Comments on: A Thin Film Solar Installation Revisited

By: Uncle B

Uncle B — Thu, 17 Dec 2009 22:17:09 +0000

The astounding devaluation of the U.S. dollar and the inherent hyper-inflation spirals about to befall the American investor may prove the Solar cells to be more valuable and more useful than the current “Gold Rush”. Interest rates about to soar on loans make fixed rate investments with a solid return relative to the price of fuel based electricity may be the golden opportunity America has to present to the lucky people to live here! Nobody has announced free Uranium give-aways just yet, and I don’t hear of hoards of volunteers trying to build reactors to save the nation either! With the devalued dollar and more to come, I don’t see the value of a Solar electrical output ever losing value! Long as they last long enough to pay off initial costs, everything after that is gravy! folks pure gravy! Don’t kid yourselves A decade from mow power will certainly not be cheaper! only in a fool’s paradise folks!

By: Uncle B

Uncle B — Thu, 17 Dec 2009 22:17:00 +0000

By: ECD Fan

ECD Fan — Thu, 29 Oct 2009 16:43:17 +0000

Carlton: What makes you think that electric utility costs will increase over the next twenty years? Utility rates in Japan declined between 1985 and 2004.

http://www.uow.edu.au/~sharonb/japan.html

By: ECD Fan

ECD Fan — Thu, 29 Oct 2009 16:43:00 +0000

Carlton: What makes you think that electric utility costs will increase over the next twenty years? Utility rates in Japan declined between 1985 and 2004.

http://www.uow.edu.au/~sharonb/japan.html

By: Carlton

Carlton — Thu, 27 Aug 2009 18:21:07 +0000

Do the ROI calculations take into account the average annual increase in electric utility costs over the next twenty years? That could change the ROI time frame considerably, especially as fossil fuels begin to decline and “conservation” forces the utilities to increase rates.

By: Carlton

Carlton — Thu, 27 Aug 2009 18:21:00 +0000

By: equitydr05

equitydr05 — Thu, 25 Jun 2009 19:02:32 +0000

TruthSeeker neither speaks the truth or seeks it. He is hell bent to degrade Unisolar products and uses half-truths and inuendo to spread his vile interpetation of how things are. He lives on a Yahoo message board and has been put on ignore by most of the regulars there.

By: equitydr05

equitydr05 — Thu, 25 Jun 2009 19:02:00 +0000

By: ECD Fan

ECD Fan — Tue, 16 Jun 2009 20:17:45 +0000

A follow-up to this story has been posted at: http://ecdfan.blogspot.com/2009/06/thin-film-solar-installation-revisited.html

By: ECD Fan

ECD Fan — Tue, 16 Jun 2009 20:17:00 +0000

A follow-up to this story has been posted at: http://ecdfan.blogspot.com/2009/06/thin-film-solar-installation-revisited.html

By: TruthSeeker

TruthSeeker — Tue, 05 May 2009 23:45:21 +0000

Reuben: Fair points, but remember that the dark blue laminates, glued to the metal panes, will actually heat up the roof in the A/C season. Thus, depending on how good (and expensive) insulation was used by Magco, airconditioning costs could have actually increased. This is quite different from regular glass solar panels, which cast shadows and improve air circulation, and thus, coll the roof.

By: TruthSeeker

TruthSeeker — Tue, 05 May 2009 23:45:00 +0000

By: Reuben Thonerfelt

Reuben Thonerfelt — Sun, 03 May 2009 03:30:33 +0000

For Ms. Bennet,

In order to make Magco’s claimed $9,000/yr savings and using just 10 cents per kwh they will have to generate 90,000 KWH; i.e. average 247 KWH/day. Assuming 10hr/day active insolation they need to average 24.7kw generation, with peak of nearly double that… 50KW, which is nearly double the inverter capacity. What is their utility cost?

However, Magco’s operational data shows 29,691 kwh after 11 months operation, which projects to annual generation of 32,390 kwh. To get their $9000 savings they must be paying their local utility as much as 27.8 cents/kwh.

I opine that to include degradation losses in this thread is only useful if we also include the beneficial effect of potential savings in HVAC systems loads, especially in A/C season; and the utility savings in load and demand shedding during peak hours, typically noon to dusk. These latter should overshadow degradation factors as they are economy sensitive variables.

Reuben Thonerfelt, PE, CEM

By: TruthSeeker

TruthSeeker — Thu, 09 Apr 2009 15:59:42 +0000

Yes, my initial estimates appear to have been too optimistic. Based on the data so far, it appears that Magco’s system will generate less than 35000 KWHs in its first year of operation, so the electrical energy “savings” will be less than $4,600 a year, almost 1/2 of the $9,000 Ms. Bennett was projecting. This project turned out to be a total disaster. No wonder she has been silent for quite some time…

By: TruthSeeker

TruthSeeker — Thu, 09 Apr 2009 15:59:00 +0000

By: TruthSeeker

TruthSeeker — Thu, 09 Apr 2009 15:25:22 +0000

Paradigm_2009: PV is still a risky, very long-term investment, even after all the federal, state, and local incentives you can get. But if you have decided that you want it, what you should be really looking is the lowest all-in system cost per expected KWHs of electrical energy delivered over the warranted life of the system. A good shortcut is to simply look at the panel’s cost per Watt, but you have to be careful: First, thin-film generates up to 30% more KWHs per rated watt than crystalline depending on weather conditions. Second, optimally tilted panels generate up to 30% more KWHs than panels laid flat to the roof, depending on the geographic location. Third, we have different warranties – Unisolar has only a 20-year warranty, promising just 80% of rated power (and likely violating even that promise), while most other solar panels have 25-year warranties. Forth, don’t ignore the balance-of-system costs (racks, installation costs, wring, etc).

Efficiency is just one part of the equation (the higher the efficiency, the lower the installation costs, the lower the wiring requirements, and the lower the electrical losses in the wiring to the inverter). But what good is high efficiency, if the panels are 5x more expensive that the others, or if they are warranted just for 5 years?

So, here is what you may want to do: You ask for quotes for the total cost of the system. Then you subtract any tax rebates and other incentives. Then you figure out how much electricity the system will generate over the warranted life of the system (for example, a 5KW, flat-mounted system with certain thin-film panels on a roof in the East Coast, can be expected give you 5550 KWHs the first year, and each year after that it will give you 55 Watts less, on average, due to degradation). You sum up all the KWHs for the 20 years (or 25 years, depending on the warranty), and you divide the system cost by the sum of those KWHs. The system with the lowest ratio wins!

Right now, systems with First Solar panels appear to be the cheapest by that measure (assuming you can get them at wholesale prices), but some crystalline panels are getting very close. Find some local distributors and installers and ask around!

By: TruthSeeker

TruthSeeker — Thu, 09 Apr 2009 15:25:00 +0000

By: Paradigm_2009

Paradigm_2009 — Sat, 28 Mar 2009 23:20:15 +0000

Truthseeker,

You raise some very interesting point, and I too would be curious to know what you would suggest as a better alternative. Also, if you are just against certain solar panel producers because of inefficiency, etc., which panels do you recommend? Thanks in advance!

By: Paradigm_2009

Paradigm_2009 — Sat, 28 Mar 2009 23:20:00 +0000

Truthseeker,

By: Garyods

Garyods — Sat, 28 Mar 2009 05:47:02 +0000

Thank you Michelle and Truthseeker for a lively, interesting and well thought out exchange.

While I agree with Truthseeker on many points including that currently solar PV isn’t currently cost effective. I have high hopes for Nanosolar and other solar ink companies in driving down the cost per watt into the sub $2.50 area within a few years.

As an old dude I remember how the country was sold on the interstate freeway idea, for those of you whippersnappers out there we were told that it was necessary for troop movements. It was outrageously expensive and many thought it was a waste of time. Yet it transformed our country.

I believe that a low cost renewable energy source, even if it takes 10-15 years to ramp up will have an equal effect.