How does HotPV™ work?
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The following description shows how the EasyWarm
HotPV™ system works, based on an example of a household with a 200L domestic hot water tank with a
2 kW heating element and a nominal 2 kW PV array on the roof:
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Two people each have a shower before work starting
at 6:30am for 10 minutes; using 5 litres per minute of hot water, which means 50 litres per
person used. This uses 100 litres of hot water, or half the tank's capacity
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Recovery energy required = 5.25 kWh (100 litres
raised from 15 to 60 degrees C)
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If it is connected to the grid, the 2 kW element
will take 2hr 37min (6:30am to 9:07am) to recover
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This is shown by the red outline in the picture
below: in a normal cylinder, the 2kW element starts heating once you start using water, because
the cylinder thermostat turns the power on once the cylinder gets cooler
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The EasyWarm HotPV™ system stops the cylinder
element kicking in - instead, with this solar PV hot water system the element waits for the
start of the solar day, when there is sunlight available to heat the water: the blue curved line
below shows the PV (photovoltaic) generation curve from a nominal 2 kW solar
array
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This is accomplished with our unique VOV™ or
"variable output voltage" inverter
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Our VOV™ inverter sends the element whatever power
is produced by the solar panels once they start generating - 50 Watts or 1000 Watts or 2000
Watts - whatever the amount, the power is directed to the element and starts to heat the water
until the water is hot
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The EasyWarm VOV™ inverter is not connected to the
grid, and is supplied with the HotPV™ system exclusively from EasyWarm
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In the picture above, the blue curve shows the
cylinder being re-heated gradually by this unique solar PV hot water system until the preset
thermostat temperature is reached - around lunchtime in this example - the heating is achieved
by the PV panels, not from grid power. If more hot water is used during the day, Hot PV™ will
continue to reheat the cylinder while there is sunlight available
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Looking at the red column in the picture above,
without the EasyWarm HotPV™ system, 95% of the energy would come from the grid (at utility
pricing), while only a small fraction will be supplied by a normal grid-connected PV array -
this is shown by the small triangular area under the blue curve starting at around 8am and going
to just after 9am
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With the HotPV™ 2kW PV rooftop generation system
in this example, 100% of the energy used to reheat the water that you used in the morning would
come from your own PV system (if the sun is shining)
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The EasyWarm HotPV™ system is normally supplied
with our HotPV™ controller which ensures that on days where there is not enough sunlight to heat
your water, your cylinder is able to be electrically boosted from the grid, which means that you
will have reliable hot water even on cloudy or wet days
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That's HotPV™ - Solar Hot Water made
Easy!
EasyWarm HotPV™ - contact us
today..
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Contact us via
email>>
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