Title: Breaking Through Output Control Barriers with "DC Link" – The Challenge of Solar + Storage Systems in Hokkaido
Article Source: Solar Journal
Solar + Storage System Q&A
1. What is DC Link?
Answer: DC Link refers to a method in which the DC power generated by solar panels is charged directly into the battery without being converted to AC even once. Because the panels and battery are connected on the DC side, conversion losses are minimized and highly efficient operation is achieved. Since the system can be configured with a single hybrid inverter, it is ideal for new installations.
2. What is AC Link?
Answer: AC Link refers to a method in which the DC power generated by solar panels is first converted to AC by an inverter, and then charged into the battery via a separate PCS (Power Conversion System). This configuration is suitable for retrofitting storage batteries to existing solar power generation systems. In Japan, many residential storage systems adopt this method.
3. What are the differences and relationship between DC Link and AC Link?
Answer: The difference lies in whether the solar panels and battery are connected on the DC side or the AC side.
Key differences:
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Number of conversions: DC Link requires 1 conversion (only during discharge), while AC Link requires 2 or more conversions.
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Efficiency: DC Link offers higher efficiency (approximately 90% or more), while AC Link is slightly lower.
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Equipment configuration: DC Link uses a single hybrid inverter, whereas AC Link requires an inverter plus a separate PCS (2 units).
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Ease of installation: DC Link is simpler, while AC Link is slightly more complex.
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Suitable application: DC Link is ideal for new installations, while AC Link is suited for retrofitting existing systems.
Relationship:
Both methods are ways to realize "solar + storage" systems, and share the common purpose of maximizing the effective use of generated power, responding to output control, and maximizing electricity sales revenue.
4. What is a Battery Inverter? Is it the same as a PCS?
Answer: Yes, that is correct. A battery inverter is the same as a PCS (Power Conversion System). It is a device that performs bidirectional conversion between AC and DC, connecting the storage battery with the grid and loads. It converts AC to DC during charging and DC to AC during discharging.
Differences based on coupling method:
SEAFOREST – Your Solar + Storage System Specialist
SEAFOREST supports a wide range of solar + storage systems, from residential homes to industrial applications. Depending on your requirements and installation conditions, we can propose both DC Link and AC Link system configurations.
Our systems maximize the utilization of solar-generated power in the following ways:
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Selling electricity to the grid
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Charging storage batteries
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Directly supplying power to customer loads
We provide system designs that eliminate waste and optimize the use of generated power.
For inquiries, please feel free to contact us.
Head Office: Xiamen Haisen Industry & Trade Co., Ltd.
Room 2206, No.6 Hubin East Road, Xiamen, Fujian, China (〒361010)
Contact Person: Kaku Guo
Tel: +86-592-5657925
Fax: +86-592-5628163
Mobile/WhatsApp: +86-1360-6089-112
Web: www.seaforestpv.com / www.seashineforest.com
USA Branch: SEA FOREST ENERGY STORAGE SOLUTION CORP
18780 AMAR RD STE 106 #357 WALNUT, CA 91789
Japan Office: Ezaki 080-4667-6168
Japan Distributor for Perovskite Panels: IU Solar Co., Ltd.
4-3-21-702 Hiraiso, Tarumi-ku, Kobe, 655-0892
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Our company (Brand: SEAFOREST) has over 14 years of experience in new energy trade with Japan. Based on our management philosophy of "Sincerity, Altruism, Innovation, and Progress," we are committed to providing superior products, faster delivery, and professional service.
Please feel free to contact us. Our expert staff will propose the optimal system for your needs.
