Long distance transmission to beat the duck curve.

Solar power is often discussed as one of the most promising forms of renewable energy, but it has a problem. It only generates energy during the day. This isn't too much of a problem, because a lot of our energy needs also happen during the day.

However, there is a peak of energy consumption in the evening, when everyone gets home from work and sits down to watch Netflix and eat their microwave dinner for one.

You can see the effect above, in the famous duck curve.

So called because it looks like a duck.
As well as a lack of energy in the evening, you can see that increased solar capacity leads to an excess of capacity during the day.

My immediate thought is that we need to reschedule our day. Let's make sure we do all the high energy activities in the middle of the day, and accept that evenings are going to be an expensive time to plug in and play.

But what if we could mitigate that problem a little? If we could extend the peak of solar by just a few hours, it would help cover that problematic duck's neck.

It may be night time here, but it's always day time somewhere. So how about getting energy from where it's still day and transmitting it to where it's evening?

This article about China's new super grid says that they use UHV transmission to send electricity hundreds or even thousands of kilometers. Ultra High Voltage means up to one million volts (1000kv).

By contrast:

In Britain, most of the National Grid operates at 275kV or 400kV.  

This isn't an experimental technology:

China’s existing UHV lines have delivered more than 160 terrawatt-hours of electricity since they were commissioned, about the same as the annual consumption of the state of Ohio or half what Britain uses in a year.

There are limits. The longest transmission planned currently is about 2000km. Though with improved technology, perhaps longer transmission distances could be achieved.

Let's take an example.

The USA is split across 3 time zones. That means that if solar energy was shared, it could generate an extra 3 hours of electricity. Enough to put quite a dent in the duck curve.

Imagine sharing electricity between New York and LA. At more than 3000km, it would be stretching the limits of current transmission technology. It would also mean that some energy is lost in transmission.

Currently the states of the US lose between 2% and 13% of their energy during transmission and distribution. UHV lines could increase this problem... but since peak solar production is already more than is needed, it might not be as big a problem as expected.

The next step would be to use superconductors as power lines. They could seriously cut losses due to long distance transmission and require lower operating voltages. There is already a prototype set up in Germany, though it only stretches for 1km and must be cooled to -200C... obviously there's a way to go yet.

Thinking about the idea, there are obvious pros and cons.
Pros:

• Eliminate the worst of the duck curve.
• Build solar arrays in places with a lot of sun and transmit to places without.
• Find a use for the excess peak energy generation you get with solar energy.
• Reduce the need for batteries. 
• Superconductors would reduce the need for UHV and transformer stations.

Cons:

• Technology is not mature yet.
• Energy lost in transmission.
• High cost of long distance infrastructure.
• Vulnerable to political disruption.
• Fragile in the face of physical disruption.
• UHV could be dangerous...

It's certainly an idea that deserves further investigation.