That is a pretty good way to track MPP... I suppose there is no such think as partial shading in space ? Otherwise you have to work even harder at it.
You can also find the max power point by measuring the Voc and then running at a fixed percentage of that open circuit voltage. If not THE MPP, it's a good starting point at least for non-shaded PV arrays.
Making the hardware efficient to within 99.7% is going to cost a lot of money and be larger than wanted. It's easier to get high efficiency with larger systems than anyone has talked about here on SED. Besides, PV is inexpensive enough these days, just buy an extra module or two. That will most likely be less expensive that trying to find an MPPT controller that is greater than 99.5% efficiecent.
Also, designing the system so that the PV Vmp is at or below battery voltage is not a good idea. These days you can design the system so that the Vmp is always at least one PV module's nominal voltage is above the nominal battery voltage so even if one panel gets shaded, the rest of the array's Vmp will be above battery voltage. Designing this way also keeps the copper loss smaller, especially if the array is far away from the batteries and controller. You will lose more than that 0.3% just in the copper wire anyway, typically.
I was meaning that depending on the situation, you might not be able to find an MPPT that is 10$ more efficient though ? MPPTs are usually in the low to mid 90% range hardware efficiency as it is. Some even really high. BUT accurate efficeicency is hard to measure from what I have found.
If his basement was incredibly well insulated he probably wouldn't even nee d a heater. There is usually enough appliances in the basement that it can stay warm. Typically it is the windows that let the heat in/out. Absent those it doesn't take too much to keep a place warm or cool.
--
Rick C.
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They don't use efficiency, they use a measure called coefficient of perform ance, COP, which is ratio of useful heat output to totality of input energy required to produce it. Electric resistance heating actually has higher CO P than the average fossil fuel burner, but the cost factor does the electri c in.
If a utility burns gas to make electricity, and I use that electricity in resistive heaters, to heat my house or to heat water, I *think* it would be more efficient to burn the gas locally, for the heat.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
re like NT not understanding what is being said and.
old, dry air is then passed over the other end of the heat-pump circuit to warm it up again (and recondense the refrigerant that little bit faster).
oes lower its RH.
ic properties, which is on average lower in moisture content, and which the n drops RH as it warms.
an indoor air, or warmer or cooler. Swapping air with the outside world is ventilation.
anism by which the great majority of houses are dehumidified.
If you are getting worried by damp patches on the walls, dehumidifiers atta ck the problem directly. NT is in evasive mode here.
old, To remove the moisture you must cool the air to below the dew point.
el dehumidifiers don't use chilling at all. Nor do box-of-salt type ones, e ven though they're of minimal use.
, but some hardware stores cater for people with little money and even less sense. As NT admits, they don't work well enough to be of much use, and th ey certainly aren't cost effective.
enerated by heating, but strictly for tiny volumes of air.
merely an invitation to enter into his spiral of madness. I'm not intereste d in doing so & don't care what he has to say.
helpful pontification.
I've never seen one. What sort of volume are they used to desiccate?
Laboratory desiccators have a volume of a couple of litres, and silica gel works fine for them. Anything bigger and the approach gets impractical.
Ignoring dessicant wheel humidifiers is being less than comprehensive, but they wouldn't have been an option for Dan's basement and skipping any refer ence to them didn't make "To remove the moisture you must cool the air to b elow the dew point" any kind of half truth (which implies a deceitful omiss ion, even if NT were is too dim to appreciate what he was saying).
noun: half-truth; plural noun: half-truths
a statement that conveys only part of the truth, especially one used de liberately in order to mislead someone. "the nuclear industry has often resorted to half-truths and cover-ups"
That's exactly the approach I was using: set the buck converter's UVLO setting to near the 45-degree edge of the IV curve, so that's where it was always running. At low levels, a large electrolytic saved up solar-panel energy in that region and extracted energy in chunks whenever enough had built up. Other than the capacitor and the ULVO setting resistors (assuming accurate hysteresis UVLO), no other parts were required.
The wheel slowly rotates, drying room air on one side, and drying the desic cant on the other. Pass hot air through it, which then circulates around a metal compartment. The metal is cooled by the room air, forming condensatio n thus removing damp from the compartment. Condensate drips into a containe r or down a pipe. These machines are ideal for unheated spaces, where compr essor types become near useless. For always warm areas the compressor type gives better energy efficiency - or can if well designed.
more like NT not understanding what is being said and.
cold, dry air is then passed over the other end of the heat-pump circuit t o warm it up again (and recondense the refrigerant that little bit faster).
does lower its RH.
stic properties, which is on average lower in moisture content, and which t hen drops RH as it warms.
than indoor air, or warmer or cooler. Swapping air with the outside world i s ventilation.
chanism by which the great majority of houses are dehumidified.
. If you are getting worried by damp patches on the walls, dehumidifiers at tack the problem directly. NT is in evasive mode here.
cold, To remove the moisture you must cool the air to below the dew point .
heel dehumidifiers don't use chilling at all. Nor do box-of-salt type ones, even though they're of minimal use.
ts, but some hardware stores cater for people with little money and even le ss sense. As NT admits, they don't work well enough to be of much use, and they certainly aren't cost effective.
egenerated by heating, but strictly for tiny volumes of air.
s merely an invitation to enter into his spiral of madness. I'm not interes ted in doing so & don't care what he has to say.
unhelpful pontification.
l works fine for them. Anything bigger and the approach gets impractical.
t they wouldn't have been an option for Dan's basement and skipping any ref erence to them didn't make "To remove the moisture you must cool the air to below the dew point" any kind of half truth (which implies a deceitful omi ssion, even if NT were is too dim to appreciate what he was saying).
deliberately in order to mislead someone.
"
so when his ignorance has been shown he comes out with more ignorance & bs. What's new.
You must know the 45 degree curve is a moving target. The constant current level will vary with insolation and the constant voltage portion of the cu rve will vary with the temperature. So you will give up significant effici ency area by not adapting to the the moving knee of the curve.
What your system is doing is essentially setting the voltage output of the solar cell to a constant level, a rather crude approximation to the MPP.
--
Rick C.
-+- Get 1,000 miles of free Supercharging
-+- Tesla referral code - https://ts.la/richard11209
s more like NT not understanding what is being said and.
he cold, dry air is then passed over the other end of the heat-pump circuit to warm it up again (and recondense the refrigerant that little bit faster ).
it does lower its RH.
mestic properties, which is on average lower in moisture content, and which then drops RH as it warms.
r than indoor air, or warmer or cooler. Swapping air with the outside world is ventilation.
mechanism by which the great majority of houses are dehumidified.
on. If you are getting worried by damp patches on the walls, dehumidifiers attack the problem directly. NT is in evasive mode here.
he cold, To remove the moisture you must cool the air to below the dew poi nt.
wheel dehumidifiers don't use chilling at all. Nor do box-of-salt type one s, even though they're of minimal use.
nuts, but some hardware stores cater for people with little money and even less sense. As NT admits, they don't work well enough to be of much use, an d they certainly aren't cost effective.
regenerated by heating, but strictly for tiny volumes of air.
is merely an invitation to enter into his spiral of madness. I'm not inter ested in doing so & don't care what he has to say.
r unhelpful pontification.
gel works fine for them. Anything bigger and the approach gets impractical.
but they wouldn't have been an option for Dan's basement and skipping any r eference to them didn't make "To remove the moisture you must cool the air to below the dew point" any kind of half truth (which implies a deceitful o mission, even if NT were is too dim to appreciate what he was saying).
d deliberately in order to mislead someone.
ps"
s.
NT finds "ignorance" in any post which doesn't absolutely share his (freque ntly bizarre) point of view, and "half-truths" in any formulation that he d idn't come up with.
The volume of bs he posts based on this eccentric point of view is enormous , and the useful content non-existent. He doesn't like it when he gets call ed on it.
That makes him one more of our resident wastes of bandwidth. I waste a litt le more bandwidth being rude about him, which I shouldn't, but some itches do get scratched.
iccant on the other. Pass hot air through it, which then circulates around a metal compartment. The metal is cooled by the room air, forming condensat ion thus removing damp from the compartment. Condensate drips into a contai ner or down a pipe. These machines are ideal for unheated spaces, where com pressor types become near useless.
I wonder why NT thinks that? Passing hot air over the drying half of the wh eel and letting the room air cool the desiccant enough to let it work again as a desiccant is heating the space being dried.
The thermodynamics aren't going to be impressive. Heat pumps are designed t o be thermodynamically efficient, and they can certainly take water out of the air in unheated spaces - there isn't much there to take out when the ai r is cold, but that doesn't stop them taking out what's there to be extract ed.
- or can if well designed.
NT clearly hasn't got a clue about thermodynamics or vapour pressures. Ther modynamics is notoriously hard to teach, and NT is rather too willing to st op thinking when he fixes on a delusion that he likes.
nt level will vary with insolation and the constant voltage portion of the curve will vary with the temperature. So you will give up significant effi ciency area by not adapting to the the moving knee of the curve.
e solar cell to a constant level, a rather crude approximation to the MPP.
Yes, a fast autotuning is a lot faster than a periodic sweep
re like NT not understanding what is being said and.
old, dry air is then passed over the other end of the heat-pump circuit to warm it up again (and recondense the refrigerant that little bit faster).
does lower its RH.
tic properties, which is on average lower in moisture content, and which th en drops RH as it warms.
than indoor air, or warmer or cooler. Swapping air with the outside world i s ventilation.
hanism by which the great majority of houses are dehumidified.
. If you are getting worried by damp patches on the walls, dehumidifiers at tack the problem directly. NT is in evasive mode here.
old, dry
eel dehumidifiers don't use chilling at all. Nor do box-of-salt type ones, even though they're of minimal use.
ts, but some hardware stores cater for people with little money and even le ss sense. As NT admits, they don't work well enough to be of much use, and they certainly aren't cost effective.
egenerated by heating, but strictly for tiny volumes of air.
merely an invitation to enter into his spiral of madness. I'm not interest ed in doing so & don't care what he has to say.
It's not electronics but I'd say it is about the same amount of work and it does involve some soldering of copper just with much bigger joints. It will function considerably better although obviously it works best in midsummer when you might be glad of the cool air in the basement.
esiccant on the other. Pass hot air through it, which then circulates aroun d a metal compartment. The metal is cooled by the room air, forming condens ation thus removing damp from the compartment. Condensate drips into a cont ainer or down a pipe. These machines are ideal for unheated spaces, where c ompressor types become near useless.
because it's correct
r cool the desiccant enough to let it work again as a desiccant is heating the space being dried.
you don't say
they're quite practical.
some refrigeration dehumidifiers are, some clearly aren't
re isn't much there to take out when the air is cold, but that doesn't stop them taking out what's there to be extracted.
so another topic you don't know enough about to avoid bsing.
y - or can if well designed.
ermodynamics is notoriously hard to teach, and NT is rather too willing to stop thinking when he fixes on a delusion that he likes.
I (Jeroen) wrote: > > snipped-for-privacy@gmail.com wrote: > >[Snip!] >
Now that I understand better how that MPPT circuit is supposed to work, I simulated it (in C, not in LTspice). It works very nicely indeed, periodically shifting back and forth a few percent over the optimum at both sides. The averaged power drawn from the array is well over 99% of the optimum, as you stated.
A very nice feature is that it needs to know neither the number of cells, nor the expected current. A very nifty circuit indeed.
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