Hawaii homeowners who were among the first in their neighborhood to install solar photovoltaic panels are finding that being an early adopter is paying off.

Although PV panel prices were higher, the relatively modest amount of solar power on electrical grids a few years ago meant that systems could be installed quickly with no extra charges from the utility.

For many of those arriving late to the party, getting a PV system on their roof has become much more problematic. A surge in PV system installations across the state is flooding utility grids with unprecedented levels of intermittent solar energy that the systems were not designed to handle. Utility executives say the intermittent nature of solar energy poses potential safety and reliability risks in areas with high concentrations of rooftop PV panels.

The situation has prompted Hawaii power companies to adopt a cautious — some say overly cautious — approach to allowing additional PV systems in highly saturated areas. While the majority of utility customers who want to go solar are still able to proceed with their projects, those in highly saturated areas are facing delays and additional expenses for utility-required protective equipment.

In some highly saturated areas of Maui and Hawaii island, utility officials are telling customers that their solar projects will have to be put on hold from 12 to 18 months until engineering studies are completed and protective equipment is installed. The added equipment can cost a single homeowner as much as $2,500 per kilowatt of solar generating capacity, or $12,500 for an typical 5-kilowatt system.

To be sure, Hawaii’s electric utilities are far ahead of their counterparts on the mainland in the percentage of their customers that have PV systems. Maui Electric Co. has the highest in the nation at 5.4 percent of its customers having installed solar panels as of the end of 2012, according to the Solar Electric Power Association. Hawaiian Electric Co., Oahu’s utility, was second at 5.2 percent, followed by Hawaii Electric Light Co. on the Big Island at 4.1 percent and Kauai Island Utility Cooperative at 3.1 percent, according to the report. The next-highest level of solar energy penetration for a major utility was 1.5 percent at San Diego Gas & Electric.

The growing levels of solar energy saturation prompted HECO on Sept. 6 to announce a host of changes in the way it handles applications for residential PV systems. One of the things HECO did was to say the costs for any equipment upgrades needed due to increased solar installations would be shared among new PV customers whose homes are on the same circuit.

HECO also began asking customers and PV companies on Oahu to contact the utility before starting work on a solar project to check the saturation level in their area. KIUC implemented a similar policy earlier this year. MECO and HELCO have been doing it for more than a year.

Of the 416 circuits, or neighborhoods, that make up HECO’s electric distribution system on Oahu, 81 circuits, or 19 percent of the total, are in the highest category of PV saturation, according to the latest figures from the utility. That means the solar power generated in those neighborhoods exceeds the amount of electricity being consumed at certain times of the day. That pre­sents problems for HECO because the excess solar power flowing back into the circuit could cause voltage spikes that damage household appliances or injure utility crews working on power lines. (To check the PV saturation in your neighborhood on Oahu, go to bit.ly/XTpcYy Opens in a new tab.)

Kirk Maluo, an Ewa resident who recently decided to add panels to his existing PV system, discovered that his home is on one of the highly saturated circuits. When Maluo bought his first PV panels more than a year ago, he was able to have the system installed and hooked into the HECO grid within three weeks.

After buying an electric vehicle recently, Maluo decided he wanted to install additional panels totaling 2 kilowatts of generating capacity. That’s when he found out about HECO’s new rules.

Maluo said the utility initially told him that because of high PV penetration on his circuit, he would have to wait an undetermined amount time before he could activate his new panels. He also was informed that he would have to pay for equipment upgrades, although he wasn’t given a price.

After pressing HECO further, Maluo said he learned that he would have to wait at least two to three months for the utility to complete an engineering study, and then pay anywhere from "$750 to several thousand dollars per kilowatt" for any necessary equipment upgrades.

Maluo questioned why HECO wasn’t better prepared for the day when solar energy would become such a significant part of its electrical grid.

"They knew this was coming. If they’d charted out the trajectory of PV growth, they would have known they’d be reaching saturation. They shouldn’t have been surprised. Now everyone’s in limbo," Maluo said.

North Kohala resident Patrick Mervin said he submitted paperwork to HELCO in January seeking approval for a planned 3-kilowatt PV system. He borrowed about $20,000 to finance the project and paid a Hilo-based PV company $1,000 to design the system.

After not hearing anything for several months, Mervin said he called the utility and was told the delay was the result of "an engineering problem" stemming from high PV saturation in his area. Several more months passed, and Mervin had still not been told whether his project would be allowed to proceed. Mervin said he called HELCO last week and learned the utility plans to conduct a "pilot study" sometime next summer or fall that will determine whether his area will be opened to more solar.

"It is pretty clear that solving this is not a priority and if they slow it down enough, maybe everyone will forget about it," Mervin said. "It seems to me to be a straightforward engineering problem that they are vigorously avoiding."

When Big Island resident Jeff Thacher told HELCO he plans to install a 2.6-kilowatt PV system on his home in Naalehu, the utility told him he would have to pay $2,700 on top of the roughly $17,000 he paid for the system itself.

A letter from HELCO informed Thacher the charge would cover his share of the cost of installing "relaying equipment to protect the grid and customers from damaging voltages." Thacher said the charge made him think twice about installing the PV system, but he decided to go forward with it anyway.

Roland Shackelford, vice president of Renewable Energy Services, a Hawaii island solar energy company based in Paauilo, said he was shocked at the price HELCO quoted him for equipment upgrades that would be needed for a planned 3-kilowatt system on his own home.

"They wanted $2,500 per kilowatt plus tax for a total of $7,800.12. It was a deal breaker for me," he said. Shackelford said he will take the money he would have paid HELCO and invest it in batteries for his PV system that will allow him to disconnect from the HELCO grid.

If his battery project is successful, Shackelford said he plans to use it as a prototype for similar systems his company can offer to its customers.