Harbor Freight
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Item: 45-Watt Solar Panel Kit
Item number: 90599
Retail price: $249.99
Frequent sale price: $149.99-$169.99
Best price: $129.99 (with coupon)
Target price: $139.99 (with coupon)
Item Link
Available at: Harbor
Freight USA and online at Harbor Freight Tools
|
We have a lot of products that are currently being tested and
rarely do we write a review before we've completed our full evaluation.
This product is so hot that we feel obliged to publish our preliminary observations and set a tentative target price.
We're doing this because people are frequently paying over what we feel
is a realistic target price for this item and we want to issue a price
advisory ASAP for the benefit of our readers. (
Click here
to view our Q & A which has an explanation of how we determine our
target prices.) All others, please pay the full retail price to help
better support Harbor Freight so that the rest of us can continue to
enjoy these deeply discounted prices. Our price advisories are for our
'inside club members' only (AKA readers) which is obviously free and
only a click away from any spot on the Internet. (In case you're not
getting our sometimes strange, often sarcastic sense of humor, you're
there now.)
| We have special interest in energy conservation and alternative energy
sources and have purchased quite a few products related to these
interests from Harbor Freight and from other suppliers. In
our tests Harbor Freight has been consistently striking out but with
their 45-watt solar panel kit they may have hit a home run. This
is by far the lowest price anywhere for low to medium wattage solar
panels, and the charge controller and compact fluorescent light bulbs
are a bonus. |
Pricing Solar Panels
A rough rule-of-thumb for purchasing large-scale solar panels is that
$5/watt is a good price. This is on LARGE projects (i.e., a minimum of
several hundred watts); seldom do small or even medium-sized panels
reach this price. Many small-scale solar-panels cost up to $10/watt
(see Harbor Freight's own product,
5-Watt Solar Battery Charger,
which normally sells for between $10 and $12 per watt without a charge
regulator). These 45-watt panels, at our target price, are just
$3.11/watt. That's figuring the solar-charge regulator, light bulbs,
and hook-up wire are FREE! At the full retail price these panels would
be $5.55/watt and that's what (pun unintended but I'll use it ;)) many
educated buyers consider a reasonable bargain. And if you buy this kit
at the higher sale price of $169.99, you'll be paying just $3.78/watt
for a medium-sized panel which is a great deal too. (You can do the
math on the rest of the sale prices and buy when it's right for your,
i.e., considering immediacy of need
versus cost savings.)
We want to see you buy them low, so we've set our target price at the
lowest sale price we've seen with any regularity. (Yes, we've actually
seen the "best price" of $129.99 a couple of times this year.) Don't
expect them to go on sale often at this price; they sell plenty of
these panels at higher sale prices to buyers who think they are getting
a great deal -- and they are! It's just that we set are target higher
(eh, lower numerically?) and want the best deal out there. At our
target price of $139.99 you're paying just $3.11/watt. Be advised,
however, that
we only expect this kit to hit our target price several times a year, so your own need will dictate how much higher you must pay for the item.
What They Do
Solar panels convert the sun's energy into usable electrical energy.
They contain a photoreactive material embedded in a glass matrix which
generates usable electricity when exposed to light (
Click here to read an article from the Wikipedia that explains this process in detail.).
Individual solar cells each produce a small amount of electricity which
is combined with other solar cells to produce a usable level of
electricity. For example, 24 separate solar cells that each produce 0.5
VDC can be wired in series to make a solar array that produces a total
of 12 VDC. This is almost enough electricity to charge a car battery or
a standard battery used for storing solar energy for home use but not
quite. Charging a 12V battery effectively requires a higher charge
voltage, usually around 15 to 18VDC. So add another 12 solar cells to
the solar array and you bring the total voltage up to a total of 18V
for the solar array. Now you have obtained a commonly used voltage for
a solar cell array.
| Different solar devices use difference charge voltages. The most commonly used voltages for full-sized solar
panels are 12, 24, and 48V outputs. (Typically,
multiples of 12 are used to correspond with the 12V deep-cycle
batteries normally used to store the electricity.) Smaller solar
devices such as yard lights operate at different voltages typically 1.2
or 3.6V. All of these solar panels consist of small individual solar
cells wired together to reach the required working voltage. |
Although a solar cell array with 36 individual cells may reach the
required working voltage of 18 volts, the current output is likely to
be very low with each cell only produces about 0.4 amperes. To increase
the current output, two solar cell arrays are connected in parallel
which doesn't change the output voltage but does increase the current
flow to the sum of the two separate solar arrays. In this example, the
solar panel consisting of our two solar arrays would produce 18 volts
at 0.8 amperes for a total output of 15 watts (watts = voltage x
amperes). Bingo, you've just constructed a 15-watt solar panel such as
those contained in the Harbor Freight kit described here and you only
had to solder 72 individual solar cells together (each with two
soldered connections). Of course you also had to 'sandwich' them
between two sheets of protective glass and seal it well against the
weather plus build a frame to support the glass and protect the edges.
And don't forget a blocking diode to prevent the battery from
discharging through the solar cells at night (You could omit the diode
if you don't use battery storage, but that would be bad design because
you might later want to add a battery and forget you skipped this step
and then spend weeks trying to figure out why the solar panel wasn't
charging your battery properly.). So you can make your own solar panels
if you wish, but it's a lot of work even though you can usually save
some money.
| When wired in series voltages increase (voltages values are
additive) and current flow remains the same. When wired in parallel
voltages stay the same while current flow increases (amperage values
are additive). Solar panels consist of individual solar
cells wired in series to produce the required voltage and banks of
these series-wired solar cells connected in parallel to produce the
desired amperage output. The current (amperage) available at the output
voltage yields the wattage rating of the solar panel. All
specifications provided by the manufacturers are for optimal not
typical conditions. |
The published specifications for a solar panel are under ideal
conditions which means a very bright light striking the panel at just
the right angle to produce maximum electricity while keeping the panel
cool enough so it doesn't loose efficiency from heating (solar panels
loose efficiency as they heat up, so adequate heat dissipation is
needed to maintain solar-cell temperatures within the acceptable
range).
The industry standard is for a solar panel to produce 80% of its specified output under typical conditions.
Often they produce more, but don't be disappointed when they only
produce 80% of the package specifications. All solar panels are rated
with this inflation factor (tested under optimal conditions rather than
typical conditions), so you are still getting what you paid for, it
just cost a little more for each usable watt than what is calculated in
theory. Both the angle in which they are mounted to receive the sun's
energy and the mounting itself designed to minimize heating effects are
important considerations for obtaining the rated output of solar panels.
What's Included in the Kit
The Harbor Freight kit includes three 15-watt solar panels, a charge
controller with built-in voltage converters to provide 3, 6, 9, and
12VDC outputs, two 5-watt compact fluorescent light bulbs with matching
sockets, solar-panel mounting frames, battery clamps, and wire to
connect the parts. They even include a plug adapter for use with the
different types of sockets commonly found on DC-powered devices. Of the
components included in this kit, the wiring is the one which you should
replace almost immediately. Harbor Freight uses a lighter gauge wire
than would be recommended by solar-power enthusiasts. Lighter wiring
means more power loss before the energy is stored or used and as you
should understand from the previous discussion of how much power they
produce, energy loss is not something you can afford. The rest of the
components are very good quality (but see below) making the kit a
popular purchase by many experienced solar-power enthusiasts.
 |
Accessories included with the
Harbor Freight 45-Watt Solar Panel Kit. The solar panels are so cheap
at our target price that we just figure this stuff is free. The
charge-regulator alone is worth more than a few bucks and puts out
3,6,9, and 12VCD for charging other devices!
|
These panels and the included charge controller are designed to operate
at 12VDC. This is a common operating voltage for solar panels although
many operate at higher voltages, usually as multiples of 12 (e.g.,
24VDC, 48VDC). This kit gives you (technically, sells you) three
15-watt panels for a total of 45 watts. In actuality, you won't get 45
watts but more like 35 watts or so from these panels. Even that will
depend on the weather conditions, time of the year, and the angle in
which they are mounted relative to the equator. If it's not already
obvious, people experienced with solar power don't purchase 45-watt
kits expecting to run 45 watts worth of equipment.
| There have been a number of online reviews mentioning problems with the
charge regulator. Most of the reported problems do not seriously affect
its operation (e.g., the display seems to fail or misread the voltage),
but we are currently investigating this in our own tests. In the final
analysis it doesn't really matter much because we are buying this kit
for the solar panels. |
The kit is well designed as a remote solar-charging station complete
with a charge controller that has on-board voltage conversion for 3, 6,
9 and 12 VDC outlets. This allows you to directly charge various
devices operating at these voltages with rechargeable batteries.
Whether used for mobile (e.g., RV) applications or for stationary
remote charging stations where AC power is unavailable, this feature
expands the usefulness of this system considerably for many people. The
only item missing is some means of storing the electrical energy for
nighttime use, unless you're only running or charging your equipment
during the day. Most people will need to add a storage battery to this
kit (see below).
|
How much power should you expect from this
kit? Assuming the solar panels produce 80% of their
rated power, you have 36 watts to work with. If you're running your
solar-powered devices throughout the day and night, you need to
generate over twice as much electricity during the daytime as your
system requires for 24-hours' use. On a bright summer day you might get
12-hours of strong sunlight, so you would need a set of solar-panels
that produce twice the wattage used by your electrical system, or as in
our example based on this Harbor Freight kit, you have half of the 36
watts (18 watts) of usable solar power. A more realistic estimate based
on varying weather conditions across the seasons and on storage loss
would be 1/3 the nominal power of the solar panels or around 15 watts.
That should be sufficient to keep one 15-watt compact fluorescent bulb
lit 24 hours a day. Fortunately, you probably turn your light off
during the daytime so you could run two of these lights at night. The
good news is that if you only use your lights for half of the night (6
hours in our example), you can run four 15-watt compact fluorescent
lights giving the illumination equivalent of four 75-watt conventional
bulbs, and that ain't bad. Nonetheless, it should be
painfully obvious why energy efficiency is an important part of the
solar-powered equation. (And Harbor Freight has helped
you to get started by providing two energy efficient 5-watt compact
fluorescent bulbs in their kit.)
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Energy consumption adds up fast in a typical household. Even a few
standard incandescent light bulbs exceed the capacity of this small
solar system. That's why there is so much emphasis on decreasing energy
use when switching to green power (e.g., solar panels, wind turbine
generators). The easiest way to visualize this is to consider a 75-watt
incandescent light bulb; a 75-watt bulb takes, eh, 75 watts to power.
The same amount of light is obtainable with a 15-watt compact
fluorescent bulb, and now you see so many solar-powered applications
use these types of bulbs or LEDs. (Wow, too puns in two sentences.) If
you don't get it yet, do the math for just three lights and you quickly
see how 225 watts of incandescence lighting is easily replaced by 45
watts of fluorescent lighting. LEDs have a similar low
energy-consumption profile. OK, let's try one more math example: under
optimal conditions 12 hours of sunlight charging would run your three
compact fluorescent lights, eh, for 12 hours, but your three
incandescent lights would run for under 2 1/2 hours with the same
charge time. Get it now? You have to switch to low energy-consumption
devices whenever possible.
Approximate Equivalence in Lighting Power between Compact Fluorescent Light Bulbs (CFL)
and Conventional Incandescent Light Bulbs
|
Compact fluorescent light bulbs at 1000Bulbs.com
Shatter-Resistant CFL including 14-watt floodlights
All colors of CFL at discount prices
|
9-watt CFL = 40-watt incandescent
13-watt CFL = 60-watt incandescent
15-watt CFL = 70-watt incandescent
23-watt CFL = 100-watt incandescent
30-watt CFL = 120-watt incandescent
|
Compact Fluorescent Light (CFL) Basics
Click here to read an expanded version of this information.
Compact fluorescent lights are basically, well, compact fluorescent
lights. They are the same technology that has been around for over 75
years compacted into a smaller package.
In other words, they're simply fluorescent lights, but unlike their
larger grandfathers, they have their starters/ballasts and other
circuitry necessary to make them work miniaturized into a package which
fits into standard light sockets normally reserved for incandescent
light bulbs. Of course they're
improved in other ways as well, being quiet running and available in a
variety of color temperatures that make them much more pleasant for
home use. They are so much more energy efficient and safer (because of
their lower operating temperature which decreases the risk of
electrical shorts and fires) that the manufacture of standard
incandescent light bulbs will be discontinued in the United States in
the not to distant future. Fluorescent lights have always been a
favorite in large-scale operations (e.g., industry, schools, offices)
because of their energy savings and low maintenance (around 10,000
hours between bulb replacement). CFLs find their way into private homes
in the United States and Canada as awareness and concerns about
green-house emissions mature. They have long been a favorite in Europe
and other parts of the world where residential energy costs are
considerably higher than in North America. And of course, we find them
indispensable for use with solar-powered applications that generate
only small amounts of usable electricity.
The numbers are downright staggering:
A CFL uses about 1/3 the energy of a conventional incandescent light
bulb and lasts around 10-times longer. Over the life-time of the CFL,
this saves around $45 at an 8 cents per kw utility rate and double that
with our actual delivered utility rate in Western New York (i.e.,
$90!?!).And the fact that YOU can make enough electricity at home to run them is even cooler.
|
There are a few things to note about compact fluorescent light bulbs (CFL).
First, they work with mechanical and relay types of switches and
timers, but you need special dimmable CFLs to work with most light
dimmers and electronic switches such as X10 controls. Second, they come
in a variety of color temperatures: cool is the standard appearing, typical fluorescent light that many people like for area and general ambient lighting; warm better emulates a conventional incandescent light which most people prefer for reading; and full spectrum
emulates the natural light of the sun and is used for ambient lighting
and some applications find it suitable as a plant light; CFLs even come in an assortment of colors.
Third, the life-expectancy of most CFLs is around 10,000 hours so you
'earn back' your higher initial investment in energy savings (see
below), replacement bulb costs, and cooler running lights (this can be
very important for some applications, especially with old fixtures
which can overheat when used for long period with conventional light
bulbs). 1000Bulbs.com
carries a very wide assortment of CFLs as well as LED and other types
of lighting. Read through their online listings carefully to find the
CFLs that best suit your individual needs. Don't be overwhelmed with
all of the choices -- buy a couple of different types (e.g., color
temperatures, styles) and experiment to find what works best for you.
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What to do with the Extra Power Generated during the Daylight Hours or how to turn the lights on at night
Of course solar panels only make electricity when exposed to light, so
for most of us this means during the daytime. To have electricity
available at night, some method of storing the generated electricity
must be used. For small-scale solar systems, this usually means storage
in deep-cycle batteries. Regular automotive-type batteries will work,
but they don't work very well. Batteries used in automotive
applications are designed to deliver a large amperage (while starting
the engine) for a short period of time and then to be fully charged by
the vehicle's electrical charging system (e.g., alternator). The
batteries used in solar systems are designed to deliver a lower
amperage over a longer period of time and most importantly, to
discharge to a level that would damage conventional automotive
batteries. That's why they're call "deep-cycle" batteries. (Even
deep-cycle batteries will be damaged by discharging too much, and
that's why charge controllers are designed to limit how far the
batteries are allowed to discharge while providing power.)
There are several choices in deep-cycle batteries which can be used.
Although not considered optimal, the batteries used for the house
lights in RVs are acceptable. Alternatively, golf cart batteries are
considered among the best; these batteries are usually 6-volt and
require that they be used in pairs connect in series to obtain the 12
volts typically used with solar panels. For those with unlimited
budgets, there are specially designed batteries for solar applications.
These are expensive and probably not worth the investment for most of
us. And finally, if you have an extra automotive battery that is still
in working condition, you can use it to store the output from your
solar panels although it is the least efficient of all the battery
choices. (On the other hand, free is good and we have gotten quite a
bit of use out of old car batteries that weren't adequate for our
vehicle use [can't chance having a dead battery] but do provide some
storage capacity for our solar systems.)
You may have heard about 'storing' extra electricity on
the grid through your local electrical utility company,
but this is not going to happen with this
kit from Harbor Freight. Solar-energy systems that produce a lot of
electricity (in the kilo [thousands of] watt range) usually convert the
12VDC (or other DC voltage) to 120VAC using an inverter. At times when
they are generating more electricity than what they are consuming at
the moment, they need a way to store this excess power. Electrical
companies in many (most?) states now accept power generated from
private parties: net-metering is where your 120VAC is
connected through a special device to the power grid allowing you to
'store' extra electricity at your local power company. When you are producing more electricity than what you need,
your electrical meter actually runs backwards. Other times,
you are drawing power from the grid to supplement any electricity
produced by your solar-panels and the meter runs forwards as usual.
How does this system compare with those larger systems? You may wish to purchase an inverter for 120VAC (we have
one, see What We're Doing Now below), but you only
need a small 300-watt or so inverter because you really won't' have much electricity to convert.
You need a larger capacity
inverter than the 45-watt solar panels generate at any given moment
because you would need to draw stored power from your battery when
using a 120VAC inverter. Otherwise, you wouldn't be able to run any
120VAC devices because the solar-panels themselves only
produce a maximum of 0.375 amperes at 120VAC and that's insufficient to
run anything directly.
And of course this doesn't figure the actual power loss during the
12VDC to 120VAC conversion (inverters are only 80-90% efficient in
their power conversion).
|
Assuming 10 hours of bright sunlight this system might produce around
0.360 kw which means a 5 A 120VAC tool could run for about half an hour
on a day's charge. The electrical load at your home
greatly exceeds this capacity even with all of the lights, TVs,
radios, air conditioners, etc. turned off; the refrigerator and phantom
loads such as the LDC-TV, VCR, and other devices in standby, the
cordless phones on-charge, and numerous other hidden electrical loads
will be over a kilowatt. Your utility company isn't too worried about
the competition. To seriously
consider net-metering you would need a 3 to 5 kw system
or 67 to 111 of these 45-watt solar panel kits. And to actually get
serious about generating your own electricity, the average home
probably needs a 10 to 15 kw system -- now you're spinning the meter
backwards.
|
For most applications this system is well matched with a single
deep-cycle battery. There are of course always exceptions. In a
situation where the solar-panels generate electricity for several days
before the energy is used, then two or even three batteries might be
appropriate. For example, if you were charging batteries used with a
sump pump that is only used periodically, then this 45-watt system
should be sufficient to maintain several batteries as power sources for
occasional use. However, if you're drawing down the battery with
regular use or if you're using power while trying to recharge the
battery, a single deep-cycle battery is all that this system is capable
of handling.
Popular sources for deep-cycle batteries are Walmart and Sears. The
current cost of a deep-cycle battery at Walmart is around $70, while
the Sears DieHard is around $120. Other popular sources are automotive
supply houses such as Auto-Zone and Pepboys. Keep in mind that these
batteries are only expected to last a couple of years, although we
stretch our battery life to 5 years or more with our use patterns. If
you want a special solar-panel storage battery, expect to pay upwards
of $200.
How Much Power Do You Need?
Probably more than you can afford. It's not about going off-the-grid
for most of us; it's about making a contribution, any size contribution
to reducing the use of carbon fuels (i.e., your carbon footprint).
Consider this kit more educational than practical and you get the
point. Of course there are applications where it's reasonable to
presume you can generate all of the electricity that you need. Remember
that 15-watt-looks-like-75-watt compact fluorescent bulb? Well, you can
run several of these for hours each night on the power produced by a
small-scale photo-galvanic system. But don't expect to run you heavy
machinery or even regular fans for long; they take a lot of power.
| To design a solar-powered system to meet your electrical
needs you must first define your electrical needs. You
do this by calculating the total wattage required. Add up all of the
devices that you wish to power using the simple formula: watts =
amperes x voltage (120VAC or 12VDC). Then multiply this figure by the
number of hours you wish to power these devices and you have your total
watt-hours of energy needed. Once you've computed your total wattage
requirement you can decide if producing your own electricity is a
viable option. (The fact that we're talking watt-hours here
and electricity is sold to you from your power utility by the
kilowatt-hour should be a big hint of how far off-the-page you are when
trying to run much of your household off your own solar-powered
electrical generating station.) Of course if you wish to run
your devices after the sun goes down you also need to calculate how
many watts total are required including the nighttime usage and to
allow for adequate storage of this electrical energy (usually using
special deep-cycle batteries) for use when your solar system offline at
night. |
If you're living in a cabin in the woods without electrical power, this
system (or better yet a couple of them) can have a real impact on your
life. You could run an electrical water pump for a limited amount of
time. Use the low-wattage compact fluorescent lights throughout most of
the night and even have a yard light. Your radio would run well, but
not that TV unless it's a small LCD model and then only for a few hours
each day. But hey, you're living in a cabin in the wood without
electricity and any of this is a great improvement in your overall
quality of life.
Now for the rest of us. This size system is invaluable for getting
electricity to areas which do not currently have electricity available
such as out building or even a yard light (Did you catch that pun?).
The same limitations apply as for the cabin in the woods, but you could
run your yard lights, a special (low wattage) attic fan, or even have
120VAC for limited use in areas that are impractical to wire to your
home or shop electrical system. And that's an improvement in the
quality of life for you too. And you're doing all of this while
learning about solar-power AND reducing your carbon footprint. Not a
bad deal, especially for under $3/watt if you buy the Harbor Freight
system at our target price.
Will these Solar Panels Save You Money on Your Electrical Bill?
You've probably heard about a lot of incentives for buying solar and
other sources of clean energy. (Incentives that have been available for
the past few years pay up to 1/3 back on the total installation cost
for qualifying systems in residential use.) The current rules for
Federal tax credits specify, however, that the installation must be
done by a certified (in solar energy) electrician to qualify.
Incentives offered by many local utilities usually have the same
qualifying restriction. So, the cost subsidies that you've heard about
for solar energy simply don't apply for the do-it-yourself installers.
In a word or two: we're screwed. (The Obama administration may loosen
up some of these restrictions, so check for changes in the Federal
laws.) So how about the actual dollar savings for producing your own
energy without any subsidies? Well, the box below does some realistic
calculations to answer this question.
Cost-Savings Calculations for Solar Panel Installation
- This 45-watt system should produce around 80% of its rated
power for an average up to 10 hours per day. That's 450 watt-hours x
80% efficiency = 360 watt-hours or 0.360 kW/day.
- With National Grid in Western New York we're currently
paying about 16 cents per kW delivered (the stated power price is only
around $0.08/kw but that doesn't include all the delivery charges,
taxes, etc.)
- This system saves (or earns, depending on your perspective)
around 5.8 cents per day or $1.73/month. That's a whopping
$20.74/year
- Figuring a 10-year life for the solar panels the system
should payback $207.40 over its lifetime. (Solar panels are considered
to produce around 80% of their nominal power for 10 years as their
power output gradually declines over the years of use. They usually
produce appreciable power much longer, but 10 years is the normal
life-expectancy for their rated output.)
- If the system were purchased at our target price of $139.99
that would cost us $152.24 after we've paid our 8.75% local sales tax
(gee, shouldn't these system be at least tax exempt?).
- Now, subtract the purchase cost from the payback in
electrical energy generated ($207.40 - $152.24) and you have a net
savings of $55.16.
- That doesn't look too bad, but wait, that's your return over 10 years or $5.52/year.
- Another way to view this as an 'energy investor' is that
you earned $55.16 on a $152.24 investment. That works out to be 3.6%
per year which isn't actually bad considering today's down market and
poor rate of return on cash investments.
Of course the above calculations presumed that you're using the power
as you generate it. If you have to store the power in deep-cycle
batteries, the calculations become down-right dismal.
- On sale you should expect to pay $60 or more for a no-name,
deep-cycle battery. If you can push it to 5 years' use from the
battery, you still need two batteries to cover the 10-year period used
in this calculation. That means a minimum investment of $120 in
batteries (I'll forgo the calculation of sales tax here. You get the
idea.)
- Subtract the $120 battery cost from the 10-year payback of
$55.16 and you've lost $64.84 on your investment or around 8%. That's
not bad if you've invested with Maddock!
A couple of things should be clear from these simple calculations.
- Tax and local utility company incentives are very important
for making investment in alternative energy sources cost
effective.
- Keeping the initial cost low by shopping around for your
supplier is also very important when possible. (Thank you, Harbor
Freight.)
- Small-scale users who don't qualify for the tax and utility
company incentives 'invest' in solar and other alternative energy
sources because it's the right thing to do (i.e., saving-the-planet) or
because it brings power to areas that are off the grid.
Harbor Freight Reviews we believe
that every killed kilowatt counts, so kill a kilowatt or two when and
where you can. We invest in these small-scale systems to
make a small contribution while sometimes bringing electricity to a
hard to reach area around our home or shop. |
If you are using all of the power you're generating as you produce it
during the daylight hours (unlikely but possible) or if you are
net-metering with this system (not going to happen), then you are
actually earning back 'interest' on your investment comparable to what
is being paid today with the current low return on cash investments.
If, like most users, you have to store surplus energy generated during
the day for nighttime use in a deep-cycle battery, you're actually
losing money by 'investing' in this system. So, we're back to that
cabin in the woods (this is a metaphor, in case that's not obvious by
now). If this power source provides electrical power for a location
otherwise without power, it's a great investment. If it's designed to
supplement existing power from the grid, it's not a good financial
investment but it's still a great ecological investment. Of course all
of your investment is what investors call "at-risk" because one large
hail storm or small tornado could wipe it out. Still, you choose, which
makes the most sense for you, saving a few bucks, breaking even, or
making a small contribution to saving-the-planet.
Another View on Solar-Panel Storage Batteries
The "experts" in solar power and other alternative energy sources will
usually tell you that this won't work, but hey, it works OK for our
purposes. We use old automotive batteries for storage on
some of our systems. The normal nighttime draw off the
battery in one of our applications is very low -- a regular 12-volt
automotive battery has a lot of power to drive 20 or so low-wattage LED
lights throughout the night. Most of the potential (i.e, stored) power
from the 12-volt automotive battery is for emergency use during power
outages. Otherwise, its routine nighttime use is for 20 LED yard lights
and a 12-watt compact fluorescent light in our Cabana. (Don't know what
a cabana is? Keep reading our review; the answer is revealed below.) We
also have a 400-watt inverter attached to the battery to provide
occasional 120VAC power to this remote location.
Long after the battery is unsuitable for reliably
starting a vehicle, a normal 12-volt automotive battery still has quite
a bit of life left in it. This assumes, of course, that
the battery hasn't been sulfinated by being left too long in a severely
discharged state or suffered other damage. But if you can use it, the
net cost is the $5 exchange value normally paid when you exchange your
old battery (in Western New York) for a new one. A net saving of well
over $55. This also meets our strategy of recycling
through reuse. |
Our Evaluation
As stated in the opening of this commentary, it's too early for us to
really evaluate these panels beyond their specifications and general
appearance. We can verify that they do produce electricity (How much?
How long?), that they are somewhat resistant to the elements outside
(Hail proof? What about strong wind?), and that they're a great price
(but worthless if the panels aren't any good).
| Harbor Freight has put together a nice little package
here: two 5-watt compact fluorescent light bulbs with
fixtures, a charge controller, and three 15-watt solar panels. They
even provide the necessary cabling, albeit flimsier than what you may
want. All you add is a storage battery, preferably a deep-discharge
type but anything will get you started. On a bright day, the 45-watts
of solar power should keep your two compact fluorescent lights easily
running throughout the night. In fact, this system should be able to
easily support two regular 15-watt compact fluorescent bulbs, but on a bad
day hope you have some charge leftover from the previous sunny day. |
What We're Doing Now
We currently have several projects underway involving Harbor Freight's
15-watt solar panels. Two of the projects involve ventilation. The
first one merely adapts a ventilation kit discontinued by Harbor
Freight to provide ventilation and light to a cabana (AKA fancy tool
and lawnmower storage 'shed') by increasing the number of panels from
two to three (the original 30 watts of power is insufficient to run the
fan) and by adding 120VAC power to the same location (We're combining
this with a 400-watt power inverter). The second application involves a
more ambitious project of providing ventilation to a large attic area.
We are exploring special low-wattage fans and other innovations in this
project. The third project involves converting our wired AC-powered
low-voltage yard lights to solar power (the lights are currently
powered by a 12VDC transformer that runs off 120VAC). This is a
two-step process: first, we'll convert the low-wattage incandescent
bulbs to even lower wattage LCDs; second, we'll switch the power supply
from 120VAC to our solar system which will use a battery to store the
electricity generated during the day for use at night. (Of course we'll
have to build a small photocell circuit that turns the lights on after
dusk.) All of these projects also include the Buffalo Winter Test, so
we'll be evaluating the solar panels' durability under Northeast
weather conditions. Finally, all projects also involve fabricating new
solar-panel mounting brackets that permit better placement of the
panels and a substantially stronger frame. (We get high winds at our
suburban Buffalo location that the factory-supplied panels would most
likely not be able to withstand.)
How far off-the-grind will these projects put us once they're
completed? Well, at the next major power outage we will at least be
able to enjoy our yard lights, go to the attic to catch a breeze, and
read a book in our tool shed. Not far off-the-grind perhaps, but it's a
good start. (Oh, when we get tired of roughing it we can fire up the
Onan genset to power the large-screen, plasma HDTV.) Of these items
off-the-grid and working during a power outage, the yard lights will
probably attract the most attention. Neighbors may wonder, "how is it
that your generator is so quiet that we can't even hear it?" Of course
my reply will be, "because it only runs during the daytime" (the sun --
it will be interesting to see how many can figure it out, but there I
go again with what some consider a strange sense of humor).
We will revise this article as we progress on these projects. Announcements will be sent through this
Harbor Freight Reviews Discussion Forum when significant revisions are made. Meanwhile, stay-tuned for further progress and important developments in these projects.
| Another place where solar systems really
shine is for RV
use. Most RVs use 12VDC for the house lights, water
pump, and ventilation and cooling fans. All these devices are
manufactured with the intention of minimizing their wattage-load
because when 'parked' RVs are usually running on their 12VDC deep-cycle
house battery(s). Ah, deep-cycle? Yes, they already have a deep-cycle
battery or two as part of their standard running gear. Some RVers
(including us) like to do a lot of dry-camping or boon-docking where
they run without any auxiliary 120VAC power (called "shore power"),
sometimes for an extended period of time. A couple of these 45-watt
systems from Harbor Freight (or even a single one) can keep a
boon-docker running dry for days if not weeks. Some really conserving
types might even run indefinitely with two 45-watt systems. In any case one or two of these
systems would extend the dry-running time considerably as long as the
microwave isn't used too much or the LCD-TV left on all night. |
Summary
We have commented on some of our reviews of Harbor Freight's other
solar products that they seem to be striking out on solar products.
This buy is so hot that they are almost vindicated (not really for the
thousands of people that must have bought their inferior solar
products) or at least starting to 'average up' their reputation on this
product line. We can't really evaluate this product based on our own
personal experience (which is a hallmark of this
Harbor Freight Reviews Discussion Forum
unlike the other online tool reviews), but we can comment that others
have found these solar panels to be very satisfactory. Oh yes, they are
plenty of complaints too, but the overall consensus of other online
reviewers is that these are reasonably good solar panel. And
considering the exceptionally low price for this product, we
cautiously and tentatively add this solar-panel kit to our
Hot Buys list.
You don't really invest in these small-scale solar-power
systems to save money. Rather, you invest for some
combination of several other reasons:
- To get electricity to areas that are off the grid and otherwise would remain without power.
- To have a source for a limited amount of emergency backup power.
- To help save-the-planet by decreasing your carbon footprint.
- Because it's fun!
The fact that you can save a bit on your regular electrical bill just
makes that payback a type of subsidy for whatever application led to
the original investment. In other words, it's not really costing you
$152.24 (our cost with sales tax) to meet one of your other purposes
for buying this system; it just takes a while to get your payback or
cost subsidy directly from the ultimate energy provider, the sun. Used effectively over a 10-year period, this system is
damn near free! |
Bottom line: The specifications
on this package make it one of the best buys on solar panels anywhere
and one of the better buys from Harbor Freight's extensive inventory of
products. We have a tentative buy recommendation for this item and will
revise our review as more data are available. Meanwhile,
proceed with caution but if you're in the market for intermediate-size solar panels, this is the product.
Copyright 2010 Beaux Arts USA (Reproduce freely, but play fair, cite the source.)
We have lots of items currently being
evaluated at Harbor Freight Reviews
.
It's often a slow, tedious process to review each item personally but
we're banging them out as we can. We hope that you find our
first-person reviews useful in your purchase decisions and that you
visit our website regularly for updated material. Happy Sa(i)ling!