What is an off-grid solar power system?
Off-grid solar power system is a system that uses solar energy (green and clean energy) to provide stable power to AC devices when there is no grid or grid is only used as a backup.
Building an off-grid solar power system is a difficult task that many people want to but don't know how to start. It is common for us to design and build a complete off-grid solar power system in areas where there is a shortage of electricity or for the concept of environmentally friendly, but how to build it reasonably? This article will use the simplest language to help you answer various doubts about building off-grid solar power system. Rico Chen, founder of CNBOU, engaged in the off-grid solar power business for ten years, we have collected a lot of information in the sales of about 15000 inverters each year, and finally presented a set of relatively reasonable off-grid solar power system solutions.
It depends on whether your off grid solar system is running at a full load for a long time or using it occasionally, just like: induction cooker or kettle, etc. Because if we only use several minutes or less than half an hour, we don't need to match with solar panel with same power. Solar panel with 900W can generate electricity 4.5kWh in 5 hours, the electricity consumption of 2kW pure sine wave inverter in an hour is 2kWh, if just use occasionally, it will be enough. Of course, you may say I have many LED lights used in the off-grid solar power system of the farm, that you may need configurative 6*300W Mono/polycrystalline solar panel. Meanwhile, you need to replace the Mppt solar charge controller that is twice as large. Here we highly recommend Mppt solar charge controller. Although PWM is cheap, its efficiency is 20%-30% less than that of Mppt, which will lead a waste of your solar panel.
It depends on how long you require your system to run on batteries without any assistance? There are many types of 5KW off grid solar inverters on the market, what we see are usually two types:
1. Solar panel input is less than 5000W
2. Solar panel input is greater than 5000W.
When you need to install off-grid solar system on your boat dock, I think it is a professional work. Boat dock is usually built without grid, if we need to apply for a transformer to power a separate boat dock, it will be very expensive to achieve. Therefore, choosing an off-grid solar system for free, eliminating the need to build a transformer to provide grid (about $20,000) and not having to pay for the usual grid, is a good solution for your boat dock.
Off-grid solar system on boat dock from a solar energy system can power the following:
●Washing machine, microwave oven
●Charge to Mobile phone, laptops, tablets
●Party accessories like speakers, TVs
Many owners of boat docks wonder if off-grid solar system will cover all their use cases or not. The answer is yes. This off-grid solar system can work all year round.
If you live in a city, building a completely self-contained off-grid solar system may not seem particularly appropriate, either for economic reasons or for environmental reasons. Maybe you don't have enough roof space to build a solar panel for your entire home, and since the electricity supply in cities is stable and relatively inexpensive, building such an off-grid system may not seem to meet the goal of cost savings.
If you are in a rural area, or in a less developed area, it is possible to build a stand-alone off-grid system to meet the electricity needs of your house. We first need to calculate the electricity consumption of your whole house, if it is a new house then you need to calculate the power and average time of use of all the electrics, if it is an old house then you can check your electricity bill to see how much electricity you use each month. Considering that the electricity comsumption is relatively high in summer and winter (mainly air conditioning), we recommend you to ask a professional EPC to do the calculation while spring and fall are relatively less. To create a stand-alone off-grid solar system to meet the year-round electricity consumption of your entire house requires accurate calculations. In addition to calculating electricity consumption, we also need to consider the weather and climate of your location. The sunshine is different in each region, and the energy produced by the solar panel will be very different. Although we know that the electricity generation in summer is always greater than that in winter, we have to calculate according to the sunshine situation and install enough solar panels to supply the electricity demand of the entire house. Once we have the exact amount, we can measure if you have enough space on your roof. When considering the installation of solar panels, it is very important to install them in a south-facing direction, as the sun shines much more often in the south than in the north.
After we confirm the size of the solar panel to be used and the installation space, we select the appropriate MPPT solar controller and sine wave inverter. We suggest to use an MPPT solar controller that 20% larger to facilitate the use of later expansion. The inverter needs to be larger than the peak power, for example, you have air conditioner, refrigerator, these are inductive loads, instant start power is very large, choose the right power inverter will make the system more stable operation.
A house runs on solar power alone is completely achievable. After we understand the most basic calculation, it is still recommended to hire a professional installation company to build the independent off-grid solar system.
It depends on how big an off-grid solar system you are going to build, usually an off-grid solar system consists of the following parts:
· Off-grid solar inverter
· Solar Panel
· Solar panel bracket
· DC and AC circuit breakers
· Connectors and cables
Of course, this is only the cost of hardware, if you need to ask the installation company, it may also needs to spend some fees.
If you need to build a small off-grid solar system, you only need 1000W inverter, and our latest Hestia series 1000W off-grid solar system kit will be very suitable. It integrateds with a 40A MPPT solar charge controller, 1000W pure sine wave inverter and 12.8V 100Ah LiFePO4 Battery. The 40A MPPT solar charge controller can support a maximum of 600W solar panel input in the state of a 12VDC system, and our unique design will allow you to additionally expant 3 sets of the 12.8V 100Ah LiFePO4 battery. The total battery capacity will reach 5.12KWh.
Hestia series off-grid solar system is currently the most suitable system for DIY, the build-in 40A MPPT can support 12VDC/24VDC/48VDC battery system, and the maximum power of the inverter can be matched with a 2000W pure sine wave inverter. If you have enough hand-on ability, we can configure a 48VDC 2000W pure sine wave inverter, so that the entire system will become a 48VDC system, the build-in 40A MPPT solar charge controller will support the largest solar panel input to 2000W. And for the build-in 12.8V 100Ah LiFePO4 battery, we have reserved an interface, which can connect 3 BL-1280 battery in series externally to make the whole system achieve 48VDC. BL-1280 battery can support a maximum charging current of 1C, if you have a 2000W solar panel, it will fully charge the battery in 2.5 hours. 2000W pure sine wave inverter can meet most loads, this is completely a DIY design, and teh combination you like will give full play to its perfromance. Even if you need to upgrade in the future, you just need to repurchase the inverter module.
The off-grid solar system designed by a professional company does not require any cost for a certain period of time instead of cheaper. After calculating the total power of the load used in your house, according to the local sun exposure, a professional EPC company will calculate a reasonable configuration, such as how many watts of solar panels and MPPT solar charge controller, how many watts of the inverter, how many Ah of the battery. Even in the rainy season, there is no need to worry about the insufficent electricity.
Let's design a simple off-grid solar system of a tiny house. The list of the equipments in you house is as follows:
1. Led lights 50W
2. Induction hobs 1800W
3. Microwave ovens 1000W
4. Washing machines 360W
5. Rice cooker 500W
6. Juice extractor 200W
7. Electric fans 65W
8. Refrigerators 130W
This is a common equioment of tiny house. The largest load we see is induction hobs 1800W, but the time of using induction hobs is usually very short, we estimate the daily usage time to be one hour, which means it requires 1.8kWh of electricity. Microwave ovens are calculated to be half an hour and 0.5kWh of consumption. Washing machines are used half an hour every 2 days, a total of 0.09kWh per day. Rice cooker is used twice a day for half an hour each time, which is worth 1kWh. Juice extractor is used for one hour every day, totally 0.2kWh. The lamp is used for 5 hours which is 0.25kWh. Electric fans is 10 house for 0.65kWh. Refrigerators, 24 hours for 3kWh. After we are clear about those, we can calculate how many batteries are needed.
|5||Rice cooker 500W||500W||1|
We calculate that the electricity used in a day is 7.49kWh, when configuring the battery, we need to configure a 15kWh battery. After knowing the battery capacity, we calculate how many watts of the solar panels are used. Assuming that our sunshine time is 5 hours per day at full load, and the max. allowable charge of the battery is 150Amp (1C), but because there are 5 hours of sunshineevery day, we can fully charge the battery in 5 hours, so a 3kw solar panel is enough. It is enough to use 48V system equipped with a 60A MPPT solar charge controller and 3000W pure sine wave inverter, which can meet the power supply of the whole house.
1. 3000W solar panel
2. 60A Mppt solar charge controller
3. 3000W pure sine wave inverter
4. 51.2V 300Ah LifePO4 battery
This confihuration can basically meet the daily needs, even if there is no sun for two consecutive days, you can still supply power normally. Of course, if your load is not that much, you can reduce the configuration appropriately. And installing sucn an off-grid solar system, it will be completely free, without any additional electricity bills.
Off-grid life is becoming a popular way of life at present. Whether it is home off-grid or RV off-grid, inverter is an indispensable part, but the high price will discourage many people. And generally speaking, the higher the power inverter, the higher the price, if all you need is a small off-grid system, a 400 watt power inverter will suffice. The range and number of items that a 400W inverter is capable of powering boils down to their actual electricity usage (measured in watts). A 400W inverter can run any number of devices as long as it is less than 400 watts.
A 400 watt power inverter can run the following appliances:
· Small TV
· Game console
· Portable Audio
· Portable Coffee Machine
· Small refrigerator (100-400W)
How long will a 400 watt inverter last?
It depends on the load and the size of the battery. The inverter can always work as long as the load does not exceed 400W and there is a large enough battery. A computer with a power of 200W is used in a 400W inverter with a 12.8V/100Ah battery, and the inverter will last for six hours.
Run time = battery size / inverter load
If you are using a 12.8V/100Ah battery, under the condition that the load power does not exceed 400W, it is only necessary to calculate the working time of the inverter.
However, CNBOU BP series pure sine wave inverter 300W is designed with a 20% margin, which can run for a long time at 360W, and its peak power can also reach 720W, which can basically replace a 400W inverter. The BPlus series 300 watt power inverter can be adjusted to 350W through software, and its peak power can reach 1050W, which can fully meet the daily work of small power loads. This will be a good choice.
We will end here with 300W-5000W small off-grid solar power system, these come for a large number of actual customer cases we have collected and then recommend. If you want to know more about the information, please contact us. Also if you have batter suggestion, please let us know, and let's contribute to the development of off-grid solar power system.
Author: Rico Chen By CNBOU