Northern Power Systems Corp, the distributed energy power systems specialist, has started to offer a full suite of megawatt-scale energy storage solutions. Decentralized Energy spoke to Chris McKay, the Director of North American Sales at Northern Power about the range’s various battery types and capabilities.

The company has already qualified and begun integrating batteries from three industry-leading suppliers with different chemistries for a variety of use cases, and anticipates adding to this list of qualified solutions:
Chris McKay of Northern Power
UniEnergy Technologies – vanadium-redox flow batteries

Eos Energy Storage – zinc hybrid batteries

Samsung SDI – lithium-ion batteries

McKay spells out the main reasons Northern Power’s offering is proving attractive to a broad and growing clientele, but its previous experience in wind turbine installation is telling.

“Well, it’s really three things The inverter is one, the controls and software that we have somewhat more important. Thirdly, our ability to provide a turnkey solution.”

“A wind turbine has really complex subsystems, a blade generator, inverter, the braking, yaw system, weather and vibration systems that monitor the tower. That all comes together to make a fully wind integrated wind turbine simply integrated to the grid.”

“We’re taking that same integration capability and applying it on the battery system. In the battery, there’s the battery and thermal management, fire protection and of course inverter, converter and DC connection and interconnect at AC side, breakers and relays to meet the grid requirements. It’s that combination of integration control, inverter technology and ability to do a turnkey project.”

“Interestingly a wind turbine project is not so different to some batteries. We’re talking large heavy items that need to be logistically sent to a site, civil works for concrete pads, electrical work for wiring, protection at site and installation commissioning. In the end, they are both distributed energy projects that require a lot of the same skills to do a turnkey job.”

While Vermont, US-based Northern Power, now a multinational, made its name in wind power, it is now well set up to facilitate a growing market in distributed energy. The company isn’t developing small scale or large, utility-scale storage. It’s somewhere in the middle.

“Our sizing is for 1 to 5 MW systems which will be at substations or co-located with renewables and has to do with grid services – frequency regulation, peak shaving, serving in the wholesale market or performing an energy services contract for utilities. There are a lot of small municipalities and co-ops that really understand that they can lower their operating costs with energy storage but are not necessarily ready to make the investment. And we are working to provide energy as a service for some of those smaller power groups that don’t have the resources to go and manage the implementation of new technology.”

At the moment the company is aiming its storage effort predominantly in the areas in which it already has a keen presence – the north-eastern US. McKay says that’s where their relationships are strongest and ‘the economics are strong.’

“Opportunistically we will provide equipment bids in other places, such as in Washington and California at the moment. We are not the lead on those projects but we are providing equipment. But our biggest effort is reserved for where we can be the lead on a project.”

The Washington state (Pullman) project includes a 1 MW / 4 MWh system with flow batteries from UniEnergy Technologies. The company is also active in a pilot project in Brazil in conjunction with Engie using Eos batteries being installed at an existing location with more than 5 MW of wind and solar capacity.
Chris McKay
The Engie project is currently at testing phase with the French giant looking to qualify the solution for global roll-out. The storage equipment Northern Power will be involved in, involves stabilizing and streamlining that wind and solar output.

Resiliency has, due to unfortunate recent events, become a buzz word in the US, and none more so than the east coast of the US, where hurricane Sandy wrought devastation. There is a growing appreciation about what storage and distributed energy storage can do to maintain critical services and businesses, when superstorms or cyberattacks happen.

The company recently responded to an RFP (Request for Proposal) for a facility at Burlington Airport, Vermont.

“Energy storage systems need to provide multiple benefits in order to have payback. The site could be utility owned but customer sited so the utility can operate the battery for their financial operational benefits. Say to help with coincidental peaks, monthly peaks, annual peak, demand frequency regulation, but if the grid were to go out the battery then switches over to resiliency mode and can then help the airport with backup power relatively seamlessly.”

While there are plenty of operators demonstrating storage credentials, McKay points to the advantage Northern Power has in having different partnerships with different companies, offering different storage technology options.

“I don’t know a lot of groups actively engaging with projects with such a variety of technologies. Its gives us a lot of credibility and we come in with a consultative mentality to help people learn how energy storage can help them, the pros and cons.”

While some systems might have a lower cost they may need earlier replacement or come with higher operating and maintenance costs. Some may have a higher first cost but have a longer life. Some are better for little cycles, others better for one cycle a day, so Northern Power helps people understand the technology choices and how it fits into what they are doing.

“There are groups who only do one thing,” says McKay. “They are going to try shoehorn you into that solution and make their best case that that particular solution will work for you. We can help people look at a wider variety of options.”

“No one really knows what battery technologies will end up being the winners so we want to make sure that as different technologies make progress and take the lead that we are positioned to be able to leverage that. If you only use one kind and that kind is left behind by an emerging tech you get left behind. We want to make sure we’re working with a variety so as people make progress and come up with innovation and come up with cost and performance improvements that we are able to pull that in to our solutions set and leverage that.”

The company’s power conversion platform comprises a liquid cooled modular system, which can be a single or dual converter configuration. The core power modules are replaceable so it’s a fully contained module that can be disconnected and replaced in the system within 15 minutes.

If there is a component failure the module can be removed and replaced with a spare module. The component can then be repaired within the power module and put back into service. This design is critical within a wind turbine.

“It’s very expensive to send engineers and high-end field technicians up into the top of wind turbines to do repairs. What you can do is have a service person go and replace a module without needing to be an electrical engineer and that module can be brought to ground to be repaired in a shop where it’s a lot more economic to do that kind of work.”

An important aspect of the company’s equipment is how robust its inverter technology is, originally developed for renewables. Because of the high reliability and low mean time for repair for wind turbines, the company can bring that technology out to energy storage.

“Solar is not as demanding on inverters as a wind application. The sun will come up and go down and it’s more of a steady output that is required. For a wind turbine converter, its rapid changes from the gusts that are coming so the inverters for wind turbines are designed for high thermal demand rapid changes in power output. Inverters designed for a 20-year life like a wind turbine are generally being asked to move into a less rigorous application when it comes to energy storage. So, we are feeling good about the ability to take a wind energy converter and apply it to energy storage.”

McKay is enthusiastic about the growing strength of the decentralized energy sector and the potential for the company to work inside it.

“Our objective is to grow the business and capitalise on this new industry. This is where the solar industry was around 10 years ago – some of the same forces are at work. The financial markets had to get accustomed to financing for solar and solar is largely a distributed technology and it paved the way. When it was getting going, utilities thought it would be too hard to manage so many generating modes on the grid. Now it’s a solvable issue and you can leverage a lot of those financial players to finance batteries instead of solar.”

“A lot of the reason inverters have come down in cost is because of solar, a lot of the reason the utility interconnect policies are worked out are down to solar, the hybrid vehicles and electric vehicles growing year after year -some of these other industries are feeding and directly contributing to the viability of grid connected energy storage.”