SA Affordable Housing January - February 2020 // ISSUE: 80 | Page 20

FEATURE
needing electricity for a pump or an
energy-efficient doors, windows, appliances,
electronic control, so they can be used
and home electronics; and high indoor
without access to the electricity grid.
environmental quality.
“PV solar panels absorb and convert
“The City’s Energy2040 goals include a 37%
sunlight into electricity, a solar inverter
reduction in carbon emissions, with 21%
changes the electric current from DC to
coming from energy efficiency. The built
AC, connecting to the house’s wiring. A
environment (commercial and residential) is a
battery storage system allows for days
large energy user and accounts for
without sunshine, though this is an
approximately 33% of energy consumption and
expensive option that should be included
58% of carbon emissions in Cape Town.
in the original finance deal.
Reducing demand and improving efficiency
“The installation of solar systems in the
measures through building design principles
construction of housing developments is
Barry Bredenkamp, general
and practices is of utmost importance.
certainly a step in the right direction in the
manager for Energy Efficiency
“The transport sector consumes 64% of
fight to conserve natural resources, save
at The South African National
energy
and accounts for 34% of carbon
Energy Development Institute
money on utilities and combat the
emissions in Cape Town and provides an
(SANEDI).
negative effects of climate change. The
immediate opportunity to significantly reduce
prices of these technologies have reduced
the City’s emissions. To become a lower carbon,
significantly over the past three to five
more
resource
efficient,
resilient and equitable city, Cape Town
years and the technology has come a long way in terms of
must be remodelled with increased densification and mixed-
quality and are designed to last anything from 10 to 20 years,”
use in areas of economic activity, with modal shifts to public
says Bredenkamp.
transport and smarter mobility such as electric vehicles and
more efficient private transport through, for example, higher
COOL SURFACES
passenger occupancy and flexible working arrangements and
Cools Surfaces roof coatings, formulated for South African
increased efficiency in water, energy and waste management, in
conditions, can reduce internal temperatures by as much as 2°C
the use of construction materials and the increased use of
to 4°C, as SANEDI has proven in large-scale informal housing
renewable energy sources.”
settlements. “Cool Surfaces refers to all materials and
technologies, such as white roofs, light-coloured pavements
and specialised cool coatings used in the construction of the
building envelope to improve thermal comfort through surfaces
that reflect much of the solar energy and release much of the
stored heat energy.”
Cool Surfaces are light coloured polymer-based paints or
coatings with infra-red light reflecting pigments. They can be
used to passively cool buildings, and the energy absorbed is
lower than dark coloured materials.
“Reflective roof surfaces not only have an impact on
individual buildings but deploying them across a whole
community can have a net effect on reducing overall local
ambient temperatures in a localised area (the so-called heat
island effect). Furthermore, the deployment of reflective
materials creates sustainable job and skills opportunities for
low skilled workers in both rural and urban contexts.”
CAPE TOWN TAKES THE LEAD
The City of Cape Town has launched a booklet about resource
efficiency to inform residents and developers about the
sustainable use of water and energy in our homes and new
developments. The booklet also advises on how to consider our
natural environment as we are building a resilient Cape Town
that can withstand the impact of climate change. It can be
downloaded here or from http://bit.do/
ResourceEfficiencyCriteriaDevelopmentGuideline.
According to the booklet. “Recent technological
advancements in building materials and construction
techniques make the process of building an energy-efficient
home less challenging. Most energy-efficient homes have
several things in common: a tightly sealed thermal envelope;
controlled ventilation; high-efficiency heating systems;
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JANUARY - FEBRUARY 2020
SAAffordHousing
THE FUTURE
Bredenkamp expects the use of solar heating to become much
more ubiquitous in South Africa over the next five to ten years,
as renewable energy comes with government support as seen
in the recent energy plan which anticipates a big shift from coal
to renewables such as solar, though more prominently wind.
“From an electricity tariff point of view people will be
encouraged to move to solar heating,” he says.
A study published in the Journal of Real Estate Research
notes that business owners are showing increasing interest in
sustainability and that when browsing for office space,
prospective tenants often prioritise buildings with eco-friendly
features, high energy efficiency and similar attributes. The
study concludes that this is more than a passing trend and
constitutes a significant pattern that property investors need to
consider. The same will most likely apply to housing.
“Retail malls or commercial properties with lots of under-
used roof space are ideal for solar power generation,” says
Lance Green of SolarSaver. “Solar installations make particular
sense for retailers as they require energy consistently during
the day, seven days a week, with demand usually peaking at
midday. This mirrors daylight hours when the supplementary
energy produced by grid-tied solar installations is available.”
As a result, Green says that SolarSaver has seen strong for
solar from the retail property sector. As an example, SolarSaver
installed a 250kWp system at Lifestyle Mall in Rustenburg in
mid-2018. Since then the system has produced 387 840kWh of
electricity, supplementing roughly 20% of the mall’s power
needs. SolarSaver has completed similar installations in Cape
Town, Johannesburg, Durban and Windhoek.
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