In this episode of Powerbytes, Mike Gemolva is our special guest to walk us through what's new in the area of Combined Heat and Power (CHP) or Cogeneration. Most importantly how users can save money by increasing efficiency by utilizing these methods.
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Lou: As more and more facilities work on ways to gain efficiency, become more green, and lower costs, it only seems reasonable that they investigate the use of what's called Combined Heat & Power. While it's not necessarily a new topic, there are some advances in fuel performance I think we should discuss.
Lou: Joining me today via the Cat Electric Power Hotline is Mike Gemmolva from his office in New Orleans. Mike has over 20yrs of experience with Switchgear and Generator Paralleling Controls. He is a part of Caterpillars Power Integration Team or P.I.T. Crew as we like to call it. Mike, thanks for joining us today.
Mike: Thank you for having me Lou.
Lou: Mike, let's start at the beginning: What is Combined Heat and Power or CHP as it's often called in the industry.
Mike: Combine Heat and Power or CHP is also known as Cogeneration. It is basically production of electric power through the genset and then utilizing the waste heat associated with creating that electric power to create more efficiencies through the steam and hot water and cooling applications that can be associated with that heat. So, through the capture and utilization of that engines wasted heat, the efficiency of that plant can reach 90% or more as compared to a pure electric power application where a genset is actually only using about 42% of the available efficiency from the fuel.
▪ So, in a typical non-CHP genset, Natural gas is used to power the engine generator set, generating electricity.
▪ The Generated electricity is used to power facility loads or is exported to the utility grid.
▪ The efficiency of this configuration is approximately 42% which leaves 58% of the fuel energy wasted. Typically, through the radiator.
▪ Adding CHP components and controls increases the overall efficiency of the system by up to 40%.
▪ This is accomplished by recovering heat from the engine’s exhaust, jacket water and aftercooler circuits
▪ The recovered heat can produce steam, hot and/or cold water depending on the heat exchangers used.
Lou: Before we dive in too far, can you take us through the key components of a CHP installation and the role they play?
Mike: One of the 1st things we look for in a CHP project, is an Piping and Instrumentation Diagram or P&ID. This is basically the mechanical equivalent of a oneline for us. From this we can identify the Exhaust, Jacket Water, Aftercooler and Lube Oil circuits along with the associated components of each circuit such as:
• 3-Way Valves (Flow/Temp. Control)
• Temperature Sensors
• Heat Exchangers
So, for instance the Jacket Water heat recovery is using the hot water from the engine cooling for process hot water like steam. Whereas the Aftercooler circuit is also producing hot water but not hot enough for steam application but can still be hot enough for facility hot water supply. Each of these processes are using Heat Exchangers. The heat exchangers are transferring heat from one medium (glycol/exhaust) to another. Typically, water. 3-Way valves, Radiators, Pumps and Variable Frequency Drives (VFD’s) also play a key roles in each of these processes by managing the flow of water through the engine skid.
Lou: What can facility owners expect to gain from using CHP?
Mike: On a recent project we had a customer with energy usage of 21,000,000kw at 12c/kwh, so that’s roughly $2.5M in cost of electricity. Once the CHP system was installed they were able to reduce the amount of energy being imported from the Utility and drop that demand charge down to 16,000,000kw at 4c/kwh and only have to pay for 5,000kwh at 12c/kwh because they were avoiding the peak charges. With the maintenance cost and additional gas for genset their energy cost were now at about $1.82M. That’s a $700k reduction.
• The HEAT side of the CHP package will provide roughly 50% of their needed hot water. Estimated total annual utility cost reduction of 31%. = $1.2M
Lou: At the top of the show I mentioned that this is not a new technology. Can you elaborate on that and what IS new today?
Mike: Sure. So, CAT and its dealers have been involved in CHP since around 1960. Dealers have supplies CHP packages using Power Modules, Gas Engine Driven Chillers, Ancillary equipment and Switchgear for some time now. One of the things that is new is the new Caterpillar High Density high efficiency gas engine. There’s also been a loosening of regulations on gas as an emergency power supply. This is due to some of the more recent natural disasters like Hurricane Sandy where gas was readily available, but the diesel storage tanks had flooded. So now people are looking at the requirements for backup power to have standalone fuel. Then there’s also the environmental push for a cleaner burning fuel. We’ve also developed a master control panel that provides centralized process control, generator control, and operator interface into one cabinet. The panel automatically responds to the process sensors and controls system components I mentioned earlier to balance customer demand, engine protection, and alarm response for BOTH thermal and electrical circuits.
Lou: Mike could ANY facility use and benefit from CHP?
Mike: Just about. Some of the industries we engage with for CHP are of course Industrial Sites, District Heating, Greenhouses and Renewable energies.
Lou Summary: So Mike it sounds like a user can really benefit from CHP in any one of three ways, 1) Lowering energy usage and hence cost, 2) avoiding demand charges by avoiding peak demands (lower cost), and 3) by moving from diesel to natural gas, we are lowering a user's carbon footprint thus making them more “green” Would you agree?
Lou: There you have it folks. Thank you for joining us today on Power Bytes. For more information on CHP go to www.cat.com/CHP or contact your local Cat dealer. If you’d like to suggest other topics for the program or have some feedback to share, please write us here at [email protected] or visit Cat Electric Power on Facebook or LinkedIn. As always don't forget to subscribe to this podcast. Have a great day.