The green grid
Most renewables are easily transformed into electricity. In fact modern societies tend to replace traditional fuels with electricity because it is inherently more efficient and causes less pollution at the point of use.
Electricity – better, renewable electricity – has a huge potential to replace not only conventional, risky and polluting fuels such as coal and uranium, but also the use of fossil fuels for transport, buildings and manufacturing.
One plan now being talked about in Europe, and increasingly in North America, is to create a continent-wide “super-grid” of high-voltage direct-current cables to link up the many possible sources of green electricity.
It could be the missing link that will turn renewables from being a niche source of energy into the powerhouse of Europe.
- The super-grid would connect the big European nations like Germany, France and the United Kingdom with big sources of green energy.
- It would tap into:
- Iceland’s geothermal power,
- the vast solar energy resources of North Africa,
- wind turbines in the North Sea,
- hydroelectric dams in Scandinavia,
- hot rocks in the Alps, and
- bioenergies in Central Europe.
- It would be more than just a “European” grid – it would also be a peace dividend for the politically less stable and poorer regions of North Africa and the Middle East, replacing European oil and gas dependence with enhanced investments in solar power in those regions.
The idea of a super-grid to transport renewable electricity over long distances is seen by some as the exact opposite of the conventional “green” idea of local renewables for local use.
The super-grid makes big beautiful.
Of course local use of renewable energy such as solar-thermal heating and PV-panels on roofs will have its place, but it cannot provide the amount of energy needed by large cities and industrial manufacturing in highly developed infrastructures.
The plan for a supergrid has attracted the attention of the Obama administration, which wants to build a “smart” national US electricity grid to move solar energy from the deserts of the southwest and wind power from the plains of the Midwest to the industrial and population centres in the east.
Addressing the biggest disadvantage of renewablesThe SUPER-GRID addresses the biggest disadvantage of renewables: their variable power supply. Higher wind speed provides more power than lower wind speed, and when the wind stops blowing, the turbines don’t turn. Solar power shuts down at sunset.
But a super-grid in combination with good power storage capacity gets round that.
When the wind is blowing hard in the North Sea, and when not all electricity is needed by the customers, for instance, the energy can be stored by pumping water into reservoirs in Norway, ready to power hydroelectric turbines when the wind drops.
When the sun sets in the Sahara, Germany could switch from African solar power to geothermal energy from the Alps or Iceland, and biomass power from Eastern Europe.
Excess renewable energy could also be stored in the form of hydrogen, which in turn may be used to fuel the cars of the future.
There are already a few super-grid links in place.
- A submarine cable in the Channel, Britain taps into French nuclear power.
- Denmark swaps its wind power with Norwegian hydroelectricity.
- The national grids of Italy and Greece are linked beneath the Mediterranean.
IT COULD BE A blueprint for India, or northeastern Asia or the North American continent or southern Africa.
In all these areas, by linking up different sources of renewables, we can make them much more reliable, because each provides back-up for the other.