PG&E Makes Huge Solar Deal

[ravenscape]

http://origin.mercurynews.com/politics/ci_8767338



Pacific Gas & Electric today will announce the largest series of solar-power contracts in the utility's history. The deal, to buy as much as 900 megawatts of electricity- or enough to power 540,000 California homes each year - involves five plants to be built during the next decade.
If the solar-thermal power plants designed by Oakland's BrightSource Energy become operational, a significant amount of power for PG&E customers could come from the sun that beats down on the Mojave Desert. "From what I know, this is the biggest commitment ever in the history of solar," said John Woolard, BrightSource Energy's chief executive officer and president. "It's a fairly significant undertaking on both sides."


BrightSource uses what it calls distributed power towers, or DPTs, in which sunlight from thousands of movable mirrors are concentrated to heat water to more than 1,000 degrees in a boiler to make steam. That steam feeds a turbine that makes electricity.

The first distributed power tower demo will be a small plant in Israel.

And PG&E is not alone. Florida Power and Light, and Conn Edison also plan to farm the Mojave for power.

In the immortal words of Robert Heinlein, "It's raining soup. Grab a bucket!"

[Garnet]

About time.

I could never understand in all the years I lived there why every house in Phoenix, AZ didn't have solar panels on the roofs.

[Worldtraveller]

About time.

I could never understand in all the years I lived there why every house in Phoenix, AZ didn't have solar panels on the roofs.

Exactly. Even with the incentives offered (complete tax credit, not just a refund), very few homes in Az had any kind of decent solar or wind generators to supplement the grid.

When I build a house, I plan on connecting it to the grid, but only as a backup, I'm hoping it will be energy independant.

In terms of actual environmental impact, has anyone done a study of what it takes to produce a modern PV panel, wind generator, et all, compared to the long term savings? I wonder if the chemicals and other resources and by products of the production really offset the long term environmental impact (I'm pretty sure they cover the economic cost).

Cheers.

[Quizalufagus]

In terms of actual environmental impact, has anyone done a study of what it takes to produce a modern PV panel, wind generator, et all, compared to the long term savings? I wonder if the chemicals and other resources and by products of the production really offset the long term environmental impact (I'm pretty sure they cover the economic cost).

Are PV panels capable of covering economic costs? I've been told that they're extremely expensive to produce because production requires a supercooled environment. I know a chemist who's working on a way to make them at room temperature, but I don't think he's made much progress on that front.

[Ray Moscow]

Over here home solar heating installation is quite expensive, and the utility bill savings don't cover the cost (at least in the case I looked at for an acquaintance).

And that's just for low-tech heat, not relatively high-tech electricity generation.

Bummer.

[Bright Life]

That is wonderful news.

[Obi-too]

These are solar thermal plants not Photovoltaic plants.

The difference is they use solar reflectors to concentrate light and heat molten salts. The salt goes to a heat exchanger which boils water and the steam is passed through a traditional steam turbine. It works like a PWR nuclear plant but uses sunlight.

One major concern is keeping the salt above it's melting point so it doesn't solidify in the piping. If I recall correctly the melting point is >~ 120-220 C (an American using Metric?).

The largest plants like these are in Spain right now. BBC News Article (http://news.bbc.co.uk/2/hi/science/nature/6616651.stm)

You can see how bright they get. Don't get in the focal point or you'll vaporize.

I personally lean toward a more distributed model because if forces changes in usage and building design.

[ravenscape]

These are solar thermal plants not Photovoltaic plants.

The difference is they use solar reflectors to concentrate light and heat molten salts. The salt goes to a heat exchanger which boils water and the steam is passed through a traditional steam turbine. It works like a PWR nuclear plant but uses sunlight.

One major concern is keeping the salt above it's melting point so it doesn't solidify in the piping. If I recall correctly the melting point is >~ 120-220 C (an American using Metric?).

The largest plants like these are in Spain right now. BBC News Article (http://news.bbc.co.uk/2/hi/science/nature/6616651.stm)

You can see how bright they get. Don't get in the focal point or you'll vaporize.

I personally lean toward a more distributed model because if forces changes in usage and building design.

I agree with you, but I think this one plays to the strengths of the power companies and grid controllers. As such, it is a new cog in one small part of the network, not a revolution.

[lpetrich]

Are PV panels capable of covering economic costs? I've been told that they're extremely expensive to produce because production requires a supercooled environment. I know a chemist who's working on a way to make them at room temperature, but I don't think he's made much progress on that front.
I looked for stuff on manufacture of semiconductor devices, and I didn't find anything on any process that requires supercooling or cryogenic conditions.

However, some processes require the opposite -- a lot of heat. So there might have been a misunderstanding somewhere.

In particular, zone refining, for making highly-pure silicon, requires a lot of energy for melting the silicon. In zone refining, one end of the ingot gets melted, and the melted zone gets moved from that end to the other end. As it moves, it picks up impurities, which tend to avoid being incorporated into the crystals of re-solidified silicon.

[espritch]

When I build a house, I plan on connecting it to the grid, but only as a backup, I'm hoping it will be energy independant.


I've actually been thinking about building a house as well, and this is a big consideration for me. I've been reading up a little on passive solar design (which involves designing the house to better utilize solar heat in the winter and avoid excess solar heat in the summer) as well as solar panels.

I've also been reading about geothermal heat pumps which exchange heat with the ground instead of the air. This is actually such a great idea I'm amazed it isn't being used everywhere. It is more efficient to move heat than to generate it and because the temperature underground tends to stay constant year round, the temperature gradient you have to maintain is a lot smaller than with a heat pump that tries to pump heat into hot air in the summer and pump heat out of cold air in the winter. The only downside is that it cost more to install initially due to the cost of burying the heat exchange pipe.

[Worldtraveller]

I have been told bya fairly reliable source that there are at least a few dozens of homes here in Wichita that use ground based heat exchangers.

The home I plan on building will likely be in Arizona (assuming we haven't completely screwed up the water tables by teh time I retire), so solar will be a big part, both in passive and PV.

Our house here as a very nice 'sunroom' with the southmost half of the ceiling being glass, the floor is just laid brick, so it holds heat fairly well, and there is a thermostat controlled fan that blows the warm air into the main part of the house (it's noisy, though so we use that during the day while we are at work). This kind of arrangment would work much better someplacewhere the sunlight is more consistent. :p

[Garnet]

What do you do in the summer, Worldtraveller?

[seebs]

PV panels are getting better, both in efficiency and cost. I don't know that they've quite reached breakeven, but they're getting a lot better.

[Worldtraveller]

What do you do in the summer, Worldtraveller?

Hrm? You mean with the sunroom?

Or something else?

[Garnet]

What do you do in the summer, Worldtraveller?

Hrm? You mean with the sunroom?

Or something else?

Sorry. Yes, how do you handle the heat from the sunroom?

[Worldtraveller]

What do you do in the summer, Worldtraveller?

Hrm? You mean with the sunroom?

Or something else?

Sorry. Yes, how do you handle the heat from the sunroom?

Oh, the fan can be shut off manually. And the sunroom has windows on 3 sides that open, two of them almost floor to ceiling, and the room has a second thermostat controlled fan that blows outside.

Usually, we just leave half the windows open all summer and don't bother with the fan. :) It's one of ther really nice things about this house. I just wish I could take advantage of it to grow veggies, but I keep killing them. :p

[Garnet]

Sweet. Something like that would work really well here in Michigan, I think.

[Quizalufagus]

I looked for stuff on manufacture of semiconductor devices, and I didn't find anything on any process that requires supercooling or cryogenic conditions.

However, some processes require the opposite -- a lot of heat. So there might have been a misunderstanding somewhere.

In particular, zone refining, for making highly-pure silicon, requires a lot of energy for melting the silicon. In zone refining, one end of the ingot gets melted, and the melted zone gets moved from that end to the other end. As it moves, it picks up impurities, which tend to avoid being incorporated into the crystals of re-solidified silicon.

It's entirely possible that I'm just not remembering correctly--I haven't thought about this stuff in years. Interesting info regarding zone refining, though. Thanks.

[clivedurdle]

About time.

I could never understand in all the years I lived there why every house in Phoenix, AZ didn't have solar panels on the roofs.

But they did from the 1890's until the 1920's when gas came along!

[Plognark]

In terms of actual environmental impact, has anyone done a study of what it takes to produce a modern PV panel, wind generator, et all, compared to the long term savings? I wonder if the chemicals and other resources and by products of the production really offset the long term environmental impact (I'm pretty sure they cover the economic cost).

Are PV panels capable of covering economic costs? I've been told that they're extremely expensive to produce because production requires a supercooled environment. I know a chemist who's working on a way to make them at room temperature, but I don't think he's made much progress on that front.

Nah, it's the fact that the silicon needs to be insanely pure and flaw free to be useful, and the process to cut the wafers off needs to be pretty god damn precise as well.

PV panels can cover their cost, but given how expensive they are you won't see a return for many years.

[Plognark]

I have been told bya fairly reliable source that there are at least a few dozens of homes here in Wichita that use ground based heat exchangers.

The home I plan on building will likely be in Arizona (assuming we haven't completely screwed up the water tables by teh time I retire), so solar will be a big part, both in passive and PV.

Our house here as a very nice 'sunroom' with the southmost half of the ceiling being glass, the floor is just laid brick, so it holds heat fairly well, and there is a thermostat controlled fan that blows the warm air into the main part of the house (it's noisy, though so we use that during the day while we are at work). This kind of arrangment would work much better someplacewhere the sunlight is more consistent. :p

Geothermal heat pumps. Ingenious contraptions, a little expensive up front, but quite good.

Not that this doesn't use the earth's heat per se, it simply uses the constant ground temperature as a sink or source to move heat around as needed. It's like an air based heat pump that uses the soil or group water instead of air.

[Plognark]

When I build a house, I plan on connecting it to the grid, but only as a backup, I'm hoping it will be energy independant.


I've actually been thinking about building a house as well, and this is a big consideration for me. I've been reading up a little on passive solar design (which involves designing the house to better utilize solar heat in the winter and avoid excess solar heat in the summer) as well as solar panels.

I've also been reading about geothermal heat pumps which exchange heat with the ground instead of the air. This is actually such a great idea I'm amazed it isn't being used everywhere. It is more efficient to move heat than to generate it and because the temperature underground tends to stay constant year round, the temperature gradient you have to maintain is a lot smaller than with a heat pump that tries to pump heat into hot air in the summer and pump heat out of cold air in the winter. The only downside is that it cost more to install initially due to the cost of burying the heat exchange pipe.

Missed this earlier. Yes, geothermal heat pumps are awesome. You're stuck with forced air if that's what you're going to use, given current technological offerings, so it's only economical for a new construction or an existing home that already has the duct work from forced air heating and/or cooling.

The ducts cost about as much as the coils and exchanger; sometimes more. :(

[clivedurdle]

Saw an interesting discussion about heat pumps that once you add in the cost of pumping the fluid around there is not much of a gain - but I suppose a fully integrated system - very high insulation, pv to produce electricity, solar in various forms, some wind wave tidal and hydro would work!

I want to see cities retrofitted to green eco standards!

[Plognark]

Saw an interesting discussion about heat pumps that once you add in the cost of pumping the fluid around there is not much of a gain - but I suppose a fully integrated system - very high insulation, pv to produce electricity, solar in various forms, some wind wave tidal and hydro would work!

I want to see cities retrofitted to green eco standards!

Everything I've read has indicated that that's not true...although there is a scale to it. The larger the geothermal system, the more efficient it is compared to similar scale heating and cooling systems. This is part of why you see it a lot with industrial buildings or schools, but it's not that common for residential. The upfront costs are also a lot higher than traditional systems.

Any costs associated with pushing the exchange fluid around are still less than the cost of fuel or pumps for traditional methods.

NY state has some case study examples here (http://www.nyserda.org/programs/geothermal/default.asp).

[Mike PSS]

Saw an interesting discussion about heat pumps that once you add in the cost of pumping the fluid around there is not much of a gain - but I suppose a fully integrated system - very high insulation, pv to produce electricity, solar in various forms, some wind wave tidal and hydro would work!

I want to see cities retrofitted to green eco standards!
Pumping water is cheap. Pumping air is expensive. Think density and heat carrying capacity.

[Plognark]

Saw an interesting discussion about heat pumps that once you add in the cost of pumping the fluid around there is not much of a gain - but I suppose a fully integrated system - very high insulation, pv to produce electricity, solar in various forms, some wind wave tidal and hydro would work!

I want to see cities retrofitted to green eco standards!
Pumping water is cheap. Pumping air is expensive. Think density and heat carrying capacity.

^ this.

Granted, geothermal heat pumps ultimately link up to a forced air system under most current set ups.

I'd like to see them linked to something like a mini-split (http://www.alpinehomeair.com/viewcategory.cfm?categoryID=97) system, where you pump the liquid heat exchange fluid to spot coolers/heaters as needed.

That type of system is about 20% more efficient than a well build traditional centralized forced air system, but still not as efficient as a geothermal system. I'd love to see how a system that marries the two would work, but so far I've not found anything to employ a combined system like that.

[clivedurdle]

Enjoy!

(explore this site!)

http://www.channel4.com/4homes/ontv/grand-designs/houses/C/cumbria.html

(An underground dwelling!)

http://www.channel4.com/4homes/ontv/grand-designs/features/green_building.html

[Mike PSS]

Saw an interesting discussion about heat pumps that once you add in the cost of pumping the fluid around there is not much of a gain - but I suppose a fully integrated system - very high insulation, pv to produce electricity, solar in various forms, some wind wave tidal and hydro would work!

I want to see cities retrofitted to green eco standards!
Pumping water is cheap. Pumping air is expensive. Think density and heat carrying capacity.

^ this.

Granted, geothermal heat pumps ultimately link up to a forced air system under most current set ups.Probably because the forced air system is already in place OR the geothermal system is an adjunct to an HVAC system.

I'd like to see them linked to something like a mini-split (http://www.alpinehomeair.com/viewcategory.cfm?categoryID=97) system, where you pump the liquid heat exchange fluid to spot coolers/heaters as needed.

That type of system is about 20% more efficient than a well build traditional centralized forced air system, but still not as efficient as a geothermal system. I'd love to see how a system that marries the two would work, but so far I've not found anything to employ a combined system like that.In an industrial plant that is how I design heat exchange systems. All the heat transport is via liquid and only at the process equipment (like an air dryer), where the heat is needed, is it exchanged. I use less than 5% of the energy recovered on the pump, but if I used air to recover/transport the heat I would use over 40% of the recovered energy just to move the air.

Designing your own system costs more than the out-of-the-box systems on the market. But the efficiency gain may pay for the increased cost.

[Plognark]

Pumping water is cheap. Pumping air is expensive. Think density and heat carrying capacity.

^ this.

Granted, geothermal heat pumps ultimately link up to a forced air system under most current set ups.Probably because the forced air system is already in place OR the geothermal system is an adjunct to an HVAC system.

I'd like to see them linked to something like a mini-split (http://www.alpinehomeair.com/viewcategory.cfm?categoryID=97) system, where you pump the liquid heat exchange fluid to spot coolers/heaters as needed.

That type of system is about 20% more efficient than a well build traditional centralized forced air system, but still not as efficient as a geothermal system. I'd love to see how a system that marries the two would work, but so far I've not found anything to employ a combined system like that.In an industrial plant that is how I design heat exchange systems. All the heat transport is via liquid and only at the process equipment (like an air dryer), where the heat is needed, is it exchanged. I use less than 5% of the energy recovered on the pump, but if I used air to recover/transport the heat I would use over 40% of the recovered energy just to move the air.

Designing your own system costs more than the out-of-the-box systems on the market. But the efficiency gain may pay for the increased cost.

Whoa, that's awesome...got any links or reference stuff for how such systems are set up? Common residential systems just don't seem to exist for that type of efficient build.

[Plognark]

Enjoy!

(explore this site!)

http://www.channel4.com/4homes/ontv/grand-designs/houses/C/cumbria.html

(An underground dwelling!)

http://www.channel4.com/4homes/ontv/grand-designs/features/green_building.html

My grandparent's home was a hill-side structure. My grandfather used a composting toilet and they grew a full vegetable garden on the roof.

[Mike PSS]

^ this.

Granted, geothermal heat pumps ultimately link up to a forced air system under most current set ups.Probably because the forced air system is already in place OR the geothermal system is an adjunct to an HVAC system.

I'd like to see them linked to something like a mini-split (http://www.alpinehomeair.com/viewcategory.cfm?categoryID=97) system, where you pump the liquid heat exchange fluid to spot coolers/heaters as needed.

That type of system is about 20% more efficient than a well build traditional centralized forced air system, but still not as efficient as a geothermal system. I'd love to see how a system that marries the two would work, but so far I've not found anything to employ a combined system like that.In an industrial plant that is how I design heat exchange systems. All the heat transport is via liquid and only at the process equipment (like an air dryer), where the heat is needed, is it exchanged. I use less than 5% of the energy recovered on the pump, but if I used air to recover/transport the heat I would use over 40% of the recovered energy just to move the air.

Designing your own system costs more than the out-of-the-box systems on the market. But the efficiency gain may pay for the increased cost.

Whoa, that's awesome...got any links or reference stuff for how such systems are set up? Common residential systems just don't seem to exist for that type of efficient build.
No links for residential, sorry.

Even in the industrial systems it's a DIY type design.
Pump Vendor
Pipe Vendor
Coil Vendor
Heat Exchange Vendor
Civil Engineering for Site (with construction permits)
General Engineering for configuration
General Contractor for Installation

And all of these disperate vendor designs and equipment have to work together at the end of the day. There is no off-the-shelf answer since each heat recovery solution may be unique to each plant.

And it gets worse in the smaller scale.
Look for a pool or sump pump for your conveyance.
Piping could be PVC or plastic.
Coils could be old HVAC stuff or even car radiators (these could be found with attached fans too at the junk yard).

You see what I mean...

[Mike PSS]

Enjoy!

(explore this site!)

http://www.channel4.com/4homes/ontv/grand-designs/houses/C/cumbria.html

(An underground dwelling!)

http://www.channel4.com/4homes/ontv/grand-designs/features/green_building.html

My grandparent's home was a hill-side structure. My grandfather used a composting toilet and they grew a full vegetable garden on the roof.
I personally prefer a couple more steps between my toilet and my vegetables. :yuck:

[clivedurdle]

No links for residential, sorry.

Even in the industrial systems it's a DIY type design.
Pump Vendor
Pipe Vendor
Coil Vendor
Heat Exchange Vendor
Civil Engineering for Site (with construction permits)
General Engineering for configuration
General Contractor for Installation

And all of these disperate vendor designs and equipment have to work together at the end of the day. There is no off-the-shelf answer since each heat recovery solution may be unique to each plant.

And it gets worse in the smaller scale.
Look for a pool or sump pump for your conveyance.
Piping could be PVC or plastic.
Coils could be old HVAC stuff or even car radiators (these could be found with attached fans too at the junk yard).

You see what I mean...

We may have an alternative to school here!

Everyone hunting out stuff, designing, thinking about how to make it work, learning, experimenting, negotiating, cooperating, project managing!

What is the word? Barnstorming?

[Mike PSS]

No links for residential, sorry.

Even in the industrial systems it's a DIY type design.
Pump Vendor
Pipe Vendor
Coil Vendor
Heat Exchange Vendor
Civil Engineering for Site (with construction permits)
General Engineering for configuration
General Contractor for Installation

And all of these disperate vendor designs and equipment have to work together at the end of the day. There is no off-the-shelf answer since each heat recovery solution may be unique to each plant.

And it gets worse in the smaller scale.
Look for a pool or sump pump for your conveyance.
Piping could be PVC or plastic.
Coils could be old HVAC stuff or even car radiators (these could be found with attached fans too at the junk yard).

You see what I mean...

We may have an alternative to school here!

Everyone hunting out stuff, designing, thinking about how to make it work, learning, experimenting, negotiating, cooperating, project managing!

What is the word? Barnstorming?
Sorry clive,
I'm missing your intent. I'm reading this two or three different ways.

Please elaborate.

[Plognark]

Enjoy!

(explore this site!)

http://www.channel4.com/4homes/ontv/grand-designs/houses/C/cumbria.html

(An underground dwelling!)

http://www.channel4.com/4homes/ontv/grand-designs/features/green_building.html

Enjoy!

(explore this site!)

http://www.channel4.com/4homes/ontv/grand-designs/houses/C/cumbria.html

(An underground dwelling!)

http://www.channel4.com/4homes/ontv/grand-designs/features/green_building.html

My grandparent's home was a hill-side structure. My grandfather used a composting toilet and they grew a full vegetable garden on the roof.
I personally prefer a couple more steps between my toilet and my vegetables. :yuck:

As do I, admittedly. It took a few years for the stuff to break down, so it's not exactly a direct transit from toilet to garden. :D

[Plognark]

No links for residential, sorry.

Even in the industrial systems it's a DIY type design.
Pump Vendor
Pipe Vendor
Coil Vendor
Heat Exchange Vendor
Civil Engineering for Site (with construction permits)
General Engineering for configuration
General Contractor for Installation

And all of these disperate vendor designs and equipment have to work together at the end of the day. There is no off-the-shelf answer since each heat recovery solution may be unique to each plant.

And it gets worse in the smaller scale.
Look for a pool or sump pump for your conveyance.
Piping could be PVC or plastic.
Coils could be old HVAC stuff or even car radiators (these could be found with attached fans too at the junk yard).

You see what I mean...

We may have an alternative to school here!

Everyone hunting out stuff, designing, thinking about how to make it work, learning, experimenting, negotiating, cooperating, project managing!

What is the word? Barnstorming?
Sorry clive,
I'm missing your intent. I'm reading this two or three different ways.

Please elaborate.

I think that he, like myself, likes the idea of making awesome stuff out of regular old junk laying around. :cool:

[Worldtraveller]

Makes me wonder if there would be a market for a individual home sized off the shelf unit, and if it could be made inexpensive enough as an off the shelf design to justify it?

I wonder, if one could come up with a design that uses mostly off the shelf components, as noted above, for a single dwelling home, that could fit that criteria. I also wonder about the economy of scale, both for mass production, and for larger residence/commerical sites.

How feasible would it be to have a system that could be scaled up for a large apartment complex, for instance? Hrm....

[Mike PSS]

Makes me wonder if there would be a market for a individual home sized off the shelf unit, and if it could be made inexpensive enough as an off the shelf design to justify it?

I wonder, if one could come up with a design that uses mostly off the shelf components, as noted above, for a single dwelling home, that could fit that criteria. I also wonder about the economy of scale, both for mass production, and for larger residence/commerical sites.

How feasible would it be to have a system that could be scaled up for a large apartment complex, for instance? Hrm....

<parks backhoe in driveway with a shuttle semi behind, knocks on door>

"Pardon me sir, would you be interested in our new DIY system for heating and cooling your house?
Just dig up your yard, put the plastic pipe in, connect it to these heat exchangers and duct this into your central air system."

I don't think Home Depot has the room for these "packages".

http://www.firstratelogistic.com/images/CIMG0194.jpg

It's doable though.

[Plognark]

Makes me wonder if there would be a market for a individual home sized off the shelf unit, and if it could be made inexpensive enough as an off the shelf design to justify it?

I wonder, if one could come up with a design that uses mostly off the shelf components, as noted above, for a single dwelling home, that could fit that criteria. I also wonder about the economy of scale, both for mass production, and for larger residence/commerical sites.

How feasible would it be to have a system that could be scaled up for a large apartment complex, for instance? Hrm....

I'm certain it could be done. I don't know about 'off the shelf', but it would all use existing technology.

Might become more popular as fuel costs continue to explode.