Renewable power requires smart grids

Monday, 22 June 2009 06:24

Renewable power sources have been a hot news item lately for their potential to replace fossil fuels and reduce the amount of carbon emissions produced. Before renewable power can be relied upon for a significant portion of the world’s power supply, however, pressing questions will have to be answered.

Electricity is difficult and expensive to store and so is transferring wherever it is needed at a moment’s notice. This is why there is so much talk about smart grid technology.

A smart grid could determine the best time to charge the batteries within electric cars when rates are lowest. The system could also find the most efficient way to transfer energy from a plentiful supply to another geographical region where it is needed.

The world needs a smart grid to account for those times when the wind isn’t blowing or when the sun sets. Electricity is needed all the time.

President Obama mentioned Boulder, Colorado’s SmartGridCity project when he announced the stimulus package that included $11 billion for smart grids. Boulder is rapidly becoming the first city in the world with a true smart grid – at a cost of $100 million. Smart grids do not come cheap. The population of the entire Boulder metropolitan area is about 300,000.

Virtual power plants may be able to fill the gaps. Experiments have begun with the concept and if it can be proven to work it wouldn’t require big changes to the country’s power infrastructure.

Virtual power plants consist of groups of dispersed power sources of renewable power – wind or solar, for example. The groups would be treated as a single entity, the virtual equivalent of a single large power station.

Power companies tend to install wind or solar power without considering the best way to use the intermittent supply or how to transfer it where it is needed. Power companies are concerned with matching their region’s energy needs and nothing more. If the energy supply can’t meet current demand, blackouts occur and the power company tallies huge economic losses.

With the increasing investment in renewable power, power grids will have to get smarter to adapt to the less reliable renewable power sources. Wind farms have been popping up all over Europe and, more recently, in the United States. As wind farms begin to account for a bigger share of the world’s energy supply, energy companies are beginning to consider how to better manage the supply.

Adding micro-generation to the mix, where homeowners are allowed to install wind turbines or solar panels at home, creates more headaches for the grid operators. Homeowners would be able to sell small, excess quantities back to the power grid.
Virtual power plants could help here as well. The virtual power plant would be made up of the hundreds of micro-generation sources into a single unit and would only exist in cyberspace. Even if the sources were a hodgepodge of solar, wind, hydro, and biomass the virtual station could still be treated as a conventional one, but one that is producing clean, renewable power.

The idea has been demonstrated small-scale in Woking, England. In September another test of the virtual power plant concept will be conducted in Spain. The Spanish project will use data generated from renewable energy generators and discover ways to repackage it as a virtual power plant.

Spain hopes to find 100 megawatts of renewable power in the region that could be packaged as a large enough virtual power source to supply a population of 300,000 with half its needs during peak times.

The effort is in its early stages but a successful test could save the European continent billions of dollars in infrastructure costs.