By the year 2050 the global population is predicted to exceed 9 billion, of which 70% will live in urban areas as the trend of “urbanization” progresses. Under such circumstances, it is critical to address global-level issues including increasing energy consumption, traffic congestion and waste due to urbanization, and major demographic shifts in the population such as aging, by realizing social infrastructure which is energy efficient, environmentally friendly, and smart. In other words, “establishing smart communities” has never been more important.

This smart grid project was a collaborative project conducted in cooperation with the New Mexico state government and two U.S. Department of Energy (DOE) national laboratories (Los Alamos National Laboratory and Sandia National Laboratories). NEDO carried out smart grid related demonstration tests in two locations in New Mexico: Los Alamos County and Albuquerque.

Project Structure and Partners

In Los Alamos County, we conducted a demonstration of a smart grid system to regulate the introduction of 1MW of solar power into a power distribution feeder system with a total demand of approximately 2-5MW. More specifically, this included testing the operation of a microgrid that can absorb fluctuations in solar power generation through a 1.8MW-level storage battery system; testing coordinated operations between HEMS and the power grid to absorb surplus solar power generation in residential-level storage batteries placed in prototype smart-houses; and testing residential demand-response with the participation of about 900 households.

In Albuquerque, we retrofitted an existing building in a new development area called Mesa Del Sol with a gas engine, phosphoric acid fuel cells, and thermal storage layers, changing it into a smart building that can operate as a microgrid to sustain its own power supply. Additionally, we conducted tests to show the high reliability of the building system by demonstrating an independent power supply capability during times when mains power fails. We also demonstrated how the buildings distributed power supply could be used to mitigate 500kW of solar power generating capacity installed by our U.S. partners on the project.

〔1〕 Demand-response testing with seasonal power pricing took place in Los Alamos with residential participants over two years (2013 to 2014) in summer and winter, finding reduced energy consumption during evening peak hours in each household (up to an approximately 10% energy saving effect).

This shows that adequate demand-response planning and implementation can save energy during peak hours, which may not only mitigate the “Duck Curve” problem (increased connections of solar power to the grid result in a considerable reduction in power demand during the daytime, expanding the gap between peak demand and supply capacity and increasing the need for additional power supply in a short period and in a timely fashion in the evening) experienced in areas heavily reliant on solar power such as California, but also reduce the capacity requirements for storage batteries within the system.

〔2〕 In Los Alamos, we demonstrated technologies that successfully absorbed the variations in power output resulting from the massive introduction of renewable energy (solar) to deliver consistent power flow at the edges of the microgrid by using EMS in conjunction with NaS and lead storage batteries to control the fluctuations.

There are at least 2,000 small to mid-sized power supply companies in the United States that currently purchase electric power and standby supply from the wholesale power market at variable prices. EMS technology enables them to purchase power during off-peak time periods that may lead to additional economic efficiency.

〔3〕 This project was the first of its kind in the United States where a transition to uninterrupted, automatic power was successfully achieved using a commercial building microgrid.

Amid the expanding availability of cheap shale gas, this result demonstrates the potential commercial applications of new building models that provide self-sustainable power through the use of generators like gas engines.

〔4〕 We successfully completed a demonstration of an automated HEMS, an advanced form of visualization-oriented HEMS which can automatically control the power supply in houses with distributed power sources and storage batteries. In this project, HEMS successfully showed the potential of cooperative control capabilities by integrating EMS requirements (pricing signals and load conrol signals) received from utility companies.

Through the project, technologies that will be integrated in automated HEMS, which is seen as being the next-generation technology to follow the visualization-oriented HEMS that are currently commercially available, have been established. We expect the market introduction of automated HEMS technologies in response to the needs of greater local power production and consumption control associated with increased on-site power generation (such as photovoltaics).