14-1016 v2.X Emergency Generator (Part II)

Question:

After careful review of both the existing technology and the previous LBC Dialogue correspondence on this issue, we respectfully request reconsideration. We believe the ruling is in error for two reasons: 1) It conflicts with LBC’s well-established policy of granting exceptions for emergency combustion generators; and 2) As described below, there is no reasonable or feasible alternative to the proposed generator. The exception for emergency back-up systems that include a diesel generator is easily referenced in the Dialogue, and our project team relied on this guidance in its original LBC feasibility study. See, for example, these exchanges: (Q: “Our project will make use of large (500kW-to-1MW) diesel generators for emergency power.” LBC Response: “As stated in the previous dialogue post, diesel generators are acceptable "if the program of the project requires an emergency back-up system.[1] Q: “We also examined the difference between a combustion-engine generator feeding an electric-motor fire pump and a combustion engine-driven fire pump. [...] We concluded that a combustion- engine driven fire pump was the most appropriate solution for our facility.” LBC Response: “Exception I07-E6 4/2010 Emergency Power Systems allows for the use of combustion based emergency generators. A combustion engine drive fire pump for emergency use is comparable to a generator and therefore would be allowed under this existing exception.”[2]) We believe that the above referenced rulings are still appropriate given the existing state of the market, and should be applicable in the case of our project as well. We spent the week investigating your suggestions and following up on your research to arrive at this conclusion. A concise explanation of our findings is offered below. While it is true that manufacturers (Kohler, Blue Star, Taylor) make 400kW LP generators, these are all rated for Liquid Natural Gas. The rating changes for Liquid Propane (it is “re-rated”) to only 295kW. Because Liquid Propane’s BTU content is higher than the equivalent amount of LNG, it is hotter burning. Hotter burning combustion requires a larger engine to process the combustion. In reality, the 400kW generator is only 60% as efficient as designed when using Liquid Propane as a fuel. Therefore, we would need to purchase three 400kW generators (plus paralleling equipment) to have enough emergency power to back up our 750kW system. The cost of this option $608,150.00 above the cost of the diesel emergency generator. Another option we looked at is using five 150kw propane generators (by Generac) and related parallel gear. This system requires five individual feeders from each generator to the parallel gear and one feeder from the gear to the main switchboard. Like the option described above, this system would require a much larger equipment footprint than a single diesel generator. The multiple tanks are only part of this requirement for increased building footprint; propane itself requires nearly twice as much storage space as diesel, because it is not nearly as efficient.[3] While we have not priced the tanks required to feed this system, we do know that one central tank is not an option, and multiple tanks would be needed to provide reliable supplies of fuel to the generators. (This is also the case with the 400kW generators.) Before pricing the tanks, this option has an added cost of $127,000.00. A few more points to consider: We cannot find a single engineer who agrees with installing a system like those described above, and we’ve talked to multiple firms and manufacturers throughout the United States to see if there is a better solution (or even a reasonably equivalent solution) than the diesel combustion generator, to no avail. The generator is not a crutch for the system; it is an emergency-only safeguard. During normal operation the building is self-sustaining, but it is critical that there is system redundancy for emergency situations (earthquake, severe weather power outage, etc.). This is not unlike a building that operates Net Positive Water, but has a back up to the city's water and waste systems for emergency issues. We feel that requiring our project to spend additional funds of between $150,000 and $608,000 for a complicated system of multiple non-diesel emergency generators is alienating to us and to anyone who wishes to build manufacturing facilities within the Living Building Challenge framework. Please know that if a non-diesel fix for this application was sensible, we would not argue the ruling, and we would be thrilled to be trailblazers for future projects contemplating this problem. Unfortunately, we cannot conclude that this is the case. We must respectfully request your reconsideration of the ruling, based on the above facts. We are happy to provide you with manufacturing specs on the above systems for your evaluation or records, and hope that this response provides a useful analysis of the state of the current market on large propane-fueled emergency generators. [1] https://ilbi.org/action/community/dialogue/energy/imperative-seven/486527417#891885933 October 9, 2012 [2] https://ilbi.org/action/community/dialogue/energy/imperative-seven/242502531#804169735 June 27, 2014 [3] http://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf

Answer:

While the referenced Dialogue Posts are not relevant to a 3.0 project since those exceptions were eliminated per the 3.0 August 2014 Energy Petal Handbook (EPH p 13), and first costs are specifically excluded as a reason for granting an exception to the Challenge, the Institute agrees that a new Exception is warranted in this case due to the significantly increased complexity and material impacts of the larger non-diesel system. v3.0: I06-E11 Industrial Emergency Backup Industrial facilities may use diesel backup power, for emergencies only, if they can demonstrate the team has minimized the amount of backup power required and that the best possible alternative systems available would still have a significant negative impact on health, industrial function or the project site environment. Exception Documentation: 06-a Exception Narrative


POst ID 2526

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