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European Super Grid (wikipedia.org)
77 points by nabla9 7 months ago | hide | past | favorite | 33 comments

> allow wide sharing of the total European hydro power resource, which is about 6 weeks of full load European output

I'm surprised it's this big. This sounds like enough grid scale storage/dispatch to do 100% renewables. Particularly if some of this hydro can be converted to also pumped storage in summer just to shift energy during the day.

I'm in Portugal and was surprised to find out our grid is a net exporter in winter (wind+hydro) and net importer in summer (a lot of fossil and very little solar yet)[1]. Getting to 100% renewables should be easy for us. Solar works very well here and is being ramped up fast and the hydro solves the grid scale storage/dispatch problem. Our total hydro is 14 weeks of full load, which is 2x but I was expecting it to be a much bigger difference.

[1] https://docs.google.com/spreadsheets/d/1UTUjhrBF04MP38b4WlQx...

> This sounds like enough grid scale storage/dispatch to do 100% renewables.

I might cover short-term variability but not seasonal differences. In Germany PV generation varies by 5x between summer and winter and in the Nordics it's obviously even more extreme. Unlike some other locations peak consumption also doesn't coincide with peak production since more energy is needed for heating during winter than for ACs during summer.

Hydro and wind have the opposite seasonal variability to solar. And since some hydro allows shifting energy during the day even in summer it may be enough for a mix that solves both seasonal and daily/weekly variability. Build enough wind and solar to cover the total energy needs evenly during the year and use those 6+ days of hydro to shift energy during the day/week to solve the unreliability. Maybe 6 days of hydro is not enough for that but it's probably not 60 days either.

Additionally we will need to live with a supply constrained electricity net. Sometimes there just isn't more available and variable pricing will be needed to reduce demand. Of course the Texas power crisis showed that even if prices rise 50x some people will stubbornly keep using power regardless and basically go bankrupt. But perhaps this is just because nobody is used to actually matching demand to supply vs the current situation where supply is always matched to the demand at all costs with (rolling) blackouts as the only effective measure to reduce demand.

I imagine that in a near future where most cars are electric (and thus transportation is a significant part of electricity demand) it should be quite easy to temporarily reduce demand, even in winter: just stop commuting for a few days (at least all office workers). Also big industrial consumers could be incentivized to reduce demand when supply is too low. It might require some design adjustments, but shutting down most industry and working from home for say 0-5 days a year is surely more cost effective than massively overbuilding renewable energy supply, making giant batteries.

Priorities should probably be 1. More grid interconnections (even out supply variability), 2. cheap long term storage like hydro, 3. demand reduction. I think we need all three to transition to a 100% fossil free future.

> Hydro and wind have the opposite seasonal variability to solar.

There isn't much growth potential for hydro since it's more dependent on geography than the others and many sites are already occupied. Short of mega-projects trying to exploit ocean currents.

> Build enough wind and solar to cover the total energy needs evenly during the year

That means you need to overbuild PV and wind independently, which may be an option but a costly one. And you'd still need more storage, 6 days are too short, there are lulls that last longer than that.

If seasonal storage can be built then it would complement both sources and could decrease the required overbuild factor. So it's still good idea to pursue it to reduce cost and reliance on a single source type.

> There isn't much growth potential for hydro

But there's significant potential in wind, particularly offshore.

> That means you need to overbuild PV and wind independently, which may be an option but a costly one.

Quite the opposite. Exactly because wind and solar have opposite seasonality you need to overbuild less in total with the sum of both than you would independently. See the spreadsheet. The 100% renewable scenario only requires 15% overbuild in total and it's all in solar which is now the cheapest electricity source ever. It also maintains net exports to the rest of Europe over winter which is probably when those exports are most valuable.

> And you'd still need more storage, 6 days are too short, there are lulls that last longer than that.

Even when in a "lull" the sources aren't at 0. 6 days of full load fills gaps much larger than 6 days.

> If seasonal storage can be built then it would complement both sources and could decrease the required overbuild factor.

It would have to be very cheap to be competitive with only 15% of overbuild, particularly of solar. I don't think any of the existing or proposed technologies come even close.

> Hydro and wind have the opposite seasonal variability to solar.

What? North eastern India (e.g. Leh) has hydro only in summer as the snowpack melts. In winter it can be -30 C with limited solar resource.

There's so many exciting projects[1] going on in Europe in this space. The offshore Danish wind power island and the massive wind farms off the UK coast for example. Given how windy[2] the coastlines around Britain and Ireland are, it's great to see this in development.

One project I'd like to see get implemented is connecting Iceland to Britain to give 24/7 renewable baseload energy via undersea cables to Britain and potentially to mainland Europe. This would reduce the need for so many battery capacity being built out[3].

[1] https://news.ycombinator.com/item?id=25558986

[2] https://www.windy.com/?55.176,-3.587,7

[3] https://www.reuters.com/article/us-iceland-energy-britain/ic...

[3] makes me wonder if we could simply convert Iceland to a giant geothermal power plant, and power most of Europe..

Sure, it would take some investment, but isn't the technology already here?

The Swiss tried geothermal power at large scale but the initial tests caused two earthquakes of 3.5 and 3.4 respectively. They then stopped the project.

Maybe somebody else has examples of well running geothermal power plants but at least the Swiss are quite vary of them.

Iceland does lots of geothermal power.. indeed power intensive industries like aluminum refining favor Iceland due to low power cost.

Sure, it's hard to know how far geothermal in Iceland could scale..

But there is an active volcano, how much worse can it get? :)

That’s what I often think. We have the technology. Sure it will take some time to iron out the kinks and there will be transmission losses but we can do this with current technology.

Despite all the recent talk the real barriers are lack of political will and investment, it was viewed as an emergency we could pull it off very quickly indeed.

That'd be quite the underwater cable. It'd span about 900 km to get to the Scottish mainland:

* http://www.gcmap.com/mapui?MP=r&R=900km%40BIHN

1050 km to reach the tip of Norway (or Ireland).

So what? Use the https://en.wikipedia.org/wiki/Faroe_Islands as junction, and branch from there to Scotland and Norway.

Each branch wouldn't be that different in distance from the part between Cyprus and Crete from the https://en.wikipedia.org/wiki/EuroAsia_Interconnector or the related https://en.wikipedia.org/wiki/EuroAfrica_Interconnector

And what a juicy military target those undersea power cables would be in such a situation (Unfortunately)

Transnational electricity transmission doesn’t get enough credit - right now I suspect the ROI is an order of magnitude beyond that of utility scale storage.

East/West HVDC certainly has the potential to multiply the utility of solar installations and cut down a lot of the need for storage. Of course you may still have issues when you reach ocean borders, but there's a good chunk of the northern hemisphere where it looks like a great fit.


Looking forward to this coming online. Very beneficial for Ireland after Brexit.

The European electricity market is not affected by Brexit. This is very beneficial for other reasons, of course: increased imports/exports, increased resiliency, etc.

This is incorrect. "All of Ireland's energy interconnections with Europe run through Britain. And since the U.K. is no longer part of the EU’s internal energy market (IEM), both islands have been suffering from increased supply volatility." [0]


A second source if needed: https://www.mondaq.com/ireland/renewables/1023934/brexit-the...

You're right. I was incorrect to state that Brexit hasn't affected the electricity market. Obviously there are different trading procedures in place now.

But there's no evidence that energy volumes moving between the EU and UK have declined since Brexit. In fact, trade volumes have increased on last year, due to the new France-Angleterre 2 (IFA2) interconnector coming online in January.

Additionally, there are multiple further new interconnectors under construction or being planned for the 2020s. Despite changes to the details of how the market operates, the UK will be increasingly closely tied to EU energy markets by virtue of being more physically connected to them.

UK interconnectivity with Europe to rise despite Brexit: https://www.powerengineeringint.com/world-regions/europe/uk-...

Now dam the med for hydro.

On one of the diagrams on this page, there are locations for proposed projects of different types, and all the photovoltaic projects are in western Europe. Why would you not want some of these in north Africa, if there are going to be links across the Mediterranean?

Given the conditions in North Africa, you'd rather have the higher efficiency solar power of the "solar thermal power plant" rather than the lower efficiency photovoltaics.

Solar thermal is more efficient than photovoltaics in terms of energy captured per unit of surface/land area. However, photovoltaics are significantly cheaper per unit of energy generated. So, solar thermal makes more sense in space-constrained environments rather than vast deserts.

Solar thermal also makes more sense where you're directly utilising the heat generated, eg: for industrial processes. If you're just using that heat to spin turbines to make electricity, you're adding a layer of inefficiency.

AIUI, photovoltaics also lose a lot of efficiency when they heat up, so the ideal place to use them is somewhere cool but with a lot of sun.

In contrast, solar thermal runs at extremely high temperatures to begin with, so even in a hot climate, there's a huge temperature difference from which to extract power.

It seems to me that mirrors would be cheaper than photovoltaics, and the power-plant itself is a fixed cost, so most of the cost must come from the motors and electronics needed to angle the mirrors, and the maintenance of that.

I wonder: could you have a system where the mirrors are all fixed in place, and you simply move the target as the sun moves. (Or at least move a smaller set of mirrors/lenses that refocus the light onto a fixed target)

Yes, the ongoing maintenance costs associated with turbines are significant. Lots of moving parts, high temperatures, high pressures, etc. Photovoltaics, on the other hand, are very low maintenance.

There's also a nice scalability aspect to PV: if you want to expand your plant's output, it's really just a matter of adding more panels as you need them. Where as once you hit the limits of your collector/turbine/etc, you pretty much need to build a whole new plant to expand it further.

One of the world's largest solar farms is in Dubai, obviously an extremely hot region. It contains a mix of PV and thermal technologies, though it sounds like they are leaning towards more PV for future phases:


Their O&M is higher than the 'capacity' figures make it seem. They run under 25% capacity on average.

This site https://www.scottmadden.com/insight/solar-photovoltaic-plant... estimates $60 per kW-year for maintenance. Half cleaning; most of the rest in inverter replacement. How does that compare with turbine I wonder.

This is from 2010 so I'd imagine the figures have likely changed significantly since then, along with all the economics of photovoltaics. Today's inverters are almost certainly more reliable than pre-2010 models.

Cleaning is certainly a cost in dry areas where dust can coat the panels. But generally not in temperate climates where you can rely on self-cleaning via regular rainfall.

It's also more environment friendly that photovoltaics panels, which are almost impossible to reuse.

I'm not sure what's so difficult in reusing glass and aluminum and resurfacing wafers.

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