Comment 22 by Reckless Monkey :

As for storage, there are a few options solar thermal plants using pressure vessels.

At the risk of wandering a bit off topic, - if steam boilers on solar power towers (http://lisas.de/projects/alt_energy/sol_thermal/powertower.html) were used, then transferring hot water under pressure to fireless railway locomotives or even steam, tractor units, this would provide short range powerful transport, provided they could be refilled from the main boiler as needed. The heat can also be stored in various ways at the power-tower.

Solar Power Towers @link - Heat storage and transfer
As already mentioned there are two main fluids which are used for the heat transfer, water and molten salt. Water for example is the oldest and simplest way for heat transfer. But the difference is that the method in which molten salt is used, allows to store the heat for the terms when the sun is behind clouds or even at night. Molten salt - better: the heat of it - can be used until the next dawn when the sun will be back to heat the cooled down salt again.

The molten salt consists of 60% sodium nitrate an 40% potassium nitrate (salpeter). The salt melts at about 700°C and is liquid at approx. 1000°C, it will be kept in an insulated storage tank until the time, when it will be needed for heating up the water in the steam generator. This way of energy storage has an efficiency of approx. 99%, i.e. due to the imperfect insulation 1% of the stored energy gets lost .

Fireless locomotive links below:-

http://www.martynbane.co.uk/modernsteam/hvalentine/fireless3.htm

http://www.youtube.com/watch?v=f0wvPDgDloA

In places like sunny desert areas power towers at intervals could power a railway system.