ASHRAE Journal - April 2021 - 38

TECHNICAL FEATURE

Using a Mobile Modular
Energy Unit With PV
Panels For Heating
BY RAIMONDS BOGDANOVICS, STUDENT MEMBER ASHRAE; ANATOLIJS BORODINECS, MEMBER ASHRAE; JURGIS ZEMITIS; ALEKSANDRS ZAJACS

The importance of mobile energy sources cannot be overestimated. In many fields, such
as military, scientific or travel, it may not be possible to connect to a stationary electricity grid. For this reason using a diesel generator is common for generating electricity
to charge devices and provide HVAC for temporary shelters. This article investigates a
newly designed and built mobile modular energy unit (MMEU) with photovoltaic (PV)
panels to provide heat and ventilation for a tent in Riga, Latvia, EU.
Using a diesel generator to generate electricity is not an
ideal solution. This is because of its noise and dependence
on liquid fuel. According to manufacturing data, the noise
level at 1 m (3 ft) distance is 75 to 85 dB(A), which is classified as loud noise. Liquid fuel requires large amounts of
storage, creates air pollution and has a risk of explosion.
One solution to generate electricity autonomously
and in an eco-friendly manner is using PV panels. For
example, a mobile PV system coupled with a fuel-fed
generator as a reserve energy source for nomadic camps
in Norway and Russia was modeled,1 and it was concluded that by using LED lighting and certain schedules
of device charging, PV systems are economically beneficial; however wide seasonal and daily variation in solar
flux, as well as battery capacity reduction due to low
temperatures, should be considered.
With the increased interest in renewable and

sustainable energy solutions, the topic of solar energy
has become very popular. For instance, to show the capability of solar energy for many applications, McCulley2
describes the detailed design and sizing of a portable PV
system used in undergraduate research projects and for
community events. Other researchers3 described and
tested a portable solar-powered cooling system (PV panels on top of a car) for vehicle cabin cooling.
Proper design of the unit is very important in the case
of the power-to-weight parameter and flexibility. For a
portable system, energy density is more important than
efficiency and should be used for selecting and designing such systems. These two objectives may lead to a
very different design, operation and/or performance.4
The military actively researches using portable energy
sources. For example, The U.S. Naval Air Warfare
Center Weapon Division5 tested a 5 kW trailer-mounted

Raimonds Bogdanovics is a scientific assistant, Anatolijs Borodinecs is a professor, and Jurgis Zemitis and Aleksandrs Zajacs are researchers at the Heat, Gas and Water Technology
institute in the Faculty of Building and Civil Engineering at Riga Technical University, in Riga, Latvia.
38

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