Solar Peaker Plants - Just Waiting for Cells?

SolarDave · Heavy Crude Joined: May 19, 2005 Posts: 377

There is a name for power generation that works only during periods of high demand, and that means the hottest, sunniest days of summer.
The name is "Peaker Plant." Solar photovoltaic installations are Peaker Plants, and they should only be compared to other PEAKER PLANT technology. Nuclear power generation is "Baseload Generation." For that matter, so is Coal. Don't even try to compare baseload and peak generation costs and performance. They are not comparable.

Peaker plants are designed to pump out lots of electricity for a very short time. They are never designed to run continuously. Here is an example:

Chicago Peaker:
Cost: $120-$150 million
Maximum run-time per year: 1500 hours
Planned runtime per year: 1-2 hours/day, 5%-10% of the year (18-72 hours total PER YEAR)
Maximum output: 300 Megawatts
Peak price/megawatt for electricity (Year 2000) $6,000/MWh
The plant is expected to generate between 5,400 and 21,600 MWh/year.
Price/MWh needed to pay for the plant in 2 years: $13,888 (5,400 MWh) - $3,472 (21,600 MWh)

Let's look at what we can get if we spend the money on Solar Photovoltaic panels:

$150,000,000 spent on PV at $5.00/watt installed: = 30 Megawatt solar plant.

If the solar plant enjoys 250 sunny days each year, it will produce roughly 30,000 MWh/year, all during peak usage times.

It looks like roughly the same amount of power will be generated per year by the solar plant, but only 1/10th as much during peak times. We would need to invest $1.5 Billion to generate the same peak capacity - 300MW - as the natural gas fired peaker plant.

However, if we invested 1.5 billion, the solar plant would generate 300,000 MWh/year, with almost all of the power being generated at peak times (and electricity costs). Let's make a guess at the return:

300,000 MWh * $3,472/MWh = $1,041,600,000

Look like the solar plant could pay back in a year and a half given the lower estimate of peak power pricing.

This posting is for discussion only, not for real. It is a fantasy to suggest that 300 MW of photovoltaic cells are available for this purpose, and that would build only ONE peaker plant. The US has >hundreds< of Peaker Plants now and many, many more planned. The price for the power is also a guess - it would probably be lower, but even if it were 10 times lower there would still be a payback during the solar plant's lifetime. On the other hand, $5/watt is a high estimate for large-scale solar photovoltaic costs. If that cost were lower, payback would be faster. Finally, it goes without saying that the cost of natural gas and electricity will all go up in the future, making the solar plant even more cost-effective by comparison.

But imagine - if we could ramp up the production of solar cells, we could profitably generate peak power with them today. And we could replace or not build many natural gas fired equivalent systems today. Solar power is not waiting for cost-effective applications. This one exists today. We are just waiting for enough solar cells to be manufactured to make a difference.

If we invested billions in solar cell production capability, instead of spending the same capital on increasingly difficult to find oil and natural gas, we would be able to start shifting to solar power for this purpose "now."

As always, please point out any calculation errors....

References:

Is Regulated Electricity Anti-Green?

Solar electric power plants (30-40 cents/KWh)
"Approximately 30 percent of Wisconsin plant’s non-coal capacity is provided by natural gas-burning peaker plants. However, they actually produce less than 5 percent of Wisconsin’s total electricity because they operate only during peak demand periods."

Global Green USA
"What we’re talking about is putting up enough solar to offset the need to turn on that peaker plant."

Peaker Inefficiency

Wisvest Corp. opens new peaker plant

Starvid · Posted: Mon Jun 27, 2005 4:52 pm Post subject:

Is this "Chicago Peaker" natural gas powered?

Anyways, solar must be compared with other "peaker plants", like hydro electricty (which is both base load and the ultimate peak load). Hydro electricity costs 2-3 cents per kWh. I believe solar power is about 15 times as expensive.
_________________
Peak oil is not an energy crisis. It is a liquid fuel crisis.

SolarDave · Heavy Crude Joined: May 19, 2005 Posts: 377

aahala · Intermediate Crude Joined: Feb 03, 2005 Posts: 954

I'm not sure I follow all your figures, but I'm pretty sure something
isn't quite right in them.

If it were really true solar cells were substantially cheaper to provide
peak power, then the solar industry would be 50 or 100 times larger
than it is. There's no inherent reason, other than demand, that the
production of silicon inputs and cell production couldn't increase greatly.

I like the idea but it isn't so because the numbers doesn't (yet) permit it.

JohnDenver · Light Sweet Crude Joined: Aug 29, 2004 Posts: 1845

There's a shortage of silicon:

SolarDave · Heavy Crude Joined: May 19, 2005 Posts: 377

aahala · Intermediate Crude Joined: Feb 03, 2005 Posts: 954

SolarDave

Here's one reason cells can't now be a lot cheaper than the peak plant.

The utilities know the numbers. If one wanted 300MW of solar cells,
they could get it within a year within current world production capacity
because they should be willing to pay a price up to the price of
the plant, which--if I take your numbers correctly--would be a lot higher
than the present market for the cells. The 300MW would be perhaps
one fourth the current world production capacity; I think you could get
a fourth by paying 50% more the present market price.

(Part of the issue is that peak can occur without the sun shining.)

MarkR · Posted: Tue Jun 28, 2005 1:57 am Post subject:

Can you redo your calculation with sensible numbers?

$6000/MWh is an absurdity - a one day (8 May 2000) result of grid mismanagement and corporate corruption. To give an example - at that price it would cost you $1 to boil water for a cup of coffee.

Typical peak power prices are in the range $70-150 / MWh, with an average of about $100.

Starvid · Posted: Tue Jun 28, 2005 5:06 am Post subject:

aahala · Intermediate Crude Joined: Feb 03, 2005 Posts: 954

There's a hierarchy of dependability from various peak power sources
and this is reflected in the cost a utility is willing to pay.

Near the top is the peak power plant. Below that is hydro -- the amount
available in the future will depend on water levels and to some extent
this will be known weeks or months into the future. Not enough time
to build new plants, but perhaps enough to scramble for other means
to provide peak.

Below those is solar. The ability to accurately predict whether the sun
will shine or not on a particular location is quite limited. Therefore this
mans of peak power will not merit the costs of those sources above it.

Even below that is wind. To use wind as a peak power source its
cost must be really low compared to the others because to assure
one unit of power will be available at a particular time, you must
have and pay for many.

The order is of course dependent of local conditions and one can imagine
somewhere on earth the sun alway shines or the wind always blows during
peak demand. Etc.

SolarDave · Heavy Crude Joined: May 19, 2005 Posts: 377

SolarDave · Heavy Crude Joined: May 19, 2005 Posts: 377

Frontierenergy1 · Posted: Tue Jun 28, 2005 9:30 pm Post subject: Solar Peaking Plants

You may want to investigate the SEGS Plants that were built near Kramer Junction California in the late 80's and early 90's. These were solar linear trough thermal plants with the following outputs: (The best that I can remember...)

SEGS 1 and 2 = 10 MW each
SEGS 3, 4, 5, 6, 7 = 30 MW each
SEGS 8, 9 = 80 MW each
and if it had been completed SEGS 10 would have been 160 MW.

I dont know of the status of these plants at present - they were designed by LUZ Corp . They operated on solar during the day and natural gas at night or low light conditons in the Mohave desert.

This is close to the 300 MW that you were discussing but at a much higher efficiency than a PV Plant. PV requires inverting DC to AC and there some losses here as well as the lower efficiency of PV compared to Solar thermal.

Not that I dont think that PV intertie is bad idea- but 300 MW of roof top solar PV would be more efficient than centralized PV Power- no line losses.

The first photo in the message titled "Solar Growing like Weeds" is one of the SEGS (Solar Electric Generating Stations) . At this point in time it is almost 20 years since the first one was constructed.

MD · Posted: Tue Jun 28, 2005 10:01 pm Post subject:

There are no technological barriers to prevent PV manufacturing from following a normal production profile leading to commoditry status. Up until now, the barriers have been market manipulation by enegy producers in the form of a market flooded with cheap oil, suppressing demand for PV.

Now that geology has wrested the primary manipulation tool from OPEC and the Majors (yes, I lump them together, the stains are still visible), demand will be able to follow it's natural course, and PV can take it's natural place in the market.

Be careful you don't read into my post what is not there. No where did I suggest PV can replace oil, nor did I suggest it would even come close. (why am I eggshell walking for doomers?..good grief!) All I am saying is that the kwh rate can drop substantially in real $ cost, and will, if circumstances allow. Germany and Japan are fortunately helping drive production by driving demand.
_________________
"Don't ever become a pessimist... a pessimist is correct oftener than an optimist, but an optimist has more fun, and neither can stop the march of events."
Robert A. Heinlein

md@peakoil.com

SolarDave · Heavy Crude Joined: May 19, 2005 Posts: 377