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MAY 2026
The correct approach is to focus on ensuring when the 
diesel is on it is loaded efficiently and use the battery to 
enable that and absorb any variations. The result, then, 
is to use the battery to handle peaks and resize the genset 
down. A 200-kW genset running near its efficient operat-
ing point, supported by a battery that absorbs peaks and 
recharges during off-peak periods, will burn dramatically 
less fuel than the 500-kW unit it replaces—not because the 
battery did more work, but because the diesel is now op-
erating where diesels work best. Further reinforcing those 
benefits, the diesel will now avoid wet-stacking and also 
reduce maintenance intervals, benefits that apply to parties 
besides just those paying the fuel bill.
The fuel-savings figure we used to cite for this approach 
was 15-20 percent, or up to 30 percent. In other hybrid in-
dustrial electrification applications, where SPOC has used 
these very same principles, some fleet wide savings are now 
averaging 80 percent. The mechanism is the same in every 
case: the added technology is there to support the engine, 
not replace it.
This is also why we say, “it’s easy to build a bad hybrid.” 
A hybrid sized without an honest operational profile or 
built around the assumption that the generator will just be 
replaced with a battery, will under deliver. A hybrid sized 
around the genset’s efficient operating window, with the 
battery doing the shaping work, will not.
THE OPPORTUNITY HIDING 
IN THE ARCHITECTURE
There is one more layer worth understanding, because it is 
where a lot of the unrealized value sits.
A battery is just a DC voltage source. To connect it to 
anything and make it do useful work, you need an invert-
er. The inverter is what dictates how the battery actually 
behaves—what functions it performs, how and when it re-
sponds, how it integrates with the rest of the system. Many 
people think the subject of DC power distribution comes 
up because batteries are also DC. The reality is that batter-
ies make us start considering bi-directional power flow, as 
we start combining and orchestrating multiple loads and 
Face tomorrow with confidence.
For nearly a century, we’ve been a trusted insurance,  
risk management and consulting partner for businesses, 
communities and people around the globe. Customizing 
programs and solutions tailored to your needs.
Damon L. Nasman
Senior Vice President
Marine Department, GGB, Gallagher
D: (206) 262-6375 | C: (206) 850-1525
E: damon_nasman@ajg.com
AJG.com | The Gallagher Way. Since 1927.
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