For now, pv has two kinds of typical applications, grid and off grid system. Grid system, which is based on the grid, adopt “more than personal use, the electric grid” or “the grid” working mode. off grid solar power system is not dependent on the grid, relies on the “storage and use” or “storage before use” working mode. With no power or often in areas of the family, off grid pv system has very strong practicability.
Because the network is rigid demand, so relatively high profits. As a parallel installation personnel, if you want to do a off grid project, you need to change some of your ideas. If you continue to use the thinking of interconnection to be off grid, you may not be able to conclude the transaction, or to meet customer requirements.
The off grid solar power system cannot be included in the ROI
When we invest in real estate, stock, such as industrial project, we need to calculate, how much money we can earn each year, how many years can take back the principal. Grid generation is state subsidies. Power stations is a kind of investment behavior, the customer concerned about most is the return on investment. But when we bought the necessaries of life such as mobile phone, computer, clothes, we will not calculate how many years can earn back the principal. off grid system.
In addition to a handful of local electricity prohibitively expensive and very rich, most of them are in order to meet people’s basic living demand, if the same off grid users calculate return on investment, may not be able to recover for 10 years or 15 years, the idea of customer may cancel installation off grid. off grid solar power system in the economy can not be seen as the cause of the grid system is much more expensive than the interconnection system off grid system.
High cost of off grid solar system
Off grid system consists of photovoltaic array, solar controller, inverter, battery and load, etc. Compared with the grid system, battery quantity more, 30-40% of the cost of power generation systems, it is almost the same with the component. And also the life of the battery is not long. Lead-acid batteries generally 3 to 5 years, lithium battery, generally 8 to 10 years, after the need to change.
The same power of inverter, off grid price is 1.5 ~ 3 times of grid inverter. off grid inverter is more complex than grid inverter. Grid inverter general controller, booster and inverter, are kept separate from the quaternary structure, costs about twice the grid inverter.
Under the same power, off grid inverter overload capacity of more than 30% higher than grid inverter. Grid inverter, a former level components, the output power grid. Generally do not need to overload capacity, because there are very few element output power. If off grid inverter output is greater than the rated power, the off grid inverter output connected to the load, a lot of the load is inductive load. Starting power for 3 to 5 times the rated power, the overload ability of off grid inverter is hard Numbers. Equipment power will increase, this means that the cost will be high.
off grid inverter output is low. The photovoltaic (pv) grid market share of about 98%, off grid market share of about 2%. Shipments is very low, can’t automatic production, raw materials and production costs are much higher.
Why should the off grid pv system be equipped with energy storage batteries
In photovoltaic off grid system, energy storage battery of relatively large, the cost similar to solar module, but life is much shorter than the solar component.
Photovoltaic power generation and electricity load time is not necessarily synchronous
For a component in a photovoltaic off grid system, input, used to generate electricity, the output load. Photovoltaic (pv) power generation during the day, only to electricity only when in the sun. Usually generating the highest at noon. At noon, however, demand is not high. Many families use off grid power station electricity at night. What should we do with produce electricity during the day? First of all, the energy storage device is energy storage battery. Wait until peak demand, like seven or eight in the evening, and then discharge.
Photovoltaic power generation and load power is not necessarily the same
Photovoltaic affected by radiation is not very stable, the load is not stable, such as air conditioners, refrigerators, etc. Load will lead to an unstable system, the voltage fluctuation. Energy storage battery is a kind of power balance device. When the photovoltaic (pv) power is greater than the load power, the controller will be extra energy to the battery for storage. When photovoltaic power generation can not meet the needs of the load, the controller send battery to the load.
How big of a solar system do I need to go off-grid for homes?
Most data suggests that a typical American home (2,000 square feet home) consumes approximately 11,000 kilowatt-hours annually. So, when we divide our total consumption by the expected output of one solar panel, we see that roughly thirteen solar panels of this size would be enough to power a home of that size.
In addition to the above three, off grid system design and the design of the grid system is different. Components, inverter, storage battery must be customized according to user needs. Only change the thinking, can make a perfect off grid system. If you want to know more about 10kw off-grid solar system price, Please contact Maxworld Power.