In order to overcome the problem of unstable supply for PV power, a number of projects have been underway in the U.S. and Europe, aiming for flexible power-demand management, via the utilization of the emerging IoT technology.

The potential of such R&D effort is affirmed by a report, titled "Demand Flexibility: the Key to Enabling a Low-Cost, Low-Carbon Grid," publicized by the Rocky Mountain Institute (RMI) of the U.S. in Feb. 2018.

The study was carried out with Texas as the simulated environment, since the state's unique power-supply system makes it a suitable environment for the study. Excluded from the two major U.S. grids, one for the western and the other for the eastern region, Texas boasts an independent grid, dubbed "Electric Reliability Council of Texas," as well as abundant resources in solar energy and wind power, on top of substantial thermal power capacities. Based on the state's existing power supply-and-demand structure and market resources, researchers looked into the effect which can be created by flexible demand management.

In the study, it is assumed that the following resources are available for the flexible demand management program: 4.2 million households and commercial establishments which install water heaters capable of supporting demands, 3.9 million households and commercial establishments with ceramic heat-storage systems, 3.7 million customers with air-conditioning system capable of coldness storage, 15 million households with socket power management, and 11.5 million customers owning electric cars capable of power storage.

Those facilities will function as contingent power sources, able to lower peak load of the state's grid by 24%, reducing the need for back-up power facilities, as well as the need for upgrading power transmission and distribution network, in addition to cutting maintenance cost, with total savings estimated at US$1.5 billion a year. Moreover, fuel cost for thermal power can be cut by US$400 million and CO2 emission can be reduced by 4 million tons, 23% of the state's total.

Meanwhile, increase off-peak power consumption or store excess power, thereby shrinking the wholesale power rates between peak and off-peak period by 56% and cutting idle capacities of wind power and solar energy by 40%, which would increase renewable-energy sales by 36%.

The study finds that the effect of flexible demand management on sales can stimulate the development of renewable energy, without inflicting extra costs on utilities or taxpayers, on top of lowering the cost and enhancing the reliability of gird.

Moreover, the flexible-demand management system can be installed within a short time, a far cry from power plant which needs at least five years, such as the projected coal-fired thermal power plant in Shenao, northern Taiwan, which will not come on line until 2025.

The study underscores a fast, low-cost, and green option for power supply, an alternative to building more power plants, which is time consuming, not only needing massive fund but also entailing massive CO2 emission. It sheds light for Taiwan on how to solve its thorny power problem.

(Collaborative media: TechNews, first photo courtesy of Allagash Brewing via Flickr CC BY 2.0)