Let’s be optimistic and say in a few years our solar panels will hit around the maximum theoretical conversion rate at 85%
Show me a pathway to do it. I am not familiar with any technology that can acheive even 50%, let alone 85%.
Let's remember also that it isn't just efficiency, it is efficiency for the price. Thin film is less efficient than crystalline silicon, for example, but it is cheaper to produce.
Multiply by 24 since the article said it was averaged over the entire 24 hr period
I think your math might be faulty too. @240 watts per m2 per day in Arizona as per the article you are averaging 10 watts per hour, 240/24. That is 10 watts an hour per m2 over that period.
I don't see the point in going to square feet. But that amounts to less than a watt per square foot per hour, not 22.3 watts.
Evolution has had about 3 billion years to work on the problem. Photosynthesis isn't good for more than about 5%.
1400 watts per square meter with no atmosphere
We live at the bottom of an atmosphere.
The actual figure varies with the Sun angle at different times of year, according to the distance the sunlight travels through the air , and depending on the extent of atmospheric haze and cloud cover. Ignoring clouds, the daily average irradiance for the Earth is approximately 250 W m -2 (i.e., a daily irradiation of 6 kWh/m 2 ), taking into account the lower radiation intensity in early morning and evening, and its near-absence at night.
http://en.wikipedia.org/wiki/Insolation
Right now, I think most panels are more towards 25% conversion rate.
Your estimates are incredibly rosy. Slash that in half.
Typical solar panels have an average efficiency of 12%, with the best commercially available panels at 20%.
And there are other factors at play as well.
Uncertainties in revenue over time relate mostly to the evaluation of the solar resource and to the performance of the system itself. In the best of cases, uncertainties are typically 4% for year-to-year climate variability, 5% for solar resource estimation (in a horizontal plane), 3% for estimation of irradiation in the plane of the array, 3% for power rating of modules, 2% for losses due to dirt and soiling, 1.5% for losses due to snow, and 5% for other sources of error. Identifying and reacting to manageable losses is critical for revenue and O&M efficiency. Monitoring of array performance may be part of contractual agreements between the array owner, the builder, and the utility purchasing the energy produced.
http://en.wikipedia.org/wiki/Photovoltaic_system
In a sunny place like Arizona, you get an average of 240 watts of sunshine per square meter over the course of a 24 hour period. Throw in photovoltaic efficiency ranging from 10-20%, and you are only getting an average 24-48 watts out of a square meter of PV. A typical house might range from 110 to 300 square meters of living space, so the roof area would be about as much, unless it is a two story house, in which case you are talking about half. Taking a nice-sized 2000 square foot single story house, which is 185 square meters, you only get 44.4 kilowatts of total solar energy in sunny Arizona. If you have really efficient solar panels that can hit 20% (and I don't think those are very common), you are talking about only 8.8 kilowatts of daily output.
A Nissan Leaf battery delivers 90 kilowatts of power.
http://en.wikipedia.org/wiki/Nissan_Leaf
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