Solar rooftop system - efficient power-saving solutions for multiple parties

11:14 - 15/06/2020  |  1049 views

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In recent years, installing rooftop panels become popular to enterprises and households in Quang Binh province. Solar rooftop system is encouraged to invest by the Government. Accordingly, the demand for solar rooftop system is higher and higher along with the updated policy of purchase price of power impacted significantly on the development rate of the system for the last year.

The power sector supports and encourages the development of solar rooftop system

Encouragement mechanism of the Government and the coordination of the power sector

The Prime Minister has issued the Decision No. 11/2017/QD-TTg dated 11 April 2017 regarding the encouragement mechanism to develop the solar power projects (SPP) in Vietnam. Accordingly, the selling price from SPP including the solar farm and solar rooftop system is USD 9.35 cent per kWh, multiple with the exchange rate in 2017 is equivalent to VND 2,086 per kWh. After that, MOIT issued the Circular No. 16/2017/TT-BCT dated 12 September 2017 to regulate the project development and the standard Purchase Contract applied for SPP. The regulation boosts and provides guidance for the Buyer and the Seller to prepare the contract considering legal matters suggested by the MOIT.

To promote the development of rooftop solar system, The Prime Minister has issued the Decision No. 02/2019/QD-TTg dated 8 Jan 2019 to amend some articles of the Decision No, 11/2017/QD-TTg dated 11 Apr 2017. Based on that, instead of selling only the redundant amount of power from the solar rooftop system applied the offset mechanism, the investors own their rights to sell all the amount from solar power with preferential price, at the same time, purchase the electricity from the national network with the average price of VND 1,720 per kWh through the two-way meter install free by the power sector. Even though, the power sector purchases the higher price of solar power source than the current average selling price, it prioritizes the mutual benefits of the society and the households to support and promote this development.

Recently, the Government further issued the Decision No. 13/2020/QD-TTg to replace the Decision No. 11/2017/QD-TTg being expired to in-time announce the policy to promote the solar power projects in long term. Correspondingly, the solar panel system is the renewable energy supported by the Government to commit the contract till 20 years with very competitive price which is US 8.38 cent per kWh, equivalent to VND 1,943 per kWh.

Benefits of the solar rooftop system

The advantages of this source of energy is one of the eco-friendly renewable energy, no exhausted. This source could reduce the pressure on the load of national network, save the cost for investment of expanding the transmission line, whereas, its nature is the diffuse energy with in-place consumption by taking advantage of the available ground of the investors. Therefore, this is one of the efficient solutions for serving the increase of manufacture and household demand. The investors could save due to not spending on purchasing power from the network, low cost of operation and maintenance. Furthermore, this kind of project shall not be influenced by the master plan and ground employment of the Government, encouraged various groups of the society to join the power supply market.

Moreover, another clear benefit of installing the solar panels on the rooftop is thermal insulation and protecting the house from the weather impacts such as the sun, radiation, etc… These solar panels could absorb the heat and toxic radiation to cool down the house, also save the cost consumed for cooling equipment in-house during the hot weather.

Operation mechanism and the investment efficiency

The solar rooftop system includes solar panels, inverter set connecting to the network and a two-way meter. This meter measures the power consumption in both network, input from the national grid and output from the solar panels. When the usage capacity is equal to the capacity of the solar system, the load will prioritize to spend all from the solar panels and will not consume from the national grid at all. When the solar rooftop system generates more than its consumption, the load will prioritize the solar energy, and the redundant capacity from this network will be sold to the power sector through the two-way meter.

The suppliers of solar panels announce over 25 to 35 years of aging for their products, warranty duration up to 25 years. The inverters are guaranteed for over 10 years. Therefore, investment on the solar rooftop network has long beneficiary time with low cost of maintenance. Installation price for the system costs VND 13 to 16 million/kWp approximately, the household commonly could select the system with installed capacity from 3 to 5kWp. Each kWp of capacity could generate 4-5kWh power to consume every day. Currently, according to the Decision No. 13/2020/QD-TTg, with the purchasing price of VND 1,943/kWh, if the investors install the solar rooftop system about 3-5kWp, the time to return on investment shall be 6 to 8 years. After that, the investors will be totally benefited from the long lifetime of the solar panels with up to 25 years.

The potential of development the system in Quang Binh province

According to the evaluation of MOIT, the Central and Southern part of Vietnam have great potential of solar energy with the radiation rate from 4.2 to 4.8kWh/m2/day. Until the first Quarter of 2020, there is 26,146 projects of solar rooftop system with total capacity of 521.8 MWp, the output connected to the national grid in this quarter is 90.34 million kWh. There is 179 projects in Quang Binh province only with total capacity of 1,400 kWp, the amount of power generation connected to the national grid is 281,987 kWh and the purchase amount of those power capacity is VND 547.9 million. The local enterprises have paid attention to the investment of this kind of energy as the effective solution to save the cost of manufacture.

The manufacture enterprises followed this trend as well. Being one of the elements to make the product price, cost of electricity remains significant proportion of the price. Application of renewable energy helps the enterprises to improve their competitiveness. Gach Ngoi Cau 4 JSC is one of the companies installed the biggest solar rooftop system in the province with capacity of 194 kWp, the output connected to the grid during the first four months of 2020 reached 22,138 kWh. Not only spending the output to manufacture, reduce the electricity cost due to not purchasing from the national grid, the company also generates almost VND 50 million from the redundant capacity sold to the national grid. Moreover, there are hundreds of households in Dong Hoi city and communes installed the solar rooftop system with the appropriate capacity from 3 to 10 kWp.

The solar system with capacity of 70kWp at Paradize Thien Duong Co., Ltd.

Currently, the available rooftop amount at Quang Binh province for solar rooftop system is still high. With the advantages of climate, this system will bring high economic efficiency to the investors as well as saving cost during hot season.

Author: Y Tho – Viet Dung

Translator: Hang Pham

11:14 - 15/06/2020  |  1049 views

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