The home solar energy storage system mainly uses the idle resources on the family’s existing buildings, such as roofs, wall facades, balconies, courtyards, etc., to install and use distributed photovoltaic power generation systems; it has a small installation capacity and many installation points. The grid connection process is simple and the benefits are obvious and direct. It is also a distributed photovoltaic power generation application form with the highest state subsidy in China.
A small distributed photovoltaic power generation system with an installed capacity of 3 kilowatts has an annual power generation capacity of 3650 kWh, which can generate 91250 kWh in 25 years, which is equivalent to saving 36.5 tons of standard coal, reducing 94.9 tons of carbon dioxide and 0.8 tons of sulfur dioxide.
In China, there is a national subsidy of 0.37 yuan per kilowatt-hour of electricity (some places also have provincial subsidies and local subsidies). Unused electricity can also be sold to the national grid. In the past, it was expensive to use electricity, but now it is sold to make money. The rate of return is as high as 10% or more, the investment is three to fifty thousand, and the income is twenty-five years, that is photovoltaic power station. Some countries also have good financial subsidies for solar and wind power generation.
According to the mode of spontaneous self-use of surplus electricity to the grid, the total revenue of photovoltaic power generation = electricity savings + excess electricity sales revenue + state subsidies + local subsidies.
Calculated in this way, most parts of the world will be able to recover the cost in 3-6 years, and bring 25 years of stable cash flow. The profitability of home solar energy storage system and photovoltaic power generation is still good.