zinc-air battery

[brackwell]

Looks good to me.  https://cleantechnica.com/2018/09/28/nantenergy-says-zinc-air-battery-ideal-for-grid-storage/

[biff]

Good one Ken,
               "Battery storage will be the end of the conventional grid"
                        Lets hope so.
                                  Biff

[RIT]

The company in question has just launched its solution to the 'world' but has been developing and supplying systems for a number of years. One thing they are not so good at is publishing any stats on the batteries.

One general issue with rechargeable Zinc-Air batteries has been their cycle efficiency. While not so much of an issue for non-grid tied systems where many other factors are more important than just efficiency, for grid-tied systems having a battery that may only have around 50% cycle efficiency is more of an issue. Few people are going to consider a solution where you only get out 1kWh for every 2kWh you put in.

[djs63]

Does any one know if any one has tried making their own battery big enough to run some or all of a house?

Making a battery is probably laborious and boring but charging it may be an impossible problem?   

[Scruff]

One thing they are not so good at is publishing any stats on the batteries.

Run a mile.

[billi]

The company in question has just launched its solution to the 'world' but has been developing and supplying systems for a number of years. One thing they are not so good at is publishing any stats on the batteries.

One general issue with rechargeable Zinc-Air batteries has been their cycle efficiency. While not so much of an issue for non-grid tied systems where many other factors are more important than just efficiency, for grid-tied systems having a battery that may only have around 50% cycle efficiency is more of an issue. Few people are going to consider a solution where you only get out 1kWh for every 2kWh you put in.

Not sure about that efficency quote  , but  i think lead acid ones are above 80% , and way under 100$ per kWh ,   from personal experience  its  pretty easy to reduce the needed electric units  from a battery to a minimum  per day  if  usage is shifted to  renewable production times ,  it does not bother me too much how efficient my battery is  cause there is too much ellectricity provided anyway ,
Oversizing the PV makes more sense to me then  paying much more towards a 10% more efficient battery

Billi

[biff]

Rit,
     I would agree with Billi on the question of the efficiency of the Batteries,
   More PV and a close eye kept on what electricity is being used and how it is being used.
 In our off grid applications,, "More is better" seems to work.
                                        Biff


   

[Scruff]

Not sure about that efficency quote  , but  i think lead acid ones are above 80%

Glossing over peukert corrected discharge (average discharge ~C40)
My 4 year old FLA golf carts are ~95% efficient.
It's very easy to see with an Ah counter set 1:1 that reads >100%

[RIT]

Rit,
     I would agree with Billi on the question of the efficiency of the Batteries,
   More PV and a close eye kept on what electricity is being used and how it is being used.
 In our off grid applications,, "More is better" seems to work.
                                        Biff

That is the reason why I said grid-tied. The 2 situations are very different. Off-grid you just max out the generation capacity to make up for efficiency issues, and the reports indicate that zinc-air batteries are very low maintenance, which for many installations is far more important. Placing, for instance, lead-acid batteries in an out building that will be serviced every 6 months would not be a good idea. 

A grid-tied solution that is using energy from the grid and storing it in the batteries is a different calculation. There is zero value in storing overnight electricity at 8p per kWh, if the daily rate is 16p per kWh with just 50% efficiency, there is no way for the system to break even, let alone provide a return on investment.

[glyndwr1998]

I watche a good documentary by NOVA the search for the superbattery, its on netflix, but i watche dit from youtube.

Very interesting developments going on, was also interesting to see lithium battery design and technology which was not flammable, so safe, guy was even cutting the battery bouch cell up into pieces with a scissors whilst it was til powering a light board display.

Battery design is changing very quickly and getting safer, especially for electric vehicles.

Interesting times ahead.

[Justme]

It's very easy to see with an Ah counter set 1:1 that reads >100%

AH counters & counting is a cr*p way to see the efficiency & if its fully charged or not.

[biff]

Good point RIT,
            The moment your on-grid battery is full and stays full, you are earning money on the export.
 I will have to push deeper into my thinking cap before making future suggestion.
       Biff

[Scruff]

AH counters & counting is a cr*p way to see the efficiency & if its fully charged or not.

Righto Justme.
Interesting you say that without asking me how I calibrated it or how long it took.
Which of these would you say is most accurate?

[billi]

Oh .... smartgauge , Justme will like that 

Anyway RIT  where are those 50 % efficiency numbers coming from ?

And it makes no sense to me for a grid tied battery storrage for utilising dirty  cheaper night time grid units ,  without any consideration to include renewable installs like PV on roof or  winenergy ,etc

[RIT]

Oh .... smartgauge , Justme will like that 

Anyway RIT  where are those 50 % efficiency numbers coming from ?

And it makes no sense to me for a grid tied battery storrage for utilising dirty  cheaper night time grid units ,  without any consideration to include renewable installs like PV on roof or  winenergy ,etc

The only figures I could find came from Wikipedia, which is the reason I made my original comment about the lack of detail being published by NantEnergy - if you are going to launch a product it helps if you give useable details about it. In the last week, they have generated a fair amount of PR based on the stated low-cost of manufacturing per kWh, but in a grid-tied deployment, the lifetime operating costs will be more important.

While many people on this forum may have local generation in the form of PV or wind, the vast majority do not and am unlikely to ever have. If you take the UK market as a whole grid-tied storage is about stabilizing daytime output and demand (variable wind turbines and PV meeting the evening demand) and the best use of all overnight generation options by time shifting it to general daytime usage, so reducing the maximum amount of generation capacity that must be installed (saving the deployment of the odd HPC). Regardless of whether this is done via large storage farms or small home-based units the efficiency of the solution is going to be an important factor.