Archives de catégorie : Renewable energy

PV+PSP vs. STE in Chile (updated)

??????????????????????????I’ve been saying this many times: the competition is not between solar thermal electricity (STE, or CSP: concentrating solar power) and photovoltaics (PV), but between STE and PV+storage, mostly PV+pumped storage plants (PSP, or PSH: pumped storage hydropower). But I was not expecting to witness this in North Chile – one of the dryest places on earth, one of the best for CSP but not really good for hydropower. This was without taking account of the possibility of Okinawa-style, seawater PSP. The Espejo de Tarapacá project developed by Valhalla Energy, associating a large seawater PSP of 300 MW with 600 MW of PV plants, would represent a significant challenge for STE. It remains to be seen, however, how the economics work, and in particular if the lowest cost of PV makes a difference large enough to compensate for the losses in PSP, significantly greater than in thermal storage. But this might well be the case.

I talked on Friday 19 with Francisco Torrealba, promotor of this project. He said the cost of the PSP is USD 1300/kW because it needs minimal civil works for the upper reservoir, only tunnels and power chamber (about 13% of the overall costs). It benefits from an important head of 600m.

Its expected round-trip efficiency would be 78%. The storage capacity is about 80 000 GWh, 260 hours at full power.

A power purchase agreement (ppa) at USD 100/MWh would provide 90% of the revenues of the project, while another 10% would come from capacity payments. The ppa will be made with the PSP part of the project, delivering 200 MW 24/24, 7/7. PV power will produced at USD 70/MWh and sold (?) on the spot market (so there might be two financial entities, one PV selling, one PSP buying from the spot and selling to the mines). The cost of storing one kWh would be about USD 50/MWh but only 2/3 of the electric output would need to be stored so on average the additional cost to the PV would be about USD 30/KWh.

Valhalla energia is currently finalising the environmental impact assessment and hopes to sign a ppa with a big mining company on the SING (sistema interconectado norte grande) in early 2015, then to get environmental approval by July.


Swansea Bay’s tidal lagoon

Ever heard about this Project? Quite interesting indeed, and a quick introduction would be this paper in the New York Times. You may also want to admire the nice website of the developer.

However, as I told Beth Gardiner of the NYT, I’m not sure the current project design is the best possible one. I’d like to explain here a little more this concern or, rather, my hopes for a better design based on the alternative concept of « tidal gardens » as set forth by François Lempérière. Continuer la lecture

12 réflexions sur la transition énergétique allemande

  1. Il s’agit avant tout d’éolien et de solaire photovoltaïque
  2. Il n’y aura plus de centrales fonctionnant « en base »
  3. Les options de flexibilité sont nombreuses mais ne reçoivent pas d’incitation
  4. Les réseaux sont moins coûteux que le stockage
  5. Les pointes de consommation peuvent être couvertes à moindre coût
  6. L’électricité et la chaleur doivent être davantage intégrées
  7. Le marché actuel de l’électricité valorise les kWh mais ne garantit pas la sécurité d’approvisionnement
  8. L’éolien et le photovoltaïque ne peuvent pas se refinancer sur un marché fondé sur le coût marginal
  9. Un nouveau marché de la transition énergétique est donc nécessaire…
  10. … qui devra favoriser la flexibilité de la demande…
  11. … et doit être développé dans un cadre européen.
  12. Le kWh le plus rentable est celui qu’on économise.

Telles sont les douze thèses sur la transition énergétique allemande publiées par Agora EnergieWende, club de réflexion berlinois. C’est court, cela va à l’essentiel, c’est facile à lire, je les recommande vivement.

One, two, three!…

Nothing to do with Billy Wilder – although that would be more fun. I’m talking of the debate that rages within the EU about its energy and climate policy to 2030: should it be based on three targets, as it currently is, i.e. one target for greenhouse gases, one for renewable energy, and one for energy efficiency? Or should it be based on one single, CO2-only target?

Continuer la lecture