RMIT's $1.2m bid to feed home solar to grid

Australian
22 February 2011, Page: 31

RMIT University researchers and local inverter manufacturer MILSystems have begun work on a $1.2 million project to better integrate home generated solar power into the electricity grid. Households with renewable energy generators such as solar panels and wind generators are helping to reduce emissions.

However, surplus energy from household renewable energy sources fed back into the grid could cause issues for electrical distribution networks to deliver a high quality electricity supply at a regulated voltage. "The issue that is beginning to emerge both around the world and also in Australia is that when you put larger numbers of these conversion systems, these energy injection systems, back into your electrical distribution grid you essentially muck up the way the grid works", RMIT researcher Grahame Holmes said.

There can be significant challenges in controlling the voltages between the utility substations and consumers. Voltage levels may exceed safe limits in the grid and the electrical supply to that part of the network may fail. Professor Holmes and his power and energy research group within the RMIT Platform Technologies Research Institute are embarking on a two year project with MILSystems to address the problem.

They will develop a leading edge reactive power control (RPC) inverter to better regulate the flow of power within the grid that results from energy injected from renewable systems. The project has been supported by a $647,000 grant from the Victorian Department of Primary Industries Sustainable Energy Research and Development.

MILSystems will develop the advanced inverter for their part of the project and RMIT will explore how to control and co ordinate large numbers of these inverters. "It is translating the principles of control from small numbers of large capacity technology, which is the present approach, to large numbers of small capacity technology", Professor Holmes said. "Secondly, it is adapting the control strategies of one way energy flow, which is the present understanding of power systems, to a two way energy flow".

Professor Holmes, who is Innovation Professor in Smart Energy Systems at RMIT, said solar injection systems were causing operational problems. He said once the work was completed, appropriate regulatory standards related to solar power systems could be amended to allow the implantation of RPC inverters in the community within the next few years.