New House Thermal

On Monday, August 7, 2017 at 11:10:56 AM UTC-5, Steve Leonard wrote:
You could ask the folks flying at Uvalde if the solar farm just to
the east is a good thermal source or not. The center is about
2 miles to the east of the airport.

I was low there Saturday: solar farm didn't trigger, but upwind
stuff (oil production) did (fortunately).

On Monday, August 7, 2017 at 4:53:28 AM UTC-7, wrote:
On Monday, June 26, 2017 at 4:23:32 AM UTC-4, wrote:
The Treasure Coast Soaring Club will soon have a new house thermal. Florida Power And Light is in the process of building a 400 acre solar power plant within 3/4 mile from our airport. Heat from this type of farm should make for a great house thermal. Anyone out there with experience flying over solar farms? Thanks, Bob

Solar panels are being installed in a rapid pace. i would expect this and the sister project only two miles apart to be completed within late fall. this should be interesting to see what thermal activity is created.

You have a fundamental misunderstanding about solar power: they don't generate heat, they consume solar radiation (which reduces heat, much like a body of water).

On Thursday, August 10, 2017 at 8:17:40 PM UTC-7, 2G wrote:
On Monday, August 7, 2017 at 4:53:28 AM UTC-7, wrote:
On Monday, June 26, 2017 at 4:23:32 AM UTC-4, wrote:
The Treasure Coast Soaring Club will soon have a new house thermal. Florida Power And Light is in the process of building a 400 acre solar power plant within 3/4 mile from our airport. Heat from this type of farm should make for a great house thermal. Anyone out there with experience flying over solar farms? Thanks, Bob

Solar panels are being installed in a rapid pace. i would expect this and the sister project only two miles apart to be completed within late fall.. this should be interesting to see what thermal activity is created.

You have a fundamental misunderstanding about solar power: they don't generate heat, they consume solar radiation (which reduces heat, much like a body of water).

Then why is my solar panel so hot?
And why is the conversion efficiency only 10-12 percent?
That seems fundamental to me.
Soarboy

You have a fundamental misunderstanding about solar power: they don't generate heat, they consume solar radiation (which reduces heat, much like a body of water).

They do generate heat, not reduce it. From the lay literature, the efficiency of solar panels is 12-20%, while the theoretical limit is just over 30%. New advancements may beat those numbers. Maybe the glass panels act as insulators, but the heat is radiated back somewhere. Also, bodies of water and suspended particles absorb light and are heated by it; water doesn't reduce heat.

If you placed a sheet of aluminum, painted black, next to a solar panel
do you think the temperature of each would be the same?

On 8/10/2017 10:57 PM, Heinz Gehlhaar wrote:
snip
You have a fundamental misunderstanding about solar power: they don't generate heat, they consume solar radiation (which reduces heat, much like a body of water).
Then why is my solar panel so hot?
And why is the conversion efficiency only 10-12 percent?
That seems fundamental to me.
Soarboy

--
Dan, 5J

Then why is my solar panel so hot?
And why is the conversion efficiency only 10-12 percent?
That seems fundamental to me.

- it's all been explained over and over above in this thread. Steady-state temperature does not equal heat energy transfer. Nevertheless, a solar "farm" may be similar in effect to a parking lot, which is more likely to generate thermals than ground covered with green plants that evaporate water.

2G wrote on 8/10/2017 8:17 PM:
On Monday, August 7, 2017 at 4:53:28 AM UTC-7, wrote:
On Monday, June 26, 2017 at 4:23:32 AM UTC-4, wrote:
The Treasure Coast Soaring Club will soon have a new house thermal. Florida Power And Light is in the process of building a 400 acre solar power plant within 3/4 mile from our airport. Heat from this type of farm should make for a great house thermal. Anyone out there with experience flying over solar farms? Thanks, Bob

Solar panels are being installed in a rapid pace. i would expect this and the sister project only two miles apart to be completed within late fall. this should be interesting to see what thermal activity is created.

You have a fundamental misunderstanding about solar power: they don't generate heat, they consume solar radiation (which reduces heat, much like a body of water).

The panels do get bloody hot in the summer sun! They should have good airflow past
the top and bottom surfaces, given their mounting angle and clearance from whats
below them. That might be more effective at transferring the heat to air, compared
whatever surface they are built over.

I'm going to guess panels over vegetation will improve the thermal activity, but
panels over desert sand might decrease it.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/...anes-2014A.pdf

The panels are taking the place of 400 acres of orange grove. Black panels vs green trees. With thier southwest orientation, based on the initial set installed on the southwest corner, I'm thinking they will be a good source for thermals in the mid-afternoon.

After reading the recent article in Soaring about how to create teepee-shaped thermal generators, I have to think there is some correlation, if the theory is correct.

Paul A.

Paul, I have just returned from flying in Uvalde Texas for 10 days. Adjacent to the airport there was a substantial solar farm. It was very close to the airport and certainly within "house thermal" gliding distance. At no time did anyone catch a thermal over the array. For your less experienced pilots, I wouldn't even consider telling them about the possibility of getting a thermal from the area. We have a good number of very knowledgeable engineers in soaring that have already weighed in with the science involved. As the say in one of my favorite tv shows, the myth of a house thermal generated by a solar farm is "Busted!""

Still can't wait to fly at your club. When the weather cools off a little, I'll bring some of the Seminole-Lake crowd. Maybe we can do a fly-in?

Best Regards,
Rich Owen

Not necessarily! A solar farm in Texas verses a solar farm in Florida does not compare.

It's not the temperature it reaches so much as the temperature it differentiates from its surrounding area that will trigger a thermal. In Texas, especially Uvalde, the soil is dry and typically very hot. Quite the opposite in Florida, where it's much greener and wet. If that solar farm is surrounded by forest, crops or wetlands, then it would absolutely produce a sufficient thermal.