Hawaiian Electric contracted to begin installing software that links the electricity in home batteries together in 2021. Approximately 6,000 home batteries on three islands will be tied together through a software grid that the  Venice Beach California company called  Swell Energy https://www.swellenergy.com company, describes as a “virtual power plant”

The software is able to aggregate the estimated energy in the linked stored batteries at any one time. The stored power can then be dispatched by HECOS central control at will into the grid. The more power they are able to utilize from the solar supplied home batteries the less HECO has to generate from a fossil fuel powered generating plant. This is especially advantageous during peak periods when the electric company has to rapidly provide extra electricity on to the system. Instead of having to use a fossil fuel to power the additional electricity so as to avoid a brown out, the company is able to simply redirect the home battery produced energy, to where it would be needed. Swell Energy promotes the idea that its technology can relieve the HECO grid of ‘excess renewable energy as production spikes, reducing peak demand and providing 24/7 fast frequency response to balance the grid.”

Hawaii’s grids usually become saturated with solar power at mid day. Increasing amounts of that power through programs like self supply is being stored in home batteries. Swell is contracted by HECO to produce an estimated number of kilowatts that they will provide. In a program similar to Net Energy Metering, the owners of the batteries will be paid for the power provided to the grid.

In other states such as Vermont the use of this kind of software is increasingly common. Green Mountain Power, the largest utility there, used a special battery incentive to link 2,567 home batteries together. These devices are said to have provided this utility with an additional 13 MW of flexible capacity from batteries.

The expectation is that on the Hawaii system the SWELL virtual grid will generate 25 MW of solar and 80 MW of battery capacity.