HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
<<  <  Page 2/3  >  >>
GM
User Rank
Iron
Re: Solar panel entrepreneurs
GM   11/24/2011 1:02:08 AM
NO RATINGS
Jerry,

Its a great idea of plugging in a PV module into your typical household socket...but...

Pretty dangerous without proper safeguards.  Illegal in some places, and underwriting an insurance policy for this type of product would be problematic.

An AC module (typical DC module with a microinverter) would work best.  But lets say a person without much electrcial knowledge tries to do-it-yourself the project and plugs in and backfeeds too much current into a socket, feeding a wire before it is protected by a breaker.  Maybe you have some clever idea.  

If Im not wrong many people have thought about this idea cause then you could Home Dept or Lowes this product for everyone.  

The idea is great, just needs some clever engineers, lawyers, and a shit load of money to bring to the general public.

Keep working on it though!

 

Geof

fire-iron.biz
User Rank
Gold
Re: Solar panel entrepreneurs
fire-iron.biz   11/23/2011 10:20:12 PM
NO RATINGS
Jerry D.,

Obviously you know nothing about coal or world affairs so please stop parroting the nonsense media hype.  Your numbers are also wrong as your other statements.  If you wish to have a serious discussion of the topic, we must be realistic about this which means addressing the three biggest issues: 1- Start-up cost; 2- Storage; 3- Maintenance.  Those three things alone make going total solar cost prohibitive for the majority because it's impossible to even obtain an ROI.  One of my clients had three different companies submit bids to take his little 1400 sqft home off the grid, after subtracting all the rebates, incentives and tax breaks, all three bids still exceeded the combined value of both the home and property.  Even if there were zero maintenance or repair costs, it would have taken him over 50 years to just to obtain a ROI.  Fact of the matter is, unless technologies radically change, for the majority of homes, solar is not viable for anything more than a limited supplemental electrical source but is very viable for other applications.

If you want to complain about something, try complaining about the massive waste being caused by the insanity of ethanol mandates and subsidies.  Complain about the massive energy sources and materials going into landfills that's costing us a fortune instead of being properly utilized.

Jerry dycus
User Rank
Gold
Re: Solar panel entrepreneurs
Jerry dycus   11/23/2011 7:21:19 PM
NO RATINGS
Littlejohn, sadly your numbers too are wrong.  I do this kind of stuff, design and build RE equipment.

Converting PV to grid is about 98% eff.  Almost  nopne of the other numbers you have are correct.  For instance for solar power one only gets about 4-6.5hrs/day of rated power because morning and evening output is lower.

So you are suggesting we keep subsidizing oil, coal which today runs 25% of the fed budget to pay for the 30k US deaths/yr just from coal and another 10k from oil and 200k hospital stays/yr.  Then bridge, buildimng, crop, forest, stream, riverlake air ocean pollution ,etc damage. How about the mercury poisoning of fish so bad one should eat it more than 1/wk now.

Then there are the oil wars, supporting oil dictators and terrorists, costs only because of oil. Then the $500B for overseas oil sucks jobs that could be made here.

There is NO such thing as clean coal. It's filty, poisonous from mining to use.  To say that you would have to be delusional or work for big energy. Which are you?

Nukes are way too expensive as I can do 5x's as much RE for the same cost. Once smaller, far safer like the Hyperion nukes can be ok. Ask Progress customers how they like nukes? They are paying $.05/kwhr on their bills for 10 yrs without getting a watt of power.

Put these costs in FF's and RE is far cheaper.   Smart people will get ahead of the curve instead of parroting big energy propaganda to keep people in debt.

LittleJohn
User Rank
Iron
Re: Solar panel entrepreneurs
LittleJohn   11/23/2011 5:03:37 PM
NO RATINGS
Actually, Jerry, I think it is your math that is a bit off.  This is not to hack on Solar power.  Of all the alternative power technologies, I think Solar has the most potential.  Again, not a solar expert here, but the average over the world of solar energy reaching the Earth ia 164 Watts per Meter Squared.  At the equater it is something like 600 Watts.  So if you live at the equator and have a 12 hour day you get 7.2KWh of Energy.  As far as efficiency goes, you are both right.  There is some exotic stuff in the 30's.  There is one I have read about that is 40%.  I believe the typical silicone that is used in most panels is 8%.  As I understand it, the efficiency of most panels is determined by the lease efficient cell in the panel.  I know that manufacturing efficiencies has helped that quite a bit, but if you have a bad cell you might get a lower conversion.  I think what you are talking about (mid teens for efficiency) is achieved by using solar concentrators which have boosted efficiency as high as 15%.  I am not sure if that is commercially available now or not, but I have read about it.  So if you say you had the 15% model, so your number would be 7.2KWh x 0.15 = 1.015KWh. The next problem is that you need to convert that DC power to AC power to use in most of your house or to sell it on the grid.  That conversion is also typically not a very efficient process.  There is the cost of the convertor to consider, but I am talking more about the actual energy loss.  You loose about 10% in this conversion so you are down to 0.9KWh at the equator with a 12 hour day.  This is all assuming you keep the solar panel square to the sun all day long.  Most of us have a hard time turning our house to face the sun or tilting our roof to match the angle of incidence of the sun light through the seasons.  For that matter, most of us do not live at the equator or enjoy 12 hours of sunlight per day, particularly in the winter months.  If you use the global average, 164 Watts per meter, you get 0.265KWh/M^2.  Assuming your 4KWh is average (I have no idea on that one), you would need a roof of 15 Square Meters to meet your needs.  If that is 1/4 of your roof, great.  That again is assuming you could pan and tilt your roof to match the sun.  It also assumes you don't have a lot of cloudy days.

I again am not hacking on Solar.  I am kind of an "all of the above" kind of guy.  My uncle's cabin is 100% solar and uses 100% DC power and it is cool as hell.  My inlaws use Solar to heat their pool in Las Vegas.  I have looked at Solar for my own house primarily on the basis that I believe utility rates are going to rise.  I just think it is important to recognize it is not yet a panacea.  If you live in the Desert Southwest, have an applicaiton that needs to be off the Grid, or have some disposable income that you would like to be green with, give it a go.  I'd prefer to not susidize other peoples solar panels with my tax dollars, having the government doll out my money to companies based on political cronyism (ie. Solyndra), and forcing utilities to purchase excess power from solar adopters driving up my energy bills (if they wanted to buy it that is great, but forcing anybody to buy anything by force of law us just wrong), but I am fine with Government sponsered R&D of solar.  How about this for a compromise:  We let Oil Companies Drill for Oil, we encourage Utilities to generate as much power as they need to via Nuclear and Clean Coal, and we use 100% of the extra generated Tax Revenue to Research alternative energy until they develop super cheap solar cells that everybody will want to buy because it just plain makes sense.

 

Donald662
User Rank
Iron
Re: Solar panel entrepreneurs
Donald662   11/23/2011 3:52:14 PM
NO RATINGS
Sorry, but your numbers are way off. Solar energy at the surface of the earth is about 1 KW per Sq. Meter. Of that, single crystal solar cells will get you anywhere from 12% (low) to 21% (high) so your calculations are simply wrong. Do some homework before you post. A well constructed solar panel can yield up to 200 watts per square meter. You get conversion loses of course so the total is less than 200 watts. But your figure of 25 watts per square meter is simply not correct.

 

Jerry dycus
User Rank
Gold
Re: Solar panel entrepreneurs
Jerry dycus   11/23/2011 1:48:22 PM
NO RATINGS
 

AT your math is way off.   On the ground with the sun directly overhead power is about 1.1kw.

Even up north like Ohio in winter 50% or so gets through. One reason is low humidity which blocks light.

PV eff generally is 14-22% in present panels. Only thin film is as low as you say but they are a small market. Then again they also cost 35% less/wt.  So you trade area for cash.

It only costs $.60/wt for a gridtie inverter and retail panels are under $1.50/wt, sunelec.com among many other suppliers.

Solyndra went bankrupt because China dumped $b's of panels at below cost, dropping panel prices by 65%!!  How would your business do if your income dropped by that much?

Well shopped and especially if you install your own panels with just wiring in help, can cost less than  coal power even in many areas.

It boils down to most eff homes only need 1/4 of their roof with PV to supply it's energy needs, even get a check back from the grid.

I average 4kwhrs/day electric useage supplying heat, hot water, A/C, workshop, business, everything including my EV's so yes some only need 1kw of PV/4hrs/day to be zero energy. We get 5.5hrs/day on average. Such a grid tie set up costs me under $2k for 25-30 yrs of power.  In fact I'm thinking about building them as 1kw plug and play fold out kits you just plug into any 120vac outlet. I bet others will do this soon if they are smart.

 

Alpha-Theta
User Rank
Iron
Re: Solar panel entrepreneurs
Alpha-Theta   11/23/2011 1:01:40 PM
NO RATINGS
Interesting article.  Solar energy will definitley be in the mix of energy sources from now on but there are a few quick calculations that can give us some insight as to how important it might be and where it might actually be practical.

1st, in space with no atmosphere and pointed at the sun, there is only about 1,100 watts (about 1.5 HP) of solar energy per sq meter available.  On the surface of the earth, pointed at the sun, the average energy available is only about 250 watts / sq meter. The efficieny of solar cells, while improving, is less than about 10% so that gives only about 25 watts / sq meter that is available (during the day when you are pointed at the sun).  So, it takes a lot area to provide enough power an average house which needs maybe 1 to 2 KW and forget trying to power automobiles directly in anything close to the configurations we are used to. 

Also, in addition to the cost of the cells themselves, you have the cost of converting the power to a useful format, especially if you want to try to sell back excess energy to the grid. We might also ask exactly how green are solar cells when you consider that a large factor in thier cost is the power needed to manufacture them.  I don,t claim to be an expert on solar energy so my numbers may be off some but considering these factors, I'm not too surprised Solyndra went belly-up. I'm just surprised our government lent them the money to fail. 

While I think there is a place for solar cells, I'm just not sure where that will be when the "new & innovative" factor wears off.  It seems like converting solar energy using giant (acres) collectors in the desert that heat water to make steam might be a more practical approach in the long run.

I appreciate any insight so comments welcome !!

Ann R. Thryft
User Rank
Blogger
Re: Solar panel entrepreneurs
Ann R. Thryft   11/23/2011 11:47:22 AM
NO RATINGS

How disappointing that the kid's "discovery" was based on slipshod methodology. However, it still seems likely that studying the way in which solar energy is harvested by the original collectors--trees--is a smart idea.


Beth Stackpole
User Rank
Blogger
Re: Solar panel entrepreneurs
Beth Stackpole   11/23/2011 10:58:51 AM
NO RATINGS
It is a shame that his theroy is being debunked and in such a public forum. I agree with you, burn0050, that there are likely merits to his ideas and hopefully scientists, solar experts, and perhaps some entreprising students, including this one, won't be deterred and will continue to explore the idea and make progress.

Beth Stackpole
User Rank
Blogger
Re: Solar panel entrepreneurs
Beth Stackpole   11/22/2011 1:42:38 PM
NO RATINGS
There's a whole movement around biomimicry, or taking cues from nature to incorporate into design and engineering. Some of the effort is aimed at achieving more sustainability in  design while some of it can simply be chalked up to taking cues from the master: Mother Nature. I did a story a few years back on an innovative flooring company practicing the approach. Check it out.

<<  <  Page 2/3  >  >>


Partner Zone
Latest Analysis
An Israeli design student has created a series of unique pieces of jewelry that can harvest energy from default movements of the body and even use human blood as a way to conduct energy.
Made By Monkeys highlights products that somehow slipped by the QC cops.
Artificially created metamaterials are already appearing in niche applications like electronics, communications, and defense, says a new report from Lux Research. How quickly they become mainstream depends on cost-effective manufacturing methods, which will include additive manufacturing.
New software from Carnegie Mellon allows 2D objects -- digital photos, old photos, and even paintings -- to be manipulated in 3D using models found online.
Sharon Glotzer and David Pine are hoping to create the first liquid hard drive with liquid nanoparticles that can store 1TB per teaspoon. They aren't the first to find potential data stores, as Harvard researchers have stored 700 TB inside a gram of DNA.
More:Blogs|News
Design News Webinar Series
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
7/17/2014 11:00 a.m. California / 2:00 p.m. New York
6/25/2014 11:00 a.m. California / 2:00 p.m. New York
5/13/2014 10:00 a.m. California / 1:00 p.m. New York / 6:00 p.m. London
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Aug 18 - 22, Embedded Software Development With Python & the Raspberry Pi
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Last Archived Class
Sponsored by igus
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service