Elon Musk the saviour of renewables?

I have to say I think he looks like a cross between Q from Star Trek and Pee-wee Herman.   Not sure if that is good.

Tesla have announced their PowerWall home battery.   Of course this has caused a flood of articles about how this will be the end of power grids, how everyone can run from solar energy etc…   The usual mix of tree-hugging greens and ‘tech’ pundits simply not understanding the device.

This is the obvious outlet for the new Tesla battery uber-factory.   It will cost Nevada enough so we might as well all get some use from it.   Unless Tesla make a cheaper electric car their market will be quite limited and the factory will be a bit pointless.   I’d love to try their model S with 4 wheel drive and 0-60 in 3.1 seconds.   Proper brutal!   But it is the far side of $100k!   And I’d for that sort of cash prefer a Maserati!

The PowerWall comes in 2 variants and so far every article I’ve seen has not noticed the important differences.   Each one can be connected in multiples to give more capacity.

There is a 7kWh ‘daily cycle’ model which is designed to work with solar or other unreliable power sources to give you power when you need it.   Only capable of a peak 3.3kW or 2kW continuous.

The other model is the 10kWh ‘weekly cycle’ which is designed for less frequent use.   Prices seem bonkers cheap at $3k for the 7kWh daily unit and $3.5k for the 10kWh backup unit.   Very likely the installed cost will be much higher!

Now you put together a system using lead acid batteries and an inverter/charger.   Eight 120Ah deep cycle cells would give you about the 10kWh performance.   However well managed Lithium Ion batteries should out last and out perform lead acid.   And Tesla are quoting a 10 year life!   Pretty impressive!

So will this be the end of the grid as we know it?   Haha!!   Good one!   If the sun don’t shine during the day you won’t have any charge in the batteries.   So you will always need some sort of backup.   And the energy efficiency of your house will always be key too.   You can’t cook using one of these powerwalls. (although it doesn’t say if having 2 or more increases the output or just adds runtime)   It would struggle to run a toaster and kettle at the same time, so breakfast would have to be made carefully.

Will devices like this help the power grid?   Heck yes.   My next project is to monitor the line voltage where I live to see the effect of the 4 houses around me with solar panels.   I want to see how much how high it gets during a nice sunny day.   I saw 249V on my meter once and that is getting close to the peak UK voltage of 253.   Storing the spare solar energy rather than dumping it into the grid is a good idea.   Although people will squeal about the loss of the feed in tariff.   Personally I think the whole feed in thing should be scrapped.   It is keeping prices high and the MCS scheme is effectively a monopoly.

Would I get one?   Have to see the installed price first.   And I’d hope other such devices come along to keep the prices sensible.   But yes, I probably would.