Centralized or Distributed?

To clarify, I’ve been thinking about a lot of different question systems:
Fluther, the questions that are asked on News.yc, reddit, the new programming forum proposed by Joel Spolsky, and was wondering what the benefits were of centralizing. Is it a worthy cause to try integrating fluther comments into a system like that or vice versa?

The same goes for energy systems. As we pump up the grid with distributed renewable energy, should we start creating isolated, self sustaining grids, or is it better to mix it all together in a soup of coal, nuclear, wind, solar, hydro, hamster?

Maybe I can say something about energy systems… from a “user” point of view, sure, as I’ve no technical idea of how they work or anything else.

You see, I live in Chile, more precisely, on Viña del Mar, which is on the central region of the country and very close to Santiago, the capital.

In Chile, there’s something called “Sistema Interconectado Central”, something like “Interconnected Central System”, which centralizes all energy produced from all kinds of sources; actually, it works only on a portion of the entire territory, between the third and the tenth regions, where something like 93% of the population lives.

Our main energy source is hydroelectric, so on rainy years everything is peachy, but on dry ones… not. There are other sources, like thermic generators working on gas, but gas is produced in Argentina, and since last year Argentina also had energy issues, they close the valve and we had no more gas.

All in all, this system has some benefits, the main is that when one power source is short, you can increase the production from other sources. It also has some disadvantages: when there’s increased consumption on one region, all others become affected. Also, there are some other flaws which are not really related to the production of energy, but to the distribution: years ago, it seems that there was very little redundancy in the distribution system, so if there was an issue affecting the main power lines, a huge portion of the country was affected… luckily, it appears that someone realized that and now that doesn’t happen anymore.

I am a fan of centralized. Easier, faster, and cheaper.

I think that both types of system have their place and ought to be integrated where possible. As @gooch points out, centralized solutions tend to be easier to design and cheaper and faster to implement in certain ways. Distributed solutions usually offer better fault-tolerance and self-healing (particularly in terms of networks). IMO a combination of both approaches can offer the best of both worlds if properly implemented.
The Internet offers some examples of this mixture of types: for example, multihomed root DNS servers use distributed architecture to implement a centralized service.
Solar panels generating electricity in different areas using special inverters can be tied together into a “subgrid” which is a distributed power-generating network with failover. Another type of inverter (grid-tie) allows a set of panels (or a set of sets, as above) to attach to a local power grid (a centralized-ish system) to charge auxiliary batteries when the grid is working and to feed power to the grid when the grid goes down.
They are just tools in the box. One is not better than the other, only more appropriate for a given situation.