MIT says solar power fields with trillions of watts of capacity are on the way

MIT says solar power fields with trillions of watts of capacity are on the way. This is a very good thing unless they forget to have a protective Plexiglas surface on the arrays. We all know what HAIL can do our cars but could you imagine what HAIL could do to an array as large as they say is coming? I've seen cars that were hit be destroyed with dents and broken windshields all over the place. So let us hope they won't forget to somehow protect those surfaces with anything that will prevent destruction.

 

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Modern solar panels are rated for hail. A common rating is 1" hailstones at terminal velocity (52mph.) Some are rated even higher.

 

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That's good, is that rating on each solar panel?

 

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...from : http://renewableenergysolar.net/can-my-solar-panels-withstand-a-hail-storm/

- begin quote - " Solar Panels and Hail: Can My Solar Panels Withstand a Hail Storm?
With zero moving parts, solar photovoltaic (PV) panels are one of the most durable energy generation technologies known to man. With minimal upkeep, your installation can continue operating at peak performance for decades. In fact, many solar installations from the 1970s are still generating clean, free energy for their owners.

So solar is durable but is it durable enough to withstand extreme weather conditions like falling hail?
Solar Panels and Hail: See the Proof


The crystalline cells that make up most solar panels are actually quite fragile. Left exposed, they crack easily and can dramatically reduce the total power output of your system.

However, todays high quality solar PV panels usually come equipped with laminate, glass, or acrylic casing to protect the crystalline cells underneath. Under test conditions, these protected panels can withstand high velocity hail pellets shot from pneumatic guns.

In fact, SolarWorld’s new glass-glass protective casing can take on hail stones shot at velocities of 260+ mph. Just to put that into perspective:
Solar panels designed around international standards can withstand hail stones traveling at 50 mph
The terminal velocity of a 1-centimeter hail stone is 20 mph (this is the fastest speed that hail of this size can travel when falling from the sky)
The terminal velocity of an 8-centimeter hail stone is 110 mph — more than 50% less than what the highest quality solar panels can tolerate

In other words, damage from hail is exceedingly rare. What’s more, solar panels don’t usually take direct hits from falling debris. Due to the tilted angles of standard roof- and ground-mounted solar PV installations, most impacts are glancing blows.

This brief 2-minute video illustrates how incredibly resilient today’s solar panels truly are. The panels featured in this clip endure everything from hail to baseballs to utility vehicles (yes — utility vehicles). Kinda puts solar panels and hail in perspective, doesn’t it? " - end quote -

...again, from, and much more at : http://renewableenergysolar.net/can-my-solar-panels-withstand-a-hail-storm/

 

Depends on the panel. The 1" hail is a pretty standard rating - but some do more, some do less.

 

China leads world in production and use: Will install in 2015 more than three times what US installed in 2014. I'm glad to know hail can almost never damage the panels. Solar cells are always made in panels the size a couple of men can easily install (or smaller) and generally speaking, are more economical if they do NOT track the sun per annual KWHs generated. (I.e. a few more provide the same output at less capital cost than those that do have sun tracking motors, controls, etc.) Very modular for "roof top" installations. Note the panels have no latitude tilt. - Possibly to avoid wind torques in the "once in 30 year storm" ? Also note the rows are about a panel length apart but contact each other side to side. That, and their lack of tilt, will double the rain fall on ground between the rows and the panels are higher than need be, unless cows will graze the rows of growing grass. The Chinese lead the world in solar cell production and use and know what is best.
See these facts in photo below.

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Source? How long is "on the way"?

Found it:
http://www.computerworld.com/articl...ions-of-watts-of-capacity-are-on-the-way.html

2050.

In general, time horizons over 30 years are equivalent to never. That's about how far away Peak Oil and fusion power have been for the past 30 years.

 

Perhaps this link will help.

http://www.google.com/url?sa=t&rct=...qYGQBw&usg=AFQjCNFQ2tmzdIA1823kj9KtoeZeQpMlYw

 

Well, except there's no fusion right now. There are over a hundred billion watts of solar - and it's growing exponentially. Betting against improvements in/proliferation of semiconductors has, in general, been a bad bet.

 

The local paper had a big story about 2 years back about a local dude spending $40,000 to a solar panel system on his house. They made a big deal about the electric meter spinning backwards during the Summer. At the end, they barely mentioned in Winter, his system provided less than 25% of his needs.

If I multiply my highest monthly electric bill ever by 12, $40,000 is 37 years of electric bills. Bring that down to 2-3 years and I'll consider solar.

 

Those numbers are a bit odd. A $40,000 system is around 8 kilowatts - which even in a bad solar area (say Massachusetts) will give you about 32 kilowatt-hours a day. Your average home uses 24 kilowatt-hours a day.
If he's not breaking even then he's using way more than the national average. (But if he's doing that, then his bills are correspondingly higher, and his savings consequently greater.)

Breakeven times right now are around 4-10 years depending on location, incentives and power prices. They probably won't get much lower than 4 years.

 

True - you can't schedule invention (but people still try). Like the necessary inventions to make solar cheaper.

If we use a fairly high $0.18/kWh for the above scenario, we get 19 years, simple payback. A big part of the reason that solar has exponential growth and paybacks quoted below 10 years is the absurdly high subsidies (@50%, that's $2.50/watt or $0.09 /kWh if the panels last 20 years). But exponential growth and absurdly large subsidies are mutually exclusive in the long run. That's part of what will slow solar's growth over the next few years.

 

What inventions are necessary to get solar cheaper? Panels themselves are at .64/watt, and inverters are at .25/watt. Those are the only technically advanced parts of a grid tied solar power system - and they come in at under $1/watt. The balance of system parts (conduit, disconnects, wire) are all mature technology needing only economy-of-scale cost reduction.

 

So...you are saying that solar costs have bottomed out? I was unaware. I thought it could still get a lot cheaper. That bodes worse for Solaris growth potential than I thought (residentially anyway).

 

No - just that no fundamental inventions are necessary to make it cheaper.

 

Storage tech.

Thermal solar is far cheaper at capture than panels even at the current level of research, and lacks only storage tech to take over the electrical grid entirely.

 

Yes, and it can be even more efficient (perhaps 50% more so) with a practical solution to its fundamental problem, which I invented long, long ago and patented.
See: Long expired US patent 4033118 (mass flow solar absorber thermal system.)

It appears to be very attractive. I publish two papers of mathematical analysis in Applied Optics just before applying for the patent. Both are referenced in the patent. I split the analysis into two parts and never in either paper even hinted they were related to a solar thermal energy system.

Also described in my patent is a wonderful chemical storage system that is very compatible with the invention. Sulpher has two oxides SO2 and SO3 and a reversible reaction between them (endo thermic one way and exothermic the other) and they are gases easy to store as liquids. - All is described in my patent. Storing energy in chemicals can have essentially zero loss, even if the energy surplus is stored for a month! Back then there were "mountains of sulpher" near coal fired power plants, not only with no cost, they would pay you to take it away!

Here, just below, is the fundamental problem of solar thermal, that I recognized and solve at least four decades ago when few were concerned about how their grand childer would make it thru "peak oil" (term not even known to me back then, but I knew only solar was not finite).

If the absorber is very hot for good Carnot limited conversion efficiency a large fraction of the solar energy striking and heating the absorber leaves again as IR radiation.
If the absorbers is lower in temperature the T^4 IR loss can be small, but so is the maximum conversion efficiency.

My absorber, a hole, always had essentially unity absorption coefficient and yet very low re-radiation losses even when producing "red hot" temperatures near its limit - the softening point of quartz. Thus it can have high conversion efficiency, absorb all the high concentration solar flux on it, yet re-radiate essential zero IR!

You can see how I achieved all this with cheap materials by reading my patent on line, for free, at the US parent (and TM) office web site.
Crudely speaking: I invented a solar photon "fish trap" for solar energy that "IR fish" could not get out of built on fact solar radiation goes thru glass but IR does not.

Some engineers at Shell were quite interested in my invention for endo-thermic chemical processing, driven by solar energy. We exchanged several letters (before internet existed). Then they contacted Shell's licensing and legal departments to see how we could proceed. They got their wrist slapped - were told to have no further contact with me, but one did send me a private letter telling what had happen. The legal Department was concern that any similar applications for solar endo-thermic processing shell might develop would be vulnerable to action by me.

 

So what, exactly could or must be done to drop the price by, say, half?

 

Well, installation costs are currently running around $4.50 per watt. Of that, less than $1 are the "hard" stuff (solar panels, inverters.) The remainder is BOS (racking, conduit, wire, disconnects) plus labor and permitting.
BOS will go down with economies of scale and better rack designs. Racks are currently made from very heavy gauge aluminum channels, and those are expensive. Going to stamped metal brackets and rail-less mounting systems will help there. Prewired conduit and increased use of nonmetallic conduit / direct exposure wiring will bring down labor and materials cost. Elimination of external disconnects (not needed) will help. Permitting process needs streamlining; in many jurisdictions it is a painful week-long process, when it should be no harder than adding an outdoor spa. (Indeed, it should be a lot easier.)
Labor is going to be reduced by adding features that speed installation. Roofs with mounting hardpoints identified will greatly reduce installation time.

All of that would probably get us into the $2.25-$2.50 per watt range. Other countries are already in the $3/watt range mainly due to much simpler permitting and less onerous installation requirements.

 

Companies like Vivint.Solar (www.vivintsolar.com), SolarCity, etc. are installing home and commercial, and selling the electricity generated to the owner for 80% of the prior cost from the power company. The install is typically no cost to the owner.