Metrics make a difference in evaluating solar and auto efficiency

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?? 5.5g/100m versus 3.6 g/100m, for a savings of 2 gallons every 100 miles. ... 34 mpg to 50 mpg is the same as switching from 2.9 g/100m to 2 g/100m ? only half as big a gain.? What moronic math & conclusions! The first case is a 34% reduction in gas consumption per mile, the second is a 31% cut. So the reduction is about the same on a percentage basis, but what counts is the charge at the pump. OTOH going from 18 to 50 MPG means a 64% reduction in gas consumed and 2/3 fewer stops on long trips. Sounds like a good deal to me. Whether the hybrid-plant cost premium is worth it almost beside the point.

Solar water heaters are one of the big answers, just some pipes and glass, Photovoltaics? Only if the Goverment can continue to subsitize them. At this rate they should be able to keep subsidizing for at least 6 more months before they are totally broke. If you are off grid then OK. On grid forgetaboutit. Coal is the answer as soon as we design a good scrubber. Until then Nuclear.

Lets keep changing how things are measured to keep people totally confused. Today people do know 28 mpg ride is cheaper than 18 mpg ride. Change to 5.5g/100m they will have to wonder if that is grams per 100 meters or what? Problem comparing the cost of grid vs solar is comparing a monthly fee to the purchase of a system. One is a fixed up front cost vs the other has an unknown fee every month forever. Armed with the knowledge $1/w competes with grid, you understand as least its costing more than grid power based only on that cost. Compare solar cost by $/kwhr is about as meaningless as you can get. What assumptions on solar hours were used? Time value of money? Grid $/kwhr cost increasing over the same time period? Are the assumptions based on the life time of the panel or electronic or what? I see tremendous opportunity to snow customers on a system, in fine print claim the output is based on the mountain tops of Colorado, yet the system is sold in Wisconsin. Claim system is good for 50 years on cost bases with 25 years warranty on panels, not including installation cost in the $/kwhr number etc. Very bad idea. Calculate the "present value cost" of the grid power using the same time period as the solar system cost, state interest rated used, assumptions on power increase cost. Now you have two "today" cost to compare basing your choices on. (Make sure you include meter reading fees!) Homes are built off grid, people are shocked at the cost to bring grid power into their home with the ongoing monthly power cost. Comparing all the cost up front allows for a simple comparison of the choices. Easily make changes in assumptions seeing how the two cost then compare.

Having a proper measurement unit to evaluate Solar Power "System"'s efficiency is necessary to overcome the hype.

Clearly, we need a systems efficiency approach to a figure of merit for PV Solar. But those who believe that it's only a matter of time before things reach parity with fossil fuel need to revisit their physics. The Quantum Efficiency of Silicon, or the various III-V mixes being used simply don't allow for another factor of 3 or 4x improvement. And right now, PV solar costs between 4x and 5x that of fossil fuel generation. There's a significant gap. Coal is plentiful. We know how to control the effluent gases, even though we're not doing a super job of doing it, right now. Even $150/bbl oil won't make PV Solar a stunning economic investment, absent government subsidies. When you add up cell efficiencies and inverter efficiencies, it makes the idea of PV-Steam solar stills look extremely interesting. And it justifies the cost of the transmission lines and real estate, to locations where they pay off. Rotating steam turbines are well proven and highly efficient. There is a forecast which says we will demand 40% more electricity in 10 years than today. The present economy may slow that growth, but we don't have that much capacity online at present. We must build plants. The question is, what, and at what environmental, social, and economic cost.

I find it encouraging that we're beginning to quibble about the details. Back when solar was $10/W, nobody cared what the inverter cost was because nobody could afford it anyway. When we start quibbling about the details, I know we're getting close.

Of course solar is not cost effective yet. It is a relatively young technology for terrestial energy production. How many people 15 years ago would have thought a disk drive would be 80 bucks for 300G when back then they were 1000 bucks for 2G. As engineers become adept at making solar for power the price will fall. Oh, and I have a friend in Hawaii paying 40c/KWh. So power pricing is very region specific.