Scam Alerts

Re: Scam Alerts

So far, except for some seriously technical uses (like space shuttle)--Painting things light colors will keep the surface from getting as hot under the sun and better reflect UV (colors towards red tend to degrade faster because of UV absorption).

I don't think there is any paint out there that you can slap on the side of a home and save any money on your heating bills.

From this thread:

Cooling Solar Panels for Improved Power Output (clipped from thread)

BB. wrote: »

Niel is correct... Generally what radiates heat well also absorbs heat well.

I remember years ago that NASA spent a bunch of time and money trying to find the right "paint" that would reflect heat from the sun well and radiate heat to space well... If I recall correctly, the best material was not much better than any of the other options.

In the case of solar panels, I am not sure that it would make any difference at all... You have a slight insulation effect (paint is not a good conductor of heat, plus the back of the panels are plastic--also not a good heat conductor). And, you may end up with warranty problems--paints have solvents and additives which could attack the membrane materials on the back of the panels.

If you want to keep your panels cool--ensure there is at least 5-6 inches of airspace behind/under the panels and a way for air to circulate.

Ah--found one NASA report from 1983 (PDF file)... Has a whole bunch of information about colors/materials and their absorption and emission of heat. Hmm, looking at the results--I would probably be more tempted to paint the back of the panels white than black... Very similar emission results, and much less absorption with white.

But of so much variability (materials, coating thicknesses, the way it is applied, mounting differences, etc.)--You would really have to do A/B testing of your specific panels and coatings.

Don't think it is worth doing it...

-Bill

Re: Scam Alerts

See post #30 above from "Russ"... He tried it on a job and found SuperTherm did not add any measurable insulation effect.

I find it difficult to believe the claims myself.

-Bill

Re: Scam Alerts

We had a thread here about 1 year ago:

Magniwork

I still like my comment: Your money will power their home for a month...

-Bill

Re: Various Power Savers (Redux)

TypeDr wrote: »

Please bear with me as I am a total newbie here. I should have figured that there would already be discussion and consensus regarding the Power-Save 1200, the KVAR PU-1200, and others, all in the $350-$399 price range.

For the unit its self (motor run capacitor inside a metal box with wires and a pilot light--Probably ~10x -20x its retail worth.

Now--I am not sure, but that cost may include a person coming out to your home or business and sizing the unit to your needs... More on your "needs" later.

There's also one brand, the Electric Saver 1200, which says it does the identical job as the first 2, but for $97.75.

Only 3x-6x over priced...

1. Would whatever savings (if any?) on the electric bill be worth 1/4 the price? Or are the whole lot of these just hollow promises?

As with any good sales job--there is a bit of truth that is, usually, spun way out of proportion to any real return on investment.

Short answer, in the US, probably no utility charges for "poor power factor" for any home, and probably most small businesses...

If you owned an oil refinery with megawatts with of electric motors--you bet your bottom dollar that utilities charge utilities based on VA and kVA/kVAR (all basically the same thing) and if you could cut ~45% of your industrial power bill, you would install banks of capacitors to reduce VA/kVA usage.

So the simple answer is you will save zero to pennies or a dollar or so per month on a typical home power bill.

2. KVAR posts a Fact Sheet from the Program of the U.S. Department of Energy, which is attached at the end of this post. Is this really from the DoE?

Possibly--The claims are true--as far they go... If you have big motors (A/C, industrial pumps, agricultural pumps, etc.), and your motors are not already power factor corrected (more small appliances are coming with power factor correction), and you are a (typically) large business that is charged for poor power factor--You will hire an electrical contractor to measure and calculate how much capacitor to place you each of your loads--and most likely these PF correction capacitors will be switched to turn on and off with the load.

Note that "bad power factor" from a running motor can actually become "bad power factor" from a capacitor that is permanently "on".

So, if you have an A/C system that runs during the summer--and put a big capacitor on there but don't switch the "Power Saver" unit--When the motor is running, you are near PF 0.95 --- But now during the winter you still have the capacitor connected so instead of a "-"0.65 power factor, you may have a "+"0.65 power factor--the utility will still charge "extra" if you follow their rules to run the capacitor load.:roll:

Plus you can have bad power factor because you have lots of computers, florescent light bulbs, etc. -- And the capacitor will not help at all--because these are "non-linear" current loads:



A capacitor will do nothing to change the power factor of this type of load (Note: 120 VAC voltage is yellow line. The Blue Line is current from the load...)

Anyway, we can go down the details if you have more questions. AC power and all of these issues are actually a very complex set of mathmatics.

Take a look at the discussion about power factor, power supplies, and generators. It does matter--but you have to understand the underlying issues and how they affect your particular setup.

-Bill

Re: Scam Alerts

Interesting.

Where is your planned installation?

It may be that the utility does not care (if you have a listed GT Inverter)... Usually the local building department/fire insurance company cares about using listed components for Home/Business electrical wiring including the solar array.

I know some folks live where nobody really cares or does electrical inspections--Or, in many (most?) cases, the building inspector may not even climb on the roof to check if Listed components are used.

-Bill