The Ministry of New and Renewable Energy (MNRE) has issued clarification for DC system configurations applicable to Off-grid and Grid-connected Solar PV applications.

The MNRE indicated that a clause in the guidelines for establishing solar DC systems for off-grid and grid-connected applications was being wrongly interpreted. As a result, the MNRE provided a clarification so that all activities can take place in accordance with the governing rules.

The MNRE clarified the Bureau of Indian Standards (BIS) standard and/or the international standards for solar DC systems must be specified alongside their technical parameters. For example, solar panels should comply with the IEC 61215 standard. At the same time, ETD50 LVDC specifications and SEG4, SysLVDC standards should also be followed, wherever applicable. This applies to Solar DC systems and Solar DC mini/micro-grids with DC appliances.

The Solar DC systems guidelines for off-grid and grid-connected applications were issued on August 21, 2017. Key highlights of the guidelines include:

• In view of safety, voltage for DC systems should be limited to 60 volts.
• BIS Standards and/or international standards must be specified for all equipment alongside their technical parameters.
• Selected cables must have a voltage drop that is less than 3 percent and a power loss that is less than 2 percent. Cable thickness should not be more than 10 sq. mm.

An MNRE official involved in formulating the guidelines said, “It was necessary to clarify the DC solar standards as these will mostly be utilized in villages and areas that are far flung and, if proper standard devices and equipment are not used, it will add an extra cost of repeated servicing and cause the systems to not perform as expected.”

“The other reason why this clarification has been provided is to tie up loose ends. Now there’s no loophole that lets installers say that the BIS standard wasn’t mentioned or wasn’t made clear by the ministry,” added the MNRE official.

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