PowerOptimal Elon 100 User manual

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Elon 100
Solar PV Water Heater
Quick Reference Guide
V 1.06
2019/07/08

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The Elon 100 enables you to connect solar photovoltaic (PV) panels to your electric
geyser. It stores energy from the sun in the water in your geyser –effectively using
the water as a battery. The unit can also function completely off-grid if you have
enough solar panels connected (See the table on the next page).
In order to be able to heat the water in your geyser during the day (to “charge the
battery”), the water needs to be below its set point temperature when the sun
comes up and the panels start producing energy. Otherwise the energy cannot be
stored in the geyser.
To ensure that the water is below setpoint temperature later in the morning, the
Elon 100 switches off power from the grid early in the mornings. You will start the
day with hot water, but the water in the geyser will gradually cool down as you use
hot water during your morning routines. This means that, by the time you are done
with your morning showers and washing the dishes, the water in the geyser will be
below its maximum (set point), ready to be heated with solar energy.
The water will be heated gradually over the day, and in the afternoon the Elon will
switch over to grid electricity in case the water is not at set point temperature yet.
(The closer you set the efficiency dial to "MINIMUM", the earlier in the day it will
switch back to grid power.) This means that, by late afternoon, the water in the
geyser will be hot again and ready for use –charged with solar energy.
What does the Elon 100 Solar PV Water Heater do?

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Heating water takes a LOT of energy. A household geyser can use up to 40% of a
house’s electricity. Heating a single 200 litre geyser from 15 °C to 60 °C will use over
10 kWh. This is about the same amount of energy burnt by a person running a
distance of over 100 km at 10 km/hr, or enough energy to watch more than 120
hours of TV
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.
The more solar panels you have on your roof, the faster the Elon 100 system will
heat your water. Typically, the number of panels has been selected to heat water
over most of the sunlight hours (from morning to afternoon). This will be slower
than heating water using grid electricity. So you can expect a gradual temperature
rise from morning to afternoon.
Here is an approximate guide to what you can expect:
For example, if you have 4 solar panels, the system will (on average over a year)
produce enough hot water for 3 showers per day (using a low-flow showerhead).
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46” OLED TV at 82W.
How much energy will my system produce? What should I expect?

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The amount of energy from the sun depends on your location, the time of year as
well as the orientation of your solar panels. The best direction for panels in South
Africa is to face north, at an angle of about 25 to 35° from horizontal.
Although Gauteng (Johannesburg / Pretoria) & Cape Town may seem quite similar
in terms of total solar energy per year, Cape Town has winter rainfall and Gauteng
has summer rainfall. This leads to Cape Town having much lower solar electricity
production than Gauteng in winter.
How do seasons and my location affect solar energy production?

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Turn the dial on the controller to set how much of the day the unit will run on solar
power only. It is generally best to just leave it pointing straight down.
Solar
only
Solar
only
Solar only
Solar
only
How to adjust settings on the Elon 100 controller
Efficiency
dial
Override
button
Mains &
Solar
indicator
lights
When there is too little sun:
Press the override button for
5 seconds (until the red light
starts flashing) to force the
system to use grid (mains)
electricity for one heating
cycle. To switch to grid power
permanently, press the
override button for 15s (until
red light comes on
permanently). To switch back
to normal operation, press the
override button again for 15s
(until red light switches off).
Mains
Mains
Mains
Solar
only
Mains
Noon
Midnight

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The closer you set the dial to “Solar Only” (in other words, the more you turn it anti-
clockwise), the bigger the portion of the day that the system will use solar energy
to heat the water in your geyser.
However, you might not have a sufficient number of solar panels to heat all the
water in your geyser every day (and some days will have rain or cloud). So it is best
to set it so that it switches back to grid power before you start using hot water again
late afternoon. This will ensure that you always have hot water in the mornings and
evenings.
How can I increase my savings?
You can increase your savings by reducing your hotwater use and by changing your
routines.
The best time to shower for maximum savings is in the mornings.This ensures
that the ‘solar’ day starts with the water in the geyser at lower than set point
temperature (in other words the battery is not fully charged).
If you have enough solar panels for the number of people and overall level of hot
water use in your household (see the table on page 2), you can further increase
your savings by setting the Elon efficiency dial to “SOLAR ONLY”. This will ensure
that the unit will never use grid (mains) power for heating water. You can still boost
with mains power (such as on a cloudy or rainy day) using the override button as
described earlier.
General hot water energy saving tips
•Shower, don’t bath
•Install water-saving or low flow shower heads (these also save energy
because of reduced hot water use!)
•Reduce shower duration
•Check that your geyser is well insulated
South Africa is a water-scarce country –reducing hot water use saves both energy
and water!
What settings should I use?

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The Mains & Solar indicator lights indicate the following conditions:
Lights
Meaning

Mains (red)
light flashing
Grid (mains) electricity is being used to heat water

Solar (green)
light flashing
Solar power is being used to heat water. Rate of flashing
indicates rate of solar energy supply

Red & green
alternating
No power is being supplied to the geyser element. (Either
the water is on temperature already, or the unit is in solar
mode and there is not sufficient sunlight)


Red or green
flashing very
fast
Isolation fault (contact electrician)

Red light ON
Solar power switched off (only grid power allowed to
geyser). Press and hold override button for 15 seconds to
switch solar power on or off. To switch off both solar and
grid power, turn the dial to SOLAR ONLY and then switch
off the solar power with the override button as described.

Both lights
OFF
No power to unit (e.g. no sun and a power failure, or no sun
and geyser breaker at DB board is switched off)
What do the lights on the controller indicate?

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Desired
state
Actions
DB board
geyser
switch
Controller
dial
position
Lights
✓Solar ON
✓Grid ON
This is the default state.
ON
Anywhere
outside
the “Solar
Only”
zone
Normal
operation
(green
and/or red
flashing or
both
alternating)
✓Solar ON
Grid OFF
Turn controller dial anti-
clockwise to the “Solar
Only” zone indicated on
the controller. Note:
you can still boost with
grid power for one
heating cycle by
pressing the Override
button for 5s.
ON
In the
“Solar
Only”
zone
Green
flashing or
both lights
alternating.
Red would
flash if
override
button has
been used.
Solar OFF
✓Grid ON
Press Override button
for 15s until the red
light switches on
permanently. Grid
power is now always ON
(24 hours per day).
ON
Anywhere
outside
the “Solar
Only”
zone
Red light on
Solar OFF
Grid OFF
Turn efficiency dial all
the way anti-clockwise
into the "Solar Only"
zone. Press Override
button for 15s until the
red light switches on
permanently.
ON
In the
“Solar
Only”
zone
Red light on
Controller settings for switching off solar or grid power

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(See the full User Manual at www.poweroptimal.com/manuals for more extensive
troubleshooting information.)
Problem
Possible Cause
Action
I have hot water in the
morning, but not in
the afternoon
Insufficient solar energy.
The system is using grid
power to heat the water
overnight, which
ensures you have hot
water in the morning.
During the day, the
system is relying on the
sun to heat, which is
why the water may be
cold.
If it is a once -off problem:
Press the “override” button
to boost your water temp-
erature with grid power.
If it is a regular problem:
Turn the controller dial
clockwise to use grid
power for more of the day
(note: this will increase
your bill). You can also wait
until later in the afternoon
to use hot water again.
I have no hot water in
the morning or the
afternoon, the red
light on the controller
is on and the dial is in
the “Solar Only” zone
Your unit has been
switched off (holiday
mode)
Press button for 15s until
red light switches off, or
turn dial clockwise to a
position outside the “Solar
Only” zone.
I have no warm water
in the morning or the
afternoon and the
lights on the controller
are off
There is no power to
the system.
Check that the “geyser”
switch in your electrical
distribution board is not
switched off. If not, call an
electrician or your installer.
There is warm water,
but my electricity
consumption is too
high.
See page 5 on how to
reduce your hot water use
& optimise solar energy
use.
The system
performance is worse
than it used to be
The solar panels are
dirty (or it is winter
season –see p. 3)
Clean the panels with
water only.
Basic troubleshooting

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•Much longer life and lower maintenance than solar geysers or heat pump
systems. Solar PV panels last 25 years or longer. This means that you will
benefit from free solar energy for decades.
•Easy installation - no plumbing changes for retrofit
•You can use your existing electric geyser
•No noise (unlike heat pumps or solar geysers with circulation pumps)
•Lower weight of rooftop components compared to solar geysers means
easier installation
•No tank on the roof (unlike thermosiphon solar geysers)
•Hot water during power failures
•Better winter performance than solar thermal
How can solar PV water heating be more cost-effective than solar thermal?
Isn’t solar thermal efficiency much better than solar PV?
It is true that solar thermal collectors are more efficient per square meter (area)
than solar PV modules in collecting solar energy. However, overall efficiency must
also include factors such as heat loss in piping (especially in winter) and energy use
of solar thermal circulation pumps.
Solar thermal system lifetimes range from about 7 years (for cheap imports) to
about 15 years for high quality (and more expensive) systems. (In a comprehensive
analysis, Sandia National Laboratories found that about 50% of solar thermal
systems fail within a 10-year period.) Solar PV modules are routinely guaranteed at
80% performance after 25 years, and the US National Renewable Energy Laboratory
uses a lifetime of 33 years in its solar PV system calculations.
Solar PV module costs have dropped dramatically –by over 80% in the past 5 years
–and the trend is continuing. This has changed the paradigm. Whilst solar PV
systems will continue to require more roof space than solar thermal in the
foreseeable future, the key issue is not roof space, but cost. Solar PV systems have
become cost-competitive to solar thermal, and the much longer lifetimes and lower
maintenance translate into a lower lifetime cost per unit of energy.
What are the benefits of a solar PV water heater?

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You can download a full user manual on our website:
www.poweroptimal.com/manuals
You can also find an online user instruction video on our website:
www.poweroptimal.com/elon100

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Notes