TOKYO -- Hitachi will accelerate demonstration experiments to create a smart grid in Hawaii, aimed at stabilizing the supply of electricity generated by renewable energy sources.
The project in Maui uses electric vehicles to address the unstable supply of solar and wind power.
Hawaii relies on oil for 70% of its power generation, and electricity bills are 2.7 times the U.S. average, due to the high cost of transporting oil. The state has set a goal of producing 100% of its electricity from renewable energy sources by 2045, and the experiments by Hitachi are drawing attention as establishing an information technology-based smart grid is critical to meeting the target.
The experimental project has not only made electricity use more efficient but has also won praise from consumers, with participants saying their monthly energy bills have dropped.
While electricity is generated based on demand, photovoltaic and wind power generation are affected by weather conditions, making the supply unstable. As Hawaii shifts to solar and wind power, it will have to find out how to stabilize the power grid.
Hitachi aims to offer answers through the experimental project, which was launched in December 2013 by a consortium supported by Japan's New Energy and Industrial Technology Development Organization. Hitachi uses information technology to forecast when power demand will drop and charges the batteries of electric vehicles during those hours, so as to stabilize power consumption.
An experiment involving 200 electric vehicles found that their batteries are often charged between 7 p.m. and 8 p.m. However, there was concern about a shortage of power at that time, due to the decline in solar power output. The project shifted the charging time to after midnight and used wind-generated electricity.
The change has helped stabilize the power grid in Maui and has made more efficient use of wind-generated power, which tended to be wasted at night. Households have benefited from lower monthly electricity bills because local power rates are lower late at night.
The experiments entered a new stage in April, moving beyond the shifting of times for charging vehicle batteries. Two hundred electric vehicles were recently introduced that have the capability to discharge electricity, so that energy stored in their batteries can be used to power households. Each household can adjust supply and demand for electricity using its electric vehicle.
If the new phase of experiments proves successful, households will be able to reduce the amount of electricity they buy from power companies. As a result, the maximum amount of power consumption in Maui as a whole is expected to drop sharply.
There is no precedent for experiments on a smart grid involving as many as 400 electric vehicles.
The establishment of a stable smart grid is essential to Hawaii's plan to end thermal power generation in 2019.