Hledik: How Green Is the Smart Grid?

Hledik, R. 2009. How Green Is the Smart Grid? The Electricity Journal 22, no. 3: 29-41.

"A simulation of the US power system suggests that both conservative and more technologically aggressive implementations of a smart grid would produce a significant reduction in power sector carbon emissions at the national level. A conservative approach could reduce annual CO2 emissions by 5 percent by 2030, while the more aggressive approach could lead to a reduction of nearly 16 percent by 2030" (29).

Two scenarios are examined, as the concept of "smart grid" has not been fully concretized. Scenario one explores technologies that are currently available. The second explores an expansion of possible future technologies.

"At a basic level, the smart grid will serve as the information technology backbone that enables widespread penetration of new technologies that today's electrical grid cannot support. These new technologies include cutting-edge advancements in metering, transmission, distribution, and electricity storage technology, as well as providing new information and flexibility to both consumers and providers of electricity. Ultimately, access to this information will improve the products and services that are offered to consumers, leading to more efficient consumption and provision of electricity" (30).

A key aspect of smart grid technology is advanced metering infrastructure (AMI). This leads to dynamic pricing of energy.

There are a variety of pushes to produce more energy from renewable sources. These each have different goals. Doubling the Renewable Portfolio Standards (RPS) would lead to 19% of energy being produced by renewables in 2030. T. Boone Pickens calls for 20% from renewable by 2020, as does the EU. The New Apollo program wants 25% by 2025. Google's energy plan calls for 60% by 2030. Repower America suggests that 75% come from renewables in the next 10 years.

The Brattle Group's RECAP model is used to explore these scenarios using EIA data and assumptions.

"Among the key outputs of RECAP is a forecast of the CO2 emissions from both existing and new power plants. This forecast depends on both the projected mix of new plants that will be added to the system, and the operation of all power plants that are connected to the grid. Implementation of a smart grid will influence both of these. In this study, there are four specific smart grid impacts that have been modeled" (37). These are: peak demand reduction, conservation, increased penetration of renewables and reduced line loss.

Three scenarios are explored out to 2030. Firstly, a business as usual forecast, which shows average annual increases in CO2 emissions of 0.7%. Secondly, the Conservative Scenario, which posits the effects of existing ICT technology on CO2 shows an average annual growth of 0.5%. Finally, the Expanded Scenario shows an average annual growth rate of -0.1%.

Overall, dynamic pricing leads to a nominal improvement in overall CO2 emissions. The combination of dynamic pricing and information displays leads to a 5% reduction in annual CO2 emissions. "By far, the single largest reduction comes from the cleaner mix of generating capacity that is enabled by distributed resources and an expanded transmission system, amounting to a 9.9% reduction in CO2 emissions" (39).