Best Practices for Cost-Effective
Electrification of Port Equipment
W R I T T E N B Y B E N C H AV D A R I A N , P E , L C A N D K E N T S AY L E R , P E , L E E D A P B D + C
The California Energy Commission (CEC), together
with California ports, tenants and operators are
working to electrify trucks, Top Loaders and RTGs
(Rubber Tired Gantry crane) operating in port
terminals. All ports, in one form or another, have
established goals to achieve zero-emissions through
the electrification of their equipment.
Port equipment electrification offers both
opportunities and challenges. We looked back at
gantry cranes when they first came into operation
and how they grew to what they are today as well
as reefer installations, and more recently, with the
“cold ironing” of ships in the ports. Electrification
of gantry cranes, reefers and ships have similarities
when compared to electrification of trucks, top
picks and RTGs. Hence, it is worth taking a moment
to think about the requirements for electrification
of trucks, top picks, and RTGs and apply lessons
learned from the electrification of gantry cranes,
reefers and ships, to avoid pitfalls of the past.
After a decision is reached to electrify trucks, top
loaders, or RTGs, the next step is to decide the
quantity of these vehicles required for the project.
Although this quantification is not an easy process
for managers, once this quantity is determined, the
second challenge is to determine what the kilo-
volt ampere (KVA) requirement is for the truck, top
loader, or the RTG.
What is KVA and KW?
KVA is the number that measures how large an
electrical installation is. KVA is a unit similar to
kilowatt (KW). One KVA is equal to 1000 volt-ampere
(VA). Similarly, 1 KW is equal to 1000 Watt (W).
Electrically speaking, KW of power is needed
for a piece of equipment if that equipment was
100% efficient. However, due to inefficiencies, the
electrical power delivered to that same equipment
would be measured by KVA, which the utility
company would have to produce, deliver, and
charge accordingly to the end-user.
6
The cost impact of KVA ratings in an electrification
project is substantial. If the KVA rating assigned
is lower than a minimum number required for the
proper operation of a truck, then the project would
result in a failed installation, and will not serve the
purpose. An attempt to salvage the installation
would be expensive to maintain and be potentially
abandoned. If the KVA is higher than necessary, the
installation cost would be more expensive, and the
maintenance and utility charges will be excessive.
The Impact of the Right KVA
Let’s use an example of installation for the
electrification of trucks only where the quantity
involved is 100. To enable the electrical design, the
KVA rating of the truck needs to be determined.
Some projects may determine that 300 KVA per truck
is adequate. Yet there are some who claim 1000 KVA
is necessary for the truck. Some end-users, who
want to reduce the charging time for their trucks,
request a designer to use 1500 KVA. What is the
correct KVA in this example? At one extreme, using
300 KVA per truck, for 100 trucks, is like adding 20
cranes in a terminal. At the other extreme, using