Oops! Top-5 Design Issues with On-Site Power Systems

The benefits of having a reliable on-site power system to carry through natural or man-made disasters are clear. These benefits come with substantial initial investments in design, equipment purchase, and maintenance programs. But, what are some of the unforeseen costs that may surprise the owner after they take possession of their newly-constructed facility? These are the Top-5 issues that I see after construction of large facilities.

1. Not Enough Fuel!

I get that allocating space for large fuel tanks is not an easy task. On top of environmental concerns, space is always in high demand for other utilities, parking areas, setbacks, etc. Even if you can meet the fuel storage capacity required by code (72 hours, 96 hours, etc), this may not be enough after a substantial event like Hurricane Sandy where many hospitals ran out of fuel and had to rely on FEMA emergency fuel deliveries to keep generators running. Fuel is like closet space… You can’t have enough of it.

2. Exhaust Noise

Exhaust noise is an unpleasant side-effect of large standby power systems. Diesel engines are always fitted with exhaust silencers to reduce the raw noise levels emitted by the engine. Specifying the correct exhaust silencer is a relatively easy task but, lacking meaningful specifications, most generator vendors furnish their standard “critical grade” exhaust silencer. This may not be quiet-enough for projects located in areas sensitive to high noise levels. On this topic, here are a few tips:

  • “Critical Grade” and “Residential Grade” silencers are NOT the quietest options available. If you have a sensitive site, there are options for a more tailored noise attenuation solution.
  • Look out for exhaust noise reflecting off neighboring properties. Few see this coming but it can become a serious nuisance to properties that you may have thought were sufficiently-removed from exposure to the exhaust gas flow path.

3. Toxic Emissions

Newer electronically-controlled engines are much better at limiting their exhaust emissions, but complaints do happen from neighboring properties that take issue with the fumes produced by engines that are lightly loaded during weekly or monthly test runs (see related “Not Enough Load” topic below). Running generators for an extended amount of time can result in the building next door taking in exhaust fumes through their HVAC fresh-air inlet ducts. When this happens, carbon monoxide concentrations can rise to a level that prompts building occupants to complain of headaches and dizziness. Particulate matter (microscopic solids carried in the exhaust stream) is no joke either, but is less of a problem when the engines are well-maintained and running properly.

4. Not Enough Load

On-site power systems are designed to have sufficient power capacity to satisfy the facility’s long-term electrical needs. This is good and standard practice, but it can also lead to generators that are not properly loaded during the initial build-out phase. Generators that are not sufficiently loaded are likely to suffer from wet-stacking, higher emissions, and other maintenance issues. The solution, a load bank, is simple-enough to implement during design (and not really all that costly) but considerably harder to do after construction is completed.

5. Not Reaching Out to a Subject Matter Expert (early in the design process) 😉!

I offer this humbly and with the best intentions… If you have access to someone that is an expert in designing solutions for any of the above items and more, why not engage with him/her to assist in the development of your design, learn about proven methods, and apply job-specific recommendations to help improve your design work?

Whether you elect to engage with yours truly, or someone else that has earned your trust, I encourage you to seek experts on design areas that may fall outside of your core competence. I am confident that this will improve your work, and save you valuable time.

For one-on-one support, you may contact me here.

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