Grid-Tie PV System VS Off-Grid PV System

There are basically three types of solar PV systems existing today for solar power generation at home, including grid-tie, off-grid and hybrid PV systems. However, as expense and efficiency are concerned, grid-tie and off-grid systems are more popular and most installed around the world. Now let’s compare them with each other and help you decide which system should be suitable for your house.

grid-tie solar PV system
grid-tie solar PV system

Grid-Tie System

1. This installation requires your system is connected to the local national (utility) grid.
2. After the connection, the system can feed the electricity (usually extra electricity) it generates to the national grid (this helps it earns money from the grid), and your home can get the electricity from the national grid once your system stops generating electricity at night or in special conditions.
3. The current form your solar panels generates is direct current (DC), which must be converted into alternating current (AC) for home use by going through a PV inverter. The current converted by the inverter must be compatible with the voltage of the local grid.
4. The inverter also needs to be a grid-tie type. An off-grid one cannot be used here.

Off-Grid System

off-grid PV system
off-grid PV system

1. Off-grid means the system is disconnected from the local national grid and cannot feed extra electricity to earn money.
2. This installation needs storage batteries, which usually cost a lot of budget.
3. This system is suitable for installation in areas where houses cannot be connected to the national grid or where residents are far away from grids and cities.
4. It needs a charge controller which is used to charge the batteries of the system.
5. The DC from solar panels usually goes to a battery and then to an inverter.
6. This inverter is an off-grid inverter.

Grid-Tie Advantages

1. It can constantly power your house unless the national grid is down and the system meets its special conditions.
2. It can help earn money from the local government by selling extra electricity.
3. It costs less compared with an off-grid system because it doesn’t need expensive batteries.
4. It works more efficiently because its DC doesn’t to go into a battery. This process causes energy loss.

Off-Grid Advantages

1. It can be used in remote areas where national grids cannot reach.
2. It can store extra energy and use it whenever your house needs.
3. It doesn’t need the grid-connecting process.
4. It is totally environmentally friendly.

Current Condition

In comparison, residents around the world prefer a grid-tie system more, and many countries like the UK, the US, the Netherlands and China are encouraging their residents to install this system. But In India, an off-grid system seems to enjoy more welcome because many regions in the country cannot reach national grids.

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Key factors to consider before buying a PV inverter

A PV inverter is an essential part of a solar power system, and it is always sold along with the system. So you don’t have to worry about only buying one inverter, and how to make your decision before you buy it. But sometimes we need to buy them without the system attached. Based on this concern, you need to consider some factors that are key to the products themselves. Now let’s check them out.

1.Type
Generally speaking, there are two types of inverters: grid-tied and off-grid inverters. If you have a grid-tied system, you need to buy grid-tied inverter; and if your system is stand-alone, you should buy an off-grid inverter. Also inverters can also be divided into commercial and residential inverters. They have different voltages and power ranges.

2.Efficiency
Efficiency is the core element that measures whether the device you choose is good or not, because it affects how much alternating current your system or power plant can convert. If your inverter has the efficiency of 96%, you will harvest more alternating current than those who only have inverters and their efficiency is only 92%. For a family, it is power loss; and for a power plant, it is money loss, large sums of money loss! In fact, the most efficient solar power inverter is 98.5%, and most commonly-used inverter efficiency is usually 98%, 97% or 96.5% (probably micro inverters).

3.High quality
In common conditions poor quality PV inverters often have bad circuitry, poor quality seals, noise while working and so on. These conditions can affect the product’s total converting efficiency, your daily life (loud humming noise can make you crazy) and the product’s lifespan. Off-grid inverters are often somewhat waterproof (such as in the rain) and are installed outside the house. If the quality is problematic, the solar inverter will not work well.

4.Input DC range
The electricity generated by solar panels is direct current or DC, which will be transmitted to the solar inverter. But the DC has a range. If it is more than what the inverter can bear, some amount of DC will be lost.

5.Maximum AC output
By learning the maximum AC output, you can reckon how many appliances your family should have. If you want to buy more appliances, you can install more panels and buy a larger inverter for this conversion. For a solar PV power plant, this also counts.

6.Brand Influence
What’s the influence of a brand name? It has two meanings at least. One is that it can somewhat guarantee high quality and high efficiency products. For example, Sunny Boy is a famous brand. Indeed their efficiency is excellent. Their highest efficiency can reach up to 98.5%. The other is that its credit is highly-approved. A big brand name don’t often cheat its customers, because if they do so, they will lose customers and followers. Certainly the two things are absolutely correct, for sometimes big names can also mean poor quality products. At least, not all of its products are excellent.

7.Price
I believe this is the mostly concerned factor for each buyer. Anyone wants to buy cheap price products, but they also care about product qualities. There is no exception to buy a PV inverter. Cheap prices products are not always problematic, while many cheap price products are indeed problematic. Before you buy, you had better consult with some who have already bought these products or installed a solar system at home if you buy residential inverters. If you buy commercially-used products, you need to consult with those power plants owners who have installed these products. Surely, checking retail and wholesale prices online and offline is also very necessary.

8. Customization
Google is a company that allows users to customize their browsers and search engine results, and so it is loved by users. The key point is that people love to control things, especially those that are important to them. Based on this concept, some inverter designers have also allowed users to customize their inverters. In fact, this is not only a matter of control but also a matter of usefulness. If an inverter can be customized, users will have more favorable and suitable products. This counts a lot!

In addition to these concerns, you may also need to concern about many other factors. But with these factors concerned, you can surely buy high quality and highly efficient PV inverters.

What factors make high efficiency PV inverters?

Omnik solar inverter
Omnik solar inverter

Before we discuss the factors that can make highly efficient PV inverters, let’s learn the definition of what the efficiency is at first. It refers to the rate that a PV inverter converts the direct current generated from sunlight into the alternating current which is used directly by each family. After making the definition clear, we can discuss the factors.

A PV inverter is a machine which produces heat while working. Usually a machine’s working efficiency reduces as its heat grows. Indeed this is the same for a PV inverter. From this perspective, we know if it can keep cool while working, they can work more efficiently. Out of this concern, the inverter with a cooling system inside has been invented and is being used. Omnik’s micro inverters are a typical example of this kind. At the same time, to make an efficient inverter work better, users can install it in the places of a house where sunlight cannot reach, as so to make it cool. In addition, voltage optimization and inverter load are aslo two important elements that influence the efficiency. The inverter load is the amount of power that the inverter is supplying compared to its rated power. The following picture shows how an inverter’s efficiency changes as its output power changes.

inverter-efficiency-curve
inverter-efficiency-curve

Today, the highest solar inverter technology originates from Europe, especially Germany. The most excellent technology it holds is the high frequency isolation technology, which can protect the inverter from damage and make it work more efficiently. Currently the highest solar inverter efficiency can reach up to 98.5%. The most efficient micro inverters (mainly used for residential solar PV systems) have the highest efficiency of 96% or so.

In the world there are numerous solar inverter manufacturers, and some of the big names are really producing high efficiency inverter products, including SMA (98.5%), SolarEdge (98%), Advanced Energy (98%), Kaco (98%) and Siemens (98%). In fact, there are also other highly efficient products including Omnik (98.2%) that product excellent inverter products. To learn more, please check this information and clear your confused mind.

Warning
Some inverters have a high efficiency when they output in highest power, but have low efficiency when they output in lowest power; and some even have an average conversion efficiency when they output from low power to high power. Therefore, when choosing solar inverters, you need to consider whether the solar panels’ output characteristics match the features of the solar inverters or not.

Why Go Solar?

Solar Panel Home
Solar Panel Home

Why do we need to turn to solar energy for generating electricity? Indeed, there are various reasons to discuss. In this article I will show you some of the most important reasons why we should go solar today.

Free resource
Solar electricity comes from sunlight, which has worked for over 1 billion years and is still young and energetic. It can provide us with a rich resource. More importantly, sunlight is clean, and the solar PV system which converts it into electricity doesn’t produce waste during the process as other power generation forms do.

Money saving
Money saving can be divided into two sections: reducing family cost and social burden. For a family, installing such a power plant needs money as invest. In the beginning it is a little bit much, while this invest will help you save the money that you usually pay for the utility grid. On the other hand, as public electricity price rises, your family will have to pay the electricity bill more than ever before. This might not be a great deal for rich family, while it must be a nuisance.

Less noise
Factories often have noise when their machines begin to work. For a solar power plant, it doesn’t have to produce any noise because its machines are those solar panels which stand quiet all the time in the sun. For a residential PV system, the owner doesn’t even need to think about it. Solar panels are on the rooftop and where does the noise come from? The only noise should come from the solor pv inverter is just the very low sound when the inverter works.

Beneficial for remote areas
Many families are still located in remote areas where utility grid cannot reach or is too expensive to reach. For this concern, solar power plants can help do this business. Or if you are not willing to share solar electricity with other families in these areas and have a certain financial support, you may choose the independent residential power generation system.

Tech improvement prospect
Solar electricity is powered by high technology. Today’s highest sunlight conversion rate can reach up to 40%. As technology improves, higher conversion rate can be expected and more sunlight electricity is possible too. In this case more electricity can be harvested and less money will be spent on it.

Easy to install at home
As solar power technology improves, homes can generate electricity themselves too. To install this tiny power station at home is not a complicated business. Install a few solar panels on the rooftop, use some wires to connect, install a storage device (only for the independent PV system), install a PV inverter inside your house or outside it. Everything is done unless you need another meter to record your electricity generation amount. Some companies even provide software and apps to monitor the whole system, and so you can use you smart mobile phone to do the monitoring job. It is suggested that you install the PV inverter inside your garage, utility or loft (if your family has one).

Environment friendly
Our air quality now is not as standard as before, and the low quality will surely threaten our heath and can cause respiratory disease. Also, global warming is turning over the balance of the world’s climate, and the most serious culprit that causes it is greenhouse gasses which are produced by so many oil, gas and geothermal and other energy companies. So, it is necessary and urgent to protect our fragile environment by going solar. It is complete air pollution free.

Water saving
The world is facing water shortage, while many industries including gas, oil, coal and nuclear are still using so much water for cooling. This consumes large gallons of water. If more and more families can use solar electricity or build their own solar power systems, much more water for cooling will be saved for sure. This seems too big, while when you face water shortages, you will realize “how important water is for me.”

More jobs to be created
Many countries face serious unemployment including France, Spain and US. If more jobs can be created during this process, this will be a great achievement. But how? The fact is the solar energy industry is a labor intensive industry not like oil or other businesses (they are much more capital intensive). When more people go solar, more jobs will surely be created. This is its great trick!

However, apart from these advantages mentioned above, there are still other reasons for going solar. Meanwhile, we cannot ignore that solar energy can help generate electricity only in daytime, and it cannot generate as much electricity as it can in sunny days. Thus, when we choose it, we still need to consider specific conditions for specific areas and other related conditions. But going solar for us is a trend and will expand for sure.

Cut Down Solar Prices, You Will Win

solarpices

Solar energy will become the most appreciated way out for every one of us as it is used to generate power to replace biofuels which most countries in the world are still using for power generation. However, there is a loophole in developing this new business. So, what’s that? Obviously, it is the solar prices.

In spite of solar energy’s green way of generating power, people today or in the future must care about more of their own profits and well beings than other factors which even a country like the US or China is trying to promote. From this way to think further, a solar material manufacturer should get an idea: price must be the topmost concern.

However, to create a PV solar system is not only to produce some solar panels, racks or wires, but to manufacture high quality PV solar inverters. You see, they are key in converting the direct current generated from sunlight into alternating current that each family uses everyday. As a solar material manufacturer, what you need to do is obvious: cut your these materials’ prices. In a market, businesspeople in the field always fiercely compete with one another on price, and many of them compete even in vicious ways. But in the solar energy industry, you cannot do it like that.

Keeping an eye on the global solar market, one should know that solar panels’ prices are decreasing rapidly compared with the past years due to large scales of production and shipments. This is a good phenomenon for consumers, while it may not be so nice for a manufacturer. Now either the US or China is offering incentives to this industry, but this will never last long. Helped by this opportunity, a producer needs to do more things. Cut down the prices of your solar commodities, trying to meet the demands of different customers.

According to my personal knowledge of this industry, the profits in solar materials are not bad. So, how to persuade customers to buy your products not others? Yes, one should design and produce excellent solar products, I think, especially solar inverters, for they are the soul in a solar PV system. A manufacturer needs money to sustain his factory or company, so he needs profits. How to get them? You don’t have to charge labor in installing the system, and you even don’t have to charge so much the solar panels installed on a rooftop. So, charge what? Charge the inverters and their accessories!

However, probably developed counties and developing counties are different in labor payment. In the US, the UK, Australia and the Netherlands, labor price must be very high. In China or India, labor will not be that expensive. Therefore, take different measures to deal with different special problems. For one company in a developed country, large scales of production and shipment might be more favorable than lowering labor payment.

PV Inverters: Omniksol-1k/1.5k/2k-TL2

Omnik Solar Inverter

 

PV inverters are various, while those that are extremely excellent might not be that many. To meet the standards of those who want outstanding PV inverter products, today I introduce one brand that may meet your needs or help you decide which way you need to take. Now, follow me and check why.

The inverters I introduce today are the ones from the Omniksol-1k/1.5k/2k-TL2. What does the Omniksol mean? It means Omnik and solar. Omnik is a PV inverter brand specializing in developing, designing, manufacturing and selling PV products, and its technology originates from Germany. Solar means something that is related to sunlight or sun power. In the PV industry it is often combined with other words such as inverter, panel, energy and others. Once they are combined, they stand for different and unique meanings. K stands for KW, and TL is a terminology for this product and it is “transformless” for short.

Having understood the basic information of these types of items, you are now heading for the specific functions and impressive characteristics of them.

The topmost element a professional PV inverter buyer always requires is the conversion efficiency of the special product. To make you feel satisfied while viewing the brand the first time, I can tell you that these products’ conversion efficiency can reach up to 97.5%. This rate stands out among the most efficient solar inverter (the other name of PV inverter) products in the world today. You may still feel doubtful about this, but you can check information online before you judge what I am telling you here is truth or false. Along with this function, they have the MPPT (Maximum Power Point Tracking) function, and its efficiency can reach up to 99.9%.

Do you feel impressive or not? If you do, you may follow me to learn more features from the paragraphs below.

Inside each of these devices there is a Wi-Fi card, which serves to send the working information of the inverter to the outside. The thing I need to highlight here is this is the technology invented by Omnik in the world. Also, each device is equipped with the PMB (Picture Motion Browser) function, which can store all the important data that the sensor has. And each of these products has RS485, RS232, USB and the standard Ethernet port. By downloading the free controlling software from Omink’s official website, the user can monitor his or her solar energy system’s electricity output and the public grid any time he or she wants. Besides, you can also choose to install the Wi-Fi kit or the GPRS kit.

Apart from these amazing functions described in the two paragraphs above, you will also realize that you still need at least one quality from this product. What is it? It is its protection of the inside components of each inverter.

No doubt, nearly every excellent product has brilliant production of its components, so do these PV items. But they are different largely from others, for they have internalized IP65 protection, which guarantees each inverter can be installed indoors or outdoors. No matter what weather conditions, the device will seldom get affected. Even in a stormy night, you don’t have to worry about how the small device can go through such terrible weather. This PV thing is small, and so it is easy to be installed in your house.

In fact, some picky customers might need to customize their products as they always do on the internet. For this concern, the product team is working for you. To well serve each customer, the team can design and make any kind of solar PV inverter with power ranging from 1,000W to 2000W in the Omniksol-2k-TL series. However, sometimes customers may not be so accurate about which size they really need. Thus, the team can offer you reasonable suggestions so that your purchase will be so suitable for you.

Finally, if you decide to buy one of these inverters, you have its well-designed services. These products are designed of dear customers, and so if any malfunctions occur now or later, your given software will automatically send back these information to the team for repairing. If the solar equipment itself is in mess and cannot work after repairing, the team will bring another to you. And, some customers may ask: “What warranty can the brand provide for you?” No worry! Its warranty can last 5 to 25 years for different types of its products.

What Can One Micro Inverter Do for the PV system?

Micro INverter
Micro INverter

A mircro inverter is to directly integrate an inverter and a single PV pack, which will equip each PV pack with an inverter module which has alternating and direct functions and MTTP. The device will directly convert the electricity from the PV pack into alternating current, which is used for a family or for transmission.

When one part of the solar panels cannot work well, this part will all be affected. Other PV panels will work in the best condition, which makes the entire system work much better and generate more electricity. In practice, if the string type inverter meets malfunctions, the solar panels over 1000 KW will not work well. But if the mircro inverter is installed, the malfunctions occur at the moment will be reduced a lot.

In each micro inverter, you will find some shiny advantages as shown below.

Firstly, the inverter can improve the amount of electricity for the power source and track the biggest power. By using this function, the PV system’s electricity generation can be improved by 25%.

Secondly, the mircro inverter can help adjust the voltage and current of each array until the whole system reaches the balance, in case of losing balance.

Thirdly, each part of it has the monitoring function, which lowers the maintenance cost of the entire system, and makes operation more stable.

Fourthly, its configuration is flexible. If this pv inverter is installed at home, the number of the solar panel installation should be in accordance with the financial condition of the user.

Fifthly, this inverter doesn’t have high voltage and it is safer and easier to install. With its lower maintenance cost, the user will never have to depend so much on the installer. Therefore, the user will become more independent in generating electricity.

Sixthly, its cost appears lower than those of other types of solar inverters.