Some $128 billion in new and upgraded power lines will be needed to meet the EU's renewables and energy market integration goals, European grid operators say.

The European Union power transmission system operating body Entso-e released a report last week assessing the ability of Europe's grid networks to unify into a single internal energy market.

It identified 100 power bottlenecks standing in the way of that goal, with 80 percent of them relating to the challenge of integrating renewable energy sources into national grids.

To accomplish the objectives establishing new trans-European energy networks, billions need to be spent for the "refurbishment or construction of roughly [32,000 miles] of extra high voltage power lines and cables" around Europe, to be clustered into 100 major investment projects aimed at the bottlenecks.

"The fast and massive development of renewable energy sources drives larger, more volatile, power flows over longer distances across Europe and is responsible for 80 out of 100 identified bottlenecks," Ensto-e President Daniel Dobbeni said in the group's Ten-Year Network Development Plan 2012.

The system operators said their analysis showed that extending the grid by only 1.3 percent enables the addition of 3 percent generation capacity and the integration of 125 gigawatts of renewable energy sources -- all at a cost of 2 cents per kilowatt-hour for electricity consumers over a 10 year span.

Given that equation, Dobbeni urged the commission to move ahead with its efforts to identify priority projects of "common interest" to Europe and impose new draft guidelines that seek to streamline permit-granting procedures.

"Cumbersome permit-granting procedures and a lack of public acceptance for power lines are presently the most relevant obstacles" facing the efforts, Dobbeni said.

Under the proposal, each EU member state would designate a single competent authority responsible --"a one stop shop " -- for the completion of the entire permit-granting process, which would not exceed 3 years.

The biggest challenge to a the European grids revolves around how to connect up new renewable sources of generation, such as wind and solar power. Most of the problems are caused either because the direct connection of renewable sources must be made, or because a corridor is a "keyhole" between the new power sources and the mass of users.

Germany, it said, presents a prime example. Its traditional fossil fuel and nuclear power generation plants are in the south, with lines spreading from there to the rest of the country.

But because Germany's wind power sources are along its northern Baltic coast, its existing north-to-south to lines have become keyholes, incapable of transmitting sufficient amounts of wind-generated power, and so must be upgraded.

A bit more than 100 transmission projects of pan-European significance have been identified to address the grid concerns, including 1,900 miles of undersea routes and 4,300 miles of onshore routes to bring power generated on the outskirts of the European territory into its main population centers.

Some 80 percent of the projects contribute to the integration of renewable energy with 47 percent contributing "significantly" to European market integration, the Entso-e estimated.

Another overriding goal of the EU's grid infrastructure efforts -- reducing the "energy island" status of Italy, Iberian Peninsula, Ireland, Britain and Baltic states -- will be served with the upgrades, the grid operators asserted, while total generation operational costs would be reduced by about 5 percent.