Saturday, 8 July 2017

Pumped Hydro.

Consider the new Swiss Lake Mutt pumped hydro plant. Should we be building more of them? Can we?

In UK, pumped hydro has never been used as an energy storage feature. I mean it's purpose is not to store energy. Energy storage is just something it does in order to work. UK pumped hydro is used to meet peak demand. Because hydro "switches" electricity onto the grid faster than anything else can. We face peak demand every day so the capital is always in use and the plant provides the grid with electricity every day (so gets revenue daily).

RE advocates don't seem to get this. UK pumped hydro was very expensive to build but eventually pays for itself because it's constantly used. RE advocates talk of pumped hydro as an energy store mechanism to alleviate unreliables. If so, capital plant will not be constantly in use. Unless pumped hydro is regularly making money by selling electricity to the grid, it won't make economic sense.

That's probably the reason RE advocates want the grid itself to pay for storage. If the grid has to pay, existing fossil plant like gas will be paying to put its competitor (peaking provider) in place!

Technically speaking - I'm not sure that UK pumped hydro ever did pay for itself. It was built when the UK grid was one nationalized company. Their accounting systems were bizarre to most outsiders. Indeed - bad accounts - is the reason nuclear became unpopular with UK politicians in the 1990s as the grid was privatised and many of the nuclear plants (Magnox reactors) were impossible to privatise. The effect of impossible accounting on politicians is revealed in Simon Taylor's "Fall and Rise of Nuclear Power in Britain".

Sunday, 23 April 2017

Decommissioning - facts and fallacies.

I wrote this after listening to The Nuclear Humanist (Thies Beckers') response to Robert Llewellyn's (Fully Charged) snipes against nuclear power. Thies is right but there's an outstanding question he should address to Robert Llewellyn, Mark Z. Jacobson and their ilk. Do you support early decommissioning of German nuclear power reactors?

UK situation.

In UK, all the DECC decommissioning costs (to UK government) are for weapons sites (including submarines) and shut Magnox reactors (which are now all shut). Costs of decommissioning other power reactors: PWR and AGR, is solely the responsibility of the owners. EDF own all remaining power reactors. EDF have a fund growing annually for this mandated by UK government. It's a kind of tax. ~ 5% of their revenue. This is how decommissioning is handled in all Western democracies I know of.

Magnox spent fuel is all being reprocessed to remove plutonium. UK has a PUREX plant called THORP to do this. This extracts plutonium from spent fuel. That plutonium is not quite weapons grade but could provide very useful fuel for fast reactors. Alternatively - if anti-nukes have their way this plutonium will have to be disposed of too so that is cannot be used to make even substandard nuclear weapons. Only Magnox reactors will bear this extra reprocessing cost because Magnox reactors were special. The design was dual purpose. The spent fuel can be used to make nuclear weapons. Magnox are also far more expensive to decommission than PWRs because decommissioning was not considered in advance of their design. A flaw never to be repeated by other power reactor designs.

Europe and Sweden

Sweden has no Magnox reactors. Their PWR reactor decommissioning will be entirely the responsibility of the owners (via the decommissioning fund). Provided they are not shut prematurely, their decommissioning fund will bear the cost. The same kind of fund as per UK EDF reactors.

In Germany, plants are being shut too soon. So German decommissioning funds are not yet big enough to bear the cost. I wonder what Llewellyn and Jacobson think of that? Was early German shutdown a good idea?