This is the fifth and last part of a series on the electric grid.
LONDON -- European energy planners have a dream: an electricity grid spanning the continent and farther, one that seamlessly blends in the sharply rising but wildly fluctuating power coming from renewable sources and, at the same time, cuts transmission losses.
From the wind and wave-rich north to the sun-soaked south, the goal is to make sure not only that the electricity is low-carbon as part of the battle against climate change but also that it gets to where it is needed, when it is needed. The ideal would be to make the connections without consumers' being the least bit aware that one moment they are watching television powered from Scottish winds and the next from the Sahara sun.
If built in time, the so-called "supergrid" could play an important part in the 27-nation European Union's ambitious bid to get 20 percent of its primary energy from renewable sources by 2020. But there is a thicket of obstacles in front of this scheme, the larger ones being cost, bureaucracy and history.
Unlike in the United States, where most states' utilities are tied into one of two large grid interconnections east and west of the Rocky Mountains, supergrid will require links between nations and regions that haven't been connected before. "There are many technical as well as financial barriers to the development of the supergrid, but there are many institutional barriers, too," explained Keith Allott, head of WWF-UK's climate change program.
"For far too long, national grid operators and regulators have focused down to the micro level. They need to raise their sights. They have started to do it with the various interconnectors, but it has so far been slow and patchy," he added.
Cost estimates vary wildly from €45 billion ($66 billion) to a massive €1.5 trillion ($2.2 trillion) over the next 40 years -- the latter figure including all lines and equipment as well as the renewable energy generators that will be needed to produce the clean power.
The trouble with a renewable electricity source like wind -- the most widespread source of clean power in Europe -- is that it doesn't always blow, leading to accusations from critics of intermittency, unreliability and the requirement of maintaining expensive and sometimes redundant conventional backup power generating systems.
Supergrid proponents note that while the wind may not always blow in one place or at the same strength, it is always blowing somewhere. They argue there would be a need for fewer conventional backups with a technically sophisticated system that connects all the scattered wind farms from Scandinavia to Spain and feeds their power where it is needed via supergrid.
"An efficient European electricity transmission grid is a prerequisite for the large scale introduction of renewable power sources," said Britain's leading scientific think tank, the Royal Society, in a report earlier this summer.
Spain, for example, already uses renewables on a large scale. On particularly windy days, wind power has surpassed the output from all other power sources in the country. On average days, 11 percent of Spain's power comes from wind, ranking it just behind the United States and Germany in overall production.
Wind is also an important force in Italy's power sector. But no one comes close to the 20 percent of wind-generated electricity that is regularly produced in Denmark.
While wind may be the most mature sector, it is by no means the only one in Europe. Solar thermal and photovoltaic are expanding rapidly. Meanwhile, wave and tide-generated power is starting somewhat belatedly to add to the mix, along with biomass and hydro.
The more these clean power sources grow and start to produce serious quantities of electricity, the greater will be the need to make sure that none of the power, which is valuable but notoriously hard to store, is wasted. That is one of the prime arguments for supergrid.
4 key barriers
Allott's colleague Andrea Kaszewski listed four key barriers she said had been instrumental in holding back the supergrid's progress.
These are generally poor government regulation and a lack of incentives for developing better and more coordinated networks, as well as investor reluctance, bottlenecks and bureaucracy in the planning processes and protectionism in national electricity markets.
Interconnectors are high-voltage cables -- underwater, buried or carried on pylons -- linking the various national electricity grids with each other. Some have existed for years, such as the line from Norway to the Netherlands that has been supplying power to Germany for two decades.
Others are newer, and still others are under construction, in the pipeline or on hold for various reasons.
Historically, these national networks and their international links have tended to carry alternating current (AC), which generates heat and suffers substantial power loss over any distance.
Technology advances, however, have made direct current (DC) cables much more attractive, not least because they can carry electricity over long distances with less heat generation and much lower power loss. Some estimates put the power saving of DC over AC at between 25 and 30 percent.
However, because electricity consumption systems are based on alternating current, there has to be a converter station at each end of the direct current cable, adding to the construction costs. Still, the supergrid idea has taken hold, with in-depth studies from the European Commission and the Royal Society, among others. Needless to say, there are different points of view.
Some want the supergrid to simply link up national networks as they are modernized and get "smarter" with domestic devices that allow them to more closely monitor and then manipulate demand by, say, timing a refrigerator to switch off for a couple of hours to save power but without damaging the food inside.
There are meters that essentially show consumers how much it costs to switch on each light or electric appliance. In trials, these have been shown to cut household electricity demand by about 10 percent. However, there have not been long-term tests in Europe, and there is a feeling in some quarters that long-term exposure would not lead to a sustained reduction of that order of magnitude.
Further into the future, there are so-called "smart meters" appliances that can communicate with the energy supplier. These raise what is called the "Big Brother" issue, because these meters and their associated intelligent appliances tell electricity suppliers how much power is being used by whom and when.
Italy leads the way
Enel, Italy's largest utility, has installed 32 million advanced meters throughout Italy since 2001 and will begin replacing 13 million older meters in Spain with new advanced ones next year.
"We think we have the developed the largest smart grid network in the world," said Livio Gallo, head of Enel's Infrastructure and Networks Division. The meters and supporting management systems tell consumers how much electricity they are using and how prices are changing during the day, and they can adjust customers' usage automatically to reduce costs and ease strains on the transmission network.
"One of the major objectives of the smart grid concept and solution -- and we are working very hard on it -- is to have the customers actively participate in the energy market," he said. "You have to establish a two-way communication with your customers in order to keep them informed about their consumption profile [and] their generation profile if they have photovoltaic on the roof."
The $3 billion investment in new meters and systems enabled Enel to cut meter reading and operating costs and improve maintenance. "The investment was paid back," Gallo said.
Enel is also working with other large power distributors in Germany, Spain, France and Scandinavia on plans for a multi-nation smart grid pilot project involving 300,000 customers, testing advanced meters, electric car recharging and management of renewable energy.
The three-year project could lead to a rollout of smart grid technology throughout Europe if the European Commission adopts the plan and the financing is available. "The question is, who is going to pay for this? Everyone is asking that question," he said.
At the other end of the supergrid scale, the view is that it should be a completely new entity sitting directly over all the national grids.
This suggestion, which is part of the Royal Society's outline, raises questions among power producers, which could see their least efficient plants being forced to close. It also raises political hackles with many countries looking more to energy self-sufficiency than to interdependence.
Supergrid's super vision
Among the most visionary of the supergrid proposals is that from the Desertec Foundation -- a multinational think tank whose members come from 21 countries, from Algeria to the United Kingdom, and range from academics to lawyers, scientists, diplomats and businessmen.
Its vision is a high-voltage direct-current network linking Europe and Scandinavia to the Sahara, with concentrating solar power array farms across the deserts of North Africa and the Middle East pouring power into the system -- as well as keeping enough for themselves -- while Europe's wind, photovoltaic, biomass, hydro and geothermal sources also cycle in to fill overall power demands.
And it is not restricting its vision to Europe. It also has its sights on latent desert solar power in China, Australia, the United States and India. "Within six hours," says the foundation's Web site, "deserts receive more energy from the sun than humankind consumes in a year."
But for Kevin Anderson, director of Britain's respected Tyndall Centre for Climate Change Research, mega-projects like this risk being a diversion from the more urgent bid to stop the world from warming to crisis levels due to burning fossil fuels for power and transport.
"The real concern is that this distant technological utopia is a dangerous distraction from the pressing need to get our emissions down very quickly now," he said.
"Even the most optimistic views do not anticipate anything happening much before 2030 -- and that is far too late," he added. "Our research show that if we are to have any chance of keeping temperature rises this below 2 degrees Celsius above preindustrial levels, we have to start cutting carbon sharply well before that, or it will simply be too late."