Solar breakthrough? Why didn't anyone think of this before?

This may be the multi-layer solar collector I have been hearing about. They catch a different wavelength with each layer.

 

A long way from a Home Depot near you. In the solar business we have seen lots of promising ideas come along,,,,few have reached fruition however. I hope they can make a go of it and make some money and push the envelope. In the meantime, conservation, followed by Solar water and space heat, followed by large scale wind, followed by PV solar is what makes the most sense today.

PV solar is Sexy, conservation is not, but it makes no sense to generate electricity with PV, only to consume it with wasteful practices, inefficient lighting and appliances and industry.

Icarus

 

You hit the nail on the heed, mate. The only thing that will really fix that is expensive energy. People find it really hard to conserve when the perception is that there is plenty (read cheap) of something. Seems to be human nature.

 

I'm sorry but that has to be one of the worst phrased statements I have heard lately. Solar in not Sexy, it works! To generate with out also reducing is stupid. They go hand in hand. One of the topics that was brought up in the planning stages of this project was reduction in consumption!!!

I personally installed a 7.5 kW system in August of 2004 on my home and to this date in time I have generated over 60,000 kW of power. I am grid tied and my surplus feeds the grid. My power meter runs backwards during this time and I pay $0.00 for my daily power. In addition, I went through the house, "Greened" up the lighting, when it came time to replace appliances, I went "Energy Star" My yearly power bill is now about $300 TOTAL, due to Winter/Summer sun position. The system will run 25 years plus, and has added considerable value to my home when I eventually sell it. If the new homeowner does not want the Solar, big deal, I unbolt it from the roof and take it with me! Then reinstall it on my new home!!

If every home in the USA installed a minimum 2 kW system, the energy problem, would be that much less of a problem. Sure you need power plants at night, but during the daylight hours the power plants would not have to run as hard as they are now doing. Flex Alerts, a California thing, could be thing of the past.

As for those people who do not like the look of the solar panel, fine, do not install a system on your home, but you can have the privilege of paying 4 times the rate for your power consumption!!!

Solar works, and as time goes by, it gets more cost effective, and is a very viable option for power!


Just a thought ...

73 de Pat KK6PD

 

True, but it really is the foundation upon which everything else should be built (I'm including efficiency in conservation here).

 

Bah, there's another easy way to improve efficiency of cells.
Use three mirrors, mounted for AM, Noon, PM, that are angled and reflect sunlight to the solar cell, which is mounted upside down.

On the cell's back you put heat sinks.

So one 4' by 8' solar panel array with three mirrors of same size, will be much cheaper than buying three solar panel arrays (3x 4' by 8').

Plus, instead of the solar cell getting dirty, the mirrors do, and it's easy to wash them.

I've played around with small sized arrays, and those mirrors you put on a bedroom door. Shining the mirror (it bends a bit for concave effect) concentrated into a 1' by 1' solar cell makes the miliamps jump.

I'd so do that if I wasn't living in the land of plenty (snow).

 

Quick though on "focusing mirrors, and heat sinks" Mirrors only gain a slight advantage because much is lost in cell efficiency due to extra heat. (Pv cells put out significantly less power as their temp rises) Heat sinking is tricky at best, and nowhere have I seen anyone who has done it with cost effective results. We have tried the idea of using panels that are water cooled, using the waste heat to heat swimming pools for example. Didn't work very well. Using it for domestic hot water makes the panels run at too high a temp. If people like Evergreen or Keocyra haven't been able to do it there is a reason.

As for Solar being sexy. I stand by my comments. Many of my clients are all ready to spend big bucks on a PV system. They like the idea of "doing something" and they also like the idea of having a "solar billboard" on their house. When I sit them down and run the numbers they begin to blanch. Also sitting around their big houses filled with incandescent lights, fancy, poor efficient appliances, lights on 24/7, electronics on 24/7 and on and on and on. The shear volume of electrical waste in the average American house is astounding. As Tripp suggests, as long as people think it is cheap, they will waste. How many people do you know that have a fridge going 24/7 in the garage just to keep a few beers cold? How many people look for and find the phantom loads in their houses?

KK6PD, You understand the ins and outs and have made the choice and I applaud you for it, but in fact you are in the minority. You yourself have a 7kw system, which I would guess cost you somewhere north of $50k I would humbly suggest that if you have a system that large, there are lots of places you could conserve as well. $50k would buy a ton of extra insulation, solar water and space heat, VERY Hi-ef appliances etc.

We live with a 200 watt off grid system for ~ 6 months a year! (~400watt/hours/day,,no tv, but internet, radio, lights water pump etc) The other 6 months we are on grid, and consume about 10kwh/day.

Our rule to clients is conservation first, second, and then third. Then and only then do we suggest PV solar. We don't have to go back to the caves, but even if we can produce Xkwh we can't coninue to live in McMansions consuming more than we should,,,just because we can. (I am not directing this at you KK6PD, but to all of us in general). I would love to build a huge PV system and sell 98% of it back to the grid, but to build such a system just to sustain a wasteful lifestyle is crazy

Icarus

 

Icarus, dude NO OFFENSE taken, You have some VERY valid points. Just to let you know, I have spent 75k for the install, including raw stock aluminum, nuts, bolts mounts etc. ( Yes I really did build everything from the ground up!!) 30 days after being tied to the grid, I received a 50% rebate from the city of Glendale, CA, $37,500.00. That went right into the loan principal. Over the next couple years the tax credits added up to around 4k or so more , so the total out of pocket was 29k!!

I have insulated ALL walls interior and exterior, had the Attic Spray Foamed, very smart move there, My indoor pool is heated with a Solar water heat exchange package on the roof, and running the pump 1 hour a day gives me 90 degree water!!! I use a H2O2 based chemical system, so no chlorine smell!! I replaced ALL the windows with Dual glazed windows. Put R-30 in the ceiling and R-19 in the walls. Finally I painted the roof with Henrys 287 which reflects a lot (not sure what %) of the heat transfer thru the roof sheathing!! As a side note, the insulation is so good, without A/C, when its 101 outside, its 78/80 inside !!! NOT BAD!! With all that, 7.5 kW breaks almost even. As I make further improvements to the home I am hoping to break even!!! Maybe even collect a check from the Glendale Water & Power.

And the whole point being that you can lead some semblance of a normal home life with a proper perspective of how much power you are going to allow yourself to use to make your self comfortable. I could assemble the same system today with a smaller footprint, for less money. Its getting better, I am really looking forward to the next 20 years of technology advances to see what happens, but of course if you observe the Mayan calendar, in 2012 the world goes Bye Bye!!!

You win some, you lose some!!

73 de KK6PD

P.S. What part of the country do you install solar in? Whats he largest package you have worked on? I would be interested in what other folks are doing!!

 

Kudo's sounds like you've got it dialed!

I used to build custom homes in the PNW, but now I work remote sites, off grid in Northern Ontario, Canada. Not much solar (on my end) in the PNW, save passive design elements and hot water. The $$ aren't there.

The off grid stuff is all one off systems for bush camps. I mostly act as a consultant. The biggest system I have done is ~1kw 48vdc, into ~1000ahr battery bank. Add batteries and you start spending money. My own system is magic at 200 watts! We use 30ahr/12vdc! Just shows how little you really need if you have thought things through.

Keep up the good work,

Icarus

PS I was going to guess ~70k but I didn't want to insult anyone!

 

If you install more PV than you use, is there any reason to conserve?

The mantra of conserve, conserve, conserve clearly applies to a scarce resource. But it is clearly within our technology to build homes that have a net zero ongoing energy impact. The grid is required for night electricity, and can be balanced with overproduction during the day.

My experience is that PV costs about the same as grid power. I know it's a mushy number, but it's close enough for planning. Given equal prices, it seems much more desirable to spend the money on the equipment than on pollution causing power generation.

 

Urging Congress to require utility buy-backs of home generated power at the instantaneously prevailing retail rate. That would do a lot to encourage home systems even without tax credits or rebates.

 

The fact is in todays world, energy in toto is scarce, expensive and polluting. Just becasue PV solar is not polluting, doesn't mean we should waste it just because it is clean. All excess PV production (which I urge) should go to reducing other forms of dirtier, expensive etc of generating capacity.

I agree that PV solar in some climates is competitive with grid power and I urge all that can be installed, but the reality is that we are decades away from having enough clean energy alternatives to waste it.

We have to start looking at the problem much more globally rather than how it effects just our lives. What I do can have significant impact, either positively or negatively (sometimes both) on the larger reality.

So my mantra continues to be, conservation first, conservation second, and conservation third! It is what makes sense.

Icarus

 

Right now? No.

When someone convinces the utility companies to actually pay customers for excess power generated? Yes.

That's one of my biggest peeves with the system now.

 

The feed in tariffs (which seem to be gaining some support here in the States) will defo change that. People in Germany are raking in scads of cash by selling their excess power for a VERY good rate. I wonder how sustainable it is economically (it's not, really) but it's a great way to get momentum for alternatives. Once people own their power and can sell it, they'll become acutely aware of how much they make/use/sell and optimize the those parameters for max profit.

It could lead to a whole new array of smart appliances that communicate with the household energy system to maximize the amount of power sold (or minimize consumption).