Preheat Standby Diesels with Heat Pump

(Many of the stories we’ve been looking represent new technology with big potential impact, but whose commercial availability may take a while. Here’s something very much here and now that may appear to be a small niche, but which could be a valuable feature to be able to offer customers, and even to apply on a utility’s own facilities.)

“Reduce the cost and increase the reliability of a standby generator, with no initial capital outlay.”

For standby diesels to start reliably, they need to be kept warm. Standard practice (for 200 kw to 2.5MW gensets) is to attach an electric resistance heater to maintain a temperature of 100-140 degF. As a standard practice, nearly all engines have such heaters, installed either by the engine manufacturer or the distributor. (Watlow and Kim HotStart have most of this market.) Heat can be applied to the oil (which is kept flowing and at pressure), the engine coolant and of course to the fuel itself (which can turn to jelly in cold weather).

For an engine that has to be ready to go at any time with no warning, this electric load (2-8 kw) is (or should be) on all the time, and can as much as $6-8000 per year or more. It’s usually a hidden cost, buried in a facility’s overall power bill, and it’s not something engine makers talk about. Many owners and operators don’t even know the heaters are there, and O&M agreements don’t usually cover them. The average life of a heater is typically about 18 months. When it fails, it might not be noticed, leaving a cold engine at risk. Replacing heaters adds to the large costs for power — the biggest single operating cost of owning a standby generator.

If an engine is started cold, it might not even start. If it does start, and especially if it is heavily loaded immediately, heavy wear and tear will come from running cold. Engine life is shortened, and overhauls come sooner. A bad episode can wreck the engine right then and there. (One distributor for CAT told me they recommend keeping an engine warm all the time, and this includes prime power applications, not just standby/emergency. In some applications, codes require it.)

So there are three main issues: the cost for power, wear and tear from cold starts, and the unreliability — which can undercut the reasons for having standby generators in the first place.

To solve these problems, Energy Resources Management (ERM), Tampa, Florida, sells a specialized heat pump manufactured by Trane.

The 1.5-ton DH-12 air source heat pump saves 80% of the energy and cost of heating. Equally important, the heat pump (primary) runs in series with the heaters (secondary) to provide the redundant heating source needed to protect diesel engines from cold-start risk factors. In addition, resistance heater replacement costs and emissions are reduced (i.e., emissions from utility generation of the power saved).

ERM offers a shared energy savings program. Performance measurement and contracting allows them to provide the heat pump through a turnkey operation with no capital investment by the owner. Trane manufactures, installs, and services the heat pump. Successful installations include public and private sector entities such as Atlanta Hartsfield Intl Airport, MBNA, Bank of America, and the New York Stock Exchange. Municipal utilities and waste water treatment facilities have been early and frequent adopters.

While the savings for one engine may not represent a large amount of revenue, there are a lot of engines out there that could use this (and shared savings revenues continue year after year). There is also the improvement to quick start reliability to consider. This would seem to be a good fit for many C&I customers and utilities themselves.

ERM is looking for customers, of course, and for partners, reps, distributors, etc. to offer the program across the country. Call me for more information.

Nicholas Colmenares, President
Energy Resources Management, LLC
Tampa, FL

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply