Failed battery at Hawaii solar farm part of learning process, says analyst

The "accelerated capacity fade" of the lead carbon battery storage system is less a major setback, more a step in the learning process for Hawaii, according to Dean Frankel of Lux Research. Image: Flickr user: tdlucas5000.
The failure of a grid-connected storage system at a solar farm in Hawaii is part of the learning process the US island state is undergoing to integrate more PV using storage, according to analyst Dean Frankel at Lux Research.

A so-called “accelerated capacity fade” which has reportedly taken place at a grid-connected solar farm in Hawaii is not a major setback, Frankel said. MIT Technology Review, the technology news website of the Massachusetts Institute of Technology, wrote today that the first of two grid-connected energy storage systems designed to aid the increased penetration of solar on the Hawaiian island of Kauai has failed.

Connected to a 6MW solar power plant, the system, designed and installed by Xtreme Power in 2011, is lead carbon battery based and was ordered by the Kauai Island Utility Cooperative. Xtreme Power has since gone bankrupt and was bought by German battery company Younicos. A second storage system is in the process of being installed by French battery energy storage system (BESS) maker SAFT at a 12MW Kauai solar farm. Delivery of components began in October after the second project, which is based on SAFT's containerised lithium-ion batteries, was announced in July.

This site and others have frequently written about Hawaii’s position among the leading world regions for installed energy storage. Driven by the island state’s need to wean itself off fossil fuel usage and in tandem with the ongoing installation of a huge amount of solar proportionally speaking, the island’s main utility, Hawaii Electric Company, recently issued a request for proposals (RFP) for over 200MW of energy storage.

Dean Frankel, who blogged on the Hawaii Electric Company’s RFP for PV Tech Storage in May of last year, spoke to the site today to give his take on the two storage systems, the Xtreme Power’s capacity faded first project and SAFT’s second, ongoing project. When asked if the capacity fade was a setback for attempts to mitigate the variability of PV plant output into the grid, Frankel was adamant that it would not be.

“No, not at all. It’s a setback for anyone developing lead carbon because they have to go to the table and say 'why should I trust your batteries over Xtreme Power'. Xtreme Power is no longer around and Younicos [the German battery storage maker which purchased Xtreme Power in April last year] is not pursuing lead carbon so that avenue is dead, it’s just their competitors and lead carbon is a very small component of the energy storage marketplace.

“So no one is currently making Xtreme Power’s lead carbon batteries, that operation has been shuttered. Xtreme Power, before it went bankrupt had already recognised this shift so they were working with Samsung, so some of the batteries that Younicos now operates which were originally done by Xtreme Power are Samsung lithium-ion batteries.”

SAFT's Intensium Max containerised lihtium-ion batteries will power the newest of Kauai's utility-scale storage systems. Image: SAFT.
Frankel did say however that the accelerated capacity fade at the 6MW Kauai project pointed to a wider question over grid-connected storage, namely the lifetime of batteries and the need for buyers and developers to look closely at claims made by manufacturers.

“The broad question of lifetime is very important. Anyone procuring energy storage needs to ask the lifetime question of their supplier and their partners and if they’re not then they’re not doing a good service to the people paying for that system because ultimately you want that system to last as long as possible. But, is lead carbon failing in the field detrimental to energy storage as a whole? No.”

According to Frankel, remaining participants in the lead carbon battery space would have to take pains to ensure the differentiation of their products from those offered by Xtreme Power. He went on to say that while this might make a good piece of anecdotal evidence in favour of major non-lead carbon battery chemistries such as lithium-ion, it would not be likely to stretch beyond that.

The bigger question of battery lifetimes, and assurances given by manufacturers are still a grey area which needs more work, Frankel said, adding that there is also a lack of available data in a relatively new industry.

“Certainly energy storage is maturing. The key point there is that when people have lifetime claims, they really need real data to back that up and data is not always available,” Frankel said.

“Grid modelling is not always there, so it does speak to the need for better management, which does improve lifetime in certain situations, and also matching the chemistry to the applications, so if you don’t do that, you’re not going to do a good job of optimising your value of the system, and one of the value metrics that you would look at is the system lifetime – and that is a big unknown right now.

“So the onus is on battery developers to make sure that data is tested and communicated to their potential customers.” 

Frankel was also adamant that Hawaii would not back down from its wider aims of integrating more PV and using storage to do so.

“I think every single island in Hawaii and every cooperative and utility recognises energy storage because it displaces oil, for climate reasons and for economic reasons, energy storage will be a critical part of Hawaii’s grid, so it’s not going to be a major setback, it’s a learning process.”