| SOLAR Its YOUR GAIN |
| 0800 007 PEAK (0800 007 325) |
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Shedding some light on solar and heat pump hot water
heating
At Peak Plumbing we are not trying to sell you a brand or a style of hot water system, we are here to give you
independent advise on what we believe would be the best option for you and why.
To do this it is best for us to talk to you directly, to find out what your needs are, how your house is positioned
and what you expect your future demands will be.
Please find below some generic information we have put together from government information and our own
case studies in the Wakatipu. This will give you some idea of what is available and how the systems work.
If you would like to discuss your needs or talk about what your best solar and heat pump options are.
Please feel free to call us on 0800 007325 or email us at
peakplumbing@ihug.co.nz
heating
At Peak Plumbing we are not trying to sell you a brand or a style of hot water system, we are here to give you
independent advise on what we believe would be the best option for you and why.
To do this it is best for us to talk to you directly, to find out what your needs are, how your house is positioned
and what you expect your future demands will be.
Please find below some generic information we have put together from government information and our own
case studies in the Wakatipu. This will give you some idea of what is available and how the systems work.
If you would like to discuss your needs or talk about what your best solar and heat pump options are.
Please feel free to call us on 0800 007325 or email us at
peakplumbing@ihug.co.nz
"Use accredited installers,
they have been trained in
this field"
Peak Plumbing are
accredited installers with
both the Solar Industries
Association and the EECA
they have been trained in
this field"
Peak Plumbing are
accredited installers with
both the Solar Industries
Association and the EECA
Using cost comparison
computer software we can
calculate how much it
would cost to heat the
water in your house by
either Gas, Electric,
Diesel, Heat pump or
Solar
computer software we can
calculate how much it
would cost to heat the
water in your house by
either Gas, Electric,
Diesel, Heat pump or
Solar
If you have two electric
meters, one will probably
be for your hot water.
Call your electricity
provider and they can tell
you how much you have
spent on this meter over
the last year.
This will give you your
annual hot water heating
costs.
About 60%of this is what
a heat pump or solar
system could save you.
meters, one will probably
be for your hot water.
Call your electricity
provider and they can tell
you how much you have
spent on this meter over
the last year.
This will give you your
annual hot water heating
costs.
About 60%of this is what
a heat pump or solar
system could save you.
So why a solar or heat
pump hot water system ?
pump hot water system ?
The environmental reasons
The financial reasons
- Reduce green house gases (a domestic system can offset 2 tons of Co2 per
year, A swimming pool system can offset 8 tons per year) - Free up energy for use in other areas
- Reduce the reliance on other countries
The financial reasons
- Average family of 4 can save around $800 per year
- It has a pay back period (unlike nearly everything else in your house)
- On average they will pay for themselves in 5 to 8 years
- Saleability
The potential
See Steve's tips below
for helpful advice on hot
water heating
for helpful advice on hot
water heating
"check you know the
facts on what you could
be saving"
facts on what you could
be saving"
"try to find out how
much you are paying
now"
much you are paying
now"
There are lots of different opinions on the potential savings
of solar and heat pumps with data about how much better
one company's system is over another's.
But the general rule is 30% to 40% of a normal households
energy use is for generating hot water.
Using my 2.4 nuclear family as an example the figures stack
up like this.
Total house hold energy use for 2 kids 2 adults
$4287.52 ($2687.52 a year in electricity - $1600.00 a year in gas)
Hot water cost based on 30% of house hold use is
$1243.38
Based on 60%* solar fraction. Saving potential on hot water
with solar is
$746.03
* These fractions are lower than expected for an ideal house in the Wakatipu by
about 10%
of solar and heat pumps with data about how much better
one company's system is over another's.
But the general rule is 30% to 40% of a normal households
energy use is for generating hot water.
Using my 2.4 nuclear family as an example the figures stack
up like this.
Total house hold energy use for 2 kids 2 adults
$4287.52 ($2687.52 a year in electricity - $1600.00 a year in gas)
Hot water cost based on 30% of house hold use is
$1243.38
Based on 60%* solar fraction. Saving potential on hot water
with solar is
$746.03
* These fractions are lower than expected for an ideal house in the Wakatipu by
about 10%
"Use facts from
government sites that
are not trying to sell
you a product"
government sites that
are not trying to sell
you a product"
Most of the figures you
read from sites selling a
product tend to be a little
bit exaggerated, some of
the best information
comes from government
sites or environmental
agencies, as they have
nothing to gain from you
reading the information.
Please see our links page
for good sites in New
Zealand
read from sites selling a
product tend to be a little
bit exaggerated, some of
the best information
comes from government
sites or environmental
agencies, as they have
nothing to gain from you
reading the information.
Please see our links page
for good sites in New
Zealand
Hot water heat pumps
Hot water heat pumps are basically a fridge running
backwards, they take a large amount of warm air and
squeeze it to give you a small amount of high
temperature heat. Depending on the outside air
temperature they can give you the equivalent of
$3.00 of heat for $1.00 of electricity.
backwards, they take a large amount of warm air and
squeeze it to give you a small amount of high
temperature heat. Depending on the outside air
temperature they can give you the equivalent of
$3.00 of heat for $1.00 of electricity.
The Benefits
The disadvantages
|
Integrated systems where the heat pump is
attached to the hot water cylinder
attached to the hot water cylinder
Split systems where the heat pump is
separate to the hot water cylinder
separate to the hot water cylinder
The Benefits
The disadvantages
- Noise is away from living area
- less cost if a part fails
- Can be retro fitted to existing cylinder (if coiled)
- About $6k to $8k installed
- Greater choice of location
The disadvantages
- Cylinder needs to be close to heat pump
- Slightly more expensive to install
- Relies solely on outside temperature
Solar systems
| Solar systems work on the insolation effect basically it is radiation hitting a solid object, this effect passes heat energy to the object which is measured in watts per Square meter (W/m2) or kilo watt hours per day (kW.h/m2·day). There are a few things that effect how much energy is transferred to the object and the main two are cloud cover and deflection. The whole central Otago area is great for solar collection as we tend to have good sunny days even in the winter, on a sunny day in late June I have still collected 50d from my panels. |
Positioning your panels
Angle of inclination
- Inclination between ±20d of latitude (we are 45d )
- Higher for greater summer gain and lower for more winter gain
- Ideal 35d to 45d for all year performance
- Adjust pitch to maximize collection for periods when no shading
Orientation to the sun
- Orientation between NE to W
- Best collection time generally is12am to 3pm (N to NW position)
- Factors effecting orientation are shading, roof alignment
- On site orientation and shading tool
The plumbing
There are a few different ways to connect solar panels to your hot
water cylinder but the safest way for frost protection is via a heat
transfer coil in the hot water cylinder, this means we can use
antifreeze in the pipework as it does not mix with the water in the hot
water cylinder.
There is normally an electronic device that is used to pump the heat
from the panels on the roof to the cylinder.
This device will read the difference in temperature between the solar
panels and the cylinder using temperature probes in them both, it is
also possible for this device to control when the electric element can
come on to maximise solar gain and offer additional frost protection by
pulsating the pump.
water cylinder but the safest way for frost protection is via a heat
transfer coil in the hot water cylinder, this means we can use
antifreeze in the pipework as it does not mix with the water in the hot
water cylinder.
There is normally an electronic device that is used to pump the heat
from the panels on the roof to the cylinder.
This device will read the difference in temperature between the solar
panels and the cylinder using temperature probes in them both, it is
also possible for this device to control when the electric element can
come on to maximise solar gain and offer additional frost protection by
pulsating the pump.
What is the best collector flat panel or evacuated tube ?
Well this is the question that gets all solar suppliers going, its like the holy grail of the solar industry.
Personally I don't think there is much difference between them, each have some advantages and disadvantages but looking at the
performance over a whole year there is not a lot in it.
Like most things on the market today the key is to buy a brand which has a good reputation.
Both systems have been on the market for years now and are similarly priced, if one type was far superior to the other we would have seen it
take over but this has not been the case.
Some situations push more to one type than the other though and your house position and shading will be the main factors.
Personally I don't think there is much difference between them, each have some advantages and disadvantages but looking at the
performance over a whole year there is not a lot in it.
Like most things on the market today the key is to buy a brand which has a good reputation.
Both systems have been on the market for years now and are similarly priced, if one type was far superior to the other we would have seen it
take over but this has not been the case.
Some situations push more to one type than the other though and your house position and shading will be the main factors.
Flat plate collectors
- Pick up more ambient
temperature on cloudy days - Have a more manageable
temperature output (Evacuated
tubes can flash to steam) - Work better in winter as frost
and snow slide off due to less
insulation - More Aesthetically pleasing
Evacuated tubes
- Work better in Spring and
Autumn due to good insolation
and low ambient temperature - Less collection area for same
output - Easier to install and repair
- More likely to need repair
(tubes popping) - Cheaper to repair
IN SUMMARY
The New Zealand government spent a lot of money doing case studies on the viability of using solar in the residential sector, this was done to
make sure the savings for households was there before they offered funding.
The answers were obviously clear as they first offered a $500.00 grant a few years back and have now increased that to $1000.00.
This same study is now being carried out on heat pumps and I'm sure the government will soon be offering grant schemes for this type of water
heating as well.
I hope my thoughts and the information gathered here has helped you and if you would like to discuss your situation in more detail please feel
free to contact us.
make sure the savings for households was there before they offered funding.
The answers were obviously clear as they first offered a $500.00 grant a few years back and have now increased that to $1000.00.
This same study is now being carried out on heat pumps and I'm sure the government will soon be offering grant schemes for this type of water
heating as well.
I hope my thoughts and the information gathered here has helped you and if you would like to discuss your situation in more detail please feel
free to contact us.
"Make sure you are using
facts and figures based on
the Wakatipu climate"
Most case studies come
from Auckland or Australia
where the climate is totally
different to here and
might be totally different to
what you are reading.
We are currently tracking
a solar system in
Arrowtown using specific
software for this purpose,
this is being carried out
over 1 year so we will be
able to give you exact
figures of what is available
on your doorstep.
facts and figures based on
the Wakatipu climate"
Most case studies come
from Auckland or Australia
where the climate is totally
different to here and
might be totally different to
what you are reading.
We are currently tracking
a solar system in
Arrowtown using specific
software for this purpose,
this is being carried out
over 1 year so we will be
able to give you exact
figures of what is available
on your doorstep.
"We are here to help not
sell"
If you have any questions
please feel free to call us
we like to help.
sell"
If you have any questions
please feel free to call us
we like to help.
| Links to helpful solar sites |
| ENERGYWISETM solar water heating grants available *Conditions apply |