California-based company looking to use sun, rocks to provide renewable energy when needed

KAILUA-KONA — The Big Island gets a lot of sun and has a lot of rock — especially on the west side.

KAILUA-KONA — The Big Island gets a lot of sun and has a lot of rock — especially on the west side.

Now, a California-based company is looking to use both to provide renewable energy when it’s needed most — at night.

Pasadena, California-based Edisun Heliostats is moving closer to bringing its solar battery demonstration project to the Natural Energy Laboratory of Hawaii Authority. The project would test the company’s renewable technology on a commercial scale using an array of mirrors to concentrate the sun’s energy and convert it into high temperature heat. That heat is then channeled through a heat exchanger to generate electricity immediately, or it is used to heat locally sourced rock up to more than 900 degrees, the energy of which can be used at a later time to create power.

“We’re revolutionizing the idea that we can deliver the power any time regardless of when it is captured,” said Peter Stricker, Edisun’s chief commercial officer.

Edisun, founded by Idealab in 2014, is changing the concentrated solar power industry by lowering costs and providing the ability to store energy for later use.

“We are trying to do inexpensive but smart. We are trying to use every engineering tool and cost to make it economical,” he added.

Edisun got unanimous approval in concept by NELHA’s Board of Directors this week to go forward with the project at the North Kona ocean, science and technology park. Next, Edisun must submit a final proposal for approval, which Stricker expects to do in early 2016. The project would come online later that year and would likely require one employee to maintain.

If given final approval by NELHA’s board, which officials expect, the project will take over the 4-acre spot makai of Queen Kaahumanu Highway vacated last year when Keahole Solar Power closed its Sopogy operations, said NELHA Executive Director Greg Barbour. Edisun will utilize much of the existing equipment, with the exception of Sopogy’s mirrors, which Barbour said might be able to be used by another tenant within NELHA. The site is already connected to Hawaii Electric Light Co.’s grid.

“When we see somebody very reputable like the Energy Excelerator selecting them for demostration, we get very excited about that,” Barbour said. The project was one of eight companies making up the 2015 Go-to-Market cohort to receive funding. “We’re very exicted and we think it’s very cool.”

Edisun completed a successful prototype in Pasadena that produced 25 kWh capable of being stored for five hours and then dispatched to meet demand. The Kona commercial demonstration project would produce 100 kWh that could be stored eight to 12 hours without expensive batteries, Stricker said. The company uses the rock as the “battery” to store energy for later conversion to electricity.

“We’ve demonstrated that we can deliver on demand,” Stricker said.

During the Kona commercial demonstration period, Edisun will provide electricity to NELHA, not including tenants. The energy will be used to offset costs to operate the facility’s main water pumps 24/7. Barbour said the energy could reduce annual electricity costs by about 10 percent.

However, the goal, Stricker said, is to provide HELCO, if the utility agrees and government approval is obtained, the renewable technology to generate electricity that can offset the use of fossil fuels to meet demand during peak-use hours. It can also help balance load and generation on the Big Island electric grid.

“We think we’ve got a really good solution,” Stricker said. “In addition to generating and dispatching our solar power, we can take power off the grid (for use later).”