Home built off grid electricity saver

Thread Starter

Rookieme

Joined Jan 26, 2021
304
Hi all,
I watched a vidio a while ago where a guy used the econimy7 tariff at night when the energy is cheaper to charge a battery bank, then use the stored energy during the day when the energy price is at its highest,
Now i work for a UPS company (uninteruptable power supply) and remove and replace large quantities of chargers and battery banks, so my idea is to do the same,
And hopefully with all reclaimed equipment
 

MrSalts

Joined Apr 2, 2020
836
Hi all,
I watched a vidio a while ago where a guy used the econimy7 tariff at night when the energy is cheaper to charge a battery bank, then use the stored energy during the day when the energy price is at its highest,
Now i work for a UPS company (uninteruptable power supply) and remove and replace large quantities of chargers and battery banks, so my idea is to do the same,
And hopefully with all reclaimed equipment
Are you just sharing your excitement with us or do you have a question.

Are you doing it with equipment that was end-of-life in its original use or are managing to somehow "acquire" good parts?
 

Thread Starter

Rookieme

Joined Jan 26, 2021
304
Currently have a 48v rectifier from a larger UPS system charging 4x1262f-ft powersafe batterys , not sure how good these batterys are but its a start on this project

IMG-20211028-WA0013.jpeg
 

Thread Starter

Rookieme

Joined Jan 26, 2021
304
Are you just sharing your excitement with us or do you have a question.

Are you doing it with equipment that was end-of-life in its original use or are managing to somehow "acquire" good parts?
I will have questions along the way, i should be able to aquire some good parts, and it will all be used equipment
 

Ian0

Joined Aug 7, 2020
4,065
The battery discharge voltage is about 15% below its charging voltage.
A charger and an inverter would each be about 90% efficient.
The inverter has a standing power loss of about 1% of its peak power.
Economy 7 seems to represent about 33% saving in price.
It's going to be a close-run thing!

Considering that this would represent an overall increase of electricity used (in order to compensate for the losses), just how ethical would it be in terms of CO2 emissions?

Buy some solar panels instead.
 

ElectricSpidey

Joined Dec 2, 2017
2,011
" No i have done nothing yet, just aquire some parts and see where we can go with this "

Well you might want to look into whether you will actually save money, or just create some complex project that makes you feel like you are saving money.
 

Thread Starter

Rookieme

Joined Jan 26, 2021
304
Hahaha that is a very fair point, solor was my first choice as i have already done this with my caravan, on 1 12v 90ah battery i can run the tv and lights for about 10 hours ish
 

nsaspook

Joined Aug 27, 2009
9,049
No i have done nothing yet, just aquire some parts and see where we can go with this

Pete
Battery requirements are going to restrain the idea even if by some dumb luck there is a price/efficiency net positive. UPS systems are designed for rare, short events, not daily long cycles required to stash electrical energy for some dreamed about profit.. A battery bank designed for daily bulk energy storage/usage is unlikely to be made from used UPS type batteries and UPS systems not designed for bulk energy storage.
 

Thread Starter

Rookieme

Joined Jan 26, 2021
304
Battery requirements are going to restrain the idea even if by some dumb luck there is a price/efficiency net positive. UPS systems are designed for rare, short events, not daily long cycles required to stash electrical energy for some dreamed about profit.. A battery bank designed for daily bulk energy storage/usage is unlikely to be made from used UPS type batteries and UPS systems not designed for bulk energy storage.
Ok, soooo whats the options for something like this?

The batterys i plan on using would be 2v4002/4, deep cycle battery's, if i can get them, they have a lifespan of 10 years as long as you dont discharge them to much, if i could afford AGM batterys i would by them but this project is about using old parts
 

nsaspook

Joined Aug 27, 2009
9,049
Ok, soooo whats the options for something like this?
When I see a story about 'some guy' going X and saving money I look to see if there are 'other guys' doing the same. If it was realistically feasible to turn-around the rate structure to save on the utility bills those 'other guys' would be doing it too.
 

Ian0

Joined Aug 7, 2020
4,065
When I see a story about 'some guy' going X and saving money I look to see if there are 'other guys' doing the same. If it was realistically feasible to turn-around the rate structure to save on the utility bills those 'other guys' would be doing it too.
There were some very cheap rates available for short periods during the night for the charging of electric cars. There might have been money to be saved, but just after you have invested money in the equipment, the tariffs might completely change.

How about using the cheap rate electricity to pump water up to the top of a mountain, then use it to drive a turbine on the way back down.
https://www.electricmountain.co.uk/Dinorwig-Power-Station
 

nsaspook

Joined Aug 27, 2009
9,049
There were some very cheap rates available for short periods during the night for the charging of electric cars. There might have been money to be saved, but just after you have invested money in the equipment, the tariffs might completely change.

How about using the cheap rate electricity to pump water up to the top of a mountain, then use it to drive a turbine on the way back down.
https://www.electricmountain.co.uk/Dinorwig-Power-Station
From Wiki: The plant runs on average at 74–76% efficiency.

 

Thread Starter

Rookieme

Joined Jan 26, 2021
304
I live in a council owned home and have access to an abundance of batterys and chargers , there must be something i can build to save on electricity
 

nsaspook

Joined Aug 27, 2009
9,049
I live in a council owned home and have access to an abundance of batterys and chargers , there must be something i can build to save on electricity
That's magical thinking.

An abundance of batteries and chargers just means you have an abundance of energy consuming (>100% efficiency) items.
 
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