The state Legislature passed Senate Bill 2510, which is likely to increase electricity rates because it mandates that at least one-third of the renewable electricity generated by systems on each island shall be from “firm renewable energy.”

“Firm renewable energy” may have a nice ring to it — until you find out that the definition used in SB 2510 includes biomass, particularly the burning of trees. A recent estimate of the cost of generating energy from biomass is several times higher than that of clean, renewable energy, such as photovoltaic, even with battery storage.

The proposed Hu Honua project on the Big Island illustrates the high cost of biomass energy and why the Consumer Advocate opposes this project. Hu Honua, which would burn trees to generate electricity, estimates its cost per kilowatt-hour to be several times higher than the cost of existing clean, renewable energy.

The state Public Utilities Commission recently ruled against Hu Honua on a particular issue, but the project is still alive. If ultimately approved, Hu Honua would lock in its high cost of electricity for 30 years, which would be passed on in the form of higher electricity rates to customers of Hawaii Electric.

Hawaii has established a goal of 100% renewable energy by 2045. The one-third mandate of SB 2510 for “firm renewable energy” limits the flexibility of electric utilities to achieve this goal in the most cost-effective manner.

For Maui County, the one-third mandate would squeeze out less expensive clean, renewable energy and increase electricity rates. Hawaiian Electric generates half of its electricity in Maui County from renewable sources, but virtually none of it is from “firm renewable energy.” Therefore, to comply with the SB 2510 mandate, Hawaiian Electric may have to shut down its wind and photovoltaic units until it builds “firm renewable energy” generation facilities.

Oahu may face a similar problem in the very near future because it produces only 38% of its renewable energy from “firm renewable energy.” Clean, renewable energy projects that are already in the pipeline may have to be delayed.

Aside from the issue of increasing electricity rates, the mandate for “firm renewable energy” in SB 2510 is harmful to the environment and accelerates climate change. The burning of trees pollutes the air and emits carbon into the atmosphere, which warms the Earth.

It takes decades to grow more trees, and during those many years the carbon stays in the atmosphere. This scenario is distressing because most climate scientists say that we have less than 10 years to take the drastic actions needed to keep the Earth livable.

“Firm renewable energy” is supposedly uninterruptible energy. In reality, however, imported biomass can be interrupted by disruptions in production or supply chains, over which Hawaii has little or no control. There are no guarantees that biomass would be continually imported and available in Hawaii.

We in Hawaii should be sourcing energy locally to build a secure energy future. Local control minimizes disruptions and creates stability. Hawaii is fortunate to have abundant natural resources that can produce multiple forms of clean, renewable energy, such as photovoltaic, wind, geothermal, hydro and ocean.

In addition, technology advancements are increasing the energy storage capacity of batteries while reducing costs. We also can leverage solutions such as gravitational energy storage and green hydrogen. A robust mix of clean, renewable energy and a diverse set of storage solutions can ensure a consistent electricity supply for all of Hawaii’s residents.

Hawaii should strive for energy security while reducing energy rates for our people and protecting our environment and planet. SB 2510 does the opposite. Gov. David Ige should veto the bill.

Noel Morin is a climate action advocate with several organizations; Sara Bower advocates for climate action with Citizens’ Climate Lobby; Ted Bohlen is a former deputy attorney general and an environmental/climate advocate.