The brand doesn't matter, what matters is the material and the era in which it was produced. Do not purchase those wedge products that have been stored for several years, or recycled refurbished panels.
First of all, you need to understand if the environment is suitable for it.
1: Sunrise and sunset correspond to the location and angle of your solar installation. Typically, it is placed at an angle of 30 to 45 degrees. Do not place it flat, as this is the lowest yield. (Unless the power generation panel you buy is made of amorphous silicon)
2: You need to know the weather parameters. How many days does rainy weather usually last? How many days does cloudy weather usually last?
How long does good weather with few clouds or hot sun usually last?
These weather parameters determine the materials you choose andthe size of the site where you are installing the solar equipment.
Rainy and cloudy days usually last a long period of time, such as a week or more. It is recommended to use amorphous silicon power generation panels.
The principle is that your site must be large enough. Amorphous silicon has relatively low light requirements, but the power generation panels are relatively large and occupy a large area.
Or you plan to let the power generation panel cover the entire roof of your building, like me (mine is monocrystalline silicon).
If it's a night when the moon is brighter, the amorphous silicon can still continue to produce electricity, but it will generate less electricity.
Monocrystalline silicon and polycrystalline silicon cannot achieve this. The price of amorphous silicon is quite cheap. A panel of pr60W electricity production costs about 70 yuan.
If you want a 4 kilowatt panel, 67 pieces of 60W will be enough. 67*70 = 4690 yuan (excluding shipping), so the cost is low.
When rainy days are short and cloudy weather is common or lasts for a long time, polysilicon can also be considered. Polysilicon is mainly intended for cloudy weather.
The price is slightly cheaper than monocrystalline silicon.
Taking a 250W power generation panel as an example, one kilowatt costs about 2,600 yuan (excluding shipping)
If there is basically has few clouds or clear skies there. The weather is full of scorching sun. It is then recommended to use monocrystalline silicon energy production panels.
A 1 kilowatt monocrystalline silicon panel can produce a maximum power of about 1,300 watts under hot sun, sothat the efficiency is very high in sunny conditions. And it takes up a small space. On my side in column, that’s 100 watts/piece. The price is 330 yuan. If you want a 4,000 watt power generation panel, it costs 330*40 = 13,200 yuan. The power rating is 4,000 watts, and the highest rating is around 5,000 watts.
Monocrystalline silicon takes up about 10 square meters per kilowatt.
Option 1:
The most economical solution, use solar energy during the day and use commercial energy at night.
4 kilowatt crystalline silicon, totaling about 5,000 yuan including transportation costs
A 4,000 watt grid-connected inverter costs about 4,000 yuan
Ready to use, no batteries required.
Option 2:
Off-grid solution
4 kilowatts of crystalline silicon, totaling about 5,000 yuan, shipping cost included
60 wattsof amorphous silicon, the voltage is about 58V, which can charge the 48V battery. Therefore, the inverter adopts DC 48V to AC 220.
48V to 220 inverter, Zhengxuanbo/5000W nominal/peak 10000W, the price is about 3000 yuan.
Select Battery Type:
Battery is a very critical step. Although lithium batteries have good performance, they are expensive. It's a bit impractical. If you're going to use lithium batteries, you might as well just use AC power. Please refer to Taobao directly for the price of lithium batteries.
Buying lead-acid batteries directly is not cheap either. You should choose the battery capacity based on your average daily power consumption.
The formula is as follows
Battery voltage X battery capacity X0.9 loss = stored power
Consumption calculation formula
p>
Tension of the battery Capacity Efficiency ÷ 100 watt bulb = approximately 1.7 hours
Add that you need to use 20 kilowatt hours of electricity per day
Then you need a battery capacity of at least 48V400A
Go directly You need 8 12V200A batteries, each costing at least 750 yuan 750X8=6000 yuan
After using it over a period of time, you will find that the battery becomes less and less durable. Maintenance will be quite tedious in the future because the purchased battery cover is difficult to remove. For example, if the positive and negative plates of the battery are vulcanized, it will seriously affect the storage capacity.
Unless it is removed, cleaned and replaced with new battery water.
If you assemble the battery yourself, the price is quite cheap. The plastic tank of the battery is 12 V, 200 A. It is sold on Taobao for 40 to 50 yuan piecce. and zinc plates. The plates do not need to be thick, but they do need to be numerous, because this battery is focused on the contact area. The more plates, the more power is stored. For the plate size, you can search it. yourself. Each plate must be separated by fiberglass panels. (They are available on Taobao. You can buy a lot of them for more than 20 yuan. There are also lead plates and zinc plates on Taobao. They cost more than 10 yuan per kilogram. You can buy as many as you need need.) For more details, you can find a used battery to take apart, open it and take a look. I won't say much more about the battery. Either way, it's pretty cheap to assemble it yourself and it's easy to maintain in the future. Please refer to used batteries for details.