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.


Solar Power Revolution in India to Be Successful?

Gujara solar power station

As climate change and environmental issues become more and more serious, a solar power revolution is beginning to reshape the world. The UK, the Netherlands and the US have become the giants in this new industry, but how about India, a country that doesn’t seem to be so modern?

The Guardian reports that India’s current prime minister Narendra Modi has an ambitious plan of installing PV power systems in the country. Its current power minister thinks it is not a difficult task to add 10,000MW of solar power a year. This is a large number. For India, can this goal be realized as the minister has publicly said?

The fact is that India today is home to the biggest solar farm in Gujarat in Asia. India’s current renewable energy power capacity is 31,692.14MW, and its solar power capacity is 2,900MW. By this comparison, you must learn how much solar power’s role is in the country and how the country treats PV solar power. In addition, under the supportive solar power installation advocacy from its leaders, solar power begins booming in this developing country.

Besides, the government’s energy policies have also changed somewhat. Mercom Capital Group’s CEO Raj Prabhu says India has changed its policy about coal and ended its anti-dumping policy. According to him, the supreme court has suspended the coal-exploiting license, and more coal needs importing, which makes its cost much higher than ever. At the same time India’s power supply is not enough to sustain the whole nation’s power consumption. Under these beneficial conditions, India’s solar power seems to have a prosperous future.

However, there are still some unpleasant reports. For example, the World Bank’s index reports that India’s economy rank has fallen from 131 to 142. The other true fact is that India’s 80% of crude oil still depends on import. The two things cannot abruptly announce that India’s solar power plan will be affected, while it is possible that this ambition will be influenced.

Residential Solar Inverters: Stunning Features

As solar energy technology develops, even a home can now generate power. There is no secret about this, but the solar inverter installed in the solar power generation system weighs a lot. You will surely ask: “What does the inverter do for the system? Or what stunning features does this inverter have for its customers?”

Usually for a home, a micro solar inverter should be used. As soon as it is installed in the residential solar system, it will benefits its owner.

1.The solar inverter can help save money for your family.

After you have installed the PV solar system, you will be far away from paying for the utility grid providing electricity for your home. This idea has been addressed numerous times, while it still weighs big. But the difference is you can use the system to save money. Once you stop paying for the utility grid, you save money for your home.

Although you have bought this system with some amounts of money, no, you indeed have “invested” money into this system, you can return your investment by paying nothing for the grid and also by earning money from the utility grid. What does this mean? It means if you have unused electricity generated by the system, this electricity can flow into the utility grid. In this way you earn money. Also, some governments offer incentives.

2.The solar inverter can make you become power independent.

Usually we depend on the utility grid, but as you have installed the solar inverter system, you will be independent. The installed system can work independently. It doesn’t need to be connected to other foreign or centralized source of energy. At the same time when unexpected weather conditions occur, you don’t have to worry about your power supply, for this system will never be affected by terrible conditions.

3.The solar inverter makes sure the system can work effectively.

With a solar inverter, the solar system will nearly never need maintenance. The condition will last for decades. When they work, they will never make noise or release bad smells. In addition, more solar panels can be added in the future if your need grows.

Monocrystalline Silicon Solar Cells More Popular, More Solar System Installations Expected

Monocrystalline silicon is a relatively dynamic non-metallic element, and one important part of crystalline materials. Today it serves as one of the most important newmaterials, mainly used for making semi-conductor materials, solar cells for PV systems, heating systems and so on. It is also named single-crystal silicon, single-crystal Si, mono c-Si or mono-Si. In the past 30 years, In the recent 30 years, solar energy technology has won great achievements in research, commercialization and market expansion, and will also win its market share in the future.

A few days ago, NREL and the company Crystal Solar worked together and proved that mono-Si solar cells and modules that are less than 80 microns thick. More importantly, they can become less expensive through an epitaxial process. At the same time this process can help grow large numbers of cells, and their cost is about 50 cents each watt. The process shows us that cell cost cost can be halved and 100 times faster than conventional epitaxial reactors. In this case, quick commercialization for single-crystal silicon can be expected.

One data report from some large scale ground PV solar power station in Ningxia, China shows that a single-crystal silicon power station can generate power 5% more than a poly-silicon power station on average.

Single-crystal silicon and poly-silicon are two very important components of a solar PV system. Why are they called single-crystal silicon and poly-silicon? The simple reason is that they have different crystal lattices. People usually think that single-crystal silicon can be made into solar cells that are more potential in generating power. However, the cost is relatively higher. The last data shows that their costs are nearly the same when they are put into a solar PV system. In addition, single-crystal solar panels will be more advantageous in later maintenance and operation.

At present, single-crystal silicon solar PV power generation has been gradually approved, while it still seems its higher cost is now its threshold compared with poly-silicon solar cells.

In China today, single-crystal silicon power stations account for about 10% of the total number, and the rest are comprised of single-crystal silicon and a few thin-film stations. In the past years, the poly-silicon power plants have been prevalent because of its relatively cheaper price.

In the world, single-crystal silicon solar cells are more used. In 2013, new installations have passed 38GW, with 8-9GW of single-crystal silicon installations accounting for 31%-35%. Indeed, this figure is still lower than poly-silicon power installations. But if higher efficiency is considered, this cost evaluation must be changed somewhat.

Can China’s New Energy Ambition Become Reality?

New Energy
New Energy

China has set up a goal of quadrupling its renewable energy by 2030. No wonder, this is an ambition that it is difficult to achieve for China, a country which has been known as the largest coal producer and user in the world. The problems that follow are its CO₂emission and other forms of greenhouse gases. So, can China really realize its dream of quadrupling renewable energy by 2030? Yes, we have need to have a discussion about this issue.

To achieve this ambition, China has said its will install relevant policies and regulations. On June 13, China’s president Xi Jinping said his administration was working out new guidelines to change its energy production and consumption. At the same time he also stressed that the government would revise the country’s out-of-date regulations made for energy. In addition, the president also called to cooperate more with Russia, Central Asia, the Middle East, the Americas and Africa on oil and gas projects. On May 21, China and Russia signed a natural gas supply agreement of 40 billion dollars. On Nov. 9, the second round of natural gas agree framework was signed.

The evidence shown here suggests that China is making efforts in policy and practice to transform its energy consumption. This means applying renewable energy has been practiced by the world’s second-largest economy entity. This shows that to make a better and cleaner future can be expected, for the world’s largest populated country has swerved its steer to the green direction. Although this is a benign phenomenon, the miserable fact still exists. By the end of 2013, China’s renewable energy (water, solar and wind) accounted for 30% of its total capacity. Compared with this figure, its biofuels accounted for 69% of its total capacity.

So far China is still the largest carbon dioxide emission country. Based on this serious problem, many China’s major cities have been overwhelmed by haze and smog, which have already caused public health warnings. Therefore, China’s move toward renewable energy must be concrete and urgent.

According to the report of Global Research, China’s established renewable energy system is now the largest across the world. This also proves that the country is moving toward the direction that may change its own climate and terrible weather, and will probably make a great contribution to the world. Under the call of the president and his policies and regulations, China has so far begun a revolution of green energy, and more and more green energy enterprises have appeared and begun making efforts to boost this move. But whether the country will meet its target by 2030, this is still a question for us to wait and see.