CEM Blog: Technical Series #2: 5 Trouble Spots to Watch on Your Next CHP Package
As the Combined Heat and Power (CHP) market has matured over the last 30 years, so too have the options for implementing CHP technology. A CHP Owner or Developer now has a multitude of options from which to procure a complete CHP system. Particularly, for small CHP executions (i.e. < 2 MW), there are many firms who will assemble almost all of the CHP plant in their shop before shipping to site – as a ‘CHP Package’. Not all of these CHP Packages are created equal and not all are a perfect fit for your project.
In this article, and in several to follow, I highlight the areas to watch out for when implementing a CHP project using a CHP Package.
- Fire Protection - CHP Packages are typically offered with a variety of fire detection and suppression systems. The extent of fire suppression can range from very little suppression to a pressurized water system or a CO2 (or other inert gas) system to suffocate the fire. It is imperative to ensure the fire detection and warning system can be tied into the host's existing system. Of equal importance is the need to align the fire suppression strategy for the package with both local codes and standards and the fire suppression strategy of the host site.
- Building Permitting - Depending on the local building authorities having jurisdiction (AHJ), a CHP package may be deemed as either a piece of equipment or a structure. Typically, a designation as a piece of equipment is preferable and CEM has had success on most projects in convincing the AHJ of this classification. Regardless, this definition is required early in a project, as a classification as a 'structure' may require a building permit, which will drive increased design elements and likely increased package costs.
- Egress - A CHP project is typically approved and implemented on the basis of a 20 or 30-year financial model. For this reason, once the CHP package is installed it must be easy to access, service, and operate to ensure it 'delivers the proforma'. For example, it is highly advantageous to have external lighting mounted on the package to provide safe access during night hours. Additionally, for on-going service and maintenance, it is best to have a paved or well-grovelled area that provides truck access and a large lay-down area for significant overhauls. Depending on the site, fencing may be appropriate to provide security.
- Rigging and Installation - Planning the rigging and installation of the CHP package once it shows up at site is too late. Careful planning and thought needs to be put into how the CHP package will be rigged into place: Where will the crane be positioned? How large does the crane need to be? How many pieces will be lifted? Where will they be staged? Additional planning needs to go into the installation forces which will be required: Will the OEM send their own teams? Will the owner/contractor need to provide its own forces? If so, what type of trades will be required?
- Cold Weather Installation - CHP Packages make for great technology because they generate both electrical and thermal power. Just because they generate thermal power does not mean that cold weather installations do not require additional thought and planning. Designs for CHP packages where freezing may occur need to consider freezing of pipes, heat tracing, ingress of cold ambient air and what happens during a system shut-down. An engineer familiar with local weather patterns and design constraints is a valuable asset for this portion of design.
These considerations are only a few of the key elements which make-up a successful CHP package execution. In subsequent articles I will focus more closely on what goes on inside the package and what can both hinder or help the system’s uptime!