SA Affordable Housing September / October 2020 | Page 30

ENVIRONMENT & ENERGY
Know your electrical load
before investing in new
supply systems
Provided by Inframid
While many housing developers look to build energy efficient complexes, save on
electricity usage and increase the security of power supply, it is critical that they
consider the unique needs before deciding on the introduction of new elements of
power supply. This is according to Nick Oosthuizen, managing director at Inframid
and consultant in energy efficiency, who highlights the importance of understanding
your electrical load before investing in new power supply systems.
INFRAMID
Affordable housing developments “are a clear example of
why you cannot take a one-size-fits-all approach in efforts
to secure power and save energy. Loads are not only
seasonal but also vary throughout the weeks and days,” says
Oosthuizen. He recommends that you undertake an in-depth
financial feasibility study that weighs up all elements of power
supply in relation to the prevention of downtime and assuring
return on investment. “The first step is to conduct an ‘electrical
audit’ and understand your electrical load, which will help to
identify the real needs for special supply systems and avoid
fruitless expenditure. It is thus important to know your electrical
demand, load content, and electrical distribution architecture.”
Nick Oosthuizen, managing director at Inframid.
To assist in understanding electrical load needs, Oosthuizen
explains that there are at least five different segments to
consider: essential loads, critical no-break loads, non-essential
loads, energy-inefficient loads in existing complexes, and your
total load profile over time. It is fundamental to determine
these different load categories you are dealing with, firstly so
that the different types of power supply systems can be applied
appropriately, secondly to avoid over-sized and therefore
over-priced systems, and thirdly so that the potential for load
reduction and renewable energy can be considered all with the
view to achieve acceptable return on investment (ROI).
ESSENTIAL LOADS
The essential load is made up of electrical systems that are
fundamental to help the premises and households remain
operational, and to keep safety and security systems going. These
essential loads require reliable backup power supply sources in
order to maintain the electricity supply under mains fail conditions
for as long as needed. No-break loads are those elements of the
essential load that need seamless power transfer and cannot
tolerate even a split-second unplanned break in power supply
when switching from utility supply to backup power.
“These no-break loads require uninterrupted power
supply, UPS, systems when the main power supply fails,” says
Oosthuizen. As these UPS systems are normally battery back-up
and sometimes solar supported and very costly, it is important
to know exactly what size the no-break loads are and how long
they will need to be supplied by the UPS systems.
Oosthuizen lists some of the load issues that are of particular
relevance when planning power supply for an affordable
housing development planning:
₀ “Pumps, such as domestic water pumps are essential
services (on the generator side - because you cannot let
people go without water, for example.
28 SEPTEMBER - OCTOBER 2020 SAAffordHousing saaffordablehousingmag SA Affordable Housing www.saaffordablehousing.co.za