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Charles Murray
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Storage?
Charles Murray   12/2/2011 4:58:46 PM
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Grid parity is certainly a worthy goal, but questions remain about the real cost of building back-up systems to prevent blackouts when the sun's not shining. A recent editorial in The Wall Street Journal stated that renewables need "up to 90% of their capacity back up to revent blackouts." As long as we pay twice (or at least an extra 90%) for our power generation, solar will be a niche.  

Ann R. Thryft
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Re: Interface Importance
Ann R. Thryft   11/22/2011 2:03:25 PM
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It took a really long time for the polycrystalline wafer-based PV market to achieve the solar power holy grail of volumes high enough to drive down cost-per-watt. But then it seems like a very short time elapsed before it went to oversupply. This isn't atypical of semiconductor-based markets, but it is disappointing.


Ann R. Thryft
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Re: Selling Power is Illegal-?! REALLY-??!!
Ann R. Thryft   11/21/2011 12:06:19 PM
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Jim, that's incredible. Although back in the 70s and 80s we experienced similar resistance, to put it mildly, from utilities here in California about buy-back, it's now an established practice. 

Jerry dycus
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Re: Interface Importance
Jerry dycus   11/21/2011 1:44:15 AM
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     As I said the GT inverter already has shut down circuits and can't by code.   There isn't a way for it to hurt a lineman.  Please show in actual gridtie equipment how that can happen?   And as I said even if it did it would short out.  Basic physics.

         I live in Fl and would have went into production of RE but only utilities can sell electricity here by our gov bought and paid for.  Not only that but the ratepayers have to pay $.03/kw for 10 yrs to buy Progress and FPL 2 new nukes each for free!  So I'm doing EV's instead.

Jerry dycus
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Re: Interface Importance
Jerry dycus   11/21/2011 1:44:15 AM
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     As I said the GT inverter already has shut down circuits and can't by code.   There isn't a way for it to hurt a lineman.  Please show in actual gridtie equipment how that can happen?   And as I said even if it did it would short out.  Basic physics.

         I live in Fl and would have went into production of RE but only utilities can sell electricity here by our gov bought and paid for.  Not only that but the ratepayers have to pay $.03/kw for 10 yrs to buy Progress and FPL 2 new nukes each for free!  So I'm doing EV's instead.

przemek
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Re: Interface Importance
przemek   11/20/2011 10:59:10 PM
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Jerry dycus, why so insulting? I am not EE but I do understand the physics of this. I think we both agree that the electrical code requires protecting the network from back-feeding ("islanding"): http://homepower.com/article/?file=HP130_pg28_ATE_2 You are right that under most circumstances 1kW would just short but one could easily come up with a scenario where it wouldn't, e.g. when all the other neighborhood's transfer switches turn off, and the feeder wires are down, and the Pepco crew shows up to repair it. Unlikely, but possible, which is why UL 1741 is there. Standard gensets use electro-mechanical transfer switches to accomplish that. You point that new grid-tie systems have automatic transfer switches; the link above describes how they do it, with small 'hunting' around the feed V/f, which I didn't know about---quite clever, that. Still, using your 20A wall outlets seem like a wrong way to go; limited current, and just the sheer inconvenience--there are no outlets on my house anywhere near where I might put the solar panels up. The only sane way to wire them would be a dedicated circuit going up into the attic, which I would wire permanently with a disconnect in or near the distribution panel.

JimT@Future-Product-Innovations
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Selling Power is Illegal-?! REALLY-??!!
JimT@Future-Product-Innovations   11/20/2011 10:11:06 PM
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On the topic of “selling back” power for profit, I was astonished to learn from a close associate who retired from 35 years as an EE and launched a small State-Licensed Solar contracting company in South Florida, that selling power back into “The Grid” has been declared Illegal in Florida. (Really-?!) I have encouraged my associate to seek anti-trust counsel.  Learn more at http://schroedersolarenergy.com

Jerry dycus
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Re: Interface Importance
Jerry dycus   11/20/2011 9:39:09 PM
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przmek, have you ever done the math, studied or think about in any way what you just wrote?

First grid-tie inverters only work when the grid is up.  Next even if it didn't stop, as designed  from no grid signal, the load of the downed grid would short out any inverter rated at 1kw.

Many PV panels now come or equiped with a Microsine inverter that works the same but only 230wt.

 

przemek
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Re: Interface Importance
przemek   11/20/2011 7:43:50 PM
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You can't just plug in voltage-generating stuff into any 120vac outlet---it could back-feed the distribution network beyond the pole pig transformers during a power outage, and kill someone.

Jerry dycus
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Re: Interface Importance
Jerry dycus   11/18/2011 3:16:16 PM
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  The overcapacity problem like in Lithium batteries too, means one needs to make their own market with added value as the price of PV, less than $1.50/wt now retail well shopped, means making money on just panels puts them in the commodity braket, also like lithium batteries.

So how does one stand out? By taking money from other pies.  For instance installing PV it's no longer the panel price that is the big cost but instalation.  So PV makers need to build 1-1.5kw modules that are plug and play, ie, fold out hinged  or maybe bolt together panels prewired with a built in grid tie inverter.   Then one can set it up in the front/back/side yard and plug it into any 120vac outlet.

These will be profitable at $3/wt now and cut installed costs for the customer by 40% or so.  At these prices for homes, buildings in many places that pay retail power prices  is already at parity in many places.

And if all the real costs of coal, oil were in them, not only wouldn't you need to subsidize RE but RE would cost less by a good amount.

Or build, own solar farms and sell the power for profit.

It's kind of like the homeowners now who can't sell their homes because no one can get a loan. But they could do the loan themselves and sell at a better price and faster.

The bottom line is if the market you are in is soft, get another market or steal market share by innovation!!

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