Small and Light Three Phase String Inverters Appear at Shanghai Expo

omnik solar inverter
Omnik solar inverter

The SNEC PV Power Expo was held from April 28 to 30 in Shanghai, China Thousands of PV industry companies with their own solar products attended the expo. Omnik New Energy from Suzhou, Jiangsu province also appeared at the expo and exhibited its small and light three phase string inverters there for three days.

Omnik is famous for string inverter manufacturing, and so it brought its high efficiency three phase string inverters and and single string phase inverters to the expo, which drew so much attention of the expo visitors. During the three days my colleagues and many customers from home and abroad discussed issues relating to inverters many times, and one customer from India even visited our booth several times to seek a cooperation opportunity.

The inverters brought to the expo were about 10 or so, and the most attractive ones were two: Omniksol-1K/1.5K-M and Omniksol-10K-TL2. The first one is a single phase inverter, while the second one is a three phase inverter. They don’t look special, but they have their special features that are attractive to customers.

Omniksol-1K/1.5K-M is a newly-launched product by the company in 2015. It weighs 5 kg and doesn’t need any transformers as many other inverters need. The highest efficiency of it can even reach up to 95.5% and its MPP tracking accuracy can be as high as 99.9%.

Omniksol-10k-TL2 is also a new product released by the company. This three phase string inverter weighs 22 kg, which is easier to install and transport and can help save cost.

During the three days Omnik also held a product conference to show the two products to customers who came to the expo to collection information and see new PV products. After the three day expo, Omnik’s staff have already established new relations with more customers from home and abroad.

Two Ways That Make Solar Electricity Even Cheaper

solar power houses
solar power houses

Although solar electricity has already become cheaper than ever before, we still have ways to make it even cheaper. Traditionally solar goers save money by installing cheaper or fewer solar panels, buying cheaper PV inverters, or employing cheaper laborers. No doubt, these are excellent methods, but they are not essential methods. Recent industry news stories have revealed two essential methods that can reduce its price ultimately.

1.Make solar panels much more efficient than ever before.

No matter whether it is in a distributed solar PV system or in a solar power plant, one of the two most important components is solar panels because they convert sunlight into direct current. Based on this concept, scientists have researched solar panels for years, and of course their research focus has been on solar cells which are cells of solar panels. Now solar scientists have released a new invention that they can push solar panels’ average maximum efficiency (25.6%) to a new higher record 46%, a figure which is even higher than the 40.1% achievement researched by a team of Australian scientists.

However, there is an obvious question about it: are these cells more expensive than common cells since they work more efficiently? The answer is no. The study was aimed to research some cells that have higher efficiency but don’t cost too much or make financial trouble for consumers. Most commercial solar cells are made from silicon. To make them work more efficiently, these scientists have used tandem solar cells, which can generate more electricity. Their specialty lies in that they can absorb sunlight in multiple ways. If one light-absorbing material is used, the theoretical limit efficiency can reach up to 34%. But when two light-absorbing materials are combined in tandem, the highest efficiency will turn up to 46%. Their smart strategy is to combine silicon and the metal-halide perovskite, which can be manufactured at low cost.

2.Global PV inverter prices are estimated to drop 20–25% by 2020.

Solar panels are one of the two most components in solar power generation, and what is the other half? It is PV inverters, because they work to convert the direct current generated by solar panels into the alternating current that powers every house. In common conditions they are considered the most expensive products in the whole power generation system. But the good news is their prices have declined rapidly from the beginning. The most recent report from Global Data estimates their prices will continuously go down. There must be some critical reasons for that.

PV inverters’ costs have been decreasing rapidly because the global PV systems and solar power plants have dramatically grow in number and watt. According to the report, their prices are estimated to fall by 20–25% by 2020. The global average cost for them was $0.48 per W in 2010, which will drop to $0.13 per Watt by that time. Apart from massive production and installation, another great contributor is tariff cuts, which influence installations and demands for solar power too.

In addition to the two major breakthroughs, there is also one important element worth your attention. That’s market transfer. The solar market including solar panels and PV inverters markets has transferred to North America and Asia-Pacific, and China has become one of the most prominent players. Its solar panels and PV inverters are relatively cheaper, and indeed this can make solar electricity even cheaper too if you choose them.

India to Create 1 Million Jobs and Boost PV Inverter Market by Solar Ambition

PV Park in India
PV Park in India

India has been in unfavorable conditions until recently when its moves become inspirational as it targets to create miracles in the solar energy industry. As Modi took office, all kinds of projects about solar power have been put into practice or are being practiced. Recently news reports from the country have announced that India has set up a solar energy ambition of getting 100 GW of solar energy by 2022. More astonishingly, it is estimated that the goal will create 1 million job positions in India.

In the country many areas are out of reach for the national utility grids, and so these areas have been living in the dark. If some large-scale solar power projects can be built in the country, numerous families having no access to electricity will be able to rid of blackouts at night. On the other hand, when these projects are to be built across the country, human labor will be needed, and so jobs will be created. In detail, the jobs mainly come from project planning, construction, installation and operations.

By setting such a goal, India will not only create 1 million jobs to power the country’s economy and root out its high unemployment rate, but also it will boost the PV inverter market in the coming years. The basic knowledge is solar power doesn’t generate itself, it needs solar panels to convert sunlight into direct current and then PV invters to turn direct current to alternating current, which sustains each family’s power needs. In this process large numbers of PV inverters will be manufactured to do the converting job along with innumerable solar panels.

Currently there are two different situations found in the inverter market in India. One is these photovoltaic inverters will only be used in solar power plants. If so, string, single phase and three phase inverters will be produced to meet the needs. Simultaneously, other types of inverters specially made for these factories must be made. This is the majority of the total inverter market share. The other half share is manufacturers inside the country should also produce microinverters, which are the new invention in recent years. Their specialty lies in that they are only suitable for home power systems. By using these inverters, more electricity will be generated. This requires large sums of money of investment, which most Indian civilians cannot bear at all. Today, the quota for this part is very small but serves as the other half.

In addition, the media report that India hopes to make contributions to climate change by boosting its solar power. The typical example is that Modi and Obama have solidified their common commitment to fighting against climate change.

The Solar Inverters of Omnik New Energy

Omnik is a Suzhou-based company specializing in manufacturing solar inverters which include single phase, three phase, hybrid and micro inverters. Besides, the new energy company also produces monitoring devices, solar software and solar accessories. In Suzhou, China it is also able to install solar PV systems for residential and commercial buildings.

Single Phase Inverters
Omnik’s single phase inverters are highly efficient with their highest conversion efficiency reaching up to 97.8% and their highest MPPT efficiency reaching up to 99.9%. Their AC power ranges are from 1 kW to 5 kW. The outstanding feature of these products is all these inverters are transformerless. In addition, among them is one series designed mainly for the Japanese market.

Three Phase Inverters
These three phase inverters are mainly designed and produced for residential and large-scale commercial solar power plants. Their highest efficiency can reach up to 98.2% and their highest MPPT rate can reach up to 99.9%. Apart from these two features, these solar products are equipped with the IP65 technology which is water- and dust-proof. Also, the built-in Wi-Fi technology is also available.

Hybrid Inverters
These hybrid solar inverters combine the features of single phase and three phase inverters. The amazing feature of them lie in that they can be used in a grid-tied or an off-grid solar PV system with their highest conversion efficiency being 98.3%. Their AC power ranges are from 3 kW to 5 kW. Each device is designed with the IP21 technology and is suitable for any kind of installation at home.

Micro inverters
Omnik’s micro solar inverters are specially made for home solar power systems. They have transformers and their AC power ranges are from 300W to 600W. Their highest efficiency is 96.5%. They are designed with the AC/DC high frequency isolation technology. At most, 15 of them can be connected in a parallel format to convert DC.

Its monitoring devices are used to monitor its inverters, and Wifi-Kit, GPRS-Kit and PMB are its three monitoring products. Its software products include solar design software and design PV mobile apps. By using some of the software, you will be able to view the electricity statistics of your solar power system with your smart phone or iPad. Its accessories include weather station, PV model and battery.

Working principle of a grid-tied PV inverter

Before learning the working principle of a grid-tied PV inverter, you need to learn the basic function of a PV inverter. What is it? It functions to convert direct current into alternating current. Where does the direct current come from? It comes from the solar panels that absorb sunlight and turns it to direct current which a common family using alternating current cannot use. Thus, an inverter comes into use. The principle of a grid-tied inverter is similar to that of a common inverter.

The direct current generated by these solar panels is fed to an inverter. In daytime the solar modules generate solar electricity and keep feeding the inverter. As this happens the solar inverter directs the generated electricity to the household electrical loads or is fed to the grid.

The amount of electricity generated depends on the quality of sunlight. If your system produces more electricity than you need, the remained electricity will be directed to the utility grid. If you require more power than the power produced, the extra electricity will be drawn from the utility grid. Thus the utility grid serves as an infinite battery back-up for your system.

At the DC side of the system the power output of a module depends on the voltage. So by varying the voltage and the current the maximum power point can be found. Therefore, most inverters grid- tied or off-grid include a Maximum Power Point Tracking system.

At the AC side the grid interactive inverter supplies power in the sinusoidal form. The frequency of the power generated must be synchronized with the grid frequency. The feed in voltage must not be greater than that of the grid voltage.

On the occurrence of a power outage in the electricity grid, the grid-tied inverter is shut down. This shut-down ensures the safety of the service personnel who is responsible for the problem of power outage. Each grid interactive inverter must have this feature as mentioned in the National Electricity Code (NEC). This feature of autonomy is a key differentiating factor between solar inverters and grid tied PV inverters.

The quality of an inverter is essentially decided by its efficiency, which guarantees how much electricity can be finally generated and how much money one can finally earn by using the solar power system. The highest conversion efficiency is 98.5%, and the highest conversion efficiency of a micro grid-tied inverter is 96.5% or so.

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.