4-Piece Solar Light Set

09/07/10 | by theprofessor [mail] | Categories: Outdoor Living, Lighting, Solar Power

Link: http://HarborFreightReviews.com/HFRreviews.html

Solar Light
Item: 4-Piece Solar Light Set
Item number: 93863
Retail price: $14.99
Frequent sale price: $12.99
Target price: $9.99
Item Link

We've tested quite a few of these solar-powered lights over the past few years and until recently have been quite happy with them. They seemed to cruise through the first Buffalo Winter Test, survive the second, and begin to drop-off rapidly during the third and fourth summers into our testing. The current failure rate (even with battery replacements) is acceptable but disappointing considering their very strong start. Perhaps we're expecting too much out of an inexpensive (cheap?) set of solar-powered yard lights, but it's our money and we demand what we demand, and we didn't expect to have to replace them all within 4 or 5 years' use.

The good news is that about half of these solar-powered lights have survived their first three Buffalo Winter Tests providing strong lighting throughout the night after a moderately good day of sunshine. The bad news is that around half of the remaining lights fail to come back to life even with battery replacements and that those which do only provide modest lighting after a bright sunny day and have at best a faint flickering light by morning. The actual number of replacement batteries in the lights that are still working well has not yet been tabulated. It seems that at least a few are still on their original factor-supplied batteries, but we need to tally up all of the five 4-piece sets to be certain. We do note and have come to expect that they run much longer than their advertised 8 hours even during the winter months, although at this point it is difficult to recollect if they performed this well on their original batteries (our replacement batteries are rated at 2500 [Chinese] mAh, while the factory-supplied batteries are 600 mAh).

We've mounted most of these solar-powered lights about 2 1/2 feet about the ground along a fence every 8 to 10 feet for the perimeter of our backyard plus a mid-line intersection. This gives the lights plenty of access to sunshine throughout most of the year including the winter months and times the grass seems a little longer than it should be during the hot summer months (actually, it's never really all that high, imo :-/). With an couple of color-changing solar-powered LED lights (one 15 feet and another around 7 feet off the ground) and the addition of a string of 50 flashing blue LED lights stretching across a gate which intersects the area, the backyard has been quite brightly illuminated for the first several years deeming it affectionately "the puppy airport" in honor of Sasha (it's her backyard; see our "Pet Stake" review for a picture of her) and the occasional stray airplane flying overhead en-route to the Buffalo airport. The effect was quite attractive year round but particularly stunning in the quiet winter nights after a light snowfall which reflects the LED lighting brightly illuminating the entire area.

The lens protecting the photocells seemed very fogged after two or three years' use. The lights themselves are a favorite perch for Robbins and other birds and that might expose the lenses to a different type of 'raining acid.' Also, moths and other cocoon-forming insects love the inside compartment around the battery and electronic circuit, probably because it's a warmer (dark colored) protective housing for them too. The problems that we have with these solar-power lights might be related in part to the combined bird and insect attacks, but then we don't live in a desert. At least part of the lens clouding seems to be from the use of UV-reactive plastic for the clear cover protecting the photocell because it won't clean off with soap and water but does scrape off with a razor blade along with a thin film of plastic. (Or maybe it's a reaction to bird-acid, but we aren't planning on running any tests to explore this possibility without the support of a large government grant!)

Bottom line: If you can find them at our low target price, we still consider these solar-powered yard lights to be a good bargain. We've just damped our enthusiasm from the first two years when they seems to work flawlessly except for a few battery replacements. By the end of the second Buffalo Winter Test, they're definitely a mixed lot of the good, the bad, and the shine-only-after-a-bright-day (every with replacement batteries!) lights.


Compact Fluorescent Light Bulbs Light the Way to a Brigher Future

09/06/10 | by theprofessor [mail] | Categories: Lighting, Electrical, Solar Power

Link: http://HarborFreightReviews.com/HRFreviews.html

Compact Fluorescent Light
Our review of Harbor Freight's 45-watt solar panel kit prompted a brief commentary on the merits of compact fluorescent light bulbs (CFL) within the context of low-energy consuming devices. Rather than append that article with what might be considered a rather lengthy commentary given our academic propensity for prose,;) this short article is submitted as a separate commentary and review on our discussion forum.

Click here for an expanded web page version of this article complete with sample cost-savings calculations.

Most people should be somewhat familiar with these CFLs, but the continued high demand for traditional incandescent light bulbs :( suggest many have not yet seen the light :idea:. CFLs, like other fluorescent lights, require much less electrical energy to produce an equivalent amount of illumination as produced by the first-generation of household electric lighting, the traditional incandescent bulb. No longer are fluorescent lights handicapped with the ghostly artificial appearance of their bluish light or the hum of their early ballasts. Modern CFLs offer a range of color temperatures to suit the needs and tastes of any individual and they do so quietly as well as efficiently.

Color temperature refers to the appearance of light usually described as warm or cool. Warm lights are somewhat reddish in appearance and are the color temperature most Americans have grown up with from the incandescent lighting that fills the typical American home. Cool lights are more bluish in appearance and are the color that Americans are familiar with in their schools, offices, manufacturing facilities, and shopping malls. One of the aspects that had slowed acceptance of fluorescent lighting into more private homes is the artificial cool appearance of traditional fluorescent lighting. New, compact fluorescent light bulbs (CFLs) are available in a variety of color temperatures, including warm illumination which emulates traditional incandescent lighting and full spectrum illumination which is more natural, emulating sunlight. Of course the cool white is also available to light up those wide-open spaces.

Compact Fluorescent Light Basics

Compact fluorescent lights (CFL) 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.

Approximate Equivalence in Lighting Power between Compact Fluorescent Light Bulbs (CFL)and Conventional Incandescent Light Bulbs

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
105-watt CFL = 420-watt incandescent

The numbers are downright staggering: A CFL uses about 1/5 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.

What's in a Watt?

The commonly used term "watt" is actually an expression of electrical energy not light intensity. "Lumens" and "candlepower" are the terms that better describe the actual brightness, but they're unlikely to supplant "watts" anytime soon because of the years of use this term has seen in reference to incandescent light bulbs. Typical CFLs produce around 50 lumens per watt, while incandescent light bulbs produce around 10 lumens per watt. A candle produces 0.3 lumens per watt and T5 and T8 tube-style fluorescent lights can produce around 100 lumens per watt. (A low-pressure sodium light is actually the most efficient light source currently available producing up to 200 lumens per watt. Want to read next to one of these lights?)

FYI: When translated to physical energy, 1,000 W (1 kW) is approximately equal to 1.34 hp of work. (So I guess a 1 kW light bulb could pull a horse? -- viz., produce more "work.")

Candlepower like horsepower has an obvious derivation: the light intensity is compared with the brightness provided by a typical candle. The actual unit of measure is "foot candles" where 1 foot-candle is the amount of light striking an object one foot away from a lit candle. The more scientifically standardized term "candela" is approximately equal to one foot-candle. Lumens is another popular measure with each candela approximately equal to 12.57 lumens. (Actually, it's all a lot more technical than presented here, but this should give you a general idea of the equivalent "lighting power" of these measures.) Click here if you would like a simple, straightforward explanation of these terms devoid of the overly complex technical rhetoric that hamstrings the Wikipedia these days.

Most of the "watts" in incandescent lighting is actually wasted as heat energy with only about 2% going towards providing visible light Nonetheless, for a given "wattage" different incandescent lights typically provide comparable the levels of illumination. Hence, we all know what a typical 25-watt refrigerator light compared to 100-watt reading lamp looks like and understand how they're both dwarfed by those awesome 500-watt floodlights. For this reason, CFLs are often described by their equivalence to a given wattage of incandescent light, even though they actually consume about 1/5 the energy and therefore their real wattage is much lower lumen-for-lumen.

FYI: Fluorescent lights are actually 10 to 20% efficient compared with the typical incandescent light bulb which is only around 2% efficient. The actual efficiency of a fluorescent light depends on its specific design, with industrial fluorescent lighting enjoying the highest ratings of around 20% efficient, while CFLs are usually on the lower end at only 10-15% efficient (Remember, CFLs have design limitations because of their compact size.). Still, CFLs are 4 to 5-times more efficient than the typical incandescent light.

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. Harbor Freight's inexpensive lamp and appliance timer that we recently reviewed works very well with CFL as well as standard fluorescent and incandescent lights.
  • 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 (cool white is used to describe cool lighting with just a bit warmer hue that lacks any bluish overtones); warm better simulates a conventional incandescent light which some 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-grow light; CFLs even come in an assortment of primary 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), in replacement bulb costs, and in 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).
  • Fourth, the life of CFLs, like all fluorescent lights, can be greatly shortened if they are turned on-and-off frequently. It's best to leave them on if you'll be returning to the room within 15 to 30 minutes. They consume little energy during that additional time and the 'stress' incurred during starting and re-starting is more detrimental to the CFL's life-expectancy than the extra fractional kW in electrical usage is to your wallet or to the environment (e.g., 0.0075 kW for a 15-watt CFL left on for 30 minutes consuming a little over a penny's worth of electricity by our expensive Western New York utility rates or around half a cent in the rest of the country).
  • Fifth, CFLs remain somewhat larger than standard incandescent light bulbs, so there are some fixtures where they simply don't fit properly.

Modern CFLs are available in styles that replace most incandescent lighting including full-spectrum, shatter-resistant floodlights, and a rainbow of basic colors. There are even CFLs which work in three-way sockets giving three different levels of illumination and CFLs which emulate halogen lighting. And they all produce flicker-free, quiet lighting in their compact packages which fit standard lamp sockets eliminating the last excuses for not going green and making your contribution to saving-the-planet while saving yourself some money too.

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.

One Last 'Note'

We wrote this entire article discussing CFLs without mentioning that greenhouse emissions are killing our planet or without boring you with statistics on how if everyone switched to CFLs it would decrease these poisonous gasses so dramatically as to save-our-planet with one dramatic move. Well, it wouldn't. We're in more trouble than that, unfortunately. But even 25% of the population switching to CFLs would make an important difference and slow progression to the big hothouse as well as get the rest of the public more aware of the importance of conserving energy (e.g, social modeling and flocking effects). The title of this article should be self-explanatory aptly revealing our position on this topic -- see the light yet?. B)

Here at Harbor Freight Reviews we feel that everyone should do what they can, but nobody needs to surrender that comfortable 20th Century lifestyle we've all come to love and enjoy. Where you can switch to CFLs do so and do so now; start saving-the-planet today. Where you need or just want to bath in the warmth of a truly warm light (remember, 98% of the energy is produced as heat), go for it. Meanwhile, do what you can and you can easily switch to CFLs for most lighting. (End of editorial commentary ;) for now.)

Click here for a wide selection of energy-saving CFLs are discount prices. Remember that the higher initial cost is quickly recovered in energy savings and that you're doing the right thing by helping to save-the-planet too.

Bottom line: Compact fluorescent light bulbs (CBL) are the only way to go for most applications including not only solar but conventional grid-powered lighting. They provide equivalent illumination at much less cost, both energy-wise and replacement-cost-wise, and they do this while helping to save-the-planet.


Lamp and Appliance Timer

09/04/10 | by theprofessor [mail] | Categories: Hot Buys, Lighting, Electrical, Security

Link: http://HarborFreightReviews.com/HFRreviews.html

Mechanical Electrical Timer
Item: Lamp and Appliance Timer
Item number: 40148
Retail price: $5.99
Frequent sale price: $3.99
Target price: $3.99
Item link

We love this small 120VAC timer for its cost and simplicity. It has dual 120VAC outlets with a manual override switch. The on/off times are easily set in 15-minute intervals using push-down tabs. It's reliable and suitable for use with fluorescent lights including CFLs. This latter feature is especially important because electronic timers without mechanical relays cannot be used with fluorescent lights, except for the more expensive dimmable CFLs. The heavy-duty switch mechanism can handle up to 15 amps or 2,000 watts which is quite a bit of power for this small package.

We almost feel guilty setting our target price so low at $3.99. We actually thought that the normal retail price of $5.99 was fair, but hey, Harbor Freight sets the best-buy prices and we simply exploit the opportunities. :)

We use several of these timers for controlling fluorescent and LED plant lights. We also use these for back-up security lights, although most of our house lights used for security purposes are controlled by X10 circuitry which better emulates the 'lived in' look while away. At our target price of $3.99 these lamp and appliance timers are practically a giveaway.

Bottom line: A great little timer as cheap as you can find and not expect the plastic components to meltdown. Buy several at our target price and save money at Harbor Freight.

Click here for great prices on energy-saving compact compact fluorescent light bulbs.


45-Watt Solar Panel Kit

09/03/10 | by theprofessor [mail] | Categories: Hot Buys, Outdoor Living, Lighting, MoHo/RV, Solar Power

Link: http://HarborFreightReviews.com/HFRreviews.html

45-Watt Solar Panel Kit
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

Some readers may prefer to read the web page version of this article. Click here to jump directly to that page which also includes expanded material. :idea:

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.
Solar Kit Parts
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 noting 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 evaluating 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 volt DC 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.)

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.

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.

Click here to check Apex Battery for prices on "solar batteries." We consider these specialized batteries too expensive for most applications and prefer deep-cycle batteries purchased on-sale locally. If your solar-power storage battery is located indoors around people or areas exposed to sources of ignition (e.g., flames, electric motors), be sure to use the sealed type which doesn't emit hydrogen gas when charging. FYI: Apex has good prices on other types of batteries (e.g., scooter, UPS) which they ship for free when the order totals over $50.

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.

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 of 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.

  1. Tax and local utility company incentives are very important for making investment in alternative energy sources cost effective.
  2. Keeping the initial cost low by shopping around for your supplier is also very important when possible. (Thank you, Harbor Freight.)
  3. 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.

At 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 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 support two brighter 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 yard lights to solar power. 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, then 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 B) -- 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 (pun intended B)) 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 normal 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. 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.


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:

  1. To get electricity to areas that are off the grid and otherwise would remain without power.
  2. To have a source for a limited amount of emergency backup power.
  3. To help save-the-planet by decreasing your carbon footprint.
  4. 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.)


Oscillating Multifunction Power Tool

08/29/10 | by theprofessor [mail] | Categories: Hot Buys, Power Tools

Link: http://HarborFreightReviews.com/HFRreviews.html

Multifunction Power Tool
Item: Oscillating Multifunction Power Tool
Item number: 67256
Retail price: $59.99
Frequent sale price: $39.99 (with coupon)
Best price: $29.99 (special 3-day sale)
Target price: $34.99 (with coupon)
Item Link

This is another review that we're posting too early, before we've had a chance to really evaluate the tool. But because one of our main purposes here at Harbor Freight Reviews is to help our readers save money and to get the maximum bang-for-the-buck possible and because this item is currently available at its rock bottom lowest price, we're posting this "review" primarily as a price advisory. Be aware that Harbor Freight currently has three or more different coupons valid for this item, selling it for at least three difference prices. If you're an experienced Harbor Freight shopper or have read our Notes for the Novice Shopper: Everything has Three Prices commentary you already know that this is standard practice at Harbor Freight. We love'm, but they do make shopping a challenge for us 'maximizers' who strive to get the lowest price ever possible for each item.

Harbor Freight is currently offering this tool during their 3-day tent sale for $29.99; hurry, the sale lasts through 29 August (hence our hasty post). You should be able to combine this 3-day sale price with a 20%-off coupon grabbing this tool for only $23.99. The next best price is $34.99 at their retail outlets with a coupon which has been sent out in a flier and which is also available online here (valid through 16 September). Any of these three prices get you a great deal on this fine tool. They are also selling this tool with a $39.99 coupon to the unwary.

Other online reviews and comments are generally very favorable for this tool. It does perform an amazing array of tasks with the various attachments included or available for purchase from Harbor Freight. We've only used the semicircular cutting attachment so far to cut through thick, hard nylon. We had to make deep cuts recessed into the piece and the tool performed this task well which would have been impossible with most any other tool.

This multifunction tool packs quite a bit of power in a small package, so you should expect some vibration and heating as you power through your project. Take breaks frequently while working, not just for yourself to recover from the vibration and hand fatigue but also for the tool to cool down a bit. Keep your hand away from the air vents in the front of the tool which are necessary to dissipate the heat generated by its motor. And of course keep your fingers and other body parts away from the working end -- it does cut very well.

Oscillating tools such as this multifunction tool oscillate and that produces a lot more vibration that what you get with most hand-held power tools. Be careful to take frequent breaks to avoid stress injuries while working with the tool. And as noted above, the tool likes an occasional break too.

OK, we're just beginning to test out this tool and we even have more to say that time permits now, but the sale is ending soon so we have to post our comments. (The 3-day tent sale ends 29 August, but the coupon is valid through 16 September albeit the tool cost more then.) Harbor Freight allows customers to return items within 30 days of purchase and we should have further tests completed and posted by then. If not, well, you're performing your own tests with this tool and they are usually the most reliable opinion for your purposes.

Bottom line: Get them while their hot (oh, a very bad pun if you've read our review :roll:) at their best ever price. Harbor Freight's oscillating multifunction tool is a must have item for all home workshops.


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This review and discussion forum was created for those of us who love Harbor Freight(tm). It's well known to those who frequent the store that the prices are always cycling up and down, and most of us usually accept it as a personal challenge to get the lowest price possible. It's also well appreciated that some products at Harbor Freight are good, even very good, but that many others are also substandard, yes, even junk. This review and discussion forum is dedicated to the savvy Harbor Freight shopper and is intended to provide some guidance to the best and the worse buys. Similar products from other retailers will also be reviewed from time-to-time. Please be advised that everyone's experience is unique, and what works well (or doesn't work at all) for the reviewers here may or may not suit your personal needs. With this caveat and with notification that Harbor Freight Reviews assumes no liability for the accuracy of information provided here for educational purposes, enjoy the forum and good 'sa(i)ling' at Harbor Freight!


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