What happens to excess solar power?

SimonM

SimonM

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I’ve got an MPPT controller now fitted, but obviously the sun is low when it deigns to shine and I’m getting about 2.2a at the moment while the MH is parked up at home. It’s just about putting some charge back in.

However, when the sun finally starts to contribute a great deal more and the batteries finally get to be topped up to the brim, what happens to the excess power that is now no longer being utilised?

I already have it set up to send an amount also to the starter battery.
 
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The regulator cuts in and controls the amount of charge. If you have an AES fridge the excess can be used to operate it on 12v .
 
Phil should be able to answer that because his set up produces several Megawatts o_O and even he can`t use all of it :eek:
 
SimonM said:
I’ve got an MPPT controller now fitted, but obviously the sun is low when it deigns to shine and I’m getting about 2.2a at the moment while the MH is parked up at home. It’s just about putting some charge back in.

However, when the sun finally starts to contribute a great deal more and the batteries finally get to be topped up to the brim, what happens to the excess power that is now no longer being utilised?

I already have it set up to send an amount also to the starter battery.
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The situation is similar to the one in houses that are connected to the national grid, Simon.
The occupier can choose to have all electrical appliances turned on at their switches and electrical power can then flow from the power generating station through various cables to the appliances which then do their thing heating, cooling, mixing........
The occupier can then decide that they can only cope with so much fun and progressively turn some appliances off at their switches. Less power is then taken from the generating station.
This situation is analogous to the solar panel (generating station), solar controller (appliance switches) and leisure batteries (household appliances) in a Moho.
The controller senses whether the leisure batteries require power from the solar panel and switch the connection between the two on and off as necessary.
Solar panels have the potential (pun intended) to supply current but only do so when connected to an appliance via a solar controller which allows current to flow.
I hope this helps.

Colin ???
 
Colin, it certainly makes sense thank you. I suppose I’ve Heard of too many instances of overcharging woes from back in the days of zener diodes and failing rectifiers on bikes overheating and causing other problems.
 
What I do is charge everything that needs charging in the morning because otherwise the MPPT just clicks off by 11am on a sunny day in Spring or summer. If I have stuff to do on the laptop, work or music ill try and do it in the morning. I always keep the laptop fully charged though on its charger though but I find that you can pretty much use all that solar power as much as you like in the first part of the day and then it catches up in the afternoon. I dunno if this makes any sense. Ill get my coat. :(
 
barryd said:
What I do is charge everything that needs charging in the morning because otherwise the MPPT just clicks off by 11am on a sunny day in Spring or summer. If I have stuff to do on the laptop, work or music ill try and do it in the morning. I always keep the laptop fully charged though on its charger though but I find that you can pretty much use all that solar power as much as you like in the first part of the day and then it catches up in the afternoon. I dunno if this makes any sense. Ill get my coat. :(
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Exactly so.
 
Doesn't the excess just make the panels run a little bit hotter, after all the wasted energy must go somewhere.
 
shaunr68 said:
Doesn't the excess just make the panels run a little bit hotter, after all the wasted energy must go somewhere.
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In simple terms the panel is not 'working' unless current is being drawn in a similar way to a disconnected battery. Electrical heat can only be produced if current flows and voltage is dropped across a resistance.There is no wasted energy the panel is not storing it.
Similarly the alternator in a vehicle continues to turn even when the battery is fully charged. There is no wasted energy because the regulator ensures that no current is drawn.
 
What happens to the excess? What do you think makes the sun shine ? Obvious init, simples !
 
Trotter said:
What happens to the excess? What do you think makes the sun shine ? Obvious init, simples !
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That explains a lot! all these people with their solar-panel fitted Motorhomes doing the NC500.... No wonder the weather up here is so horrible :(
 
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