Vehicle to Home EV Power Station

[Phoebe]

Nissan has combined with Nichicon in Japan to produce the Vehicle to Home EV Power Station (see www.nissan-global.com/EN/NEWS/2012/_STORY/120530-01-e.html ) which has been available since last June. I asked Dean at Nissan if there are any plans for such a system here and he said 'Unfortunately there are no plans to introduce this concept as we have been advised the electrical grid in Australia is not capable of utilising the LEAF is this manner'.
However some people seem to think it is possible. www.v2g.com.au/
Seems to me there must be an opening here for someone with initiative
When I pointed out to Dean that it is possible, he replied ‘Just to clarify, you are correct, back to grid power is possible. Although as the website rightly points out it needs to be approved and implemented by many stakeholders, such as government, power companies and customers. At the moment it is very much in the hands of the government, which does not allow this type of technology to be utilised, hence why the LEAF cannot be used to put power back in the grid.’
And I wonder if he’s even got that right – investigating further

[Brian]

The first link returned ' Document not found '.

The concept of V2G should be attractive to the electricity suppliers, because EVs could absorb surplus power at off-peak times, which the suppliers could get back at peak times, thus smoothing out present fluctuations. But we are bedevilled by an excess of stakeholders and regulations.

The LEAF's voltage is similar to that of my solar panels ( although Amps could be very different ). Excess power from the solar panels is fed back into the grid. So, theoretically, feeding LEAF Power ( nice phrase ) into the house-side of the inverter could / should provide power to the grid, if the house doesn't need it . . . I think

[Phoebe]

Sorry about the typo. I've fixed it but here it is again anyway www.nissan-global.com/EN/NEWS/2012/_STORY/120530-01-e.html

[Phoebe]

Yes, when challenged Dean agreed that it is possible but he says the government doesn't allow this type of technology to be utilised. Why would the government do that when it allows solar power to be fed back into the grid. What is the difference??? Brian, you already do that and I am in the process of getting solar panels which will do that. I suspect the real reason is that not enough LEAFs have been sold in Australia to justify the development costs of the equipment, as Australia is 240v so what is being used in Japan and the US couldn't be used here.

[Brian]

I think the Japanese unit would contain a ' beefy ' inverter, plus some clever electronic controls. For example, it would need a sensor to cut off the battery supply once it got low, to prevent draining it completely. But, yes, it would only be designed for the Japanese mains of 100-110v.

I don't know if the LEAF's fast charge / CHAdeMO socket is 'live', or has to be energised by an electronic 'handshake' protocol. If it is live, it would simplify 'tapping' the batteries.

I am sure a budding Australian electronics engineer could design and build a generic unit, suitable for most EVs. But it would need volume demand to put it into production, for it to be sold at a reasonable price.

[Brian]

O.K., now we are ready for the next mains power failure ( an inevitable winter event in this area ), and my wife need never miss her favourite TV programs again.

I have installed a 2.5kW inverter to take 12volt Direct Current ( backed up by the LEAF's Lithium Ion batteries, provided that the LEAF is switched on ) and produce 220volt Alternating mains-type power.


12volt battery connections


Battery to inverter connection. Table lamp plugged into inverter proves the system is working.


Inverter, sourced from oo.com.au

Intended for limited supply to essentials only - freezer, keeping the beer cold ( oh, and my wife's digital video recorder )

[Jim Hare]

Awesome! Well done.

[duncan]

agreed....good solution to the problem (especially since tapping the high voltage battery directly is so difficult).

Do you know how efficient the inverter is? I know it's emergency supply but there must be the car's 400vDC to 12vDC one and then your 12vDC to 240vAC one.

The other interesting test would be to turn the car on, turn a load on, and see how it lasts. This guy in the states got about 24hours of fridge www.mynissanleaf.com/viewtopic.php?f=37&t=13097

[leafboi]

Brian, wouldn't the excessive draw throughout the 12v battery decrease its life?

[Phoebe]

I see. So long as the LEAF is turned on the 12v battery draws power from the main lithium battery, so you can use all the power in that battery. How nifty

[duncan]

Yep it recharges the 12v from the main battery when the car is on, and also every 5 days when it is off (as long as the charger is not plugged in).

You can still get a flat 12v battery which is a little frustrating, I would have thought a smarter setting would be to always recharge the 12v battery if it drops below say 11v. The car won't turn on with a flat 12v battery so there is no point protecting the main battery.

[Phoebe]

I believe you can jump start the LEAF with a flat 12v battery just as you can any other car

[Brian]

Firstly, as is evident, I am no engineer.

Secondly, it is for emergency, rather than regular use.

Yes, there will be electrical losses - everything comes at a price.

Duncan, the inverter claims ' Pure sine wave efficiency > 90% ' and ' Full load efficiency > 85% ', + overload protection + short circuit protection. I don't know the efficiency of the LEAF's voltage dropper.

leafboi, yes, I suppose there is the possibility of shortening the 12volt battery life, especially if this was a regular event. However, my hope is that with the Lithium Ion back up / throughput, the battery would be under less strain than if it was providing the load ' cold ' / unsupported.

Off-setting any 12v battery degradation could be a couple of factors -
1. The cost saving in not having to replace food that might otherwise have gone off
2. In any case, what price a happy wife ?

Yes, I would like to put the system to an objective test, but would need to put a Watt hour meter ( that I do not have ) downstream from the inverter to measure the draw.