Download How it fits: A basic law of thermodynamics tells us that energy cannot

How it fits:
A basic law of thermodynamics tells us
that energy cannot be created nor destroyed, but
changes from one form to another. This is the principle
that underlies the use of Solar Water Heaters. This
system uses energy directly from the sun (solar energy)
for thermal energy (heat).
Our Solar water heating system uses evacuated tubes,
which are a special design and still operate in rainy
cloudy conditions because rely on infrared absorption
rather than direct heat transfer. These tubes are round
and they can passively track the sun and absorb infrared
from the top and from the sides.
It works completely off the grid and uses a PV solar
panel to circulate water through the hot water cylinder.
It is a 100L systems, works all year round, durable and
rust free, and expected life span in over twenty years.
How it is used: Describe a way to use this practice or
technology.
This system can be used for all your hot water needs at home
including:



cooking
Showering
Dishes and other domestic chores
Nature’s solutions: Find example of the
In Cloudy conditions water temperature has been measured to be
65oC. Hence, water can be used for most household needs.
principle enabling this technology in nature (www.asknature.org )
"Begonias, which also grow on the floor of these Asiatic
forests, have an additional trick. Some cells in the upper
surface of their leaves are transparent and act as tiny
lenses, gathering the feeble light and focussing it on to
the grains of chlorophyll within." (Attenborough
1995:48)
Audit : Design a simple audit to check current practice
Investigation, experiment and model: Design
related to this technology.
simple experiments to test the range of this
technology. Build simple models to illustrate the
practice or technology.
Type of water heater used:
............................................................
Cost of water heater: .................. Safety rating 1, 2, 3
Day Time used for
day
Amount of
energy used for
day (KWh)
Cost of energy
for day
1
1. Measure the temperature of 1 litre (1kg) of
water: .............
2. Time, in seconds, how long it takes to boil the
water (raise the temperature to 100k) on the
solar cooker:..........
3. Calculate how Joules of energy it took to boil
the water: 4200x1xtemp change=......... Joules
2
4. How much electricity? 1Watt = 1Joule/second
3
4
Information sheet:
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Green Energy SA
Roy 083 305 9047
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Email: [email protected]
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Innovative practice or technology
Use the table to score risks and impacts of the practices and
technologies.
3=significant, 2=Moderate, 1=Slight, 0=None
1. Electric geyser
2. Gas water heater
3. Solar Geyser
Quality of Resource
life
use
enhanced reduced
Ecological Caron
services
footprint
restored
mitigated