Not so cheap anymore

Our energy system is expensive in three ways: 1.the initial cost of infrastructure 2.the cost of maintenance 3.the cost of fuel

The initial cost of energy infrastructure-the electrical power network,natural gas and petroleum pipelines,etc.-all of these are expensive to install.
For developed countries,this means they will keep their infrastructure as long as they can, to obtain a full return on their investments.
This is one of the main reasons we don't have a clean energy economy.
While some of the infrastructure from the old energy system can be used in the new energy system-such things as adapting pipelines to transport biofuels or hydrogen,or reducing power consumption on the existing grid-other things just aren't there that will need to be,like a recharging infrastructure for electric vehicles,or hydrogen filling stations,or a smart grid.
However,for developing countries,the high initial investment needed in infrastructure is an opportunity.Developing countries,countries largely without energy infrastructure, have the chance to avoid the fossil fuel energy system altogether!
They can move from no energy to clean energy.

Maintenance on our energy infrastructure is another cost to consider.
Much of our energy system was built between 1947 and 1975.
Some maintenance we are familiar with-road construction,auto repairs-and some are not so familiar, like "pigging".
But nonetheless all of our energy infrastructure requires maintenance,and this costs,and even more so with a fast-paced society,and ever increasing energy consumption.

The third cost of our energy system is the fuels (like gasoline or coal) or energy products (like electricity).The price of fossil fuels will only go up.
We may see them temporarily drop in price,but overall they can and will only increase in price.
The era of cheap fossil-fuels is over.
We are going farther,and deeper,and in more sensitive areas to get our petroleum and natural gas.
No longer do we drill and oil comes gushing up,as most people still believe.
Harder-to-find-and-get oil,means more expensive oil.
Lastly, the swings in prices characteristic of oil can be especially hard on oil-dependent economies,and industries.
These problems will accelerate when peak oil hits.

Check out these links (and whatever else you can find on your own about this topic):
http://www.wtrg.com/oil_graphs/oilprice1869.gif

http://www.netl.doe.gov/publications/press/2001/nep/chapter7.pdf

http://www.simmonsco-intl.com/files/Rice%20Global%20Forum.pdf