Sorry, I was busy with work...
as I am back at work...
Let me see if I can clear this up for you...
It has been observed that the 2nd Law of Thermodynamics can seemingly be 'broken' for larger systems such as stars or galaxies where material from an exploding supernovae can recoalesce to form new planetary nebulas and give rise to order again..... The order established (a few new planets scattered here and there and maybe 20 new stars or so) would still be less than the original amount (before the nova)... The energy balance would take a hit... and nevertheless small-scale order would be established. The principle being that
small-scale order can be established at the expense of large-scale disorder.
The example you allude to assumes that if enough solar energy entered a large enough system bounded by an 'imaginary' envelope in 'primitive earth' that then said flux could negate the entropic hurdles posed by a reaction... In essence, the total energy balance would still satisfy the 2nd Law, because the energy bounded by such a large system could then establish small-scale order with the difference... and then create massive disorder around it.
The flaw in said concept when applied to molecular biology is that biomolecular systems require stabilizing forces to prevent deterioration... that is, sufficient energy would have to be
channeled to a central location not only to form the highly specialized molecule (DNA in this case), but also to rapidly create the stabilizing environment that would prevent the molecule from breaking apart... There is a reason why we don't observe this phenomena anywhere in the biomolecular world today --- without enzymes that is. The key word here that slips by the minds of many people is italicized for word stress...
In star systems we rely on gravitational forces to kick-start the 'order-producing' nebulae... Said force is gradient producing in nature (think of a free-body diagram) and inherently able to channel energies into the formation of planetary nebulas or the such... all within a boundary and without the need for additional and external energy sources... that is, flux from outside the system boundary...
Back to your example... Yes although energy is entering a large scale system, it still needs to be channeled to a focal reaction point (where DNA is being formed) bear in mind the magnitude of the dimensions we are dealing with in regards to the size of DNA... A chemical reaction, with such a large entropic hurdle however, rarely 'sucks' the energy out of its medium in order to proceed due to energy flux limitations. Thus the amount of solar energy required for the gradient problem not to be an issue would require that the average water temperature rise well above its boiling point... but then that would negate the aqueous phase reaction altogether...
It was then proposed that a concentrated beam of solar energy localized via an atmospherically manifested lightning bolt could produce enough energy to create such a molecule, and not boil the entire system. This seemed to solve the problem since most lightning strikes are somewhat 'random' in nature and do not rely on a guiding force to channel energy toward a specific point. It was afterall a 'chance' path... The next problem that was encountered, however, was dynamic.... A jolt of electricity would require that the cons uent species first be created (amino acids, phosphate sugar bases) followed by the reaction the produces the DNA molecule itself...
Even with the use of lightning-like energy strikes there is never either enough energy or enough
time to get by both reactions... If one increases the amperage, more time is needed for the reaction to proceed... but if one reduces it, then there is not enough energy to overcome the entropic hurdle posed by the new set of conditions... on top of that the stabilizing medium would never get a chance to form since the electric currents propagated by lightning strikes are the epitome of 'change' and chaos... not stability. Its a big dilemma.
Based on this premise we have been able to succesfully create 'amino-acids' in laboratories with artificial bolts of electricity only to see them rapidly revert to more stable cons uent species... The kinetic perks for the formation of DNA, however, haven't allowed for experiments to create it from scratch. <-- that's not to assume it never would... but there are many kinetic limitations that oppose the formation of DNA without enzymes. And the fact of the matter is that the premise
small-scale order can be established at the expense of large-scale disorder has not been succesfully applied to the creation of DNA. Will it ever? Who knows, but that is why we pursue the answer.
I haven't even touched on the matter of information... an additional level of complexity conveyed by the DNA code itself...
So yes I am using the concept provided by the Second Law to establish the hurdle, but not solely relying on it... instead I am relying on more practical principles to show why the formation of DNA from nothing has been an empty nest for science thusfar.
On a related subject check out the following study... amazing stuff really, if we were to assume that billions of years have acted on the genetic code.