Comments on: Small-Scale Solar Thermal Capacity Is Equivalent to 245 Nuclear Plants

By: jack miles

jack miles — Wed, 07 Nov 2012 20:59:00 +0000

Nuclear is toast! We don´t need it or want it. To dangerous, too dirty, too expensive. If all homes had solar heaters installed we could do away with all nuclear and coal. It is not smart to produce electricity (specially dirty plants) and send it many miles to homes so it can be “wasted” in a glorified short circuit to heat water.

By the way a solar thermal panel has efficiencies over 85%.

By: Bill_Woods

Bill_Woods — Wed, 10 Oct 2012 06:18:00 +0000

… and ‘188 GW’ isn’t anything — you subtracted 50 GW of PV from 238 GW of wind.

By: GeorgeS

GeorgeS — Tue, 09 Oct 2012 18:47:00 +0000

Good article. Solar thermal is more efficient than solar PV and cheaper. It is good for residential but the commercial space is untapped especially in the hotel and laundry industries.

By: Matthew Todd Peffly

Matthew Todd Peffly — Mon, 08 Oct 2012 23:51:00 +0000

Two big thumbs up “fsc” you nailed it.

By: Bob_Wallace

Bob_Wallace — Mon, 08 Oct 2012 20:10:00 +0000

Obviously we can compare thermal solar with nuclear. We can compare based on cost, safety, ease to site, and time to install.

I don’t know what country you’re talking about with your coal numbers but coal use has been falling in the US. Coal provided 44.8% of our electricity in 2010, 42.4% in 2011, and fell below 35% in the first half of 2012.

We use almost no oil for electricity production in the US. Less than half a percent of our electricity comes from oil Most of the oil is used in Hawaii (which is rapidly installing renewables) and a few remote settings in places like Alaska.

I don’t think any of us even start to believe that global warming is a hoax. We do largely understand that nuclear is too expensive and too slow to install to be considered a part of the 21st Century grid.

By: Jamie Clemons

Jamie Clemons — Mon, 08 Oct 2012 19:43:00 +0000

And they don’t melt down leaving hundreds of square miles uninhabitable.

By: Madan Rajan

Madan Rajan — Mon, 08 Oct 2012 19:24:00 +0000

While we can celebrate the growth of Solar Thermal, we cannot compare it with Nuclear which runs @ 85% efficiency.

Opposition to Nuclear has helped the Coal become a bigger source. Last year, I believe Coal consumption was 3,800 MTOE which brings it pretty close to Oil Consumption, besides more heavy dirty crude is becoming more common.

If you guys believe that Global Warming is hoax. Go ahead and mock at Nuclear.

By: fsc

fsc — Mon, 08 Oct 2012 17:18:00 +0000

For a long
time I have wondered why solar heating is the ugly stepsister of sexy
photovoltaic. I have heated the water in my home and replaced natural gas
burning for two years. I am one year away from payback. You will be pressed to
get payback in 10 years with other technologies.

It is true
that solar heat will not make you 100% off-grid; but if you are considering putting
10 panels on your roof then consider a combined system of 8 photovoltaics and
two for hot water. Run the numbers and you will see the difference. If you are
considering starting small and building up, start with hot water. You get more
bang for your buck.

Nicholas:
Low grade means that unless you use expensive mirroring and tracking, the water
will not get hot enough to, say, run a metal smelter or a steam turbine. But you are right. For home use “low grade” is
definitely high enough. I had to use an isothermic mixing valve because the
water was coming out too hot for showers; and I have no intention of skinning a
chicken in my kitchen but that is how hot it was without the valve.

By: Nicholas

Nicholas — Mon, 08 Oct 2012 13:51:00 +0000

I don’t understand why it is called “low-grade heat”. It is by far the most efficient way to obtain heat from solar, because most of it is not wasted.

Almost all of it can be captured, and it is directly used to heat instead of being converted from electricity (which is inefficient).

It shouldn’t be called low-grade.

By: Nicholas

Nicholas — Mon, 08 Oct 2012 13:49:00 +0000

Yes, but that isn’t what it is being used for most of the time. Thank you for the reverse-cycle heat pump suggestion, though.

By: Louis

Louis — Sun, 07 Oct 2012 18:24:00 +0000

While it isn’t incorrect, considering many people don’t understand that difference, which makes it misleading. Is there a reason we should value your concurrence or are you just another internet expert trying to demonstrate how their position is the only intelligent one? Technically, this makes you pathetic.

By: Bill_Woods

Bill_Woods — Sun, 07 Oct 2012 17:58:00 +0000

“Photovoltaic is only 50 GW, while solar thermal accounts for the other 188 GW.”

The way I read it, PV is not included, nor CSP for electricity.

… by contrast, the perhaps less glamorous but at present far cheaper
technology of solar thermal heat collection is well ahead. …
By 2010 there was 195GW (th) installed global (118GW of it in China),
rising to 245 GW by 2011.

But as Anne said, electricity and low-grade heat are not directly comparable. If used to drive heat pumps, 1 GW of electricity can produce 3-5 GW of domestic heat.

By: JMin2020

JMin2020 — Sun, 07 Oct 2012 15:33:00 +0000

Small scale solar thermal may not compete with and replace Nuclear Power; but large scale CSP applied to molten carbonate storage systems may well do so.

By: globi

globi — Sun, 07 Oct 2012 14:14:00 +0000

Since China has approximately 150 GWth of solar hot water capacity: http://www.map.ren21.net/GSR/GSR2012_low.pdf
Chinese roofs deliver almost 3 times more output than Chinese nuclear power plants.

By: globi

globi — Sun, 07 Oct 2012 14:02:00 +0000

Nuclear power plants can also not be placed on existing roofs nor can roofs provide them with enough cooling water. In addition, uranium mining requires far more area than the nuclear plant itself.

By: Matthew Todd Peffly

Matthew Todd Peffly — Sun, 07 Oct 2012 13:48:00 +0000

Technically 245 was all solar. PV(50) and solar thermal (large and small scale) 188. So small scale solar thermal is not 245.

By: Luke

Luke — Sun, 07 Oct 2012 02:48:00 +0000

Technically, there’s nothing wrong with the title. “Capacity” is mentioned specifically – if “output” was mentioned, I might be able to agree with you.

By: Matthew Todd Peffly

Matthew Todd Peffly — Sun, 07 Oct 2012 02:15:00 +0000

Anne, I agree with you on the headline. But while you might not like low grade heat. For many applications it is perfect. And if I get it from my roof or heat it with gas or electric, it really is no different. I get hot water which is what I wanted.

By: rkt9

rkt9 — Sun, 07 Oct 2012 00:55:00 +0000

Anne, brilliant comment, I feel you are a critical thinker.
The message I got from this article, is that when we quantify solar energy, we often neglect factoring in the simple thermal energy factor that is currently being utilized from things like solar hot water for pools, showers etc.
If you have the time, (or any others that frequent this site) I would be interested in your thoughts on this recent article I read.
http://newenergyandfuel.com/http:/newenergyandfuel/com/2012/10/04/choosing-to-spend-billions-or-make-trillions/

By: Anne

Anne — Sat, 06 Oct 2012 21:04:00 +0000

“Small-Scale Solar Thermal Capacity Is Equivalent to 245 Nuclear Plants”

I find that title to be misleading.

It ignores capacity factor. 245 GW of solar (at 15% capacity factor) is equivalent to less than 50 GW of nuclear (at 75% capacity factor).

And there is more. You can not compare low grade heat (solar thermal) GW’s to high value electric GW’s (from PV, wind or nuclear). This exact same thing is done by the fossil fuel interests to downplay the role of renewables. Don’t fall into the same trap.