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HomeMy WebLinkAboutTrip Report to UniEnergy Technologies 7_23_14ENERGY EFFICIENCY EVALUATIONS Site Visit to UniEnergy Technologies Battery Company Prepared for Kotzebue Electric Association Dennis Witmer 7/23/2014 Trip report from visit to UET at their headquarters in Mukilteo, Wa. Several utility sized Vanadium flow batteries were observed in operation, company appears to be close to shipping initial commercial product for demonstration. Technology appears to be more developed than other flow batteries evaluated in KEA RFI process. Cost and performance should be modeled. Arrived at UET for meeting. UET is housed in a 69,000 square foot building that they own, though currently part of the building is occupied by another company. They will be taking over the entire building at the end of the year. The entrance to their offices was not obvious from the street (the other business is currently occupying the main entrance to the building), and the door was locked when we arrived. It was pouring rain, I tried another door, found it unlocked, and was able to enter their manufacturing space, a large room with no one present. We then went back to the main door, and met Charlie Vartanian, the Marketing director. We signed into the visitor log on an iPad. Outside reception area is office space for approximately 20 people. Met and had a brief discussion with COO Rick Winter and consultant Garth Corey, author of the white paper previously reviewed. Meeting began in conference room A, with introductions from: Rick Winter, COO Liyu Li, PhD, Chief Technical Officer, Co-Founder Charles Varanian, Marketing director Russ Weed, VP Business Development and General Counsel Ted Volberding, Director of Manufacturing Kathyrn Oseen-Senda, PhD, Senior Systems Engineer Dave Ridley, Director of Electrical Engineering Jon Horner, Mechanical Engineer I introduced myself, and briefly discussed the previous battery project in Kotzebue. There was considerable interest in what happened with Premium Power. UET discussed the environment of a few years ago, when Premium Power would “stand up in meetings and make great claims about their battery that were difficult to either prove or refute”, and that they “poisoned the well” by creating unrealistic expectations about both price and performance of battery systems. UET is familiar with diesel economics based on their discussions with Hawaii and PV arrays. However, there was much discussion about the total cost per kW-hr of energy vs fuel only costs—and the difficulty in even getting real fuel costs in remote villages. There was a discussion about arctic climate issues. The electrolyte currently in use does not freeze at 40 below, but it does become viscous and less conductive. However, it is not clear that the power electronics is hardened to the same temperature regime. Charlie Vartanian had a copy of the KEA Jessie Logan paper submitted in the summer of 2012, although his copy differed from the report available on the DOE web site, in that it had a picture of the Premium Power flow battery on it. The initial introductory meeting was followed by a “factory tour”. I requested permission to make photographs, and was told that I could take some photographs, but that they were cautious about which things I could make photographs of. I requested permission for each photograph I made from Rick Winter. First, the factory was clean and well lit, and appears to be in a “scale up” mode. The intention is to use this factory to assemble the containers that form the battery system, with 4 DC battery modules for each inverter module, each installed in a custom built 20’ conex box. Each DC battery module holds large electrolyte tanks that occupy about 80% of the interior volume of the conex box, plus 3 stacks, each of about 50 cells of 4000 cm2. One battery box produces about 250 Volts and 1000 Amps DC. There were two demonstration units operating inside the factory, the first nicknamed “ELVIS” (complete with a large poster behind it) for “Electric Leveling System” and Angus (named for the lead guitarist for AC/DC) which is cycling from full charge to full discharge every 30 seconds for 2 months (another month of testing planned) with no observed degradation in performance. ELVIS was the first commercial scale system built, and has been operating for 6 months. The battery system is comprised of several battery units (usually 4) and a power electronics unit (housed in a separate container). Each container is a custom version of a standard 20 foot conex box, built with heavier steel, and one foot higher than the standard box (dimensions of 20’X8’X9.5’) and designed to hold 40 tons of weight (well above the 48,000 pounds of a standard container). The conex box has a welded bulkhead in front of the electrolyte tanks designed to function as a secondary containment for the entire electrolyte volume, eliminating the need for a secondary containment on site. The system also has an “anti syphon” design to prevent the transfer of electrolyte to the area in front of the bulkhead in case of pump failure. There is a lower bulkhead in the stack area designed to hold 2X the volume of electrolyte normally contained in the stacks. Each battery compartment has two electrolyte tanks, one about twice the size of the others. Pumps for the electrolyte appear to be submerged inside the tanks. The tanks are made with a special process, where a full sized mold is heated and rotated, then loaded with plastic pellets which melt and coat the walls of the mold evenly, creating a thick, seamless tank. If a larger energy capacity battery is desired, larger tanks can be manufactured, which can be placed inside larger shipping containers without affecting the construction of the stack area. Each battery container has 3 stacks, all fed from a common manifold, so all stacks and cells are exposed to the same electrolyte composition at any point in time. A single cell at open voltage is used to constantly measure the state of charge of the system. The cell area is approximately 4000 cm2. Stacks are built in China by UET’s partner. The manifolding for the stacks was covered with plastic shields, and apparently was one of the sensitive items UET did not want photographed. Each battery container can provide 150 kW of power, and 600 kW-hours of stored energy. There was also a controls package inside the stack area, enclosed in a separate metal box with an air intake from outside that is vented into the stack area. Apparently there is some kind of contamination that comes off the stacks that can coat surfaces that is electrically conductive, and can affect the performance of the control circuits. Control of the entire battery string is from a single master controller, for speed. It was not completely clear how quickly the system can respond—there was mention of 8 millisecond response of the battery, but between the control system and the inverters, the total response time is something like 100 milliseconds. The control system is a PLC design supplied by Siemens. A “string” of 4 battery modules and one power conversion unit can deliver 600 kW AC, and store about 2.4 MW-hr of energy. This is intended to be the basic unit that UET will sell. Based on the phone conversation of 7/15/14, current pricing is estimated at $1000 per kW-hr of storage, or $2.4M per string, of which 80% is battery cost, and 20% is installation cost. Note that the cost of a single string is above the currently available funds in Kotzebue, and that installation costs (including shipping) are likely to be higher in Kotzebue. Prices are expected to drop by about 25% in the 2015-2016 time frame. The inverters are large industrial inverters—Packer and AEG have been the inverter suppliers they have used to date. Angus was operating with a Packer inverter. The factory is designed so that the conex containers never come inside the factory area—only the metal rack that supports the stacks is moved around the assembly area. The conex boxes (custom built in China for about $9,000) remain outside, and have the tanks installed in them. The stacks, mainfolds, electrical system, and control system are assembled as a unit and installed into the waiting conex box. In the production mode, the assembled system will have electrical and pressure tests done at the factory, but there will be no electrolyte loaded into the system until it is at the site where it will be operated. This makes the unit much lighter to ship (10,000 pounds vs the 80,000 pounds once the electrolyte is loaded), as well as less hazardous. Electrolyte will be shipped directly to the final installation site. (Note for Kotzebue: Total shipping weight is very high—about 350,000 pounds for a full string of batteries, electrolyte, and power package.) Units come with a one year warrantee and a 20 year service agreement (not disclosed what those fees would be). At the end of 20 years, UET will decommission and remove the unit at no cost (paid for by the value of the vanadium that can be recovered). The unit is designed to minimize the amount of site prep that needs to be done—obviously, the unit is very heavy, so a solid concrete pad needs to be constructed. All connections between conex units is in a single penetration located at the top of the box just behind the large doors. The conex boxes can also be bolted together and bolted to the concrete pad for earthquake mitigation. The design philosophy is to minimize the work required for field installation, and to do all the critical work at the factory, where it can be done by knowledgeable skilled workers under careful quality control conditions. The units are also designed to minimize the risk of damage in shipping. In some ways, the design philosophy is very similar to the new small scale nuclear philosophy—build units in a factory, ship them to the site, load the chemical, and offer decommissioning as part of the package. Outside the factory on a large concrete pad near the shipping dock was a “string” of 4 batteries plus the power electronics box, currently being operated (know as “Johnny Cash” for obvious reasons.) In addition, a set of five empty conex boxes were on site, the containers for the next string to be assembled. There did not appear to be any units currently being assembled, other than a single manifold assembly of curled tubes which I was told not to photograph. There was no “boneyard” of old stacks. We walked past the R&D areas, but did not go in them. The factory felt pretty empty, but it seemed that that was intentional, to allow for the planed future assembly of systems. Current production is “zero” (said with a laugh), but plans are to eventually produce one battery container per week, one “string” a month by the end of 2014, ramping up production to one string a week by the fall of 2015. In about 2 years, it is expected that the current factory will be at capacity, with the next manufacturing site to be chosen “next to a dock or on a rail line” to aid with the shipping of the heavy units. Note was made that while vanadium does not have a high power density per unit area of membrane, or by volume, the energy stored per acre is very high—about 40 MW per acre, or 160 MW-hours per acre. Figure 1 UET data display in front, electrolyte tanks for 20' conex box unit in back. Figure 2. View of "Angus", showing three cell stacks (white), covered manifolds (center) and electrical control box (on left). Note white secondary containment bulkhead . Unit was in test, switching from full charge to full discharge every 30 seconds. Figure 3. "Johnny Cash" unit behind factory, currently operating in full cycle charge/discharge mode. Note radiators for heat removal on top, as well as vents in doors of electrical unit in foreground. After the factory tour, the meeting reconvened in the conference room. Most of the remaining discussion was about the possible deployment of a battery of this type in Kotzebue. First, it was noted that the Premium Power battery was not ideally sized for Kotzebue, as it did not provide sufficient power to cover either diesels off operation (not likely anyway, given the level of penetration) or even sufficient safety margin for an EWT turbine trip. After some discussion, it was agreed that a good size for Kotzebue’s current configuration would be a 2 string, 1.2 MW, 4.8 MW-hour battery, though the cost of such an installation is beyond currently available funding. There was also some discussion about the proper way to install these batteries, especially given the experience with the Premium Power battery, which was (per agreement with the supplier) simply parked outside. Given that this would be the first of a kind in the arctic, it was felt that some kind of protection from the drifting snow was required—probably a steel building of some kind. While this construction would add to the installation costs, it would provide some measure of protection for the operation of the unit (the issue of snow blowing into the electronics being one of the major considerations). One issue raised by UET was the need for some kind of external vent for each of the battery units—apparently there is some material which should be vented to the atmosphere and not inside a building. There was also some discussion about data needs for modeling—UET was very concerned about releasing electrochemical data—they have not shared that data with anyone to date. They openly discuss their overall efficiency (65-70%), the fact that there are limits to the charge/discharge rates at the ends of cycles, and the level of electrical parasitics (8 kW for all pumps on a string of 4), they were quite reluctant to discuss. They suggested a non-disclosure agreement with KEA before they release any data about the specifics of their performance. General Company Info:  Company is wholly owned by a “private investor” (not a venture capitalist) who has invested on the order of $500M to purchase the entire supply chain for these batteries, all the way from vanadium mines, stack developer, and UET. IPO may happen, but “six years away”  Stack and electrolyte both come from China. Stack developer has been building stacks for 15 years.  Management is old and gray, engineers are young and seem happy. Seems like a good group of people  There is a reasonable level of IP protection concerns. General Impressions of Battery:  UET has built several demo units for “inside” evaluation, three of which are currently operating  Battery appears to be competently designed, with attention paid to leak prevention, secondary containment, transportation and shipping, and minimization of electrical parasitics  Control system and inverters are from known reliable suppliers  Turn around efficiency of 65-70% and cost of battery both will limit the value of this battery compared to heat sales  Risk of “First of a Kind” deployment in Alaska.