Solar-power viability boosted by Sandia technology

17 Jun 2002

Solar-power systems can now be safely hooked up to regional power grids thanks to a new photovoltaic control system developed at Sandia National Laboratories in the US.

Called a "non-islanding inverter", the technology has already been implemented in photovoltaic systems by two manufacturers - Ascension Technolgies and Omnion Power Electronics.

The key factor is safety. Previous photovoltaic power generators could not sense when energy lines had been shut down for repairs or other reasons, and this potentially compromises the safety of line workers carrying out repairs, or others who are expecting a power line to be shut down.

The new inverter includes a piece of computer code that automatically senses when a line has been shut down, converting DC to AC.

Sandia researcher John Stevens says that the goal is for inverter manufacturers to adopt the technology to make solar power a more commercially viable option. Grid connection allows the photovoltaic-system owner to sell any excess electricity and provide utilities with additional power at peak usage times.

Older inverters cannot be retrofitted with the new technology, but Stevens says that almost any new photovoltaic system will be able to incorporate it.