Big EU imports of Sahara sun-power coming soon?
Headlines to which the answer is no
The European Union might subsidise "interconnector" undersea power lines beneath the Mediterranean for the purpose of importing solar energy from the Sahara desert, according to reports.
"I think some models starting in the next 5 years will bring some hundreds of megawatts to the European market," European Energy Commissioner Guenther Oettinger told Reuters on Sunday, following a meeting with energy ministers from Algeria, Morocco and Tunisia.
A few hundred megawatts is insignificant against European energy demand, but reportedly the EU intends to back the mighty multidecade €400bn Desertec scheme, which will see such efforts scale up into the gigawatt range.
Oettinger views the idea as a fair deal between Europe and North Africa, in which the wealthy nations north of the Mediterranean get energy and the desert nations get massive investment, jobs and knowhow.
"Renewables are a two-way partnership because electricity produced here is for the home market of north African countries," he told Reuters.
"Maybe a bigger percentage of the electricity will be exported to Europe but at the same time we have to export the technology, tools, machines, experts, and so it's a real partnership, not only a partnership by selling and by buying."
Solar power plants' performance worsens severely the further north of the Equator they are situated, owing to the increased slant at which the sunlight strikes the atmosphere and the surface beneath. The cloudier skies of the higher latitudes add a further negative effect.
This means that a given solar plant delivers hugely more power if it is placed in the Sahara than it could in Europe, and most analysts believe that this more than offsets the added cost of power lines to carry the juice north. Thus North African solar is a very commonly-advocated green energy plan - so much so that it is common to read statements such as: "If just 1 per cent of the Sahara Desert were covered in concentrating solar panels it would create enough energy to power the entire world. That's a powerful number ..."
Powerful yes, but actually complete rubbish*, as well as being meaningless. The limiting factors on Saharan sun power are not area but cost and the attitude/capability of governments in the area.
However, nothing of any real note - nothing to compare with existing European fossil-fuel imports from North Africa, for instance - is yet on the cards. Reuters reports that the various industrial titans participating in Desertec have yet to present their plans to Brussels. They are expected to demand subsidies as a condition of proceeding, but these may or may not be forthcoming in sufficient quantity.
Green groups have reportedly voiced concerns that the interconnector lines might actually be used to sell cheap, dirty fossil power to Europe under the pretence that it was green.
6.8% my extrordinarily large backside. V. Poor journalism.
As El Reg knows full well the people pushing this proposal are looking at a solar *thermal* system using trough reflectors heating glass tubes carrying some kind of oil* to drive what is basically a steam turbine power station. Given that Schott glass is one of the major contributors to the design this should not come as much of a surprise.
Modern steam generated power plants can hit 33%. In principle this could be generated at DC and sent directly down a DC line to Europe followed by a DC-AC conversion but I'll assume its a AC-DC then DC-AC link with 95% efficiency (IIRC this process has been done at 98% both ways)
So 976 (actual solar constant, not that it's particularly constant) *33%*95%*95%*0.5 (for that 1/2 the full power output)
I make that 14.8% *average* efficiency per year.. Powered by the sun for the next several million years.
Very poor research. That 6.8% is a 1st generation lab system. *ALL* PV systems only *efficiently* absorb energy around the band gap. the rest is lost as heat. Solar thermal absorbs as a *black* body, at *all* parts of the spectrum.
(I'd still like to see Gallium, which would remain liquid up to 2000c, as sadly would most reasonable containers).
CSP with heat storage
As noted by John Smith 19, the Desertec systems will most likely be CSP - using large mirror arrays. This scales well and can reuse lots of tech from conventional stream cycle power plants (coal/gas/nuclear). CSP has the added benefit that you can integrate a "heat-battery" with molten salt so you can generate power after sun-down. Look up Andasol and PS20 for more info.
UK Energy Imports
The naysayers dismiss any renewable energy initiative because it won't be able to provide 100% of the UK's energy requirements, as if we're currently self-sufficient in indigenous fossil fuel/uranium reserves. Maybe there was a time when we had enough North sea oil & gas and working coal mines but that isn't the case now. They're confusing electricity generating capacity self-sufficiency with energy self-sufficiency.
I see nothing wrong with importing a substantial part of our energy requirements in the form of electricity from CSP in the Sahara instead of importing it in the form of fossil fuels and uranium.
As for storage, if a barrage was built across the Strait of Gibraltar and the Mediterranean allowed to drop about 6 metres by evaporation (The Med would dry up in about 1000 years, about a metre per year, if it wasn't constantly replenished from the Atlantic), then the Med could be used as a massive pumped storage reservoir and Solar-Hydro generating system.
Most parts of the world have deserts which could be utilised for CSP, maybe South Africa's electricity shortages could be solved by installing CSP in the Kalahari and Namib deserts?