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Solar Panel Breaks "Third of a Sun" Efficiency Barrier
Zothecula writes "Embattled photovoltaic solar power manufacturer Amonix announced on Tuesday that it has broken the solar module efficiency record, becoming the first manufacturer to convert more than a third of incoming light energy into electricity – a goal once branded 'one third of a sun' in a Department of Energy initiative. The Amonix module clocked an efficiency rating of 33.5 percent."
According to wiki this happened in July. Also, for info, they have received over 180 million dollars in grants from the government, and closed their las vegas plant in order to "focus on international opportunities".
From the article: "The solar module efficiency is the efficiency of the panel, and not the same as the efficiency of individual solar cells from which it's comprised. At the moment, solar cell efficiency can just exceed 43 percent for concentrated systems. It's the module efficiency, however, which reflects the amount of electricity a PV system can produce."
Unfortunately, this is a concentrated light solution. This means that the figures quoted for efficiency are in the presence of direct sunlight. However, this is only a proportion of energy generated from PV modules, hence the "efficacy" and therefore, total energy production, of concentrated solar solutions is less good than unconcentrated modules.
The reason comes from diffuse sunlight - light that has been diffused by the atmosphere or by clouds. This typically accounts for 10% of module illumination in direct sunlight, and much higher in the presence of atmospheric haze/cloud; even in lightly overcast conditions, you can expect unconcentrated PV to yield approx 10-15% of direct illumination yield because of the diffuse illuminance.
Diffuse light cannot be concentrated by optics, thus concentrated solar PV modules cannot utilise the diffuse light (more precisely, they can utilise it, but not concentrate it - thus if the system uses a 10:1 concentration, then the energy yield from diffuse illumination falls from 10-15% to 1-1.5%).
A boost from 30 to 33% efficiency by switching to concentrating modules could be completely wiped out by the loss of diffuse yield, even in direct sunlight. In non-direct sunlight, hazy or cloudy conditions, the yield can be reduced much more severely; resulting in a net reduction in productivity, despite the higher nameplate efficiency.
This technology is most suited to areas with the most intense direct illumination; e.g. dry areas, at low latitudes (where the role of diffuse light is diminished in proportion).
It looks like I can buy solar modules for a minimum cost of $1/Watt.
Assume an energy cost of $0.1/kWh. Assume an average of 12 hours of sunlight per day and a 50% of maximum average intensity.
$0.1/kWh * 1 year / 12 * 50% * 12 hours/24 hours = $0.01826
The monthly value that a solar cell generates is $0.01826/watt month.
Assume a yearly interest rate of 5% (monthly is 0.4074%)
Since the cost of a solar cell is $1/watt, work out the number of months that a 1W solar cell must run for to generate $1.
PV = A/i (1-1/(1+i)^n)
PV = $1, A = $0.01826, i = 0.004074
n = 62 months = 5.17 years
The warranty on the reference cell is 10 years product workmanship, 25 years linear power.
So the value of the cell over its 25-year life span is $3.15/watt, with a cost of $1/watt.
This all neglects installation and grid-tie costs, but 50% average illumination per daylight-hour is conservative in most areas. Solar cells ARE worthwhile TODAY and WITHOUT government subsidies.
Efficiencies in solar cells are irrelevant. The only thing that matters is the $/Watt.
Reference Solar Cell: http://www.affordable-solar.com/store/solar-panels/CSI-CS6P-245P-245W-Solar-Panel-STD-Frame
typically 30 years with 80-90% of the original efficiency, less if you live in a hurricane / tornado prone region.
If anyone reads the article carefully...
They state in the article that individual cells can already reach 43% efficiency - which matches the top end of that chart.
The overall efficiency of the PANEL (made up of many cells) is lower though. This 33% is the record for the efficiency of the PANEL as a whole, not for the individual cells.
25 years for reasonable ones. Of course by the time they wear out you will be able to replace them cheaply as you already have the mounting hardware and electrical infrastructure.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
http://ths.gardenweb.com/faq/lists/laundry/2004120958010854.html
"All else being equal (i.e. not including household heating/cooling issues), condenser dryers are slightly less efficient than their vented counterparts, typically on the order of ~15%. The real design intent of condenser dryers isn't improved efficiency, but the simple fact that they don't require a vent duct, permitting easy installation most anywhere (ideal for apartment dwellers, etc). "
A gas dryer is going to be much more energy efficient than an electric dryer considering that ALL the heat generated from the flame enters the tumbler. Typical power plants can only transmit up to ~40%% of the heat from their power source to the dryer heater coils.
Min energy eff electric: 3.01 lb/kWh
Min energy eff gas: 2.67 lb/kWh
Electric is 12% more efficient at point of use
Total heat efficiency including power generation:
3.01 * 40% = 1.2
2.67 * 100% = 2.67
most efficient setup would be an external venting gas dryer in a unheated space like a basement or garage since you would not be adding load to an HVAC system.
Solar cells and silicone sealant share the same property: we have no idea how long they're good for.
Originally silicone cement had a 3 year warranty. Then none failed and they made it 10. Now it's 30. I have aquariums that are forty years old that have just a microscopically thin lawyer of silicone holding hundreds of gallons of water in a glass box. We have no idea how long the stuff will last, it could be a hundred years or more for all we know.
Solar panels started being deployed in the 70s. They all still work and were expected to give 10 years service. To be sure, efficiency diminishes over time, but that's a secondary consideration to the fact newer panels are much more efficient. Somebody can use those old panels though.
Need Mercedes parts ?
Why not cite NREL's official and current chart? http://www.nrel.gov/ncpv/images/efficiency_chart.jpg
While they may have hit a new record for overall efficiency, any sort of concentrator photovoltaics require sun tracking, significantly increasing initial system and maintenance costs.
Average capacity factor for solar in the U.S. is about 0.145. That is, a 100 Watt nominal panel will on average generate 14.5 Watts throughout the year after factoring in everything - night, weather, angle of the sun, etc. In the desert Southwest it's about 0.18 (0.195 in extreme desert regions), but for the country overall it's about 0.145. The NREL assumes a capacity factor of 0.17 for PV installations in the U.S., which are predominantly in the desert Southwest.
Your quick "12 hours a day, 50% max average" assumes a capacity factor of 0.25. Almost twice the actual value.
Correct for this in the rest of your math and you get n = 120, or 10 years payback. That sounds about right as the test cases I've calculated usually wind up between 7 and 15 years.
Actually, while solar cells have an extremely long lifetime, solar modules are much more short lived. Many of the panels deployed in the 70s failed after only a few years. The main reason is that the electrical connections must survive thermal cycling. Thermal cycling also can cause delamination of materials (for example the front glass and the Si wafers). Once the module is damaged, corrosion can continue to further degrade the panel. Modern panels have more engineering to prevent module level failure, but it simply isn't practical to do accelerated testing of panels for more than ~25 yrs equivalent.
Given that most of the failure is due to thermal cycling and CPV systems get significantly hotter each day, I would expect that designing CPV systems to last for 30+ years would be a difficult problem. At 500 suns and 40% cell efficiency, that's 30W/cm^2 that must be continuously passively dissipated.
Why guesstimate solar production? Use NREL's PVWatts application: http://gisatnrel.nrel.gov/PVWatts_Viewer/index.html
Click on your city. Click 'send to pvwatts'. Enter the solar system size in kW (default is 4.0). Click calculate.
Depends a great deal of where you live, of course, because energy prices and solar radiation vary quite a bit across the USA.
Maybe not for you.
Most states have more expensive electricity than $0.10/kWh.
Also, most people who have solar go on a time-of-use rate where they can sell back power in the day when electricity is worth more and then buy it back at night when it is cheaper.
My array will pay back in about 9 years. Less with the tax rebate. And it cost less than $1280/panel installed even before rebates.
When did you measure the panel? Even at $0.10/kWh it should make a little bit more power than that during the summer. My panels are making about 800Wh a day a piece right now and the days are very short at the moment. They make nearly double this much during the summer months.
http://lkml.org/lkml/2005/8/20/95
Christ, I love it when people with zero actual experience with things dump on those things just because it makes them feel good.
Materials price:
Been dropping FAST for about three years.
Install cost:
What? You mean the cost of paying an installer? Or the cost of DIY? Neither is high.
Batteries suck:
"Batteries never die, they're always murdered". Mine are 22 years old and test the same as when new. Why? Because I don't try to fuck them like a big pile of lead-acid bitches.
Motivation:
WTF? Either you want to, or you have to, or you don't. I had to. And I wanted to. You? Guess not.
Home built panels:
Almost "why bother?", considering how inexpensive the commercial models have become.
Hail:
Are you fucking kidding me? Seriously? You do know regular commercial brands are warranted up to golf-ball sized hail? In one insurance claim, an entire RV was written-off due to tornado hail damage. The only thing salvageable? The PV array. It was undamaged.
Listen, there's a whole World of shit I know nothing about. So, what I don't so is talk about that shit as if I'm a fucking expert on the subject. Because I'll just look like a cunt if I do. Give it a try.
OK, some more math
http://www.topten.info/uploads/File/040_Rita_Werle_final_driers.pdf
efficiency of heat pump condensing dryer
best in market (according to report)
0.23 kWh/kg = 8.15lb/kWh
worst in market
0.4 kWh/kg = 5.5lb/kWh
Euro A grade requirement
0.48 kWh/kg = 4.58lb/kWh
efficiency of power generation facilities
http://www.eia.gov/electricity/annual/pdf/table5.3.pdf
natural gas = 3412/8185=41.7%
coal = 3412/10415=32.8% (roughly same as nuke plant)
distribution losses
http://data.worldbank.org/indicator/EG.ELC.LOSS.ZS
US=6%
heat energy delivered to home
natural gas = 41.7%*94%= 39.2%
coal = 32.8%*94%=30.8%
heat pump condensing dryer total efficiency based on power plant fuel source
gas @ 8.15 = 3.19lb/kWh
gas @ 5.5 = 2.16lb/kWh
gas @ 4.58 = 1.8lb/kWh
coal @ 8.15 = 2.51lb/kWh
coal @ 5.5 = 1.69lb/kWh
coal @ 4.58 = 1.41lb/kWh
heat pump condensing dryer ranges in efficiency from 1.44-3.19lb/kWh
http://aceee.org/files/proceedings/2010/data/papers/2206.pdf
gas venting dryer ranges in efficiency from 2.67-3.02lb/kWh
heat pump condensing dryers are marginally more efficient at the very high end with larger min/max range.
from same aceee.org report...
"Analysis by the UK Market Transformation Programme has reached a similar
conclusion: “In the UK, gas-heated tumble driers offer a simple and relatively cheap way to dry
laundry with a carbon efficiency that matches the more expensive and highly efficient
electrically powered heat pump driers” [Market Transformation Programme, 2007].
If the conventional natural gas dryer was further improved with modulating burner
technology, it is expected it would be superior to a heat pump dryer on a CO2, source energy
BTUs, and energy cost basis, while also offering faster drying times and a lower purchase price."