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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."
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."
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
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.
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.
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.