New connection between stacked solar cells can handle energy of 70,000 suns
phys.org
phys.org
10%? 50%?
I'm taking the lowest value of 0.75 kWh per day. A quick look with google shows average yearly consumption per home is ~10000 kWh or 27.3kWh per day. So you would need about 36.5 m^2 for a home. That is about 6x6 meters and would fit nicely on a typical house, but probably not on a apartment building and much less on a skyscraper.
I assert that the problem is in the cost of the cells, cost and storage problem of batteries(no power at night and not relying on other sources) and unawareness of the general population.
I am not an expert on the this field and would gladly be corrected.
But there are many factors complicating this kind of cost comparison. For one, pv solar pays off over years, while others are paid per as pennies per kWh used. Another complicating factor is the environmental impact of oil and coal. Do you include that? If you do, how do you quantify it?
This looks like a decent article http://greenecon.net/understanding-the-cost-of-solar-energy/...
In short, solar has a long way to go. Twenty or thirty times more expensive than the traditional sources of energy. It looks like a huge breakthrough and alternative method is needed rather than incremental improvements in current methods.
What this article is about is reducing cost by using a type of solar cell that can handle incredibly dense concentrations of sunlight. So you can use a cheap lens to take say 30 square feet of sunshine and focus it on one square foot of solar cell. Once square foot of solar cell is much cheaper than 5 square metres of solar cell. But the article doesn't go into detail about how much these high capacity solar cells would actually cost at mass consumption levels.
Their stats don't line up with the final cost to the consumer. Going by average LA energy costs
http://www.bls.gov/ro9/cpilosa_energy.htm
'Los Angeles area households paid an average of 20.3 cents per kilowatt hour (kWh) of electricity in July 2013, up from 19.3 cents per kWh in July 2012.'
Whereas, according to the linked article,
> 1 ton of coal costs $36 = $0.006 per KWH | 1 barrel of oil costs $70 = $0.05 per KWH | 1 cubic foot of gas $0.008 = $0.03 per KWH
Which may well be true, to the people with the powerplants, - but consumers can take advantage of the price of solar much more directly.
Assuming that we buy into their stats about the price of solar, (which I'm now a bit reluctant to do,) things look a bit happier; more like 1.7 times the price rather than twenty or thirty times.
They also completely ignore the cost to build and maintain a coal power plant as well as transportation costs for coal. Consider the lack of west coast coal mines has a significant impact on the west coasts electricity costs.
Worse they use a reduculus 45,000 for 2kw system which is ~3 times the going rate. Solar is far from cost effective in Alaska but there are places in the US where solar + grid is cheaper than grid power.
PS: Off grid solar is not worth it, but neither is off grid coal so it's a pointless comparison.
Off-grid is harder since there is a ton of maintenance that goes on with battery systems. That said, for a single family detached home, we're getting close to the point where there would be enough volume in the foundation / floor for charge storage in "super" caps. When we were installing the 5.2kV system on our house we looked at Maxell supercaps and it would have added another $122,000 to the install but you could have nominally fit them under the house (about 1800 sq ft of crawlspace). The reason I think such things would be better off being built into the foundation is that you really really don't want a rat to urinate on your system and cause a (brief) short. A lot of energy that can come out way to fast to be safe.