There has been much talk about renewable energy production and reduced consumption. Now, engineers are looking at the link between the two: Could smart grids and power meters start an energy revolution?
 | Labourers repair electrical pylons on the outskirts of Pingxiang, China (Photo: Reuters) |
One of the biggest problems with renewable energy is that it is so difficult to plan. Anticipating whether the wind will blow and the sun will shine isn't easy and worse, some of the best places for solar energy or wind power are far removed from consumers.
Wind and solar power exemplify the dilemma. The Sahara desert holds enough solar power potential to satisfy Europe’s energy needs many times over. Wind is abundant in the German North Sea and off the Scottish coast. But there aren't enough people to use the electricity produced in these remote areas.
The super grid
To transport electricity hundreds or even thousands of kilometers with little energy loss to Europe’s metropolitan centers, "super grids" would be necessary. Unfortunately, existing high-voltage grids, mostly built in the 1960s to 1980s, are already at their capacity limits, and every extra kilometer of conventional grid wastes energy.
While most regional grids work with alternating currents (AC), a long-distance super grid would have to be based on high-voltage direct current lines (HVDC), which suffer less loss, but come with a hefty price tag. A study conducted by the European Climate Forum estimates that producing and transporting 5 gigawatts (GW) of renewable power from North Africa to Europe would require investments of 10 to 25 billion euros, while a 1 GW coal-fired power plant currently costs about one billion euros.
At peak load, Europe consumes about 400 GW of power. However, building the renewable power plants necessary to cover portions of this demand is less of a problem, says Johan Lilliestam, energy expert at the Potsdam Institute for Climate Impact Research.
 | Picture Gallery (click on the image to start)How to harness the energy of sun, wind, water, and earth (Photo: Reuters) |
“Building the power lines is the big challenge,” he adds. “Today, you have to wait 10 to 15 years for permissions to build a new power line. If you want to build a lot of power lines all over Europe then you would have a very big problem with public acceptance.”
What is more, grids are also overstretched by the erratic production patterns that are typical for many renewable energy sources. The higher the share of renewable energy, the more complex it becomes to match supply and demand.
In Denmark, wind power currently provides more than 20 percent of total electricity generated. While the country still has offshore wind potential, it has already reached a level of penetration where wind power has become a challenge for its grid, says David Jones, CEO of Allianz Specialised Investments.
“In a large electricity system that’s well interconnected such as Germany's, this is manageable. But within a less-flexible grid system, if you have unpredictable power contributing more than 20 percent, the cost of standby capacity starts to become prohibitively expensive.”
The smart grid
This is where a "smart grid" would come into play. Dubbed, the "internet for electricity," a smart grid would link up various energy sources, such as wind turbines, conventional power plants, and photovoltaic cells, and combine them in an intelligent way, adapting to changing demand.
In its most advanced form, a smart grid could create a virtual power plant that draws on every possible energy source. Standby renewable sources could accommodate demand peaks on a calm day with little wind power. Hybrid cars, parked in a garage and plugged into the grid at night, could provide for the electricity needs of an urban home during peak demand in the early morning and evening. Biogas power plants, running on farm manure, are another standby source of renewable power. The possibilities are endless, and so are the challenges.
The first thing needed is smart power meters, which measure consumption of every application plugged into the grid and transfer this data back to the utility. This would mean that consumers have to disclose private information, but in return they could buy electricity at low price and avoid high-cost peaks.
“Theoretically you could have an automatic dishwasher that starts when electricity is cheap and stops when it becomes too expensive,” says Lilliestam. “And you would have a more detailed electricity bill that allows you to check when you need a given amount of electricity.”
A 100 million dollar project containing many smart grid features is up and running in Boulder, Colorado. Xcel, the utility behind the project, plans to use the data gathered to let prices fluctuate so that customers pay more during peak load and save when there is little demand.
The Super-smart grid
As smart grid projects take shape, energy experts like Lilliestam are already dreaming of the super-smart grid. Such a network would combine the advantages of both smart grids and super grids and transmit renewable electricity from small and large sites scattered over huge distances, while constantly matching fluctuating supply and demand loads.
In such a very large system, the wind always blows somewhere. Regional lows or peaks in production could thus be flattened by renewable power from other regions or through the intelligent combination of different power sources.
But would a super-smart grid be financially viable? Many uncertainties loom above the redesign of our electricity infrastructure. A breakthrough in carbon storage and capture technologies could turn coal power plants, currently the cheapest but most carbon-intensive way of generating electricity, into a climate-friendly alternative. Improved nuclear power plants could be another carbon-free source of electricity.
A super-smart grid might still be decades away, but transforming antiquated electricity grids into smart grids could improve energy efficiency in the coming years. UK opposition leader David Cameron has promised to invest one billion pounds in a smart grid and smart power meters if elected. And U.S. president Barack Obama has already allocated 4.5 billion dollars of his stimulus package for smart-grid technology.
One of the problems with smart grids is that they are less enticing for utilities that still profit from rising energy consumption. A new system would have to base its revenues on the electricity saved, rather than on the power sold. In the end, all the shinny new technology won’t work without dedicated consumers and politicians changing the rules of the game.
editor: Thilo Kunzemann
publishing date: March 31, 2009
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