Micro-grids for power could stave off telco outages in disasters

Regional loss of phone services like that following Hurricane Katrina could be a thing of the past if telcos follow a proposed architecture of tiny grids dedicated to powering local phone networks, a University of Texas professor says.

Trimming down the size of power grids serving telco networks could make them more resilient to widespread outages during disasters, says Alexis Kwasinski an assistant professor specializing in power electronics at the school’s Austin campus.

Decentralizing electricity distribution networks would be more dependable as well as more efficient, he says.

His architecture calls for micro-grids that can be run using whatever fuels are available and dependable in a local area. They would be used to provide the DC power needed for the telco networks in their immediate areas.

If the micro-grids produce more power than they need, they could sell it to the broader grid at a profit. Because the micro-grids are smaller than regional grids, they would also be suitable to adopt renewable energy sources more readily because the investment and conversion time would be smaller, Kwasinski says.

Renewable sources such as wind and solar would be even simpler to substitute in new service areas where there was no legacy system to replace.

"There has been surprisingly little research on disaster damage and restoration of telecommunications systems," says Kwasinski. "My survey of the Gulf coast after Katrina showed how devastating a single downed line or incapacitated substation can be. The answer is diverse power input. You integrate different types of local power sources with diverse energy delivery infrastructures through multiple-input converter modules."

The micro-grid networks would be modular, so if one failed others would stay in service, reducing the chance of region-wide outages. The energy used could be fuel cells, micro-turbines or, if necessary, the existing utility grid. The micro-grids would be isolated from surges and failures coming from secondary sources, which would include the traditional utility grid. So even if the grid goes down, the micro-grid could remain up if it had an independent energy source that was unaffected, Kwasinski says.

Excess power sold to the utility grid could help defray the costs of the micro-grids. Those costs would be further defrayed by reduced downtime, more efficient use of equipment and lower hardware expenses, he says.

"It works for developing countries who can add components to the system as they can afford it,” Kwasinski says. “Existing systems can easily be retrofitted with a microgrid system operating as a secondary distribution method. Small devices like solar panels and windmills can be added ad hoc, making for a painless transition to renewable energy at a competitive cost."