I really can't understand the logic of using a PV panel to power a resistive heater and letting all that potential heat gain go to waste and all that electricity for powering other essentials in the evening go to waste, ok if your offgrid batteries are fully topped off and there is nothing else to do with them but a basic thermal collector is the kind of thing I was discovering when I was filling a paddling pool with a hosepipe at about six years of age. Even in the UK it worked, but then again we had endless summers decades ago.
I've installed and used PV panels in some very remote locations, but they have all been tiny panels, no arrays, 10 - 30W mainly with a few at around 100W. Washing in hot water powered by the PV wasn't ever a design requirement or even something that would be tagged on as a desirable.
If I really wanted hot water for a shower in the middle of nowhere and had a roof at a suitable angle and orientation, by choice I'd always heat the water directly with a panel, maybe made of corrugated sheet covered by a glass panel. Trickling water using a circulating pump powered with a small PV panel or as they have done in the south of Italy and in Greece for many decades, big pipes, a large header tank and a thermosyphon.
Of course with the way some grid connected PV is metered (or not), in the assumptions made on the level of export (such as 50% of PV Generated), or in the payments from that export, all that you can use locally often benefits you to a greater extent than extra income (if any)
Compressed air is a rather low efficiency way of storing energy.
Isn't that compressed air just to run the sub station, it is 24kWhrs total, also remember compressed air makes a pretty dangerous device having seen an oxygen cylinder 'torpedo' across the room having had its regulator accidentally knocked off. Maintenance would be significant, rust on the inside is a significant issue in the long term.
I really can't understand the logic of using a PV panel to power a resistive heater and letting all that potential heat gain go to waste and all that electricity for powering other essentials in the evening go to waste, ok if your offgrid batteries are fully topped off and there is nothing else to do with them but a basic thermal collector is the kind of thing I was discovering when I was filling a paddling pool with a hosepipe at about six years of age. Even in the UK it worked, but then again we had endless summers decades ago.
I've installed and used PV panels in some very remote locations, but they have all been tiny panels, no arrays, 10 - 30W mainly with a few at around 100W. Washing in hot water powered by the PV wasn't ever a design requirement or even something that would be tagged on as a desirable.
If I really wanted hot water for a shower in the middle of nowhere and had a roof at a suitable angle and orientation, by choice I'd always heat the water directly with a panel, maybe made of corrugated sheet covered by a glass panel. Trickling water using a circulating pump powered with a small PV panel or as they have done in the south of Italy and in Greece for many decades, big pipes, a large header tank and a thermosyphon.
Of course with the way some grid connected PV is metered (or not), in the assumptions made on the level of export (such as 50% of PV Generated), or in the payments from that export, all that you can use locally often benefits you to a greater extent than extra income (if any)
Isn't that compressed air just to run the sub station, it is 24kWhrs total, also remember compressed air makes a pretty dangerous device having seen an oxygen cylinder 'torpedo' across the room having had its regulator accidentally knocked off. Maintenance would be significant, rust on the inside is a significant issue in the long term.
Creating hot water is the most effective way to use a couple of PV solar panels since close to 100% of the power generated will be used.
Nope, PV solar panels have very low efficiency and it is loosing huge amount of energy so STE is the way to go with good ROI
There are also other patents like this below-I like beter this idea of mounting such huge dish (10m), but its Fresnel lens probably costs a lot so much lower ROI than in the case of classic parabolic mirror, I guess
Nope, PV solar panels have very low efficiency and it is loosing huge amount of energy so STE is the way to go with good ROI
PV efficiency is essentially irrelevant unless you are going to argue that sunlight is a limiting resource. PV efficiency only comes into play if you have a very limited area to place panels.
Efficiency of converting the power produced by PV into heat is a different issue and is not "very low", in fact depending on how you use that electricity to heat water it can be very good.
As I stated earlier, direct solar hot water heating is often the right solution but not always. Using PV to heat water can be both efficient and economically rational in some cases.
Jesus that's the biggest lenses I've seen! bet that's a bugger to clean, or worse, replace!
BTW: Putting many square meters of solar PV pannels at 15%max efficiency is like those solar roads with hopeless ROI..
If you use the electricity only to directly heat water, you can not compare the value to electricity rates. There are often cheaper sources of heat than direct electricity to a tank. Even if you use electricity this may be a only on demand system, so you have less loss. Anyway the buffer can be smaller in an electric system.
With very small systems the PV way may still be cheaper than direct thermal, as the wire is cheaper and easier to route than tubings. But due to lower efficiency you need something like 2-5 times the area.
The maintenance comments are a "red herring",as the system proposed by the OP would need similar levels of maintenance.
After all,the storage tank doesn't know where the hot water came from,& needs most of the same facilities.