With the push for 'green' going on lately have you considered using 'Solar
Power' for your backup power supply?
If you wanted to have a true
uninterruptible power supply it has to last more than ten minutes to a couple of
hours why would you not? Batteries only last so long. And wind power is only
good when the wind blows constantly.
No the only true free (well almost) power is the Sun. But unless you live in
Antarctica for eight months and the Artic for the other four months you typically only get
12 hours of sun light.
So how would you have true uninterruptible power with solar? One way would be
to have a solar panel (array) that would supply your power during daylight and
charge some batteries for use after dark. This is the typical setup for a true
solar power source.
Ah but you say how much? Well it ain't cheap! If you are only concerned with
emergency contingencies such as a power outage during the day, or your car
breaks down on the road in the middle of no where, or you are a camper then
there are portable solar power arrays that are light, produce adequate power,
and cost effective.
What if you want to put a solar array on the roof of your house and sell the
excessive daylight power to the power company. You sitting down? Remove sharp
objects from your hands - $40,000. Ya, forty K bucks! Whoa! Where I live and
with the roof area on my house I can produce 8 Kilowatts a day! Ya, twice what I
use a day during the summer (Air Conditioners draw a lot of power!) so instead
of it costing me say $45 a day to cool this house I could be getting paid by the
electrical company and have the house cool. But the 40 K has me stumped at this
time. I can see the advantage but the outlay is worth a quarter of the cost of
the house, when it was NEW!
Back to the emergency or portable power supply.
You can buy one that is on a back pack with a Battery and Battery Charger
that will store the power until you need it to charge or operate a low wattage
device such as cell phone, mp3 player, but not your laptop.
If you need more power then you will need a bigger solar panel. And if you
need the power at night then you will need a battery to store the power you
collect in the day time. Some of the bigger solar panels produce enough power to
convert it to AC (you would use an 'inverter' to change the DC to AC, cheaper to
run than a gas powered generator and usable in some areas where the gas
generator isn't allowed.
These are the solar power arrays I have found that make sense -
Solar Battery Charger SE-1500 Charge Controller - 10A
Sunsei® CC-10000
$199 $39.95
Amorphous 12 Volt Solar Panel (15W) Sunforce 7 Amp
Charge Controller
$109.99 $25.99
Voltaic™ Solar Charging Backpack, Orange Panels
$219.99
So lets have a look at them -
Solar Battery Charger puts out Watts 22.5 @ 1.5A, with the Charge Controller
will trickle charge a battery.
The Amorphous 12Volt Solar Panel puts out 7 Amps at 15 watts. This is for
heavier applications such as keeping your car/rv/golf cart battery charged. Will
run small low wattage devices and requires a 'Charge Controller'. With an
'inverter' two of these panels will keep a couple of 15 Watt appliance happy with power
all day.
The Voltaic Solar Charging Backpack puts out 1 watt at 100mA, very low
trickle charge. Will charge a small battery or power small devices, not good for
a laptop.
Both the Solar Battery Charger and Amorphous Solar panels will supply enough power
for small appliances such as trickle charging a 12V battery, a laptop, a CB
radio. If you need more power you can add more panels to get more power. At $150
- $200
for the panel and charge controllers the cost for a modest array to power more
devices or higher consuming devices such as a small refrigerator. I don't see
any use for the back pack solar other than charging your cell phone or mp3
player. Might be good for those that go on long weekend hikes to the wilderness
to keep their cell phones charged.
There are larger solar panels available but those would not be portable, they
require a solid frame and may not travel very well if exposed. I checked on two
different products produced in here in Arizona that are useable on a
Recreational Vehicle but the cost is high and only one didn't require storage
when the RV was in motion.
So if you want to power more than a small low wattage device you have to add
more solar arrays. If you have one array that delivers a certain wattage per
hour just divide the total wattage by the solar panel's wattage and that will
give the number of panels you will need in your Solar Array to power the device
all day. You could also do the same with your battery back up system, most
batteries are rated in
Ampere Hours. So to arrive at the desired wattage you
would take the Amp Hours and divide that by the voltage to arrive at the
wattage. Such as your 12 volt battery is rated at 600 AH, 600 multiplied by 12
is 7200, so the battery can supply 7200 watts for an hour. So if you need say 150
watts your battery will last approximately 4 and a half hours, two batteries
will last 9 hours. Not to shabby but you will have to lug around two
batteries...
P = Watts
I = Amperage
V = Voltage
I x V = P
600 x 12 = 7200
One solar panel that supplies 15 watts with a max amperage of 7 amps will give
you 2.14 volts.
P = 15
I = 7
V = ?
P / I = V
15 / 7 = 2.14
To achieve 12 Volts continuously you would need six panels 2.14 x 6 = 12.84
Volts. Or a panel that supplies more wattage, which in turn makes the panel
larger.
Or
P = ?
I = 1.5
V = 15
V x I = W
15 x 7 = 22.5
To achieve 300 Watts from this type of panel you would have to have 13 panels,
how ever if you have three batteries and two panels you could have power in the
day along with trickle charge the batteries during the day and have plenty of
power at night.
Solar panels are increasing in efficiency continuously and the future is bright
for solar energy production.
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