So the thing about the earth is that it's big. If you have a big enough grid, it will be sunny and windy over a fairly consistent portion of that area.
It does not work that way. Long distance extreme high voltage transfer loses about 5% per 1000km, with the transformers adding another 10%, under ideal circumstances. In practice its higher, and thats on land. Sea cables lose 100x per km around 50% per 100km, again under ideal circumstances. In practice double the losses per distance, and if using existing grids, double it again, because most places dont build top end voltage grids.
Looking at maps for power prices with large hydropower dams you can easily see how most countries grids dont transfer more than around 1000km, and often quite a bit shorter. In practice this is the point where it becomes more cost effective to build new powerplants, than bigger infrastructure for transfer.
We could build grids designed for this, but never across oceans, and we are talking about an absolutely gargantuan investment, and its generally not considered as a solution for the unreliability of solar and wind. Its also why no one ever suggests to use the big empty oceans for truly large scale wind or solar etc, its always places very close to land.
Its also worth pointing out that superconductors cannot solve this, even if price and the gargantuan cooling energy requirements are ignored. This is because while superconductors transfer power without loss, they can only do so up to a limited effect, as the power interferes with the superconducting ability after that, essentially breaking it.
> Long distance extreme high voltage transfer loses about 5% per 1000km.
That's an incredibly low amount. Taking Berlin as an example, even 5000km lets you reach plenty of hot, sunny desert areas where any losses will be easily offset by vastly increased solar efficiency. Or you could spread out your wind energy sources to get more consistent coverage.
In fact that's pretty much what Singapore is doing: building a solar farm 5000km away in Australia.
this was true with ac power cables, but isn't with hvdc ones. they don't have the same capacitance issues, and add such undersea cables are becoming more prevalent. a 1400km between Egypt and Greece is expected to be completed in 2023
The oceans kill it completely, remember two oceans of 100km reduce transfer by 0.75, and thats ignoring all the other problems with the grids on the way.
We don't have a planetary grid (yet, at least). If there's a high pressure system across Europe, the whole continent can have low wind. This usually comes with either very high temperatures (in summer) or very low temperatures (in winter) which further stresses the system.
What do you consider acceptable? https://en.wikipedia.org/wiki/High-voltage_direct_current#Ad... puts the loss for HVDC at 3.5% per 1000km. That would imply 4000km with 15% loss, which is pretty good considering that wind and solar are significantly more than 15% cheaper than nuclear.
Specifically, https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#... puts the cost of wind/solar at roughly 1/3rd the cost of nuclear, so it's more (cost) efficient to spend as much on transmission as you do on generation and build a really well connected massive grid than to use nuclear.
We can transport it a fair bit further than that, but only under ideal circumstances that are rarely met, and its very rare the grid is built for it, its never been needed after all. For instance, regulatory issues usually mean that every country border crossed tends to have a transformer station, which makes minor changes at a 10% or so efficiency loss.
transmitting energy from other half of the earth (where is daylight when you are sleeping) is probably not best idea (not sure if even economically or technically possible). Also would be wise to turn off nuclear energy once you have this 'big enough grid'.
Is day and night really the problem here? Because I thought demand usually peaks at certain times of the day (e.g. early in the evening in California: https://www.pge.com/en_US/residential/rate-plans/rate-plan-o...), and actually bottoms out during the night. You would mostly use an interconnected grid (and storage) to compensate for this.
In most of the Europe the biggest use of energy for family will be heating except summer. In the future probably also charging electric car. This kind of power demand you need mostly at night when sleeping - during the day you are probsbly in the office.
Transmitting power also consumes energy - you cannot have a electric wire across pacific to transmit power from US to EU without transformers - electric power line is not a fiber optic that transmit just signal.
I also doubt we have enough rare earth minerals to make all those magnets for wind turbine and and electric car enough for whole planet. Remember also you have to decomission those windturbine after some years which is expensive
At least in The Netherlands we mostly use centralised (gas-powered) heating, so nuclear energy is a tangential factor. Also there seems to be room for improvement in insulation and centralised thermal storage (warmtenet in Dutch). Electric cars seem both like both a problem and an opportunity, because you could charge them while being at the office and partly use their batteries for powering your home at night (in case you don't need a full charge to get to work in the morning).
Regarding rare earths, we will need them regardless of using nuclear or renewables for electric cars, so that seems partly tangential. For wind turbines their reliance on rare earths seems troublesome. It's geopolitically ironic that we (Western Europeans) get our gas from Russia and our rare earths from China.
Electric cars are currently mostly charged at night (since that's when electricity is cheaper), but as solar becomes more prevalent, that will swap. Charging cars during the day is pretty easy, just require office parking lots to have chargers (and possibly subsidize).
You are right that you can't have an electric wire across the Pacific to get power from the US to the EU, but more because the EU doesn't border the Pacific. On a more serious note, Novia Scotia to Ireland is about 2600 miles, so it's on the edge of doable with HVDC, but it would be a massive project and slightly hard to justify.
I'm interested to know what rare earth metals make up so much of a wind turbine. According to https://www.nrel.gov/docs/fy17osti/66861.pdf (page 65), around 99% of a turbine is accounted for by steel, fiberglass, iron, copper, and aluminum.
Whats funny about this is, that the wind farm will not even be connected to Iceland itself! I guess they have such great geothermal resources that they don't really need more power.
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