I’ve heard arguments lately for local photovoltaic solar power (PV) from rooftops, roadways, and parking lots as a primary source of electric energy, mostly accompanied by arguments against long distance high-voltage transmission lines (HVDC). I keep picturing a revised Treasure of the Sierra Madre with bandits telling Humphrey Bogart: “Transmission lines? We don’t need no stinking transmission lines!”
I think the key to this argument is whether you are satisfied with slow incremental growth in renewable energy that gradually rises to providing 20 percent of electricity use, or if you want renewable electricity use to grow large enough to displace coal, natural gas for electricity, and even natural gas for heating and oil for transport (via ground source heat pumps and electrified transport).
Let’s look at data from the Carnegie Mellon Electricity Industry Center for one [PDF] PV system for one day in Prescott Arizona.
click image to zoom
You will note that in this example from one of the most suitable spots for solar electricity in the U.S. (a desert with both strong sun and few clouds), most of the power is delivered in an 8 hour period. In a city further north or with more typical cloud cover that would be more like five hours. Even so, that leaves 16 hours a day during which solar PV can supply little or no power. There are also short periods even during peak sun when cloud cover reduces solar power to near zero. PV without storage can only supply a small minority of electric demand. The least-expensive site-independent storage method, gigawatt-scale flow batteries, run about $350 per kWh. So seven hours of storage, about the minimum to significantly increase reliability would run $2,450 per KW. Sixteen hours storage, which would provide true (albeit not overly reliable) baseload, would cost $5,600 per KW. As long as electricity storage costs remain that high, PV is likely simply be used as supplementary power. If we don’t bring in complementary distant renewable energy, the most likely main power source will remain coal, natural gas, or nuclear energy. We are simply not likely to add that high a capital cost to already expensive solar cells.
And contrary to misleading information out there, solar PV is still expensive. The lowest price for PV systems where reliable cost information is available is $5,600 per KW of DC PV installed in Germany. (Note that part of that is electronics, installation, not just the solar cells themselves.) At a 5 percent interest rate and 21 percent capacity factor, that yields a $0.24/kWh price. (Note that the lowest price we know of in California is $7,100 per DC kWh installed, which would yield a $0.31/kWh price.) So where do lower price estimates come from? Many estimates include tax breaks, or don’t include interest, or assume maximum lifespans.
Sometimes the errors are more subtle. For example a lot of over-enthusiasm has been generated by estimates that the Sempra El Dorado PV project produces solar electricity at a cost competitive with coal. This estimate comes from an equity analyst who, like all of us outside of Sempra, does not have access to actual cost data. I will note that Michael Allman, Sempra’s Chief Executive says that the cost of electricity from the PV project is “more expensive than the power produced next door by burning natural gas.”
Now it is still likely that the Sempra El Dorado project is producing solar electricity at a lower price than your average PV plant. After all they have the connections to obtain the least expensive solar panels in the business, and with a ten megawatt order probably got the maximum quantity discount as well. Because this is a solar farm, the sort of project radical decentralists oppose, installation costs are minimized by building on ground level, tearing up existing plants and greenery, rather than incurring the high cost of installation on a rooftop, a road retaining wall, or on poles shading an existing parking lot or roadway. Maybe they obtained panels at as little as $3,000 per KW, and incurred total costs (including installation) as low as $4,000 per KW. That would yield a $0.17/kWh. This is an over-optimistic low estimate; the real number is almost certainly higher.
If you go back to that Carnegie study, you will also find that the December production for the largest PV installation is slightly over 54 percent of June output output. December demand for APS, the company who owns this site, is more than 78 percent of summer [XLS]. That still leaves slightly less than a one-third gap between winter output and demand. More capacity, rather than storage, is the answer to this kind of long term gap, so what capital cost is being increased by a third is an important issue.
Note that wind costs about one-fourth solar PV per kWh. Some wind farms, constructed in unusually favorable circumstances, ended up with total costs of four cents per kWh. The El Dorado project by the most optimistic reasonable estimate cost $0.17 per kWh. A typical big wind farm with favorable (but not exceptionally favorable) circumstances has $0.06 per kWh costs. A comparable solar PV project yields $0.24 per kWh costs. In less favorable circumstances, power from a wind farm cost $0.08 cents per kWh. Comparable solar PV costs $0.31 cents per kWh. Even if you ding wind 1.5 cents per kWh for transmission lines and transmission losses, you still end with solar PV costing more than 3.5-times what wind does. Now that does not mean there is not a place for solar electricity, and even for PV. If we are serious about phasing out fossil fuels, we can justify PV as a way to lower total system cost, and replace the maximum amount of fossil fuel. But we have to look at it as system, one that includes connection to other renewables.
For example, a recent study [PDF] by the New Rules Institute suggests that about half the states in the U.S. could supply all their own needs from renewables, and the rest could supply a substantial percentage. This is often offered as an argument against the need for long distance transmission, but actually supports it. A situation where some states can produce all the energy they need, and a bit besides, and others need more than they produce is actually the situation where you would need transmission between states. And it may be true that a state able to produce its own wind is better off doing so than importing electricity from where wind resources are better, due to transmission costs. But it is equally true that a state saves money by importing wind power compared to producing solar electricity. It is also true that this study relies a great deal on agricultural production of biofuel—which in a lot of cases does not produce net reductions in emissions, or produces very small reductions in emissions, and which competes with food production.
Incidentally, if we were looking only at per kWh cost, there would be a good argument to make for close to a 100 percent wind grid, which would need a lot of long distance transmission to get wind to low-wind states. Even with line, losses, transmission losses, and so forth, the highest wind costs would still be lower than cheapest solar costs. The reason for including solar is not to reduce transmission but to increase reliability and minimize the storage need to make a renewable grid reliable.
Just as there is more solar energy available in summer than in winter, there is more wind energy available in winter than in summer. Just as demand in states that are optimum for solar production peaks in summer, demand in states that are optimum for wind production peaks in winter. But, as with solar, wind production drops more in the summer than electricity demand does. So connecting states with high wind capacity and states with high solar capacity reduces needs for capital buildouts in both states. It reduces the number of wind generators and the number of solar panels needed.
More importantly it reduces the need for storage to cover daily drops in production. Both wind and sun are variable sources. The graph above shows not only that huge gap from well before sunset to well after sunrise, but temporary drops during peak production periods. Similarly wind tends to speed up, slow down, start and stop. According to an RMI study [PDF], interconnecting wind energy with solar energy produces more reliable power than either alone. What none of the studies focus on, but is what is most certainly the case, is that interconnected wind and solar decrease storage needs by much more than they decrease variability. Imagine for the moment a power source that pauses for one continuous hour a day. Imagine a second that pause for a half hour, three times a day. The second source loses more power to pauses per day than the first, and pauses more often. But you can bridge that gap for the second with a half hour of storage, whereas it would take an hour of storage to bridge the gap for the first. Wind and solar complement one another significantly. They each produce most strongly when the other is weakest. The average length of low production periods should be reduced much more than the reduction of total low production time, allowing more of these gaps to be bridged by storage and less by backups.
But this effect will require transmission. The strongest solar resources and the strongest wind resources tend to lie at a distance from one another. And of course there are many states that will have to be net importers of renewable electricity.
Now even so, this would tend to imply much more wind than solar energy in an optimum grid. Even though solar resources are more plentiful, they are more expensive to tap per kWh. And to some extent that is true. A lot of energy is used to generate low-temperature heat for space and hot water heating, and for certain commercial and industrial purposes. We may be better off applying direct solar energy to these purposes than over using them for electrical generation.
But there are two current technologies that may tip use of solar energy to something comparable to wind. First, we can use concentrating solar power (CSP). This uses mirrors to focus solar energy the same way we can use a magnifying glass to set fire to a piece of paper. The heat from this can drive heat engines. Not only is this less expensive than PV, but we can also store heat for later use at a cost $35 per kWh, about one tenth the cost of storing electricity. And if that stored energy is used comparative quickly, within a day or so, net thermal losses are smaller than round-trip losses in electrical storage.
If we use solar energy for electricity but only for peaking purposes, relying mainly on dispersed wind mixed with a tiny fraction of that solar energy for baseload, then we don’t need thermal storage. In that case CSP can focus sunlight on advanced (40 percent) efficient solar cells designed for aerospace use. It is at least possible that the overall cost per kWh might be even less than driving heat engines, maybe even low enough that solar would be less expensive rather than more expensive than wind, even with today’s technology. You no longer have the storage advantage, but if it was cheap enough you could “overbuild” and end up with a mixed wind/sun grid with a lot of solar electricity—one that needed very little storage in return for producing some electricity that could neither be stored or used, but simply had to be discarded. (In practice, someone would find a use for “waste electricity” something low value, but worthwhile with electricity that was truly surplus.) I emphasize this is speculation. I don’t know that we could do it. But a very smart engineer who posts under the name of Sunflower on this board has argued for very low overall costs low from combining CSP with space solar cells. If he is right, then replacing storage by excess generation follows. (And you would still use substantial wind, and some storage, but it might shift the optimum solar/wind balance closer to 50/50.)
While I think there may be real conflict between this and what radical decentralists say, I also think this conflict can be exaggerated. This is not an argument that the majority of power has to travel long distances. I think a lot power can be generated locally, depending on what you define as locally. Only a minority of power will have to travel long distances, and only a minority of that will need to travel more than a few hundred miles.
Saying that we will need transmission to convert to a mostly renewable society is not the same as saying that most of the power lines proposed by current utilities are justified. Carol Overland, in her recent Gristmill post made the point that most (perhaps all) such proposals are about merchant power to buy and sell more conventional generation, mostly coal and nuclear power.
The Sunrise Powerlink proposal is a good example that substantiates this. Looking at the EIA we find that constructing the 134-mile one gigawatt line would emit about 110,000 tons of CO2 equivalent, and that SF6 leaking from the gas insulated lines would produce even more emissions over the lifetime of the line. According to the EIA it would take 12 years just to pay back the construction emissions. Now if the line was actually used to significantly increase net renewables, payback would not be so absurdly slow. For example, if 10 percent of the line’s capacity was used for net additional renewables, it would take about eight days to pay back construction CO2, and perhaps another 8 to 16 days to pay back all SF6 likely to be emitted over the life of the transmission lines. (This assumes each kWh displaced saves slightly less than 1.3 pounds of CO2 equivalent.)
The bottom line is, just as critics say, the Sunrise link is designed to bring additional coal power to San Diego, and secondarily to connect to the Stirling solar project which most critics judge likely to fail, thus giving PGE an excuse to not meet the its renewable portfolio requirement. An early sign that this was some sort of fraud was contracting solar power from Arizona, whose quality of solar resources differ trivially from those of San Diego and surrounding areas. Arizona does have substantially greater geothermal resources, which PGE is less eager to exploit.
One possible alternative offered to renewables is recycled energy, where industrial waste heat is used for electricity generation. This is a great resource that should be exploited. But it does not eliminate the need for a mostly renewable grid. For recycled energy to produce a high percent of our electricity would require industrial burning of fuels to stay close to our current level. According to Tom Casten, total recycled energy potential is about 20 percent of current electrical demand. If we reduce industrial fuel use substantially, we will also reduce the potential for recycled energy to much less than this. That does not make it an unimportant resource or one we should not tap. There are a few cheaper means of saving energy, (cough*weather.sealing*cough), but not many. We should take full advantage of it to the maximum extent we can. But, if we seriously intend to reduce greenhouse gases we must reduce both industrial and electrical emissions. Recycled energy is a supplement to, not a substitute for, a grid that includes long distance transmission (including some very long distance transmission).
Comments
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biodiversivist Posted 2:38 am
10 Feb 2009
Solar hot water is far more efficient that photo voltaic. Seems to me that if mass produced (and by that I mean reasonably priced), high quality systems were required by building codes we could make a huge impact. A modest system here in Seattle would meet most hot water needs for a typical residence in the summer and would make a significant dent in the winter as well.
I realize that the first attempt by government to jump start solar hot water failed but technology has improved and incentives to use it will grow with increasing energy costs. Maybe it's time to give it another go.
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
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Gar Lipow Posted 3:18 am
10 Feb 2009
Look, I think if we had seriously started moving along the path of efficiency and renewables back in 1976 when both Barry Commoner and Amory Lovins were shouting for attention, we could have move along a more gradual path where for many years we got most of our power from fossil fuels, just used it more efficiently. But we wait too long. We did not deploy what we already knew how to do cheaply. We can't wait any longer for the stuff "just around the corner". We have start deploying everything we know how to do at a reasonable cost, which includes stuff that is more expensive (not including social costs) than fossil fuel. Improvements almost certainly will occur as we deploy, and when they do we can shift course. But we can't wait for tech to get better anymore. Not even near term stuff. We threw away our safety margin. Actually we are way past our safety margin. Now we are trying to slow down enough that the crash only causes cuts and bruises. If we wait much longer we will be hoping to get away with broken limbs.
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Jon Rynn Posted 3:29 am
10 Feb 2009
Now, when I to show how to shut down all coal plants, I used the example of ground source heat pumps, and I figured about $20,000 for the heat pumps for a 2500sqft "typical" residence, with 2 kw of solar pv, whoch would work out to about $10,000 for the pv (as Gar shows). But what I didn't show was the storage for that, which Gar puts at about $10,000.
On the other hand, it might be worth figuring out how a solar heater would change that equation, as BioD points out. By the way, the Chinese are building millions of these, I believe.
However, just providing the pv to take care of heating and cooling needs, theoretically, is then $30,000 per household for pv + ground source heat pumps + storage (again, back-of-the-envelope). That takes care of about 27% of electricity if we cover all residential and commercial buildings (the 27% is from my aforementioned article). That's a good chunk, and heating and cooling are important. So it seems to me that some combination of solar heating, ground source heat pumps, and pv could conceivably deal with about a quarter of electricity use (there's also industry -- here is where recycling energy comes in, I assume, so that might be another big chunk). Also, note that much of the efficiency gains that we talk about come from improving a building's ability to retain heat or cold, so this makes reducing "long-distance" electricity needs easier as well.
But we've still got half of our electricity not covered, even if we go a "radical decentralist" heating and cooling route. Now, one could argue that alot of this is not necessary, but that's a cultural issue, I suppose. But this 50% or so, if we are going to keep using it, would have to come, it seems to me, from longer distance solar/wind, of the kind Gar shows. There might be some medium distance capability, such as the brownfields that stopgreenpath mentions, and there may be some medium-sized city-based wind farms that are possible to.
So it looks like, at best, we can have a building/city-scale/continental-scale renewable energy grid.
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biodiversivist Posted 3:30 am
10 Feb 2009
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
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GreyFlcn Posted 3:43 am
10 Feb 2009
-David Ahlport
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JMG Posted 4:28 am
10 Feb 2009
By putting a solar hot water heater on my roof and insulating my attic, I've not only reduced my monthly bill, but I've taken a small slice out of the aggregate demand (I have electric hot water and an electric furnace fan). Sure, my bit is tiny, but that's the thing about baseload - it's nothing but gobs and gobs of tiny little loads rolled up together.
The 5% Project
Let's live on the planet as if we intend to stay.
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ChoppaM Posted 5:05 am
10 Feb 2009
This is perfectly true, but definitely needs spelling out for the nuclear, gas and coal lobbies and their deluded followers. And the clearer it is spelt out, the clearer it also becomes for the rest of us, and the angrier we will get at the suicidal short-sightedness of our own dinosaurs.
Buildings - retrofitted, insulated, covered with thin-film PV and solar water heaters, running heat-exchangers for air and rock, using rooftop greening to provide moisture retention, heat moderation and recreation on-site, and lower built-up area heat extremes. Constructed with energy-use optimizing windows and glass, and using optimal angling for shade in summer and sun in winter - and light conduits to reduce power for lighting.
Water - heat-exchange source; groundwater from different levels for grey water (non-drinking, lawn-watering) use, and clean water; running water providing electricity from river-turbines, as well as more recreational and economic (fish-breeding) water given reduced cooling needs. Seawater providing tidal and wave energy.
Earth - geothermal with its huge resources (volcanic areas); heat exchange (plenty of experience worldwide with small-scale HE, less with just as feasible district or urban scale HE); (speculation: why not try and tap earthquake movements and tension pre-catastrophe?); underground construction for say industrial purposes; crops and greenery for multiple uses.
Wind - windfarms and small-scale highly efficient urban turbines, etc - this is well-enough known.
Sun (water, earth, wind, fire!!) - pull together all we know about - PV, CSP, water-heating; small-scale, large-scale etc, and throw it all in the mix at every geopolitical level.
THEN THINK BIG!!
Gar hits the nail on the head when he mentions HVDC. This High Voltage Direct Current will transform our electricity transport and usage the way Tesla's LVAC project did. Imagine that! Not only could sunrich areas produce energy for many industrial and residential at once - the whole of Southern California, at least, frinstance, plus the cities of Nevada and Arizona - but on a world scale we could harness the solar resources of the Sahara to supply the whole of Europe. This last project is already being studied, and there's a trial HVDC line already being operated in Sweden.
So, if we THROW EVERYTHING AT IT NOW, we'll be well on our way. And every development over the next couple of decades (and as with AC electricity, these will follow thick and fast) will add to the goodness and savings. And if we're lucky, renewable energy will take off with the enthusiasm and diversity and unimagined human empowerment generated by computerizationa and the internet.
Sorry about the length - hard to add to what Gar said without referring to the breadth and depth of areas already working or projected or shown to be feasible.
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Gar Lipow Posted 5:06 am
10 Feb 2009
In all fairness to you, even if solar PV is driving heat pumps, you can still store thermal results rather than electricity to produce solar output. That would be a lot less.
>Baseload" is nothing but maximum non-cyclical aggregate demand of many small loads. "Small" solar -- particularly solar thermal, as biod points out, does an excellent job reducing baseload demand.
>By putting a solar hot water heater on my roof and insulating my attic, I've not only reduced my monthly bill, but I've taken a small slice out of the aggregate demand
Yeah, but I'm not sure how much all this contributes to reducing base rather than peak. Especially the solar heater.
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Pompey Road Posted 5:35 am
10 Feb 2009
The Alternative Energy Portion of the Economic Recovery plan should stimulate alternative energy production.
The vast amount of money pumped into the alternative sources should bring the price of solar and other alternatives down if China gets big time into the alternative energy manufacturing. Economy of Scale will bring the cost of most viable Alternative Energy Sources down.
However you can also get the desirable effect of raising the price of coal by $10 to $15 dollars a ton in the Eastern Coal fields if you stop Mountain Top Removal. Western strip coal will the up the slack for production lost but transportation cost will be considerable to the Northern, Southern and North Eastern Power Generating plants. They will be forced to mine underground where the cost are higher. They will still be doing conventional stripping in the Eastern Coal Fields but the cost of putting the Mountain back on the original contour as required by the 1977 Surface Mine Act will be considerable.
You have under this new administration the chance to stop both MTR and even conventional coal stripping in the Eastern Coal fields.
Stop MTR and raise the price of coal to give the alternative energy sources a chance to compete. Raise the co2 standards and you get even closer.
The eons of time and nature was good to us down here. It was not until we become civilized that destroying our habitat become fathomable or fashionable.
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JMG Posted 6:06 am
10 Feb 2009
Residential hot water is a year round steady state demand that actually tends to show up in baseload because few residential users use much hot water at home when they're at work.
Thus, even though my maximum solar harvest occurs during the demand peak hours for my utility (summer afternoons), my actual usage tends to occur at off-peak hours anyway (early mornings, later at night). So if had kept my prior all-electric hot water tank, it would kick on in the evenings and mornings when I used a load of hot water (and, therefore, sent a flush of cold water into the tank). That shows up as baseload, not as peak.
SO my usage pattern shaves the peak demand (since I don't draw juice when the system is at peak demand) . But my solar thermal system also reduces the baseload on the system (because my superinsulated 120 gallon tank does a good job of minimizing ambient losses, thus reducing electric backup element use and therefore reduce total annual use).
Since my total consumption is essentially zero during the daily peak to start with, any reductions show up as reductions in baseload demand.
The 5% Project
Let's live on the planet as if we intend to stay.
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Jon Rynn Posted 6:32 am
10 Feb 2009
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Gar Lipow Posted 8:23 am
10 Feb 2009
Also solar space heating requires a smaller temp difference than hot water. Still retrofitting an existing home with a solar space heater is close to the cost per kw equivalent of a hot water heater. So 4 to 1 cost difference between PV and solar space heater. Maybe 5 to 1, because spacing heating is cheaper. But PV can drive a ground source heat pump. So you can end up with a PV system one 4th the power of a solar space heater. Also that ground source heat pump can cool as well as heat, whereas a solar space heater can't do cooling without doubling your capital cost. (And non-electrical solar space cooling is not available for single family homes anyway, as of six months ago - at least not in humid climates. Maybe that has changed.)
What would really change this is is if Sunflowers scheme would work. Take a concentrating mirror. Focus on a 40% efficient space solar cell. With losses from the mirror and from inability to use indirect sun, say the result is 30% efficient PV. Put that into a heat pump and you end up 90% to 150% efficient use of sunlight. (Yeah, more than 100% - if you are lurking and this is new to you google heat pump and COP.) That of course is at least as good an efficiency as solar panels. And if Sunflower is right about costs, at a comparable price. Of course you still have the cost of your ground source heat pump. Note that this does not apply to water heating. The higher temperature difference means you don't gain much from a heat pump. And you need hot water all year round. So direct solar water heating is a perfect application for direct thermal solar.
The whole game changes with new homes. You can build a new home to need zero fossil fuel or electric climate control energy, or close to it at a tiny incremental cost. But in existing homes you have to consider these things.
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Nickz Posted 8:28 am
10 Feb 2009
Short term intermittency is far better handled with Demand Side Management than with central storage, especially as the number of plug-ins and EV's grows. DSM is almost free to utilities, have effectively instant response times, and has enormous capacity.
I'd also note that First Solar's panels cost $1.12/watt to make, and sell for about $2.50/W, and that in general PV prices are expected to fall by about 1/3 in 2009.
That doesn't really change your argument much: both wind and solar can be buffered by DSM, and the costs for wind and CSP should also fall. Still, these are important details.
Renewables's obstacles aren't technical, they're social: 20% of the workforce might be obsolete... http://energyfaq.blogspot.com/
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Gar Lipow Posted 8:59 am
10 Feb 2009
As to demand side management - important, but not the equivalent of electrical storage. Suppose you can have either the ability to defer 1/3rd of 9 kWh demand by 12 hours or to store 3 kWh. Looks like the same thing, right? But the diference is, if you had to you could release all three of those kWh over the course of 20 minutes, bridging a 9 kWh drop in supply for that time. Whereas if supply dropped 9 kw for 20 minutes, and you have the ability to defer 3 kw of demand, you still have 6 kw to find. So demand management is important but not the full answer. From what I've seen generally demand management can defer at most a third of demand, probably a lot less.
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Jon Rynn Posted 9:14 am
10 Feb 2009
Also, what was that gigawatt storage system at $350/kw you were talking about, is that sodium sulfur? thanks.
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Nickz Posted 9:23 am
10 Feb 2009
First Solar is a publicly traded company, and those numbers are from their investor communications. If the cost data isn't real, there will be some very big shareholder lawsuits and regulatory consequences.
"From what I've seen generally demand management can defer at most a third of demand, probably a lot less."
First, covering 1/3 of demand from storage for any significant time would be very, very expensive. Better to handle the first increment (1/3, or whatever it can handle) with DSM, and use storage as a secondary resource.
2nd, plug-in/EV charging can be scheduled when it's needed. If your problem is too much wind in the middle of the night, charging can go there, and easily be 1/2 of demand. Heck, for short periods it could be as much as you wanted: visualize 150M plug-in's pulling 6KW each, for a total of 900GW!
3rd, plug-in/EV's could also provide V2G, and provide additional supply in similar numbers.
Does it seem hard to imagine that many plug-in/EV's, or hard to imagine them ramping up quickly enough? Well, the thing to keep in mind is that they can grow as quickly as wind and solar: we could easily produce 10M plug-in/EV's per year in 10 years.
4th, it's easy to exaggerate the intermittency we need to handle, but it wouldn't take much interconnectedness to take advantage of geographical dispersion of negatively correlated wind and solar sources (your reference on this topic had sites that were all pretty close together), and
5th, we also have the option of backup by (hopefully) largely obsolete FF generation plants, so DSM (or storage) wouldn't have to handle very long (but rare) events.
Renewables's obstacles aren't technical, they're social: 20% of the workforce might be obsolete... http://energyfaq.blogspot.com/
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Gar Lipow Posted 9:42 am
10 Feb 2009
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Gar Lipow Posted 9:45 am
10 Feb 2009
NickZ
Yeah we can use fossil fuel backup. But we don't want to use too much of it, which bring me back to distance.
And yeah sources are dealing with midwest which has lots of wind and not too far from sun. But if you are talking Boston, they have plenty of access wind, but will need some distance for sun unless solar prices really drop even more.
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ce1907 Posted 12:31 pm
10 Feb 2009
Gar may or may not be correct that some big solar and big wind and new huge transmission lines are needed. I am not convinced, but I don't know.
But even conceding that Gar is generally correct, WHAT do you want to do?
Even if some transmission line is needed, not all are needed. Not all are a good idea. Not all will be compatible with a smart approach to electriciy and transportation.
Some might be. Which ones?
Believe me, the brown Dems are gearing up to demand a blank check for mining, transmissiion companies, and utilities (nukes and clean coal) -- all in the name of a "serious" approach to the climate change problem.
That may pass. But it will end badly for us and our children (and, yes, the critters).
To stop that rumbling horde, there must be a counter proposal. A better way.
Some organized vision with organized supporters and organized lobbying and PR.
Instead, we have a babble of amateur commenters (like me).
Not good enough.
Obama should be organizing a plan. He won't. He will lay back and let the brown Dem horde roll over the green DFH crowd. Frankly, the big O has very little use for the green DFH crowd anyway.
If someone is going to offer a plan, then it has to come from us. (Gore has the money and time, but, apparently, other priorities. Like commercials with Repubs sitting on couches with Dems.)
Boy, are we in trouble.
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Jon Rynn Posted 1:57 pm
10 Feb 2009
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amazingdrx Posted 3:00 pm
10 Feb 2009
And small distributed renewable smart grid is taking over.
http://amazngdrx.blogharbor.com/blog John Schneider, Northern Wisconsin
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amazingdrx Posted 3:08 pm
10 Feb 2009
HVDC is easily buried (unlike AC) with low losses (1% for 200 miles) and doesn't emit corona or electromagnetic stray voltage, so important in NIMBY issues. Placed in freeway median the right-of-way NIMBY issues would be nil.
http://amazngdrx.blogharbor.com/blog John Schneider, Northern Wisconsin
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Nickz Posted 3:27 pm
10 Feb 2009
I agree on transmission: geography matters.
Renewables's obstacles aren't technical, they're social: 20% of the workforce might be obsolete... http://energyfaq.blogspot.com/
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Colin Wright Posted 4:25 am
11 Feb 2009
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Gar Lipow Posted 5:55 am
11 Feb 2009
Basically batteries are expensive. Battery cycles are expensive. If that changes utilities will buy their own batteries for intensive use. In the meantime, utilities won't buy battery cycles from drivers at high prices routinely, for example on a daily basis. V2G will be good for a lot of uses, spinning reserve, seasonal peaks that happen a few days a year - a substitute for capital capacity that would be very lightly used. But not for time shift solar or wind production. (Also another issue. People will want to sell only a percent of their capacity.)
Perhaps the greatest potential for V2G is standard demand shifting. When I said a maximum (and a very overoptimistic maximum) of demand shifting can be one third demand, that includes V2G. If you have a vehicle that will charge in six hours, and you plug it in at work for eight, you may well be willing to delay the charge, or to having pauses in charging of up to two hours. Better yet if you only drive five miles to work, and you can recharge that in 20 minutes, you will be willing for that 20 minutes to occur anywhere within that eight hours the utility wants, all at once, or a bit at a time as the utility chooses. Even if you use your car to eat out or run errands at lunch that does not change the equation much. (And I know there are plenty of exceptions. But this certainly will apply to many people.)
If I were a utility, increasing capacity to meet demand from electric cars, I'd want a smart grid, and I'd want every electric car to be a smart appliance that supplied the following info when plugged in for charging: How many total kWh do you want? When do you want them by? How much less than that will you accept? (If the answer to that is not zero the utility will assume that you will plug in again later to make up the difference with no willingness to accept less, so may or may not take advantage of that current willingness.)
Is there a solution to combine radical decentralism with really phasing out fossil fuels? Yeah.
One is not to be too purist. Is a mostly decentralized grid that includes a percent of long distance power that terrible a thing? Especially since other components of energy like efficiency, and low temp heat storage, and a smart grid really do lend themselves to decentralization.
The other, if you really insist on decentralist purity, is to make the hydrogen path work (not for cars, but for electricity storage). When Amory Lovins writes about the advantages of decentralized power, one thing he never explicitly says, but is implicit in his arguments is that A) either that many of them apply only to peak, not base or load following unless B) base and load following is provided by hydrogen.
True local production, even with extensive demand management requires either extensive fossil fuel use (not minor, a lot) or requires really extensive storage. Where hydrogen shines thermodynamically is if you need a high ratio of stored hours to peak demand. Hydrogen stores energy less efficiently that batteries, but not intolerably so (at least not with the really expensive types of hydrogen fuel cell and electrolyzers). But efficient hydrogen has a really high capital cost, both efficient electrolysis, and efficient fuel cells to burn it in. But if you get the capital costs of efficient hydrogen (say 40% round trip loss electrolysis, storage, and energy recovery combined) to something reasonable, and you get cheap (say 2 cents per kWh) solar then it won't cost much more to store 16 kWh of electricity than to store one. The incremental capital costs are just hydrogen storage, which is not trivial, but ultra-high either.
The bad news is that this is at least two technical improvements. You need cheap efficient PEM hydrogen fuels. (But the good news is that if you get that, you have cheap efficient electrolysis - basically the same PEM fuel cell designed tweaked to run in reverse, and optimized slightly differently.) And given you are talking 40% round trip cycle losses maybe you need really cheap solar electricity. (But of course you can use the waste heat for water heating and refrigeration. So maybe solar PV competitive with wind would be sufficient. Still a heck of a jump from where we are.)
(Note on waste heat for refrigeration - moderate temperature heat running refrigerators is existing technology.)
Any way, I finally realized why Amory is so hipped on hydrogen. It is not necessary to replace fossil fuels with renewables, but it is needed if we don't want large wind farms and large CSP solar to be responsible for a lot of that production.
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Gar Lipow Posted 6:06 am
11 Feb 2009
http://www.firstsolar.com/frequently_asked_questions.php
First Solar partners with a select group of companies in order to provide clean, renewable electricity at competitive prices. We currently do not publish a price list or disclose price information for individual projects.
So the prices I gave remain true for published known prices. Some projects which keep their cost confidential may have lower costs. And I'm not disputing that prices will drop. Even at 3,500 per peak KW solar is not yet competitive with big wind. Again, note that it is big solar that is that cheap. Installation costs for building, parking lot and roadways will be higher than ground level. (Of course mega solar will incur land costs. El Dorado owns the land they put their project on, but correct cost accounting would still charge the project for the value of using this company asset. Whereas a rooftop keeps the rain off, and adding another use to that does not detract from that value.)
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Gar Lipow Posted 6:13 am
11 Feb 2009
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Jon Rynn Posted 7:41 am
11 Feb 2009
and as for hydrogen at maybe a neighborhood or city level -- although I would be very skeptical of putting tanks of hydrogen anywhere near anything because of concerns about explosions, perhaps instead of fuel cells you could just use tanks of hydrogen, produced with excess solar/local wind, then use the hydrogen as fuel for microturbines? Assuming you could get around safety issues (maybe put the things underground), wouldn't that be much more efficient than fuel cells?
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Nickz Posted 8:11 am
11 Feb 2009
First Solar provides it's KW sales volume, and revenue $ figures in it's quarterly reports, so the $2.50 figure is pretty easy to calculate.
They're the price leader, so they're under little competitive pressure. Further, they say that costs continue to fall. A sales price of roughly 2x manufacturing cost is pretty common, so I think a sales price of $2/W in the near future is a reasonable expectation. I think that could get us to $3/W for large commercial rooftop installations.
With reasonable assumptions (25 year life, 7% interest, 20% capacity factor) we get $.15/KWH which, for S CA peak retail rates, amounts to grid parity without subsidies. A milestone.
Re: V2g
V2G stands for Vehicle to Grid. I think it might be misleading to use V2G to describe Demand Side Management as applied to electric (or partially electric) vehicles.
I agree that DSM for PHEV/EV's is more important than V2G. As you note, it sidesteps battery cost issues, as well as other complexities that come from using wires in two directions.
I think it's important to maintain clarity about the timeframe and context of our discussion. If we're really talking about a grid that has a very large % of renewables, we're either talking about decades in the future, or a world in which our society makes a much, much larger commitment to dealing with energy issues than it has so far. In such a world, a very large number of PHEV/EV's with relatively large batteries is extremely likely.
In that case, it's reasonable to assume that we're talking about over 100 million PHEV/EV's, with batteries that can effectively hold 25KHW or more. Such batteries could power vehicles for days between charges, and provide enormous flexibility for DSM (much more than the 8 hour scenario you mentioned).
Finally, it's highly likely that the 2nd generation Li-ion batteries now being put into production will last longer than the vehicles they power, rendering the cost per cycle question unimportant for V2G.
There is enormous potential from creative use of PHEV/EV's, potential that we are far from understanding. I would note just one: the motors in PHEV's are extremely efficient, on the order of diesels. A fleet of PHEV's would provide backup capacity on the order of 500GW that could be sustained for days, using engines that would be as efficient and far cleaner than most diesel generators. Would we want to use such a capability often? Of course not, but it's availability would be enormously valuable.
Again, I'm not arguing for a slavish devotion to local, micro generation. I think large windfarms are likely to be our biggest source of power in the medium term, and we should build them out ASAP.
Renewables's obstacles aren't technical, they're social: 20% of the workforce might be obsolete... http://energyfaq.blogspot.com/
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Gar Lipow Posted 8:26 am
11 Feb 2009
OK, and I agree that PV solar electricity has a good chance of matching wind on a per kWh cost within a reasonable time frame, and that whether it does or not, it is almost certain to be a great deal less expensive than today.
Joh, on hydrogen I'm not a fan at all. I'm just say that hydrogen is the tech that would enable something close to pure localism. I don't expect it in the near future for all the reasons Joe Romm has gone into. Cheap hydrogen (and even cheap hydrogen is expensive) is highly inefficient. Efficient hydrogen (and even efficient hydrogen is less efficient than batteries) is really expensive. Reasonably priced hydrogen would not be an incremental improvement. It would require a breakthrough.
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amazingdrx Posted 12:27 pm
11 Feb 2009
Will these large renewable systems be necessary when solar cogeneration reaches 70% efficiency, batteries reach 10 minute charge and 1/4 the energy density of liquid fuel, and superconducting electromagnetic energy storage goes into mass production? Nope.
Keep the HVDC super grid and the factory CSP, and recycle the wind and wave machines when that happens.
Meanwhile all sorts of people in single family homes, living on farms, and communities large and small who don't mind timing their power use and putting up with ocasional emergency backup power systems can go renewable immediately if not sooner.
http://amazngdrx.blogharbor.com/blog John Schneider, Northern Wisconsin
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xjy Posted 5:48 pm
11 Feb 2009
As amazingdrx points out, the rail corridors provide a good solution for HVDC. What this means is a really mind-boggling surge in the potential for dealing with varying needs at varying times (collecting the output of thousands of any-scale generations) not just in the US, but in Canada and Mexico too, both of which countries can add pretty substantial fuel to the flames (so to speak :-)
And this is early middle term which can be planned and trialed now, as it is being (on a near-term basis) in Europe. Which means that once more the US runs the risk of lagging behind in perhaps the most important single development in relation to the usefulness, dimensions and feasibility of renewable energy. Think of the role of transport/transmission infrastructure for industry and turnover times in past leaps - rail and steam engines for knitting countries together and making large-scale industry possible in the best locations - roads for cars and trucks - and AC transmission for electricity.
While not renewable energy in itself, and not available right at this moment, it presents such an attractive solution to all the problems raised by sceptics in relation to renewables that I think it is perhaps the single most important factor in the equation for every actor in the wind, solar, geothermal, construction, wave and tidal, heat exchange industries. Which means it should be the focus of concentrated research, development and deployment immediately.
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amazingdrx Posted 1:13 pm
12 Feb 2009
Oil is showing signs of that effect, investors are afraid to put up 100s of billoins for new oil exploration, offshore drilling, and refining unless/until prices rise and show some sort of long term trend. Those billions won't produce profits otherwise.
Wind shows profits immediately.
Here's where we are really at: over 50% of us want to go green. Under 10% of our energy use is renewable and conservation and efficiency combined barely have the combined figure reaching 10% of our energy use.
Over 50% of us are willing to sacrifice some convenience and adjust our lifestyles to do it. We would be willing to give up always on 100% centralized grid power and gas guzzlers, and go for smart grid power timing and ocasional emergency backup power and plugin hybrids that make us actually pay attention and plugin our cars.
So we have 50% of us demanding change and willing to sacrifice for it, and less than 10% market pentration of green energy conversion. There is huge growth potential, only capital for mass production is missing. Government stimulation could set a fire under this commercial wave.
As it rolls out why bother with the other 50%? Let them laugh and deride and resist, who cares? We will eventually be selling them their daily dose of kwhs.
It will take years to get to 50% so let's just enjoy it, invest early in solar cogeneration on our roofs, and ground source heating/cooling, and plugin hybrids and sit back and collect our gains.
We have the numbers to demand that we be allowed to sell our power over the grid and improve grid design to accept this green energy re-evolution. mosr of our detractors, the drill baby drillers, will join in around 2020, with the final 10% cursing us until the day they go to their rewards.
The bottomline is that we have won the political battle in terms of public opinion, but the public does not realize the technology is already here, waiting for capital for mass production. We have to wake them up by example, by highlighting successful renewable smart grid and conservation efforts.
http://amazngdrx.blogharbor.com/blog John Schneider, Northern Wisconsin
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Gar Lipow Posted 5:18 am
17 Feb 2009
This elicited an indignant email from Sabra Moallem who works for the public relations department of San Diego Gas & Electric (SDG&E'). The key paragraph:
The fact is, Sunrise Powerlink won't be used to bring in coal power to San Diego because A) SDG&E isn't contracting for coal power and B) The State of California doesn't allow it. We appreciate a correction on this story. Please let me know if you'd like to discuss further. Thank you for your time.
According to the San Diego Union Tribune of Dec. 19, 2008:
In the end, SDG&E won out when the majority voted for a plan advanced by Commission President Michael Peevey that was absent absolute regulations mandating the types of power that could be carried over the line.
The vote overruled attempts by Commissioner Dian Grueneich to draft tighter restrictions requiring proof from SDG&E that the line would be used for renewable energy.
SDG&E had said it would commit voluntarily to renewables from various sources, including the budding thermal, wind and solar industries in the Imperial Valley.
SDG&E fought successfully against requirements that it carry renewables. We are relying on their word of honor. How would you feel in normal contract if the other party wanted to give you their non-binding word, but refused to offer a contractual commitment? As to the assertion that California won't let SDG&E import coal power once the line is complete, it is true that California law won't allow them to sign long term coal contracts. But they remain free to sign short term coal contracts.
As SDG&E top executive Jame Avery testified (PDF):
SDG&E would be barred from signing long-term contracts for coal-fired electricity - under PUC regulations - but left open the possibility of some short-term agreements. But he emphasized that renewable projects were queued up, in effect, for first priority on the line, although the utility could not ban electricity from any source once the line was built,
Let's also quote from the EIS(pdf):
Construction-phase CO2 emissions for the combination of activity in both Imperial County and San Diego County would be an increase of approximately 55,000 tons for each of the two years of construction (see Impact AQ-1 in Section D.11.13.1). Operation of the Proposed Project would enable approximately 1,650 tons of CO2 emissions from power plants to be avoided in 2015 (Impact AQ-3). Over the life of the project, the net GHG impact would depends on the ability of the long-term avoided GHG emissions to counteract the increase caused by construction. Assuming long-term avoided GHG emissions of 1,650 tons of CO2 annually, based on the CAISO forecast for 2015, during every year of transmission line operation would provide 66,000 tons over 40 years. This quantity of avoided GHG emissions would not fully offset the two years of GHG emission increases caused by construction (approximately 109,000 tons). Because total construction GHG emissions exceed the GHG reductions achieved due to avoided power plant emissions over 40 years of transmission line operation, the Proposed Project would cause an overall net increase in GHG emissions and a significant climate change impact.[Note: I'm pretty sure revisions have brought this payback down to 12 years.]
There is no way payback could be this slow if a significant portion of line capacity was devoted to net increased renewables. If any significant percent of the carrying capacity of that line was used to increase renewables beyond what they would be without it, to increase NET renewables, the line would pay back construction emissions in days, or at worst weeks.
According to his same EIS, the line WILL increase fossil fuel transmission. So again my forecast is that opponents who say it is ultimately going to be used to carry cheap coal from Mexico are right, probably via short term contracts.
To summarize: SDG&E assured the PUC, via testimony that is not contractually binding, the line would not be used to carry coal. The PUC, at SDG&E's request, approved the line but passed up the opportunity to impose a binding "no coal" commitment, while assuring the public that it would take swift action of SDG&E acted contrary to its non-binding promises. I wonder: did anybody wink?
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