When Hawaii Electric Light Co. officials say the island’s electric grid needs to be updated, they’re not talking about the age of the power generating stations, substations or transmission lines.
In a traditional power distribution plan, like Hawaii Island’s, power is generated, then the electricity travels on transmission lines, first at 69,000 volts, to community substations, where the voltage is stepped down to 12,000 volts, HELCO Energy Services Manager Curtis Beck said. From there, the electricity goes out on transmission lines again, this time to neighborhoods, where it steps down to about 480 volts. The electricity undergoes one last step-down, to 120 volts, as it enters a home or business.
The issue, he added, is adding in solar power generated at an individual home, which flips around the direction energy is typically traveling on the grid.
“You change the voltage distribution along the line,” Beck said. “There are questions of whether our automatic voltage adjustment equipment may work properly. By injecting power at many points, we change the whole voltage balance on that circuit.”
HELCO has seven power generating stations, and buys power from another five stations. Beck said the company does not release maps of the plants, substations or transmission lines, at the recommendation of the Department of Homeland Security.
HELCO President Jay Ignacio, at an April 3 briefing of County Council members, described grid problems associated with distributed generation, or the generation of electricity at, or close to, its use, such as when home- and business owners install solar panels.
Ignacio said more energy being fed into the grid from individual systems increases risks to personal safety, equipment damage and power quality. It also can cause outages. Problems regulating voltage could lead to fluctuations and damage to homeowners’ equipment and appliances, he said.
HELCO is fourth highest in the nation in the level of solar wattage to the grid compared to the customer base. HELCO requires a detailed interconnection study when an area of the grid reaches 15 percent saturation with solar energy. Ignacio said 15 percent is the industry standard.
Thirty states have imposed renewable portfolio standards, requiring power companies to convert specific percentages of their power to renewable or clean sources. That’s contributing to commitments to upgrade some 65,420 miles of transmission lines in the United States at an estimated cost of $170 billion over the next eight years, said Farah Saeed, energy and power systems principal consultant for the Mountain View, Calif.-based business research and consulting firm Frost & Sullivan.
Saeed said many utilities are also finding that infrastructure that worked 30 to 40 years ago can’t keep up with the new technology, smart grids and the advent of solar panels and charging stations for electric vehicles.
“Our infrastructure is rather aged and needs to be upgraded, and they need some mechanism to do a better job of monitoring what’s happening on the grid. A lot of this equipment is reaching its limit,” Saeed said. “It’s an ongoing process, but we’re just seeing an acceleration of upgrades.”