I like Sudia Design Labs’ “Sun Table” for obvious reasons, and I think it shows the way a lot of our objects will try to eke out a secondary use for themselves in the future. But Popular Logistics‘ calculation shows why it’s not exactly practical yet: The $2,200 table would generate about $30 worth of electricity a month on average, paying for itself in about six years. (Too long in my estimation, even though it’s relatively clean energy not generated by, say, coal. Although you should account for the carbon cost of its production!)
Anyway, what I’m saying is: Real close. Just need to figure out a way to get spray-on solar to cost next to nothing and simple ways to ditch the batteries and inverters and just drop all this extra electricity back into the grid.
I have to call shenanigans on that $30/month number.
The chart says that NY pays 14.54 cents/kWH. At that price, $30 will buy you 206kWH.
That’s 6.87 kWH per day.
I’ll be generous and say there’s 12 hours of usable sunlight per day. Divide that by 12, and that gives 572WH in one hour, or 572 watts produced continuously for one hour.
This is nowhere near the listed power specs for the table. I think someone dropped a decimal somewhere.
Or is my math wrong?
Solar photovoltaic system efficiency can easily be figured out by using these tables:
http://solarbythewatt.com/2009/03/30/economics-of-solar-power/#tables
For somewhere like New York, I think 4 hours of sunlight a day is realistic, averaged over the year. This gives 256 watt-hours a day, about 7.5 KWhs a month, with is about $1.10 is you ignore loses in the inverter, etc. It would take at least 160 years of keeping it clean before it breaks even at 14.5 cents a KWh.
Of course, you can only put things on it at night.
Six, a hundred and sixty, come on. What’s a hundred and fifty four years between friends?