Posted by ghio on October 24, 2009, 11:55 am
I have never used an average figure. Average figures = average system
and average performance.
How good is the data for a "closest" town that is not where you are
Yep, you will get a fraction more insolation due to slightly thinner
air mass between you and the sun. Probably not measurable. Oh, and I
never used HOMER, just the raw data.
Ah, not really as you can also check cloud cover on the same page
At 1100M, a bit
You need to know your load. Then you have to size your system
accordingly. You have access to the following parameters.
Parameters for Solar Cooking
These are your main parameters
"Parameters for Sizing and Pointing of Solar Panels
and for Solar Thermal Applications
Parameters for Tilted Solar Panels
Parameters for Sizing Battery or other Energy-storage Systems
Parameters for Sizing Surplus-product Storage Systems"
Diurnal Cloud Information
Meteorology (Wind): be sure to select an appropriate VEGETATION type
Years ago I produced a set of sun charts for the whole of Australia
in .5 degree increments with the information from this info.
The real point is that if you don't know how to use the info on this
site then the info from NREL will not be of much use to you either,
unless you have a grid connect system and you want to know a ball park
figure for the systems performance. So, unless you are willing to
learn how to use this information you are at a disadvantage when it
comes to designing a system. Learning to design systems is a need to
know type of thing, after all, how many systems do you want to
Then there is the question of your load. You said 3 watts. That is 72
Watt hours a day. It has been pointed out that the uplink could be
higher, so how many hours is the unit running at the higher power?
Lets say that the system will require 12 Amp hours a day (that is 3
watts for 12 hours and 9 watts for 12 hours) , that means that a 120Ah
battery would run the system for around 8 days with no input and a
maximum depth of discharge of around 80%.
A single 80 Watt panel will produce 5A per hour during the coldest
time of year. So if you get just 3 hours of sun in the middle of the
day the panel will produce 15 Ahs/day. Monthly Averaged Daylight Hours
(hours) for December is 9.91 in your degree position.
Do you want to know all this? Or, do you just want to run the cell
phone booster/repeater in a remote
location with out the angst? If you really don't want to know all this
then you should contact TekSolar. <http://www.teksolar.com.au> They
have a modular system that is plug and play and can match a system to
your needs. They will even build to your specs if required.
Posted by philkryder on October 25, 2009, 8:21 am
George - thanks for your help.
I do appreciate it - especially at these price.
I doubt I could cost effectively make use of an Australian consultancy
for a 3 to 9 watt load system in Santa Barbara.
I will check them out however.
Posted by ghio on October 25, 2009, 10:59 am
Well now Phil, the thing about the Australian consultancy is that
TekSolar is moving into the US market soon. They may be looking for
suppliers and retailers across the states and currently will deliver
where required. Plus you gain on the exchange rate, even if it is only
15 cents in the dollar at the moment.
They are not really into full home systems, but rather small systems
such as you propose as well as lighting systems and LED lamps.
What ever you do, good luck.
Posted by philkryder on October 26, 2009, 5:16 am
well now George, I went to their website and found it a bit confusing.
I wanted to find a simple product that would meet my 3-9 watt needs;
but, all I found was marketing info and futures.
could you give me a link to such a product I could buy now to meet my
I do find all this interesting and informative, but, I have no
interest in their plans for the US.
Posted by ghio on October 26, 2009, 12:21 pm
and they will supply it. The person to contact is John Gladdis. The
site is still being built and the reason it is on line at all is that
there a number of people in two states involved supplying information
and ideas for the site.
This is just an option, they can supply a plug and play module that
will do what you want. Or you can design a system yourself or with
with other people's advice.
My other advice stands, 1 - 80W panel and a 120Ah battery, which is
correct for you requirements and gives 8 days autonomy. Remember that
whatever you take out of the batteries must be replaced, plus a
minimum of 10% to cover battery inefficiencies. i.e. take 100Ahs out -
put back at least 110Ahs.
Of course you must make your own decision in regards to your project.
If you are unable to calculate the sizing yourself, you cannot tell
the difference that different size panels will make to the system's
performance. You must be able to know and accept your limitations. An
example; I have three vehicles. A SR 500cc Yamaha, a 30yo HQ Holden
Ute and a late model sedan. I am quite at home working on the bike and
the Holden, but the sedan goes to the garage for servicing. I don't
understand the new cars with computers at all and have no wish to
As you are asking other people what you need for the project, it is a
fair bet that you already concede that you do not have the ability to
design your own system. That leaves three options:
1) Learn how to design a system.
2) Blindly accept a system design form someone else, admitting that
you have no way to check its correctness.
3) Buy a prebuilt system.
I wish you good fortune in which ever solution you choose.