Projects with Goldwind in China and Eskom in South Africa are footholds in markets needing long duration energy storage.


Other energy storage players may have surpassed California start-up Primus Power in terms of units shifted, but a company that can count the US Department of Defense and Microsoft as end-users of its flow batteries is well prepared for tough customers.

It helps explain why Primus is finding opportunities in markets where long duration energy storage – able to deliver energy over at least four or five hours – will be prized for bridging the shortcomings of grids integrating ever-cheaper wind and solar PV generation capacity.

In 2017 Primus Power launched the second generation version of its EnergyPod, a flow battery using zinc bromine chemistry, simplifying design, components and reducing production costs. The company also signed a manufacturing agreement with Taiwanese company Foxsemicon, which has the scale and strategic location to meet deadlines for bigger shipments in China and Asia-Pacific.

In November, Chinese wind turbine producer Goldwind took receipt of one of Primus Power’s 25kW/125kWh second generation batteries, which is installed within a microgrid that includes wind turbines, a solar PV array, as well as other energy storage systems.

The installation forms part of an ongoing effort by Goldwind to assess the suitability of various batteries, including lithium ion, for addressing one of China’s biggest power-related headaches, curtailment.

Modestly, Primus Power’s chief executive Tom Stepien describes Goldwind as, ‘Happy so far with the performance’.


Capturing sporadic wind

Goldwind, a maker of gearless wind turbines, turned wind and solar PV plant developer, wants to see how the EnergyPod 2 system can respond to the sporadic nature of wind power generation.

This includes, for instance, how the battery can fill in the lull between turbines in production and the demand to export, from the grid, as well as the battery’s ability to capture energy as a result of sudden gusts of wind, Stepien explains. The battery will be tested over several months to see how it performs in a variety of wind conditions.

Despite producing electricity without burning carbon, the problem with wind and solar is they tend to generate electricity

Wind waste – 17% of wind energy generated in China didn’t make it to the grid, in some provinces the figure was higher than 40%, according to BNEF

when there is not the demand to match output, so adding more capacity without the means to sync output with demand, results in turning off generators to maintain stable grid operation. In China curtailment is costing the state-owned operators of wind and solar parks several billion dollars in potential annual revenues and the government has created policies to address the issue.

The province of Qinghai, in north-west China, has been the most proactive to date in terms of interpreting the Chinese government’s “Internet+ Smart Energy” initiative, announced in February 2016. The initiative encourages developers to add energy storage to greenfield utility-scale renewable energy projects within the 13th Five-Year Plan period, which runs from 2016-2020.

Qinghai’s interpretation of the guideline means that any of the 3.3GW of allocations for new wind capacity that are developed in the province must install energy storage that is equivalent to 10% of a wind project’s capacity. This could amount to 330MW of energy storage being built in Qinghai alone by the end of the decade.

Bloomberg New Energy Finance (BNEF), which has analysed the impact of Qinghai’s mandate, concludes there is no guarantee that all 3.3GW of wind will be built, as some developers may avoid the province, due to the lower returns from building wind-plus-storage projects, compared with standalone wind projects.

Nevertheless, Qinghai is an example at province-level of China’s efforts to integrate more renewables generation. Curtailment in 2016 of wind averaged at 17% across China. However, in neighbouring states, including Gansu and Xinjiang, these rates were highest, 43% and 38% respectively (BNEF and China’s National Energy Administration).

Flow battery technology in China may also benefit from another recent central government policy. In September 2017 the “Guidance on the Promotion of Energy Storage Technology and Industry Development” was published by the China National Development and Reform Commission (NDRC).

The document urges more investment in energy storage, including flow batteries. In regard to solar PV and, more recently, electric cars, China has shown how it can use policy as a tool to galvanise investment in new industries and markets. In the same vein, the country could rapidly emerge as a key market for several battery-based storage technologies, including flow batteries.

In this regard Stepien sees the deal with Goldwind as a vital stepping stone into the market.

Tom Stepien, chief executive and co-founder of Primus Power

“The benefit for us potentially is that China, and companies like Goldwind, are tackling a very real world challenge – how to supply industrial growth and demand for electricity with clean energy resources. Goldwind has done its homework. It took a while to earn their trust, but they could see from our demonstrations and projects what we have been doing and its relevance to the company’s objectives.”

Primus Power is not the only western flow battery company benefitting from growing interest in this type of storage. Earlier in 2018, German manufacturer Schmid Group announced a deal to supply three vanadium redox flow batteries to a leading photovoltaic (PV) producer in China.

In addition to optimising solar self-consumption at the customer’s facility, the battery installation could lead to the customer installing Schmid’s flow batteries with large-scale solar PV projects.


South Africa

South Africa is another strategically important export market for Primus Power. Thanks to a grant award by the US Trade and Development Agency to Solafrica Energy, a local developer of utility-scale solar power plants, Primus Power is supplying its flow batteries to the company.

In the pilot four EnergyPod 2 systems, totalling 100kW/500kWh, will be installed on Eskom’s grid demonstration facility to establish the technology’s ability to integrate renewables and ease choke points on the grid in order to meet demand.

Eskom, South Africa’s national electricity utility, is tasked with expanding its customer base, including outside of the two main load centres, the cities of Johannesburg and Cape Town.

“You could build a new substation, cabling and the infrastructure needed, which would be at huge cost, for meeting peak

Primus Power introduced its second generation zinc bromine flow battery in 2017 (Image courtesy of Primus Power)

demand over a window of a few hours, during certain months of the year. Or you could install long duration batteries at those choke points and pull energy from them during those hours and periods of peak demand.”

The pilot will help to inform a plan for deploying Primus Power’s energy storage systems throughout the country.

South Africa is also promising to providers of flow batteries, like Primus, due to the mining industry, where robust longer duration storage coupled with renewables can provide a stable source of power, reducing energy costs.

Primus Power is also shipping to a project in Europe.