Should You Really Use Solar Panels?

I think your to deep keep it simple

The exposed bare pex should be painted as pex is NOT sunlight resistant. It will get brittle and crack and then you’ll have to repair it

Why not use sterling generators, or other methods to extract electricity from the hot water tanks?

two questions, is Pex better to use than copper tubing?

Second, is it actually UV resistant? Most plastics degrade rapidly in the sun, even when painted.

Will America ever go metric? Are the temperatures you quote in these videos Celcius or Fahrenheit? Being scientific in nature, I would hope that you use Celcius.

Isn't PEX insulating? Will Metal tubing work better?

really late question here but in my head it makes sense. would painting this in something like vanta black increase the efficiency of this setup any more? honestly its probably overkill.

Sure you can compare the power output of PV versus thermal, but it stops short of illustrating the versatility of PV power/electricity. Today you can use PV power to drive a heat pump water heater, and suddenly solar thermal is no longer more efficient. Also, when your thermal storage has reached maximum temperature there's nowhere else to use the thermal power. With PV, you can use its versatility for a multitude of other applications. The era of solar thermal applications is quickly fading into the sunset.

Isnt using copper tubing better? Yes its more expensive but aluminium or copper or any easy to bend metal tube should be better, no? Also as an upgrade would painting it with vantablack or any other super dark paint raise its performance to way higher what it currently does?

How much would the result be effected is no glass was used and direct sunlight was used to heat the pipes

Solution to the water freezing is to use a drain back system. When the pump shuts off, the water drains back to the tank.

Thought this guy was intelligent, till I heard him say "hot water heater", which imo is the peak of ignorance. (Fun fact, there is no such thing as a "hot water heater", as hot water doesn't need to be heated, as its already hot. The proper term is just "water heater".)😚

It would be interesting to see the solar panel heating the water with a heat pump

Will you be doing a wind generator setup

Yes, thank you the energy stuff is very useful!!!!

An economical alternative is to get a scrapped two glass window that is possible to open. Paint bottom black and mount the hose.

I haven't got to the end yet but I'm thinking the solar hot water heater is going to give the solar panels a spanking

I like your videos, but you need to pass along to your son that he's not Martin Scorsese 😁

I feel like there is a flaw with this setup, but I could be wrong. To be clear I only have a cursory knowledge of relevant topics.
WIth the electric heater system, it will happily continue to dump heat into the water, which will heat the resistors, causing them to to increase in resistance, which means they should ramp up in heat production? Not 100% sure, but I know heat means higher resistance, and higher resistance means more heat.
Not sure how this will effect things, since the system cannot produce more power, I think it might reduce efficiency because it might pull down the voltage? Again lacking knowledge.

With the solar water heater however, my first issue is that the pipes do not cover the same area as the solar, not 100% sure on how that effects things, since it heats the box, and the box heats the pipes, so it might be fine, and I know you can't fill the box without reducing pump efficiency. That aside though, the solar water heater differs from the electric heater, it loses efficiency quickly as the water heats up. Ideally both would have some way to pull the energy away from the system, such as a heat pump, and measure how much it produces at peak continuous load.

Very nice conparison. If we're comparing built vs bought, should we also compare what it would cost to build a solar panel, versus buying one?

You might notice that as the water temperature rose the solar hot water system became less efficient.

Once the water gets to a useful temperature thermal losses will be quite high.

This is why commercial systems use evacuated tube collectors.

Doing these by DIY is much harder than wiring the output of some solar panels to a heater.

Should have used copper pipes or coil

I've always wondered about using a solar heater like this as a heating element for an einstein/absorption fridge based cooling system. It could theoretically be totally passive, or just a small fan for air movement inside on the cooling element. Finding suitable/safe chemical elements for relatively low pressure (pvc pipe, etc) has been the hard part. Would love to see you do a proof-of-concept on something like this.

I have a 9.6 Kw peak grid tied pv system to replace some of my electrical load and a solar water heating system to replace some of the propane gas fuel cost. Both systems do not replace all of my energy loads, but, they definitely do help. I am located 30 degrees north of the equator in north America and we get a LOT of sun most of the year. Might as well use it, as it would otherwise just heat the roof of the house. The solar water system is 25 years old now and I have had to service the panel on the roof once and just replaced the pumps in the heat exchanger this year. Set for another 25 years, I guess.
Thanks for all that you do and introduce our younger generation to the application of science.

You caan increase a bit the eficciency and lifetime of the solar absotpion by coating the painted tubes in strong solar cream

this guy is such a dbag

You couldn't do this small scale but it would be interesting to see a difference with using the PV with a heatpump water heater. I think that might bring it close enough whate the benefits of being able to use more of your land space for PV. That's my current limitation I jave very little usable space where I can align panels due south, our garage roof is oriented SE and the house roofline is to the west on perpendicular to the garage.

Apples to oranges. Thermal energy is a lot easier to capture and store.

every glass surface refects ~4% of the light

Great video! I think maintenance should also be taken into account, I would like to hear your thoughts having both systems on this. For example has the silicone/sealant held up in the sun, and the wood or other parts of the system etc

Great content. Love your work and style 👏🏻👏🏻

I think they are calling these "hydronic" systems now

This video is now dated since in many areas of the country now PV with batteries is cheaper than the grid and the main reason to be grid tied could be seen as the batteries making money from participating in grid stability, as Tesla is proving in various States and Countries.

In addition, PV feeding a Heat Pump Water heater beats plain thermal hands down. Showing that may not be too hard for you to do.

In addition, as others have noted, cooling the PV panel, at additional cost, further increases the efficiency of the PV system.

I installed two.4x10 thermal panels with 120 gal hot water tank in 1990 at my home and 8.2 kW of PV in 2016, which then made the house net-zero in energy use (thanks to insulation better than code plus other "upgrades"). Today, an additional 1.4 kW of PV plus a Heat Pump Water heater would replace the old plain passive thermal panels.

Your videos are excellent, first rate.

I wonder if using the electricity from the panels to run a heat pump will compete with the solar heater.

What was the air temperature while doing this test?
Do you think it would be worth it to make a radiator heater that can provide heat from solar water heater?
Thanks

than s
Is it possible to increase the efficiency of the water system by emptying the panel of air?
"This can be done by adjusting the edges with silicone and a refrigerator motor" ☺

Use magnifying glass to heat the inside, can burn or boil

Mostly great content on your channel. Keep it up.

Answering the question of “Should You Really Use Solar [Photo Voltaic (PV)] Panels”, however, is in the real world entirely driven by application. If you need electric power, as most do, the electrical conversion efficiency of most anything other than PV panels is zero.

You may also want to note that your claim that PV makes, “economic sense only because of tax subsidies” is old information and therefore no longer accurate. Subsidies may have been needed years ago to get off the ground, but today PV and wind power have dropped to less than $.05/kWh and are now even competitive with hydro electric power. Even with the cost of storage added in these renewables are lower cost than fossil-based peaking power, and certainly much cheaper than nuclear power. The only interests keeping this competitiveness myth alive are the fossil and nuclear lobbies. Similarly with concerns about proper disposal at end of life. These costs are perfectly manageable for PV because the trace elements still have value and can be recovered economically for reuse. But even if not, dealing with this would constitute a fraction of the cost of the much more highly toxic nuclear waste because that needs to be stored at enormous public expense virtually forever.

So yes, we all really should use PV as our primary source of electric power at least until all nuclear power plants have been retired, which appears unlikely anytime before earth's orbit is swallowed up by our own sun upon becoming a red giant star, at least if corporate utility monopolies have any say in the matter.

Pipes and pump on one is in the sun the other shaded. Also, "prebaked".

I always wanted to build a solar water heater to tie into my hot water tank to preheat the water on warm days... Could save quite a bit of electricity over time

Great video! 👍 I was curious if using a 2-way mirror below the insulator glass, and above the e-glass might increase efficiency. Just a thought.👌

How about using waste heat from your air conditioner to heat water? In South Florida, we run our AC like 12 months out of the year unless there is a cold front or something.

This solar PV water heating subject has been a pet peve of mine for over 40 years, the length of time I have culled FREE HEAT from the Sun, using a flat-plate collector thermo-siphoning to an elevated insulated water storage tank.

To me, turning warm sunlight into electricity in order to turn it back into heat again is "stupid" gone to seed!

Just my opinion, but an opinion based on 40+ years of FREE hot showers. I'm 75.

This is my second post here.

If you want to have FREE hot water year round you could do what I have done, which is to make a tracking solar concentrator that uses peanut oil as a working fluid.

Peanut oil holds a plethora of heat and will not evaporate or freeze.

I use a copper heat exchanger running through the vat of hot oil to exchange heat to make domestic hot water as well as water for space heating, and it works like a champ.

My tracking panel will get the oil up to 500°F* on a clear day no matter what the air temperature is, so it can be VERY dangerous.

I homestead in rural North Texas and mostly use my tracker to make live steam and generate my own electricity.

* My 3" x 18' round flat tracking mirror operates at a 600:1 concentration.

In the desert areas; can the system be run bass-ackwards at night for (eg) dumping heat from refrigeration?