Monday, November 30, 2009

3D Solar panel prototype: 25% more power

I just completed a major goal of the year: to have a prototype 3D Solar panel tested by an independent testing laboratory. As long time readers know, the patent pending 3D solar panel design incorporates reflectors and simple geometry to generate more power per cell. I selected TUV-PTL in Tempe AZ to perform the prototype testing--they were very responsive and helpful as this was my first time requesting performance verification of a solar panel. TUV-PTL sent me the results just in time for Thanksgiving.

TUV-PTL tested my 3D panel side-by-side with a half-size 2D/flat panel (the rows of cells in each panel were identically manufactured--same cell type, stringing and lamination process used). Adjusting for the difference in panel size, the 3D panel produced 25.4% more power per cell! under standard test conditions than the 2D panel.

I believe this is an excellent result that demonstrates the benefit of the 3D Solar panel design.

The 3D panel uses 36 cells and produced 35.6W (0.99W/cell), while the 2D panel uses only 18 cells and produced 14.2W (0.79W/cell). The extra power per cell is due to the reflectors and geometry of the 3D panel.

Sunday, November 29, 2009

Just going for a dip "in the quagmire"?

I am afraid President Obama is about to make the first major mistake of his administration by escalating the war in Afghanistan. To begin with, the has no "national" interest in afghanistan other than to disrupt what remains of al queda (and possibly decapitate the "leadership" of the Taliban that granted al-queada sanctuary there.) I hope that I am wrong, but adding 30,000+ more troops will just lead to more death (afghan and american) and more resistance by the afghan people. Plus to the extent that US forces are able to drive any remaining Al Queda out of Afghanistan, we will be driving them into Pakistan.

Fighting "the Taliban" is like punching'd think we would have learned this over the past 8 years...only the Afghani people can control their territory in anything other than the very short term. Nation-building from scratch... It makes me sad to see Obama give in the "shoot first, don't ask questions later" crowd.

Monday, November 23, 2009

Kennedy delivered the best keynote of the year at SPI

I was a little hard on the content of the CEO panels at the recent solar industry conference in CA. But looking back, I believe that this keynote address by Robert Kennedy Jr., to the Solar Power International conference in late October, was pitch perfect.

In about 40 minutes, Kennedy really captures the best arguments for supporting widespread renewables. Rather than reading my synopsis, go listen to it. I was and continue to be inspired.

Skip the last 15 min of the video, which are a Q & A with Kennedy and the SEIA president. This part was a little too SEIA "self-serving" for my taste.

Saturday, November 21, 2009

A new material may revive an old technology

In the last week or so I learned about a fascinating modern version of a millennia old technology.
I'm talking about thermal mass...this is a very popular technology among the passive solar crowd--stretching back to the dawn of civilization--and it involves building your home (or castle) with "thick" walls that absorb heat during the heat of the day (cooling the home) and release that heat during the cool night (heating the home).

Of course most modern buildings (with the exception of some "fringe" passive solar designs) do not call for walls that are multiple feet thick. Enter the "new material" commonly known as phase change material (PCM), which is formulated to accomplish the same thermal effect as a 12 inch wall in about a 1 inch package.

The PCM is engineered to absorb heat by melting at a predetermined temperature. The melting material absorbs a massive amount of energy (simple thermodynamics) if the ambient/outside temperature rises above the melting point. And when temperatures fall below the same predetermined temperature the PCM reverts to a solid and releases the stored energy. Basically the PCM acts as a "natural" air conditioner to provide cooling above a set temperature and heating below it. Once the PCM completes its phase change in either the up or down temperature direction it offers no "additional" thermal benefit until the surrounding temperature again crosses the set temperature. (I just point this out to be as clear as possible about what the material does.)

Basically the PCMs behave like ice that can "freeze" at room temperature (or whatever temperature you design them to work at). We all know that if you put an ice cube in a glass of room temperature water, the ice cube melts and the water in the glass gets chilled below room temperature. This is because the melting ice--the phase change from solid to liquid--absorbs heat from the surrounding water. Conversely you need to put liquid water into a freezer for quite some time to convert the liquid back to a solid--this is slightly harder to conceptualize but the liquid water gives off heat (to the surrounding freezer) as it solidifies.

There is a company marketing products that contain PCMs to the (home) building industry called BioPCM. There are other companies that produce PCMs for this and different applications, but this one offers an interesting "green" spin by using "bio-based materials" rather than paraffin derived from petroleum. Also BioPCM has specifically packaged its product for use in buildings (and it really looks easy to install--check their products page) which seems sensible, I have no idea about its cost, but the company claims up to 30% energy savings--FYI.

A thermal mass product works in conjunction with standard insulation (not instead of!), where the insulation slows the rate of heat transfer either up or down while the thermal mass stores (and releases) the heat that gets through the insulation to make a certain desired temperature "sticky".

Assuming you pick the right temperature for your climate, using a PCM can reduce both your heating and cooling bills, as well as increase comfort by providing temperature stability with its natural air conditioning properties. If you are lucky enough to experience zero climate variation, a PCM will do you almost no good, but if you experience frequent (i.e. daily) climate variation you will get the most benefit from a PCM.

Friday, November 20, 2009

IL residents with Solar PV check this out

The City of Naperville, IL has put together a forward leaning Renewable Energy Program.

The program allows residents and business to voluntarily purchase/support green energy via a $5 charge on their monthly electric bills. You can buy extra 200kwh blocks for additional $5/mth. Over 9% of eligible residents (~50k eligible) have signed on, including a couple dozen individually listed businesses.

The result is a $270,000/annual *war chest* to support renewable energy in IL via purchase of renewable energy credits (RECs). Although only 1% of this program is being used to support solar in IL (the rest supports wind and small hydro), it still offers real benefits.

Naperville has offered to buy 35MWh of solar RECs for $65/MWh (a.k.a 6.5cents/kwh) which is being aggregated and administered by the Illinois Solar Energy Assn. and Community Energy Inc. Click on the ISEA link and scroll down a page to "read all about it".

This program is intended to support small solar (<10kw) from IL residents and businesses only. 6.5cents/kwh is significant, because it comes on top of any net metered energy savings (9-12 cents/kwh depending on utility in IL).

If a solar owner *knew* they could get this amount for solar RECs, it would increase their "solar yield" by 50% or more. Assuming a $9/watt installed price of solar (a.k.a $3.6/watt after state and federal incentives) and 12cents/kwh net metering rate, a 4.9% solar yield increases to 7.3%.

A solar yield is one divided by the simple payback (in years). The more standard way of thinking
about a REC payment of 6.5cents/kwh is that it reduces the simple payback by 6 years (from just over 20 years to just under 14) given conditions in IL.

I like the solar yield terminology because it allows a person to think about investments in solar compared to other "competing" investment options. Keep in mind that the risk of a solar investment is much lower than most other investments. I'm willing to bet that the sun will keep rising long after the US government has defaulted on its "risk-free" debt (not that I think that will happen anytime soon either).

I don't want to blow this small program out of proportion...the offer only covers ~25kw worth of IL installed solar, but then the program "cost" is less than $2,500. I assume this is really a "pilot" program/offer which could in the future be adopted statewide...IL has an RPS of 4% renewables in 2009 increasing to 5% in 2010 (mostly from wind).

And speaking of 2010...the IL senate passed a bill this year enabling what is known as PACE (property assessed clean energy ?) starting in 2010.

What is PACE you ask? PACE allows property owners to borrow money from local governments to pay for clean energy improvements, and then the property owner repays the government through an increase in the property tax assesment in future years. Basically instead of going to a bank to get a loan to install your solar panels (which isn't really practical in many cases) and then using your savings from reduced utility bills to pay off the loan--local governments in Illinois can cut out the middle man. In addition your local government can offer a lower interest rate (than the bank which doesn't exist) because they are aggregating many solar installs as well as their property taxing authority.

Sunday, November 15, 2009

A resource for those curious about current topics in optics

For anyone interested in cutting edge Optics with a capital "O" I highly recommend the weekly colloquia at the University of Arizona, which is where I studied optics. A few weeks back I remember wishing that they would video tape their colloquia, because they are extremely informative and interesting ~1 hour long talks by THE experts of optics on their various subjects of expertise. Well I'm pleased to report that someone else thought of this over 1.5 years ago, and there is now an almost two year video colloquia archive.

Obviously not every talk will be of interest to everyone, but if you find a talk covering an area of interest to you, watching it will be most enlightening. I just watched a recent one on mirror technologies for giant mirrors--about how they make, figure/polish and test these massive 8 meter telescope mirrors that are cropping up in telescopes (and drawingboards) around the world--and was suitably impressed with the creativity of the human mind.
If you already understand optics this is a real treasure trove, if you are simply curious you will find the answer to many questions you've had and many more you perhaps didn't know how to ask. Enjoy.

Friday, November 13, 2009

Illinois DCEO expands incentives for solar and small wind.

Here is some great news if you are considering going solar (or small wind) in Illinois in the next ~6 months.

The Illinois state rebate granting authority--DCEO has a program that provides a rebate of 30% of the installed cost of solar (or small wind). In prior years the maximum rebate was capped at $10,000 per application, but this year its been expanded up to a total of $50,000 per application. The state rebate used to max out around a 3.3kw installation, but now doesn't cap until roughly 15kw +/- 5kw And they provide a 50% grant if you are a non-profit/public entity. Home owners and/or businesses can apply. Be sure to get your rebate application in before 4/30/2010!

This 30% rebate can be combined with the 30% federal tax credit to pay for over 1/2 the total cost of going solar!

For example say you want to install a 4kw solar system on your house. Lets further assume you are willing to pay top dollar ($10/watt) for a professional high touch installation, the total cost of the installation works out to $40,000, before incentives.

Total Cost = $40,000
State rebate = 30% of total cost = $12,000
Federal tax credit = 30% of total cost = $12,000
Cost after incentives = $16,000 (a.k.a. $4/watt)

Now solar panel prices have come down significatly (40%) at the wholesale level in the past 16 months, and retail panel prices are trending down too. You should be able find prices under $10/watt perhaps closer to $8/watt installed if you shop around/haggle a bit.

The average installed system cost in CA (where 2/3 of solar panels in the US are installed) was right around $8.2/watt in 2008 and might fall under $8/watt in 2009. There is obviously more competition in CA than IL, but many panel manufactures have dropped prices by ~$1.5/watt over the past year; see if you can't pocket some of that yourself. Every $0.5/watt reduction in installed cost (before incentives) reduces your simple payback by about 1 year! (assuming IL sun and net metering/rates)

Sunday, November 01, 2009

Solar Power International 2009

I attended Solar Power 2009 Conference in Anneheim, CA last week. It was a hugh show (for solar) over 23,000 attendees, up nearly 3x in 3 years. While the attendence numbers generated some buzz, the overwhelming sentiment was relief that the worst of the financial crisis is over, and assuming that the 3rd quarter is indicative, the solar industry is back on its feet and moving forward again.

Actually the Exhibit hall is getting a little too big--I spent my entire first day wandering the exhibit floor. I suppose I have only myself to blame...

They had a couple excellent speakers in Ed Begley Jr, (morning 1) and Robert F. Kennedy Jr, (morning 2). They were definately the highlights of the conference for me. Favorite factoid: total direct US solar subisidy= $1 Billion/yr, total direct US fossil fuel subsidy = $70 billion/yr. While it was nice to have some high profile politicos like the US Secretary of Labor (Hilda Solis) and the Govenor of New Mexico (Bill Richardson) address the conference, they didn't make any news.

The CEO panels (morning 2 & 3) were underwhelming, I think this was partly the fault of the panel moderators pushing their own agendas. The first moderator (german) was fixated on a national Feed-In-Tariff, and asked the panel about 5 different times how to institute a FIT in the US. [I am all for FITs, provided you get the pricing right--which probably is around $0.20/kwh, significantly below Germany's rate.] On the other hand I can't imagine one rate that would work everywhere from Maine to California, and Texas to Minnesota.

A more interesting argument coming from Akeena Solar's CEO (not in this CEO panel) is a solar manifesto--to reduce to zero pages--the paperwork required to install solar systems under ~10kw. I particularly like his analogy that it takes over 100pages of paperwork to install a couple kilowatt system in CA but no paperwork required to buy and use a 1,600 watt hairdryer (or an AC unit for that matter). I have argued before that there is no problem for me to turn on or off every appliance in my house whenever I want, but somehow "the grid" can't handle the intermittency of solar panels. (seems like a red herring to me)

The second moderator came in with some extreme (unnamed) analyst interpretation of the global solar market like a) only 1/2 of the panels made this year will be installed this year and b) in seven years there will only be 5 solar companies (??) --can you say straw man? And is solar too dependant on subsidies? (as if solar is the only energy industry that recieves subsidies); another question Does the solar industry need to take a page from the coal technology's "Clean Coal"? Answer--spot on--: we dont need to mislead the public!!!

In fact over the past 15 months, the wholesale cost of panels have declined over 40%, and incentives for solar have increased in many countries (especially the US 30% tax credit). The net result: in the US the end user cost of solar has fallen by 50% in the past 1.5 years.