Integrating renewables into a smart grid

Updating the smart grid

Despite heavy power usage, America's national grid is outdated and inefficient. Rolling blackouts and power outages are common place and as such the argument for a smart grid has never been stronger, or had as much support. However, one potential problem facing the project could be how to maintain energy demand with the need for using renewable energy resources.

With ever-increasing demand there are those that believe boosting carbon-producing power generation is necessary but as every schoolchild knows, this is an unsustainable and environmentally damaging option. Instead, increased renewable energy generation is the solution with power being generated from sources as diverse as the sun, the wind, the seas and even waste.

However, the problem with this clean energy is putting it onto the gird without it being adequately integrated with other forms of power or optimized as a reliable first-tier energy source. Such 'grid congestion' could act as a barrier to full utilization and potential renewable variability could cause reliability challenges at relatively high levels of distribution.

Not just that but much of the structure of the existing gird is not particularly well suited to fluctuating power sources like solar and wind. An example are the windy plains of the Midwest and the deserts of the Southwest that could potentially provide the whole of the US with wind and solar power. Unfortunately, the transmission lines aren't in the right place, being at the tail ends of the grid, isolated from the large lines that supply the major cities.

Also the current grid lacks the storage capacity to handle variability, such as turning solar power, which generates no energy at night and little during cloudy days, into a consistent source of electricity.

Essentially it is, for want of a better word, a "dumb" one-way system.

However a smart grid infrastructure would enable lower electricity consumption and create efficiency, and thus allow easier connect-ability for renewable energy sources onto any power grid, but what technology is needed to make this mixture of past and future energy sources work together?

Developing a better grid

This problem is known, in some circles as "the dirty little secret of clean energy" - the seemingly inability to transmit renewable energy to population and industrial centres, where the demand is highest, via a transmission grid that was never intended to serve such a purpose, but several companies have risen to the challenge.

Assorted schemes are underway all over the United States; the California Public Utilities Commission, for example, working with U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is investing $50 million in researching ways to "measurably reduce the cost and accelerate the installation of solar and other distributed energy technologies for power generation or storage, or that could reduce the use of natural gas."

Meanwhile, other utility firms have begun installing 'smart metres', devices that intelligently monitor power flow out of a house as well as into it. One firm, S&C Electric Company, has developed a PureWave DSTATCOM® Distributed Static Compensator that provides the leading or lagging reactive power necessary to meet utility interconnect standards for wind farms. Such standards require that the power factor be adjusted within specified limits and that voltage be controlled at the interconnection point, thus utilising better use of renewable energy generation.

Demand response programs such as these are already in service and are fully capable of fully integrating renewable generation into the grid efficiently and reliably, but without a smart grid system there is no way to distribute power to where it is needed.

As renewable energy is very different from the ways we generate power now, America's National Grid needs to update its infrastructure in order to better accommodate the differences and capitalize on the advantages. After all, smart-grid technologies could reduce overall electricity consumption by six percent and peak demand by as much as 27 percent. The peak-demand reductions alone would save between $175 billion and $332 billion over 20 years, according to the Brattle Group, a consultancy in Cambridge, MA

Last summer, former vice president Al Gore began arguing that the country needed to implement an entirely carbon-free electricity system within a decade to avert the danger of global warming. Projected to cost $400 billion over ten years, Gore said a "unified national smart grid"would move power generated from renewable sources to cities, increase the efficiency of electricity use, and allow for greater control over renewable resources.

Clearly the drive is there as are the solutions, the country and the government only needs to implement them.

Relevant articles:

IBM's 'smart transportation, smart planet' scheme | Breakthroughs and concerns for smartgrid | Smart grids will cut emissions, but are they secure?

Timon Singh

Timon Singh is a graduate of Liverpool University where he received a degree in Social and Economic History. He has previously worked for BBC Magazines on BBC Who Do You Think You Are? Magazine, the publication for the popular genealogy show.

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