17
votes
Accepted
Why isn't heatpump technology used for solar collector panels and boiler tanks?
Heat pumps work well to extract heat from one zone and discharge it into a zone at a higher temperature. The output of solar water-heating panels is generally much higher than the boiler tank ...
- 10.3k
15
votes
What are the disadvantages of concentrated solar thermal power?
There are no silver bullets when it comes to decarbonising the grid. That's good news: it means you can stop looking for one, and accept that every form of generation has its pros and cons.
...
- 3,751
11
votes
Can solar panels absorb heat for energy?
Yes, there are indeed combined PV-T (photovoltaic-thermal) hybrid panels that turn some of the incident light into electricity, and have a circulating fluid and heat exchanger to put some of the heat ...
- 3,751
10
votes
What are the disadvantages of concentrated solar thermal power?
Everything we do as humans has consequences of some sort. Although not a huge downside (in my opinion), critics have often cited the plant's supposed adverse effects on wildlife:
Wikipedia Article:
...
- 101
9
votes
What are the disadvantages of concentrated solar thermal power?
In the UK, the sun does not shine every day. We also need the most power in winter when the sun shines the least.
Therefore every solar power station must be backed up by anther power station that ...
- 191
5
votes
Accepted
How are solar panels at equator placed?
Basically, yes, but any shading caused by buildings / other obstructions may make one direction preferential.
You can find sites that will do simulations online...
- 15.5k
5
votes
Why isn't heatpump technology used for solar collector panels and boiler tanks?
The transmission of heat by phase change (liquid to gas and gas to liquid) IS used in some solar collectors.
These are the evacuated tube type and are the "Rolls Royce" equivalent when ...
- 15.5k
4
votes
Accepted
Did I wire these solar panels correctly?
Putting a single panel in series with two other panels that are in parallel does not accomplish what you think it does. The overall current of such a setup is limited by the single panel to 200 mA, so ...
- 6,874
4
votes
Why are there no propane refrigerator air-conditioning units that run on solar heat?
It is a lot more efficient to convert the solar to electricity and run a decent heat pump for AC and normal refrigeration. Absorption refrigeration is expensive, bulky, not terribly versatile, and has ...
- 4,597
4
votes
Why are there no propane refrigerator air-conditioning units that run on solar heat?
This was my senior team project in engineering school, in 1974. Here were our findings:
The power needed to run a small absorption refrigerator can be supplied by a solar collector of about 32 square ...
- 14.3k
4
votes
How large would a solar panel array need to be in order to supply all the world's energy?
The U.S. National Renewable Energy Lab did a study of solar installations in the U.S. in 2013 and determined that for large-scale solar PV systems, 7.9 acres (31,970 $m^2$) of land are required on ...
- 449
4
votes
Why isn't heatpump technology used for solar collector panels and boiler tanks?
You can't tie these two systems together because the demands on them are pretty much independent of one another. They each need to operate according to their own run schedule. The HVAC system runs ...
- 4,597
3
votes
Thermodynamics of an Arctic Greenhouse
There are way too many details to get into here. However, do the basic first order analysis. Determine whether there is enough solar power over a day to keep the greenhouse at some temperature.
You ...
- 11.4k
3
votes
What are the disadvantages of concentrated solar thermal power?
Concentrated solar power plants are best located in isolated areas that receive a lot of sunshine all year round, which basically means arid or semi-arid regions. Most of these regions don't have ...
- 9,642
3
votes
What happens if current provided to mono phase motor is less than rated power
Torque is proportional to current. If you can't supply the full current, then the torque will be lower than it would be otherwise.
The highest current draw is at startup when the motor is not ...
- 11.4k
3
votes
How do you calculate heat transfer due to solar radiation for a multi-layer wall given the incident solar radiation and wall specs?
How complex this is depends on your needs. Once you know the solar flux, you need to calculate how much of that energy is absorbed by the wall (a function of the surface - how much is reflected? This ...
- 7,726
2
votes
Did I wire these solar panels correctly?
That's a mess, and your labels about what is + and what is - out of each panel seem inconsistant.
For the most effective use of the panels, wire them all in series. That will put out around 15 V ...
- 11.4k
2
votes
How to extract solar energy from a wall?
While black pipe in any configuration will collect heat from the sun, I recommend not reinventing the wheel. There are many companies around the world that manufacture low-cost black-vinyl solar ...
- 7,904
2
votes
How to extract solar energy from a wall?
You might want to take a look at commercial designs -- for example there are solar panels with fluid loops on the underside to extract waste heat exactly as you want to do.
Now, on a technical note:...
- 4,199
2
votes
What tools to use for a solar powered backup?
It sounds like what you are after is increased energy security. You want a backup which would have a very low load factor - it wouldn't get much use each year. You want fast response, times of high ...
- 3,751
2
votes
Accepted
What material (preferably relatively inexpensive), can I use for absorber in a fresnel solar concentrator
Crucial to this is how you intend to exploit this energy as this will be very significant in how quickly and uniformly heat is extracted from the target.
3000F is outside the working range of most ...
- 15.2k
2
votes
CUF v/s PLF of power plants
Plant load factor and capacity (use) factor are two names for the same thing: the ratio of mean power to rated nameplate capacity.
Capacity factors between very similar or identical technologies that ...
- 3,751
2
votes
Accepted
What is the solar window (solar altitude angle range) of Bangalore?
Earth axial tilt is 23.5°. For 11°N the solar altitude at noon of the equinoxes will be 90-11=79°; 90-11-23.5=55.5° at winter solstice and - it would be 90-11+23.5=102.5° at the summer solstice, but ...
- 6,125
2
votes
Accepted
What's the name of this parameter?
It's the temperature coefficient of the panel. It varies by panel, but 0.005 (0.5%) is a fairly normal value for it. Its unit is 1/degree C. It's the rate at which cell efficiency drops off, as the ...
- 3,751
2
votes
Accepted
Which kind of thermal oil is used in solar thermal power plants and how are they produced?
Solar heating systems have been designed with many different fluids depending on the ambient temperatures and max desired temperature.
The ambient temperature is because the night-time temperature or ...
- 15.5k
2
votes
Why do monocrystalline solar cells have rounded/cropped edges?
the monocrystalline cells are thinly sliced off cylindrically-grown single crystals that look like logs. Each wafer thus produced is hence a circular disc. To make the resulting solar cell function ...
- 14.3k
2
votes
Accepted
Best metal for solar energy collection in an evacuated tube solar water heater
Copper sheet with an absorbing and poor emitting coating is available which is easy to solder copper pipe to the untreated reverse side. Guess why many flat plate collectors are made like this…
As for ...
- 15.5k
2
votes
Can air currents be used to keep dust from settling on solar panels?
Our panels stay relatively dust free as they are at an angle of 70 degrees.
This means the rain flows off nicely taking dust with it and the snow slides off as well also taking dust with it.
Having ...
- 15.5k
2
votes
how much energy is stored in a car under sun ? (car interior)
You would need to find the specific heat capacity of all the materials inside the car, which might be difficult to get, but as a first estimate you can start with the air in the car. It's specific ...
- 821
2
votes
Need a solar powered mechanical motor? that moves a leaver up and down low force and little distance on day/night
Most easy way is to buy inexpensive garden water timer. Simplest one contains ball valve with motor, two dials for setting watering period and time and is powered by two 1,5 V cells.
If you wish non-...
- 287
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