on the project.

How much energy will a 10kW solar power system produce?

The graph above shows an actual yield of a 10kW-peak solar PV system in the whole year of 2019. This system is installed on a residential rooftop located in the United Arab Emirates.

In a year, a 10kW system will produce 12,000 kWh up to 16,400 kWh. However, it all depends on the solar plant location, site condition, inclination angle, shading, and system maintenance.

How long will a 10kW PV system last?

Usually, a 10kW solar system lasts up to 30 years. Depending on the level of maintenance being carried out, solar panels, inverters, and the other system components will outlast their warranty years.

It is recommended that you perform overall maintenance checks at least twice a year. Cleaning solar panels, checking AC and DC cables, and inspecting the inverter should be done regularly to help prolong the solar PV system’s life span.

How long is the payback period for a 10kW solar system?

The payback period of a 10kW solar system is between 5 to 8 years. Again, it depends on the system’s initial cost and the kWh rate from the electric utility.

Additionally, net metering, feed-in tariff arrangement of the local utility, and system maintenance also need to be considered. After the payback period, everything you get from the system is free energy!

Conclusion

In this article, we have presented to you an example of a 10kW-peak solar PV system with the actual data of its kilowatt-hour yield in a year.

From here, you will be able to calculate how much you will save on your electricity bills depending on the kWh tariff imposed by your utility. The breakdown of the system cost is also discussed here as a guide for you and the materials you will need to build the system.

Now, you have the idea of how a solar PV system will cost you, particularly for a 10kW capacity. The decision is yours whether to invest in solar energy now or later, depending on your budget.

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