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Here's Elon Musk's Plan To Power the US on Solar Energy (inverse.com)
An anonymous reader shares an excerpt from Musk's keynote speech: Tesla CEO Elon Musk -- whose company makes electric cars and has a new solar roof panel division -- reminded more than 30 state governors at the National Governors Association meeting this weekend exactly how much real-estate is needed to make sure America can run totally on solar energy. "If you wanted to power the entire United States with solar panels, it would take a fairly small corner of Nevada or Texas or Utah; you only need about 100 miles by 100 miles of solar panels to power the entire United States," Musk said during his keynote conversation on Saturday at the event in Rhode Island. "The batteries you need to store the energy, so you have 24/7 power, is 1 mile by 1 mile. One square-mile." It's "a little square on the U.S. map, and then there's a little pixel inside there, and that's the size of the battery park that you need to support that. Real tiny."
He said the space needed. It does not have to be in the same area.
I prefer to look at production in terms of megawatt-hours-per-year-per-year. According to Wikipedia, the projected total PV output for the entire world was projected to be around 400,000 Megawatt-Hours this year
No.
The graph you link shows a production rate of 400,000 Megawatt (p) this year. Not Megawatt-hours.
Megawatt (p) = "peak Megawatt". One MW(p) of solar panels would produce 1 Megawatt under peak sun: that is, at noon, if placed normal to the noon sun. How many megawatt-hours you get from that many panels depends on how much sunlight they get (which depends on where they are, how cloudy it is, and what direction they are pointed).
Here's a map of the global insolation (short for "incident solar radiation", by the way) on a horizontal surface (which is not the optimum pointing for a solar panel): http://solargis.com/assets/gra...
Sunlight at noon is nominally 1 kW/m2, so the numbers on the top are effective hours of noon sunlight per year. Thus, if you put the panels horizontal at the "orange" regions of this map, you get about 2200 hours of sunlight. So: multiply your "Megawatts (p)" by 2200 to get Megawatt-hours.
http://www.geoffreylandis.com
Okay, let's do some Fermi math.
The US uses about 4 trillion kWh/year. https://en.wikipedia.org/wiki/...
But given a sufficient number of solar panels we only need to store enough for about 12 hours. 4 trillion / (365 * 2) = about 5.5 billion kWh, or 5.5 trillion Wh.
Watt hours to mAh is (Wh)*1000/(V) =(mAh): https://milliamps-watts.appspo...
The US generally uses 120 volts for power so that would be 45.6 trillion mAh.
I have on the desk in front of me a phone with a battery that holds about 3000 mAh and when stood on end takes up a surface area of about 618 mm^2.
45.6 trillion mAh / 3000 mAh/phone = 15.2 billion phones * 618 mm^2 = 9.4 trillion mm^2.
There are 1,000,000 mm^2 / m^2 so that would be 9.4 million m^2, and there are about 2.59 million meters per square mile, so 9.4 million / 2.59 million = 3.6 square miles.
So in order to get in down to one square mile you'd need a stack of phones four deep. This phone happens to be 129 mm high, so a stack of 4 would be 516 mm, or about 1 foot, 8 inches.
On the one hand you'd also need a lot of infrastucture to support those batteries which would also take up some area. However i'm also pretty sure that connecting over 15 billion phones in series would be far from the most efficient way to get the required battery storage.
I believe all that math works out?
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The return of Dan Quayle!
Dan Quayle would be a welcome change at this point. In this environment he'd be an intellectual.
Weaselmancer
rediculous.
Most of those [pumped-hydro] locations are already tapped.
For context, there's about 21 GW of pumped hydro capacity in the United States, which is about 1/5th of the capacity of all operating nuclear power plants in the US. But are most of those locations tapped?
No. I'll give you two general counterexamples.
1. One counterexample is the "west coast" of the lower peninsula of Michigan. There is one pumped hydro facility there, called Ludington. It's roughly 2 GW in capacity (with roughly 18 GWh in storage), and about 1000 acres in surface coverage. The lower reservoir is Lake Michigan; the upper reservoir is a man-made pond. But the geological features aren't unique to Ludington, MI -- it's prevalent on much of the lower peninsula's Lake Michigan coast, the result of dunes formed over millennia as debris blew west to east across Lake Michigan. Bottom line: there's no physical reason why one couldn't build a dozen facilities the scale of Luddington, also using Lake Michigan as a lower reservoir.
2. A second counterexample can be found at Taum Sauk mountain. The Taum Sauk Hydroelectric Power Station is a pumped hydro facility with 450 MW of capacity and 3,600 MWh of storage. The lower reservoir wasn't a pool of water at all until the facility was built; it was merely a fork of the Black River. The upper reservoir is an above ground swimming pool, built on top of the mountain. It's entirely man made. The geographic feature needed -- an elevation delta of a few hundred feet (860 in this case), with a slope common for forested mountainside, near a river -- isn't unique by a long shot.
That's two counterexamples off of the top of my head -- the Michigan coast of Lake Michigan and anywhere you've got a mountainous region with a river nearby. Plenty of technical potential.
The reason we don't have more pumped hydro is because the energy market price differential (LMP or system lambda, depending on region) between 3 am and 3 pm simply isn't large enough. It doesn't make economic sense to build more pumped hydro so long as we continue to burn coal and gas unabated, because the gap between the daily highs and lows aren't adequate. However, if we continue to retire coal and gas (and nuclear as it ages) and we continue to build solar PV, we'll see a flip where the peak price of energy drifts from early afternoon to 9 pm -- and storage will be economic, buying energy at 11am and selling it after sundown. Michigan could be the evening power center for the entire Midwest, and scattered new pumped hydro facilities on select Appalachian and Rocky terrain could easily store significant amounts of solar and wind output nearer the coasts.
Support a few technologists in Washington.
Why do you presume it will be the only factory producing batteries? It is almost inevitable that there will be more factories like it and probably sooner than you think. Never mind the fact that they already ARE producing [independent.co.uk] batteries for grid storage.
I never made that assumption. I just referenced the gigafactory because this article is about Musk. And second those batteries are to be used for load balancing and not grid level storage. And just for a little math. The US uses almost 4000 tWh of electricity annually which divided by 365 is ~11 tWh. That is 11 tWh for a single day of storage. That plant can only store 100 mWh. How many of those plants would we have to build for two weeks worth of storage? Is that even a feasible solution?
What options do you think are "better and cheaper" in the long run? Nuclear fission will never happen for political reasons if nothing else.
Of course nuclear fission is the answer. The world's leading climate scientists have called it the only viable path forward on climate change. The political reasons generally involve huge amounts fossil fuel industry money spent on anti-nuclear propaganda. Not only do I think nuclear is the least worst option available, I think it is actually a good option. It is the safest, cleanest energy source with the smallest environmental footprint. Look at nuclear energy startups such as Terrapower, NuScale, Terrestrial energy, etc. Their reactors are meltdown proof and recycle waste. They can be factory built which will further reduce costs. They can be run sustainably for 10000's of years.
We're going to be investing trillions into energy one way or another so why not pick the one that is clean and that we know works?
Well we know nuclear will work, and it is the cleanest source of electricity. Why not invest in that?
I used the word most, and not all. Also just a couple of weeks ago the national academy of science debunked the feasibility of a 100% wind, water, and solar system.
If the tax breaks and deductions are available to any and all businesses, then they are not "Oil Subsidies".
According to a Greenpeace list, US Govt. "subsidies" to Big Oil includes several categories, some of which might reasonably be considered "subsidies" but are in fact not for Big Oil specifically. Rather they are tax code elements that are available for any business, primarily in the realm of accelerated depreciation of capital assets. There are also loan guarantee and construction bond programs; again, these are available for all industry, not just Big Oil. Perhaps Big Oil utilizes these tax code items more frequently than other industries, but that does not make these "Big Oil subsidies".
The biggest "subsidy" on their list is in fact not a subsidy at all. Some years ago, the Government leased oil fields and agreed on a per barrel royalty structure. When oil was $30/BB, the royalties seemed reasonable to all parties, so the contracts were signed. In some cases, the Government failed to stipulate any royalties at all! Now, though, those royalties are a pittance and the Government wishes it had structured the royalties differently. The difference between what they are making and what they *wished* they were making is often included in the calculations of "Big Oil subsidies". Congress has moved in the past to try to retroactively modify the contracts and demanded that the oil companies accept new leases.
Greenpeace also includes several intangibles in their "Big Oil subsidies" list. Things such as
* Giving money to international financial institutions
* The U.S. Strategic Petroleum Reserve
* Construction and protection of the nation's highway system (if we had 100% EV fleet, wouldn't this be a Big Solar subsidy?)
* Allowing the industry to pollute
Keep the nature of these fake "subsidies" in mind when discussing the issue. The "Green" industry partakes of several of these same subsidies: Modified Accelerated Cost-Recovery System (MACRS), R&D credits, etc., but also receive direct no-doubt-about-it subsides. Like ethanol's $0.50/gallon production subsidy (when it was in effect) not to mention ag subsidies used to prop up the growing of the corn that goes into ethanol, billions of dollars every year going into the pockets of Big Ag, or EV $7500/car subsidy, solar subsides over the years.
So you want to pay for the money to prepay your electric bill for the next 20 years, then churn the cycle again because that's the stated lifespan of the panels?
Do you actually have a dime to your name or are you just some nimwit with no money spewing bullshit?
Extended loan periods for anything end up raping you on interest. This includes 30 year home loans.
A Pirate and a Puritan look the same on a balance sheet.