Ampt Completes Repowering Project in Japan Allowing PV System to Meet New Utility Requirements

Ampt String Optimizers simplify inverter replacements and lower upgrade costs for a large rooftop PV system to comply with new remote curtailment standards

Ampt, the #1 DC optimizer company for large-scale photovoltaic (PV) systems, announces the successful repowering of a photovoltaic (PV) system in Japan, enabling compliance with new utility requirements by Tokyo Electric Power Company (TEPCO). The project demonstrates Ampt's cost-effective and simplified solution for upgrading existing PV power plants with modern inverters.


The owner of a 200kW rooftop PV system in Odawara, Japan, integrated Ampt String Optimizers to comply with TEPCO standards while minimizing changes to the existing design. Implemented by all utilities in Japan since 2021, the new standards require real-time remote curtailment control capability for grid-connected PV solar systems to help balance energy supply and demand. To maintain compliance, many PV system owners must replace their existing inverters with modern inverters that can be controlled by the utility.

The system owner selected Ampt V600-i12-12 String Optimizers to simplify and lower the cost of deploying modern inverters in its existing PV system. Ampt optimizers are DC/DC power converters that adapt the lower voltage of an existing PV array to be compatible with modern inverters that meet the new utility regulations.

Ampt's technology performs maximum power point tracking (MPPT) on each string of PV modules to maximize power delivery and prevent energy losses caused by voltage mismatch. The optimizers then deliver full available PV power to the inverter at a DC voltage that is within the inverter's operating range.

Ampt's String Optimizers avoid costly rewiring and ensure compatibility between the existing 600 VDC solar array and new 1000 VDC inverters without voiding warranties or violating local voltage codes.

"We are pleased to complete another successful repowering project in Japan to enable compliance with utility regulations and promote a sustainable energy future for the country," said Ampt CEO, Levent Gun. "This project highlights the versatility of our String Optimizers across global markets and how our technology equips PV system owners to tackle challenges in any energy market."

"With the new utility requirement for remote curtailment in Japan, our solution offers a vital means for PV system owners to meet the new standards while minimizing costs and operational disruptions," said Ampt Japan Country Manager, Shigeki Kondo. "We are pleased to work with our customers and inverter partners to economically ensure regulatory compliance and maximize project ROI."

About Ampt
Ampt delivers innovative power conversion and communication technology that are used to lower the cost and improve performance of new PV systems, repower existing systems, and enable lower-cost DC-coupled storage. With installations and experience serving markets around the world, Ampt is the number one DC optimizer company for large-scale systems. The company is headquartered in Fort Collins, Colorado, and has sales and support locations in North America, Europe, and Japan as well as representation in Asia, Australia, and the Middle East. For more information, visit www.ampt.com and follow Ampt on LinkedIn.

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