Tesla is reportedly investigating using lead batteries at charging stations to store cheaper off-peak electricity

Could old-school lead batteries come back to life and speed-up the introduction of electric cars as part of a nationwide charger network?

That’s the thinking in the US, where industry and government are teaming-up to explore if banks of high-capacity lead cells sited at conventional fuel stations could make life easier for EV owners. Tesla is already reported to have looked at the idea.

The latest move is a feasibility study in Missouri, organised by the Consortium for Battery Innovation (CBI), and supported by a grant from the US department of Energy. “This ground-breaking project could pave the way for a much wider roll-out of EV charger stations utilising advanced lead battery technology,” the CBI said.

Modern lead-carbon cells use dry accumulators with the electrolyte held in glassfibre fleece, so there is no nasty old-school acid to leak out.

The cells are widely used in industry, with applications that include balancing energy flow out of wind turbine farms. They can be installed in large storage capacities, for example 25MWh.

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For the US EV charging network, the lead cells would be charged with cheaper off-peak electricity, to reduce the cost to a fuel station and EV owner of charging during the day. In particular, the lead batteries could help avoid the fuel station incurring “peak demand charges”, an extra fee charged to US businesses by electricity companies.

A report in February 2018 from management consultants McKinsey “How Battery Storage Can Help Charge The Electric-Vehicle Market” suggests that a fuel station could save £2400 per month in electricity costs alone by reducing the demand charge.

Demand charges can be so high for EV charging stations that they become unprofitable, says McKinsey. The consultants suggest that a fuel station owner could install two 150kWh direct current (DC) fast chargers together with 300kwh of lead cells. At peak times the lead cells would deliver the charge to customers' EVs and, through clever charger and battery management, could replenish several vehicles without triggering the demand charge.

“A system configured this way could reduce demand charges to a minimum; that would be $3000 a month that wouldn’t need to be passed on to consumers, which would substantially cut costs. Tesla has already said it is going in this direction and others may follow suite,” said McKinsey.

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Comments
14

13 June 2019

 Isn’t lead a dirty word in Eco circles...?

13 June 2019

Now I'm no electrician so I could be innocently wrong but: 

With electricity being 14p a kW peak or 7p a kW off peak, 300kwh of batteries would save £21 a night. Will add up over time but for the story to be complete we need to know how much room the 300kwh batteries take, their cost and thier life span?

14 June 2019
xxxx wrote:

Now I'm no electrician so I could be innocently wrong but:

Firstly, you wrote 14p/kW peak and 7p/kW off-peak, but you probably ment 14p/kWh peak and 7p/kWh off-peak. Thans OK, also many other people confuse units for power (kW) and energy (kWh). There was many similar mistakes also in the article. In fact, every single unit in this article was wrong! 25mWh should be 25MWh, 150kWh should be 150kW, and 300kwh should be either 300kWh or 300kW (given writers lack of expertise we can't be sure which he actually ment).   

Secondly, the underlying issue was not energy price but the price of the electricity connection. If you want to have a connection with 300kW peak power, the distribution network operator my charge you 4800£ per month but if you can limit your peak power to 150kW with the help of a battery storage the connection charge can be only 2400£ (These figures may be highly exaterated, I pulled these out of the hat to get the 2400£ difference mentioned in the article). 

 

13 June 2019

Tesla (among others) are already using batteries at some charging sites, usually the larger ones.

But it's not so much about cost savings (you'd need to store a lot of energy to charge every car that uses the station during the day). It's about grid balancing - by sipping electricity slowly but constantly, and storing it, you can connect high-power charging stations to a lower-power grid infrastructure.

13 June 2019

Tesla and other charging site operators already equip sites with battery back-up to achieve this but they don’t use lead-acid batteries (Tesla use their own lithium batteries made specifically for energy storage).

The Tesla Supercharger at South Mimms has battery backup already installed as a way of charging from offf peak but mainly to support the available grid supply at times of peak demand.

13 June 2019

Would it not be better to use nickel iron batterys instead of lead acid as batterys nickel iron can last up 35 to 40 years and handle overchageing better than lead acid

 

14 June 2019

... vanadium will probably be the way to go.

You read it here first!

14 June 2019
Clearly the Tesla mention in this press release is intended to push it up the search rankings even if Tesla has a very tenuous attachment. It's probably really intended to boost someone's investment in legacy battery technology rather than actually announce something useful.

Just to throw another option in here, if it were me I would use 20-30kWh of LTO batteries per charger stand. Then top them up with a big, central 'Redox Flow' battery in a cabin away from the chargers. That way you can have ultrafast charging then the Flow battery can deal with the grid off-load. Both technologies are too bulky to be good for vehicles but they are very robust yet with competitive energy densities. Flow batteries can also have their electrolyte changed and be as good as new and present no fire risk.

14 June 2019
The world's top battery brains have been trying invent vastly improved battery tech for years now, and none of them have come up with anything substantial.
Call me a cynic, but I don't think it's going to happen.

14 June 2019
Cobnapint wrote:

The world's top battery brains have been trying invent vastly improved battery tech for years now, and none of them have come up with anything substantial. Call me a cynic, but I don't think it's going to happen.

It's already happened. Today's Leaf has double the range and a third extra horsepower than the 2011 model, for about the same weight and price. Bump up another £10k and you can get a model with three times the range of the 2011 version and double the charging speed.

Meanwhile, Tesla's cars can drive as far as a hydrogen vehicle, charge up to 5x faster than most EVs on the road and beat an M3 at the track.

This has all happened due to the steady improvement in battery technology. Take a look at any EV on sale today from a mainstream manufacturer, and nothing close to it would have been possible ten years ago. Ten more years and we'll probably be driving solid-state cars.

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