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In 2021, rooftop solar power for households still shows great investment benefits. The problem that needs to be solved is a reasonable calculation to minimize the monthly electricity bill, not selling electricity to enjoy investment profits.
From the beginning of 2021, there is a fact that large projects are regulated, reducing the generating capacity on the grid, significantly reducing investment income from solar power. However, although the price of FIT3 to buy electricity into the grid from EVN will decrease (expected to be about 1,582 VND/kw compared to 1,938-2,162 VND/kw before), the residential rooftop solar power system is still an investment:
A household is paying about 2 million VND/month for electricity, equivalent to 773 kw of electricity with progressive electricity prices as follows:
To optimize the investment, we propose to install a solar power system for 30m2 of roof – Total installed capacity 3.23 kwp.
Assumption: Customers use 50% of electricity during the day, 50% of electricity in the evening.
From the 4th year onwards, compared to the decline in panel efficiency, the 3kwp fixed system is not enough to supply the daytime demand, so the amount of electricity to be purchased from EVN will gradually increase and be larger than 386kwh/month or 4,636kwh / five.
SolarPlus 3kwp rotating system is enough to supply the demand for daytime use for 25 years, so the amount of electricity to be purchased from EVN is stable and does not increase.
1 Rotating solar power is a smart solar power system using SolarPlus Econo directional axis technology, the system capacity reaches 150% of the fixed system.
The above investment cost, we calculate for the solar power system using JA Solar panels (Top 3 in the world) and Inverter GoodWe (Top 10 in the world). Cheap solar panels and inverters are much less efficient, resulting in a loss on your investment that lasts 25 years.
Installed power: 10 Kwp
Actual system capacity: 66.8 Kwh/day
Total sunshine hours: ~7 hours/day
Graph of monthly electricity production
Graph of annual electricity production
In addition to the issue of investment capacity, households when installing solar power also need to consider the reputation and capacity of the solar power system supplier. In the past 2020, many large and small projects have suffered considerable losses when suppliers calculated, installed incorrectly as well as advised on poor quality solar cells and inverters. As a result, some systems are not able to achieve the expected capacity, resulting in a decrease in income. Damage is also not covered by the warranty.
See more: Optimal design of rooftop solar power system: To invest without loss of capital
It is likely that from 2021 in Vietnam’s solar power market, consumers will invest in the direction of focusing on quality, choosing sustainable solutions to enjoy long-term benefits instead of investing massively as in the past time. It is expected that the market will have many technological solutions to help meet the investment needs of these households.
Increase system capacity by 150%.
BEST solution to increase profitability for grid-tied systems before 2022.