Design of solar power plants: stages and features Comment
A solar power plant is a high-tech facility, the construction of which cannot be imagined without preliminary design work.
Stages of solar power plant design
In its standard form, the solar power plant design process may include the following basic steps:
- studying the installation site, conducting engineering surveys;
- computer modeling to determine the optimal modification of equipment;
- drawing up a feasibility study;
- preparation and approval of documents.
Features of designing solar power plants
Network solar power plant
SES operates on the principle of mixing electricity generated by solar panels into a single-phase (1P) or three-phase (3P) network. It is suitable for those who want to save on electricity bills.
What should you consider when designing?
The power of network solar power plants starts from 1 kW. This is the total power of the panels, to which you need to add a small margin. For example, you can install 4 panels with a rating of 250-300W.
For a private house, a solar power plant project with a capacity of up to 5-6 kW is suitable. Everything is calculated individually and depends on consumption, so more powerful options are possible.
Since the main purpose of a network solar power plant is to save on electricity bills, its design must begin with an analysis of average daily consumption. The simplest option for preliminary calculation is to divide the monthly payment for electricity by the cost of 1 kWh. For example, the monthly fee was 6,500 rubles, and 1 kWh costs 7.2 rubles, then the monthly consumption will be ~902 kWh or ~30 kWh per day.
The network SES operates only during daylight and sunny hours, during the spring-autumn period, i.e. approximately 12 hours. Accordingly, it will be able to cover up to 50% of daily consumption, in this case ~15 kWh. A solar power plant with a capacity of 3 kW can cope with this task, since on average it generates ~15-18 kWh per day.
If you connect a network solar power plant according to the law on microgeneration, then you can cover 100% of daily consumption. This is achieved by dumping excess generated energy into the network with its subsequent free consumption, for example, during the daytime 10 kWh was generated into the network, then the same 10 kWh can be taken back from the network for free.
Autonomous solar power plant
As the name suggests, this type of solar power plant is designed for autonomous operation, i.e. to organize electricity ~220/230V where there is none at all.
What should you consider when designing?
You can choose a large number of options for solar power plants of this type, for example, starting from a 15W solar panel in combination with a 7Ah battery and a 12V LED lamp – such a kit is quite enough to organize autonomous lighting. This is a kit without an inverter, there is only 12V.
When considering a solar power plant for your home, as a starting option you can choose a kit with an inverter power of 1500W, two panels with a power of 280-320W, a 200Ah gel battery and a corresponding charge controller.
This kit is enough to provide a small private house with completely autonomous electricity during the spring-autumn period. Such a kit will be able to operate household appliances whose power consumption does not exceed 1500W, for example, a small refrigerator, TV, power tools, lighting, irrigation pumps.
If you need more powerful consumers to work, you need to replace the inverter with a more powerful one – 2 kW, 3 kW, 4.5 kW, 5 kW. However, the more powerful the inverter, the more powerful the array of panels should be, and accordingly, the battery capacity should also be larger.
Hybrid solar power plant
A hybrid power plant is very similar in composition to an autonomous one, the difference is that instead of a combination of an autonomous inverter + charge controller, a 23 in 1 combine is used, namely a hybrid inverter. The hybrid inverter combines a charge controller, an inverter and a battery charger from a 220V network. Unlike a stand-alone inverter, a hybrid inverter can be connected to a 220V network or to a gasoline generator and start charging the battery.
This is especially true on long cloudy days or in winter, when solar radiation is not enough to fully charge the battery.
What should you consider when designing?
There are many combinations of solar panels + battery + hybrid inverter in solar power plants. The choice depends on the required inverter output power. The following power inverters are available on the market: 1kW (12V), 2kW (24V), 3kW, 4kW, 5kW, 7.2kW, 10kW (48V). The rated voltage of the battery with which this inverter operates is indicated in parentheses. For example, 24V means that you will need to use two 12V batteries connected in series, 48V – 4 batteries, 12V – 1 battery.
The more powerful the inverter, the more solar panels can be connected to it, for example, a hybrid inverter with an MPPT controller for 1 kW pulls up to 500 W, for 2 kW – up to 1000 W, 3 kW – 1500 W, etc.
Therefore, with an increase in the inverter power, it is necessary to increase the battery capacity, for example, with a 1 kW hybrid inverter, a good option would be to use a 150-200 Ah battery, for a 2 kW inverter – 2 batteries of 100-150 Ah each, for a 3 kW – 2 batteries of 180-250 Ah each.
Therefore, it is very important to design a balanced system, where the power of the inverter, the capacity of the batteries and the power of the solar panels are correctly matched to each other.
Opportunities of REENERGO company
Don’t have time to understand design features? Contact REENERGO specialists who will select the optimal set of equipment and advise on maintenance issues.