Living in Hawaii has many perks, the great weather and the numerous beaches chief among them. There’s one thing that residents of the Aloha State aren’t so thrilled about, however: the high electricity costs, which, by some estimations, is three times higher than the national average.
Given the abundant sunshine in the state, more and more people are installing solar panels to generate their own electricity and slash their power bill. In fact, 10 percent of households in Hawaii get their electricity from the sun instead of from utility companies.
This trend isn’t exactly surprising, though. With Hawaii’s attractive solar tax credits and the steadily decreasing price of photovoltaic panels, it’s no wonder why more residents are jumping onto the green energy bandwagon.
Here’s the catch, though: the power grid is primarily a one-way system, and the surplus energy that solar-powered households feed into it can render the grid unstable. It doesn’t help that solar power can be subject to sudden swings, making it less predictable than other power sources.
To solve this dilemma, the local government has mandated utility companies to purchase power storage systems. Ken Silverstein of the Christian Science Monitor provides more details on this directive:
In the case of Hawaii Electric, which issued its requests for proposals last week, the storage needs are short term. It’s looking for 60 to 200 MW of storage capacity that would store electricity for 30 minutes, releasing the power during peak periods to ease congestion on the grid – or when the sky gets cloudy.
Many of today’s storage devices can inject about 15-45 minutes of power into the grid. Ultimate batteries may go for three to five hours, and run at 90 percent efficiency whereby little energy is lost during the production process. Other batteries can go for 6-10 hours, such as NGK Sodium Sulfur Battery. That duration is able to cover 98 percent of all outages, making it ideal for backup power.
Of course, utility companies still need an accurate DC current sensor to ensure that the batteries won’t become overloaded. If not, the power storage units may get damaged or become unstable like the power grid.
Fortunately, companies like Aim Dynamics offer DC or AC current sensors designed specifically to prevent this scenario. These tools, along with the batteries, serve as a viable stopgap until Hawaii can upgrade its power grid to better accommodate solar energy produced by households.
(Source: Hawaii confronts green energy’s bugaboo: batteries, MAY 11, 2014)