Electric car tipping point

[NeilBlanchard]

Denmark, and Iowa and Texas, and Costa Rica, and Spain, and many others.

[darcane]

Originally Posted by ME_Andy

I'm sure you know that California (22% renewable in 2014) and Hawaii (21%) are quickly following in Orkney's footsteps.

Orkney manages 100% renewable, primarily wind. But, I'd be willing to be that the cable connecting the island is regularly seeing large currents feeding the island and large currents from the island. Cut this cable and I bet the whole system falls apart.

The problem with wind and solar production is that you need to deal with it's variability. When it accounts for small percentages of your production, gas-fired plants can be used to pick up the slack. But over about 20% of production, you need some method of storing the electricity. Either by transferring it to another consumer (and transferring it back when the wind dies down) or in a battery of some sort. However, there are no viable batteries with sufficient capacity currently available.

Germany is a good example of this. They get about 28% of their power from renewables on a yearly basis, but have gotten as high as 78% of their consumption generated by renewables. The slack is picked up by turning on and off gas/coal/lignite plants and selling to Austria...
A New Record: Renewables Make Up 78% of Germany’s Power Consumption in an Afternoon : Greentech Media

Orkney is a very small community with an abundance of wind. This is not necessarily scalable to big cities.

That said...

My state has about 75% power generated by renewables.

[IamIan]

Originally Posted by darcane

Cut this cable and I bet the whole system falls apart.

Nope .. they have a 2 MW battery back up system part of the system there too.


Link

[darcane]

Originally Posted by IamIan

Nope .. they have a 2 MW battery back up system part of the system there too.


Link

2 MW is nowhere near enough, even for such a tiny community.

They mention the batteries in the video above. The video also mentions that one site has five turbines with a combined rating of 4.5MW and that there are 500 turbines on the island. These are pretty small turbines (some turbines are rated at 8MW each!) and he actually mentions the capacity factor (31500 hours producing 14000 MWh) so the average production is .44MW. Assuming they are all these small turbines, with similar average production, they are getting about 220MW of power from wind, with a peak capacity of 450MW.

A gusty day could fully charge those batteries in well less than a minute, a calm day would drain it just as quickly.

[IamIan]

Originally Posted by darcane

nowhere near enough, even for such a tiny community.

I agree they should expand.


But , I also can see the benefit of spending the $ on RE harvest-production 1st.

[NeilBlanchard]

They also have a fair number of tidal electrical generation systems, and the tides are pretty consistent. And I think the wind pretty much always blows - at least somewhere.

[freebeard]

Moon Power!

The technology should be made out of Biorock with all fittings in Bronze.