Pondering the notion of using an i3 as the basis of a home hydroelectric power setup. Why is this a bad idea...?

[Obioban]

I'd like to set up a home hydro electric generator and house battery. Annoyingly, the traditional components to do this are pretty crazy expensive.

That said, used i3s are cheap and seemingly have almost all the components I'd need on board (everything other than some gears and a transformer)?

Here's my basic, afternoon of pondering, concept:
1) Donor i3 is left in the "on" position 100% of the time.
2) Water wheel is geared directly into the rear axle such that it charges the battery via regen. If the battery gets full, the car would automatically switch over to coast mode with no input from me, so it’ll never be overcharged
3) House would be connected to the battery via inverter.
4) Battery temperature regulation would continue to occur via the cars standard battery heating/cooling system
5) Everything in the car is weatherproof, so it could just be parked in the mill house and not worried about beyond that
6) If we had a drought or our needs outran the battery capacity/power generation, the REx could step in to give us a bit extra
7) Unlike solar, hydro generates around the clock—so I could program the normal (driving) cars to only charge after we go to bed. This would maybe allow them to be charged (at a reduced rate) without depleting the house (donor i3) battery, significantly reducing the size of a home battery we’d need (and I believe the 2017 i3 battery is already 2x the capacity of a Tesla Powerwall). In a pinch, where we need a fast home charge for some reason, could do a high speed charge off the battery.
8) use the rest of the car as a parts car for my i3 as things break :lol:

I’m sure this is actually a terrible idea somehow. What am I missing?

 

[DaJemster]

Man...you're stable is growing. Soon you'll shoehorn the spare i3 into your Suburban if you need to transport it somewhere :lol:

 

[Obioban]

Man...you're stable is growing. Soon you'll shoehorn the spare i3 into your Suburban if you need to transport it somewhere :lol:

I'd buy a lightly crashed car for this project-- not convert my existing good one.

I feel like I must be missing something here-- seems too easy. Waiting for someone to drop the other shoe on me...

 

[vreihen]

Waiting for someone to drop the other shoe on me...

How about dropping an army boot on the idea...the Army Corps of Engineers? Rumor has it that they don't have a sense of humor when someone messes with water flows these days.....

 

[Obioban]

Waiting for someone to drop the other shoe on me...

How about dropping an army boot on the idea...the Army Corps of Engineers? Rumor has it that they don't have a sense of humor when someone messes with water flows these days.....

Seems like it shouldn't be too bad:

Whether your system will be grid-connected or stand-alone will affect what requirements you must follow. If your microhydropower system will have minimal impact on the environment, and you are not planning to sell power to a utility, the permitting process will most likely involve minimal effort.

source: https://www.energy.gov/energysaver/planning-microhydropower-system

 

[robthebold]

The i3 has a differential, so I guess that means you'll have to lock the opposite wheel in order to generate power.

And also since it sounds like you already have a waterwheel in your mill, environmental concerns are "grandfathered in".

 

[gps1539]

Power via water wheels is a great, 100+ year old idea (birth of the industrial revolution).
However, not sure if connecting your i3 is the best way to harness the the energy

 

[jadnashuanh]

A typical water wheel doesn't turn all that fast, but if you start to add gears or pulleys, you add more drag. The regen on the i3, like most, depends on the rpm...I think to maximize it, you'd need to gear that up.

BMW has demonstrated using an i3 battery pack as an energy storage solution, but I've not heard of them selling them (yet). You might talk to corporate.

There was talk about car-to-grid storage, too, coming. From what I read, that is going to become a requirement in Japan, and may move elsewhere, so at least some of the engineering has been looked at.

Anytime you talk about generating energy, unless it is entirely isolated from the grid, you need an approved disconnect/switch to protect from feeding energy back onto the grid that may be down and to maintain the phasing.

 

[Obioban]

The i3 has a differential, so I guess that means you'll have to lock the opposite wheel in order to generate power.

And also since it sounds like you already have a waterwheel in your mill, environmental concerns are "grandfathered in".

I might also have to get the front hubs spinning, as well, to keep the DSC from interfering with regen. I was thinking I might play with pulling the DSC fuse this weekend and see what that does to the car's ability to regen or not.

Power via water wheels is a great, 100+ year old idea (birth of the industrial revolution).
However, not sure if connecting your i3 is the best way to harness the the energy

I'm 99% it's not "best" from an efficiency standpoint. But, so long as it's "sufficient" (meets my electrical needs) and cheap (buying hydro equipment the traditional way very much isn't), I don't think I care/need it to be best.

A typical water wheel doesn't turn all that fast, but if you start to add gears or pulleys, you add more drag. The regen on the i3, like most, depends on the rpm...I think to maximize it, you'd need to gear that up.

BMW has demonstrated using an i3 battery pack as an energy storage solution, but I've not heard of them selling them (yet). You might talk to corporate.

There was talk about car-to-grid storage, too, coming. From what I read, that is going to become a requirement in Japan, and may move elsewhere, so at least some of the engineering has been looked at.

Anytime you talk about generating energy, unless it is entirely isolated from the grid, you need an approved disconnect/switch to protect from feeding energy back onto the grid that may be down and to maintain the phasing.

Yep, I'd gear it up for sure! Probably even move to modern times and use metal gears :lol:
(as opposed to the wood gears or belts that were traditionally used).

I have seen a bunch of articles like this from 2016 regarding reusing the i3 battery as a home battery:
https://www.theverge.com/2016/6/21/11989692/bmw-beck-automation-i3-battery-home-energy-storage

However, so far I have been unable to get any useful response from Beck or BMW regarding the product.

My goal would be to be disconnected from the grid completely, and 100% self sufficient from this.

Combine with some Space X satellite internet when available, and no more cables needed to my house at all!