Too much electricity, T1's take on it

[T1 Terry]

I've started this thread to try and focus one of the directions a bit, so here goes:

What can you do with the excess energy produced when it's not needed for immediate use... I suppose the first question is, why have that much solar or other energy generation in the first place. I guess it's a bit of a carry over from the old lead acid days, you have to fully recharge each day so you must be in float as early as possible to allow the max time for absorption charging to squeeze the last 20% into the batteries. With lithium batteries this is no longer an issue, they don't need to be 100% charged except for instrument recalibration, particularly the BMV 100%SOC reading, but that's about it, it's not for the batteries sake as such. So, some of the excess solar is a carry over that was fitted before the battery change so an unintentional excess. Others it's for more practical and dual purpose use, so I might start with that one.
Solar panels make great tropical roofs, the latest discover, thanks to young Eddie, is they make great window shades too. I'll let him put up a story and photos of how that works, but it works amazingly well. Now you end up with a huge over supply potential, rainy crap solar weather no longer exists but a lot of untapped potential is available when the solar conditions are good, so what can it be used for.........
Any ideas?

T1 Terry

[Busman]

Hmmm, lets see, storage, nopes batts are full, cooling, probably if the solar is abundant it is warm enough to need aircon ???

Run the eutectic fridge, another form of stored energy, maybe. Any phase change device.

What about welding up that broken bit ?

How about charging the electric toad, the Tesla, who are about to start flogging cars here ?

Seems to come into just 2 categories storage or use it now. The problem with "use it now" is you have to find some use that is not dependent on you having excess or in other words if there is only enough energy available to fill your batts, the alternative use does not matter.

Not sure about the extra being left over from LA thinking, in our case it is "fill up the real estate so we still have input even on the crappiest of solar days"

[bagmaker]

you could sell it to the neighbouring camper, save them starting their generator.

[T1 Terry]

I think that was Eddie's plan I remember someone getting rather upset last Easter when an offer of free power to replace a generator run was offered, generator owners get rather touchy about their smelly noise makers

T1 Terry

[dapope]

3rd time lucky
We carry a 15a charger for those in need either via the batteries or the generator

[Dot]

Still love my dependable and quiet genny

[T1 Terry]

What about Hybrid drive? You could add an electric motor and controller that coupled to the original engine and add 50Hp or more when you needed it to climb that hill or overtake, or even just to get moving again on a hill start. It would double as a brake retarder on the long down hill runs recharging the battery rather than wearing out the brakes. Well, that's the plan for Big Bus aka Rustic Inn Perfection. The 3kW of solar can recharge the batteries while we are parked up.... or maybe get our money's worth on caravan park stop over. Empty the grey water, fill the fresh water, do the washing, recharge the batteries and shop or site see if we still have time

T1 Terry

[Busman]

Thought of this but way out of my range. I remember (vaguely) we touched on this after the third bottle of red when you visited. How doable is this actually ? I would love another 50 hp at the touch of a button but is the cost/benefit there?
I have 2 Kw of solar now, could easily add another Kw on the trailer, what sort of battery bank are you talking about?
What sort of amps is pulled from a bank by a presumably 50 hp motor ?
How do you connect is so it is not running all the time ?
Assuming this is AC ? What volts ? Battery bank would require series config, wouldn't it ?

See what you have started !!!!

[T1 Terry]

Hmmm...... how long do you want the 50Hp for? this will determine motor size and voltage. 50 hp for 1 min could be achieved with a relatively small motor and controller running 48v, basically the 24v battery pack split in half, normally run as 2 separate batteries linked in parallel using 2 control circuits, the second pack switched to series connection with the first pack when required as either a load supply or a load dump if using this as regen, then returned to parallel connection when using the system as house batteries. 48kw or 64Hp would draw 1,000 amps so it would require 350Ah @ 48v. You wouldn't reach the 1,000 amps as you are only looking for 50hp, even with the motor and controller losses and the battery voltage would not drop to 48v, but if you look at the max figures, it could be done with a 700Ah @ 24v nom. battery system.
The one planned for big bus is a little larger than this, the motor can handle a lot more than the controller can dish out but 135kW would be a continuous rating if I could figure out how to put in enough batteries to supply the 450v for more than 20 mins As I'm not expecting to use any where near full power for more than a min and continuous use at even 50% would be no more than 5 mins, there is a big margin of capacity available. mind you, on solar along it would take 10 days of good sun to recharge a fully discharged pack but 2 days in a caravan park combined with solar would do it easy

T1 Terry

[Busman]

Head is spinning, think I might just add a bit of lpg !