By Jason Deign
Battery start-up Encell Technology is taking aim on emerging markets with a residential-scale product that bucks the current trend for sleek, eye-catching design.
The company’s Fused Iron batteries are visually unimpressive but able to perform better and withstand a much wider range of operating conditions than lithium-ion (Li-ion) rivals, said Encell chairman and founder Robert Guyton.
“There are fundamental trade-offs in lithium-ion when it comes to cost, cycle life and safety,” he said. “It’s a zero-sum game.”
Evaluating the trade-offs led Encell to select a nickel-iron battery chemistry instead.
Nickel-iron batteries have low specific energy and poor charge retention but are popular in mining because of their long operating life, of up to 20 years with regular cycling, and their ability to withstand harsh environmental conditions.
“It’s never been on fire”
“Nickel-iron does have huge cycle life,” Guyton explained. “It’s been around since Edison invented it 100 years ago and it’s never been on fire.
“For grid-edge storage, any time you can get better energy density it’s a plus, but cycle life is more important. And then rugged [design means] I don’t have to be really sensitive with temperature, because that just adds to the cost.”
Guyton said Encell had overcome the chemistry’s poor discharge characteristics using fused iron electrodes.
On its website, Encell asserts its products can undergo 15,000 cycles with an 80% depth of discharge (DoD) and “no capacity fade for the first 75% of total cycle life.”
The company’s performance claims have been confirmed by Sandia National Laboratories in the US, Guyton said. “We have cells that have been cycling twice a day for over five years and are over 4,000 100% DoD,” he said.
This is said to result in a market leading levelised cost of energy (LCOE).
“The Encell Fused Iron Battery is estimated to cost up to one-tenth the price per kilowatt hour on a LCOE basis in comparison to a lead-acid battery with similar name plate capacity,” claims the company.
“The LCOE advantage is even more pronounced versus Li-ion batteries.”
Guyton clarified that Encell’s current energy storage products were priced at around USD$500 per kWh of installed capacity, of which about half was the cost of the battery itself.
“If we had the ability to be produced at volume it would be below $100 per kWh,” he said. “We believe we have the lowest cost of ownership because we don’t need it to be kept at 25ªC. We don’t need cell management.”
Production facility in Florida
Encell makes the batteries itself in a 2.1MWh-a-month production facility in Alachua, Florida, formerly owned by Energizer Power Systems and purchased for “cents on the dollar,” according to Guyton.
So far the company has completed around 100 installations, mostly comprising 10kWh systems, and around half a dozen larger projects for customers such as Lockheed Martin, Google and a New York hospital.
For the latter, the chemistry had to be approved for in-building installations in downtown Manhattan, which is currently off-limits for Li-ion because of New York City Fire Department regulations.
However, the real market for the Encell storage product is less likely to be Manhattan than any number of emerging markets.
Where you want to abuse the battery
“We think it lends itself to rural electrification in places like Africa and India,” Guyton confirmed. “Any place where it’s super hot, remote, where you want to abuse the battery.”
Guyton said Encell has worked on “a couple” of MWh-scale wind farm-connected storage projects in Latin America and a 100kWh solar-plus-PV project for First Solar and Husk Power Systems in India.
There is also an up to 5MWh project underway at an industrial park in Nicaragua, where the owners want to tie existing wind and solar assets to energy storage in order to extend production by four hours a day.
The company, which was founded in 2006 but has been operating so far under the radar that energy storage analysts consulted by Energy Storage Report said they had never heard of it, is expecting rapid growth going forward.
It has a potential sales pipeline of 191MWh this year, 647MWh in 2017 and 1.6GWh in 2018. “I would say maybe half of it is geared towards projects in emerging areas,” Guyton said.