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Aloha to Solar Power

A new 12-MW solar project-complete with a 6-MW battery storage system-built on the Hawaiian island of Kauai is helping the state in its move to renewables and its long-term goal of producing 100 percent of its electricity from renewable energy.

By Paul MacDonald

It may sound like a long way off, but Hawaii's decision to move entirely to 100 percent renewable energy by 2045 stands out as an extremely large long-term commitment to clean energy among U.S. states.

Last year, the State Legislature passed-and Hawaii Governor David Ige signed-a bill that sets the goal of Hawaii running exclusively on clean energy in 30 years.

Hawaii has, in effect, become the first U.S. state to commit to producing 100 percent of its electricity from renewable energy. It will likely be from a mix of solar, wind, biomass, thermal, and hydro power, reflecting the state's current sources of renewable energy.

Tesla Batteries Chosen for Hawaii Solar Storage Project

SolarCity has selected Tesla Energy to supply the batteries for a first-of-its-kind solar array and energy storage system to be built for Kaua'i Island Utility Cooperative (KIUC).

SolarCity made the selection after conducting a comprehensive competitive solicitation in the battery marketplace, the company said. The proposed SolarCity/Tesla project is believed to be the first utility-scale system in the U.S. to provide dispatchable solar energy, meaning that the utility can count on electricity being available when it's needed, even hours after the sun goes down.

The 52-MWh Tesla Powerpack lithium-ion battery storage system will feed up to 13 megawatts of electricity onto the grid to "shave" the amount of conventional power generation needed to meet peak demand in the evening from 5:00 p.m. to 10:00 p.m.

By using the solar energy stored in the battery instead of diesel generators, KIUC will reduce its use of imported fossil fuels and also cut its greenhouse gas emissions.

Under the terms of the 20-year contract announced in September 2015, KIUC will pay SolarCity 14.5 cents per kilowatt hour, only slightly more than the cost of energy from KIUC's two existing 12-megawatt solar arrays, whose output is available only during the day.

The array and battery storage facility will be built on 50 acres of land owned by Grove Farm Company Inc. adjacent to KIUC's Kapaia power station.

The project has already received most of its required state and county approvals and is now awaiting approval by the Hawaii Public Utilities Commission. KIUC and SolarCity have requested an accelerated timetable for review of the project so that construction work can begin, with a goal of being in commercial operation by the end of 2016.

With this initiative, the government has taken a leadership position in advancing Hawaii's efforts to end importing fossil fuels and to being committed to a renewable future in the electricity sector, said Ige.

Hawaii currently produces about 21 percent of its electricity from renewable energy and depends on imported fossil fuels for producing the balance of its electricity.

The plan is for power from renewables to be phased in, beginning with a 30 percent goal by 2020, ramping up to 70 percent by 2040-and 100 percent in 2045.
Hawaii achieved an interim goal of 15 percent renewable power in 2015.

It's expected that the growth in energy storage technologies in the years to come should also benefit Hawaii and the investments in renewable energy.

All of this makes for a good fit for one of the most recent-and largest-solar projects completed in Hawaii: a 12-MW solar array developed by REC Solar located in Anahola, on the northeast side of the island of Kauai. Built for Hawaiian utility Kaua'i Island Utility Cooperative (KIUC), it is REC Solar's largest project to date.

The 60-acre PV system now generates 20 percent of the island's annual energy needs during daylight hours. The installation is coupled with a 6-MW lithium-ion battery system designed to smooth the integration of solar power on the grid.

By generating clean energy on the island, KIUC will decrease fossil fuel imports from the mainland and save approximately $250,000 a month on fuel costs alone. The new solar project displaces 1.7 million gallons of oil annually.

By the beginning of 2016, 37 percent of the electricity generated on Kauai came from a mix of renewable resources: solar, hydropower, and biomass. That's up from only five percent in 2009.


"Hawaii is at the forefront of the electric grid transformation, and solar energy is in the driver's seat," said Al Bucknam, REC Solar CEO. "REC has invested in understanding
Hawaii's unique market because we know commercial and utility-scale solar is an integral part of Hawaii's ambitious 100 percent renewables goal."

"REC Solar has more than eight years of experience in the Hawaiian islands, and we've completed 34 megawatts of commercial and utility projects here," added Drew Bradley, Hawaii Regional Manager at REC Solar. "This installation is a game-changer for Kauai and will set a precedent for utility cooperatives across the U.S."

Prior to the Anahola project, REC Solar had worked with KIUC on another project, a 1.2-megawatt fixed tilt, ground-mount solar project in Kapa'a that went into service in December 2010.

"Following that project, KIUC was looking to do something larger," explained Bradley. "They were familiar with us and happy with the work we had done, so it was a natural progression for us to be interested in doing another project for KIUC.

"The genesis for REC's entry in the Hawaii market was the Costco account," said Bradley. "When Costco started their portfolio of solar projects, the first one was the Kailua-Kona warehouse on the Big Island, and the second was their Lihue warehouse on Kauai." REC Solar did both projects.

Under the Costco solar program, REC Solar was responsible for the turnkey design, engineering, and installation of solar systems on 33 Costco warehouses, including California, Colorado, New Jersey, Puerto Rico, and Hawaii.

The two 680-kW projects for Costco were considered large at that time and allowed REC Solar to get a foothold in the Hawaiian solar market. REC Solar was also selected to design and install four ground-mount systems at the Dole Plantation and a follow-up project across the street at Dole's Fresh Fruit Packaging Plant on the island of Oahu.

In terms of the Anahola KIUC project, Bradley explained that civil work was required on the 60-acre site prior to starting installation, and for that work, they used the services of local company Earthworks Pacific.

"We tried to do the civil work selectively and leave the land, as much as possible, the way it was, but we needed to have drainage. Most of the civil work was done to contain potential storm water runoff," he says.

One of the largest parts of the project was designing three retention basins within a very tight site.

"The soil on Kauai is very red, and when you have heavy rain events, all that red soil can get washed down into the ocean."

Tourists are looking for beautiful blue, rather than red, ocean waters, washing up on the island of Kauai, which is appropriately called the Garden Isle. Although the island itself is quite compact (552 square miles) and has a small population (less than 70,000), more than 1.2 million people visit the island every year, showing how important tourism is to the local economy.

Three large retention basins, two near the bottom of the site between the array and the substation, and one on the south side about half-way up, were designed for the project. In addition, five acres of the site were set aside for the substation and another five acres for the base yard.

The retention basins on the Anahola project were large, with a total holding capacity of 35,723 cubic yards.

In terms of components on the solar array, REC Solar selected REC Group (based in Singapore), which supplied a total of 57,624 solar panels for the project. Some 24 inverters were used on the project, along with two ABB 500kV transformers. It features 20-degree fixed tilt
racking. REC Solar drove more than 8,000 hot-dipped galvanized racking piles with their own Italian-built Pauselli pile drivers.

REC Solar was the general contractor on the project and self-performed the electrical work.

"The most gratifying part of the project for us as project manager was that we were able to hire almost all the people for the project from Hawaii," said Bradley.


"Employing local people is the right thing to do, and it makes sense financially-it's a plus on all sides. We were able to find a lot of good people."

More Hawaii Solar Power? D.E. Shaw Interested in Restarting SunEdison's Solar Projects

In other Hawaii solar developments, New York-based hedge fund D.E. Shaw is said to be interested in what it termed a "commercially reasonable solution" to restarting power purchase agreements (PPAs) for three utility-scale solar projects developed in Hawaii by SunEdison, which had its previous PPA contracts canceled by local utility Hawaiian Electric Co. (HECO).

In April, SunEdison filed for bankruptcy protection after a two-year, $3.1 billion acquisition initiative that drove up its debt. The clean-power giant listed $16.1 billion of debt in Chapter 11 filings, making it the biggest U.S. bankruptcy of the year.

Earlier this year, HECO terminated three PPAs for SunEdison's 148 MW of solar projects. HECO blamed SunEdison's "apparently precarious financial condition" as the reason for the PPA cancellation of the 65-MW Kawailoa solar farm, the 64-MW Waipio plant, and the 19-MW Milani II solar project.

D.E. Shaw said it is interested in reigniting the PPA deals, according to a letter the hedge fund submitted to HECO.

The Hawaii utility's reasons for canceling the deal were based on concerns over SunEdison's financial troubles, which recently included the collapse of a $2.2 billion deal to purchase Vivint Solar, the second largest residential solar installer in the U.S.

SunEdison had challenged a termination notice from HECO for the three solar projects. SunEdison's response, reported by Bloomberg, has been to
reiterate its belief that the company remains committed to selling and supporting the completion of the Hawaii projects.

The three solar projects were on course for completion by the end of 2016, and a total of $42 million has already been invested in their development, SunEdison said.

In terms of monitoring and control for the project, KIUC has a Delta V SCADA system from Emerson Process Management in place for its existing power facilities on the island, and the Anahola power plant was interconnected with the same supervisory control and data acquisition system.

The project was challenging in that it also incorporates a 6-MW lithium-ion battery system. Industrial battery manufacturer SAFT was awarded a contract by KIUC to provide a lithium-ion Battery Energy Storage System (BESS) consisting of eight Intensium Max 20 M containers. Each of the containers provides 0.75 MW of storage, for a total of 6 MW of storage. Saft's BESS will be used to provide stability and mitigate issues caused by intermittent fluctuations that can occur with renewable power sources.

"The grid on Kauai is relatively small, so it can be affected by small events," explained Bradley. "The goal with the system is to smooth out the power and heighten the frequency and voltage band."

SAFT partnered with ABB for the power conditioning on the storage, with ABB supplying four ultra inverters. KIUC employed project capital from the United States Department of Agriculture's Rural Utilities Service (RUS) program to finance the Anahola project.

This being Hawaii, with its dependence on tourism and heightened awareness about the environment, construction projects in general face higher levels of scrutiny, compared to many states on the mainland. For the KIUC project, the review included REC Solar doing a very detailed-and lengthy-Environmental Impact Statement.

Overall, Bradley said the most challenging part of the Kauai solar project was dealing with the slope of the site and building the retention basins. "If it's flat, you still have to deal with hydrology, but it becomes so much more important when you have grade, such as we had on our site. That's why the retention basins became so important." On top of that, there was also the detailed work and meticulous planning and design work that go into incorporating a storage system.

Although it had its challenges, Bradley noted that the KIUC Anahola project was satisfying to work on-and going forward, it forms an important part of Hawaii's move toward a very high bar: 100 percent clean energy.