Posted May 6, 2019

Temporary power management alternative

Powr2's Hybrid Energy System (HES) eliminates wet stacking, increases service intervals and reduces fuel costs.

At a recent project, a rental company was running some office trailers using a 56kW generator. Inside the construction trailers were the usual items: air conditioners, computer servers, some security cameras and kitchen appliances. To keep the computers and alarms working seamlessly, the generator needed to be running 24/7. However, this was causing the rental provider with significant wet stacking and servicing issues.

Powr2 HES systems
Powr2's Hybrid Energy System (HES) eliminates wet stacking, increases service intervals and reduces fuel costs.

“Our clients obviously have to size the generator based on the highest possible power that may be required. So, in this instance, they had to assume all the lights would be on, as well as the air conditioners, microwaves, kettles, at the same time. In reality, this rarely happens, so the generator is spending a lot of time running on low loads. This leads to a condition called wet stacking which is very harmful to the engine and can shorten the engines life by many years. This condition is further exacerbated by the new T4F engines that require a certain amount of load/heat for the exhaust regen stream to work effectively,” says Toby Nunn, Powr2’s director of Operations.

In addition to this, continues Nunn, clients have certain service intervals they are required to keep, whether that be 200 hours, 300 hours or whatever they decide. "When the generator is running 24 hours a day, this can mean that servicing is a regular task. In this instance the site was in a remote location, so attending regularly for servicing was a big cost."

The Powr2 Hybrid Energy System (HES) was able to solve these issues and more. In much the same way as a hybrid car runs off battery power and only starts the engine when additional power or speed is required, the Powr2 HES powers electrical loads that are usually powered by a diesel generator until the battery is depleted or the power spikes above what the HES can manage then the HES automatically calls for the generator to start.

Eliminate wet stacking
The HES carries all of the low loads, allowing the generator to be turned off for long periods of time. The HES can set the incoming current limit from the generator to ensure the generator runs at just the right level of load. 

Service intervals increase
Service intervals increased by 6 times with the Hybrid system so generator running time was cut significantly, reducing site maintenance visits to once every 60 days instead of once every 10 days. 

Reduce fuel use
Reduction in fuel usage and the resulting carbon emissions savings saved the client money and reduced environmental impact.

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