High tension power lines carry most of their energy on the outer surface of the lines as the repulsive voltage keeps the charges on the surface. To increase the carrying cross section would be to turn the lines into large diameter hollow pipes with attention to tensile strength for the weight. This would tremendously increase wind resistance. Add to that the added strength needed in the support towers and the expense becomes substantial. If the grid consisted of fewer elements then each section becomes more important making the system more vulnerable to damage by natural disaster and terrorists.

Sand- If the circumference of a power line rather than its cross-sectional area determines its ability to conduct electricity, then I will have to opt for many parallel power lines of standard thickness rather than thicker power lines that would resemble pipelines. By making the thicker power lines more like pipelines, I meant that they might be underground rather than hanging as this could turn out to be more cost effective than building enough towers to support the quantity and weight of power lines that might be used in some cases, especially in long expanses of open space. I do not advocate the removal of any existing power lines, as it is better to have more capacity rather than less, for the reasons you stated and to minimize transmission losses in the grid. I hope this clarifies some things about this idea. Thankyou for presenting your concerns about this idea.

Grid distribution of power generated at centers has proved vulnerable to cascade failures that blank out huge setors of the country. Already solar power and efficient small generators have made entire office buildings independent of the grid. A failure would affect only one building. I wonder if it would be safer and more efficient to extend this concept so that multitudes of small generators would replace the centralized system we now have.

Power lines are kind of pipes now. They are steel cored (for strength), aluminum exterior.

Running additional lines would be good for redundancy, as well as capacity.

As for overhead vs undergound, you have to consider the labour and materials involved each way.

For local green microgeneration,it would have to become more popular to eliminate the need for more feeders. Local fossil fuel wouldn't be that efficient, unless an industry is making electricity as a bi-product of their use of fuel.

Overhead lines are the size they are because that's a sweet spot as any larger and the wind grabs them and puts too much extra strain on the wires and towers.

I read about a new type of powerline utilizing a fiber core, the same stuff as fiber optic lines, for extra strength at less weight. This allows for more aluminum at the same diameter, which is a better conductor than the steel, such that resistance is lessened even though the fiber is non-conductive.

Still there are spots where so much power is being transmitted that superconducting buried power lines are being used.

Small generators, even though they're more efficient than ever, still don't have the efficiency of the major plants. Fuel costs kill them as a widespread option as well.

It'll take more than just adding lines to increase efficiency and robustness to the network.

Have you considered the fact that there are thousands of electric power engineers in every country in the world who go to work for 40 hours a week punching numbers and actually knowing what theyre talking about to try and solve problems like this so people who don't have a clue what skin effect or tensile strength is don't have to even worry about it?

Sparky- It is quite possible that these thousands of engineers you describe may not have investigated every possible improvement to the power grid. Your assumption that they have is not conducive to the spirit of innovation usually exhibited on this web site. That said, I will address the issues you have brought up. If the wires do not have sufficient tensile strength, they can be underground instead of suspended. If the "skin effect" you are referring to is the issue that was brought up in a previous comment, that the power capacity of a cable is based on its circumference rather than its cross-sectional area, I am not completely convinced because the definition of electrical resistance supports cross-sectional area as being the critical factor. However, I am willing to concede that point because it does not effect the usefulness of the proposal. Electrical engineers will have to improve the power grid to meet new challenges such as distributed generation and the extra load of running vehicles on grid power. The hanging power lines we are used to may some day be supplemented by very high capacity underground lines in some locations. At the very least, the total capacity of the grid will have to be much greater. I suggest you keep an open mind.

Johncalusa, I think it's a safe bet that the electrical engineers have considered the rather obvious option of adding more lines. The reason they don't is cost. The improved efficiency must outweigh the cost of building the lines. If you want to make a transmission system that spans the US, the cost is going to be enormous not only because the cables will have to be either enormous or numerous, but also because they will have to be so long. But why do we need 3000 mile long transmission cables anyway? We don't need to deliver power across the continent. If they absolutely had to do it, they would design cables appropriate for the job.

Give the engineers some credit. When they design a system, they take into consideration the cost of the cables and the losses they will suffer. They have to strike a cost-effective balance. Installing underground cables costs many times more than overhead cables. Larger overhead cables would be heavier and require stronger or more numerous towers, which aren't cheap.

Dwane- I dont want to diminish the accomplishments of past generations of engineers, but engineers must adapt their strategies to current and future conditions. The balance between infrastructure costs and energy losses was probably struck at a time when energy costs were very low and pollution was not much of a concern to anyone. In general, the engineers probably built a power grid that was just sufficient to provide reliable power without failing due to overloaded parts, etc.Nobody would want to transmit power 3000 miles, but the ability to transmit power over much greater distances opens many possibilities, such as transmitting wind produced electricity from the midwest to a wider area, displacing fossil fuels such as coal, oil and natural gas.Maybe improved technology or higher energy costs will make this idea practical. Maybe they already have, but people dont realize it yet. However, most people think of other ways of producing "clean" energy, and may not consider decreasing transmission losses as an alternative approach.