As California gears up for the implementation of Proposition 64, which legalized recreational marijuana use, state regulators are trying to figure out how the new industry will impact the energy supply.

In February, the California Public Utilities Commission held a workshop to assess the potential energy impacts of widespread legal pot growth.

Panelists consisting of utility representatives, cannabis growers and regulators mulled over ways to make cultivation more energy efficient, according to CPUC officials.

“The fast growth in the cannabis industry presents a challenge and an opportunity to ensure that the choices made by the cannabis industry reflect California’s climate goals,” said CPUC President Michael Picker.

Beginning Jan. 1, 2018, the California Department of Food and Agriculture will begin accepting applications for licenses to grow pot, but it’s still unclear what the energy impacts of the industry might be.

Based on information from other states where recreational pot use is legal and California’s own experience with legalized medicinal marijuana, many growers appear to prefer indoor cultivation, according to a CPUC report based on the workshop’s findings called “Energy Impacts of Cannabis Cultivation,” which the CPUC released Thursday, also known as 4/20.

Indoor cultivation is generally seen as the most energy-intensive production method, but it is also potentially the most water-efficient, according to the report, so it’s uncertain how the state might come down on potential regulations.

About 45 percent of California growers surveyed by CalCannabis, the state’s pot cultivation licensing body, said they prefer indoor cultivation.

Additionally, local governments’ land-use decisions seem to be pushing growers indoors.

Most local governments are still working out land-use policies for commercial grow operations, but the trend seems to be that many, like Sonoma County, will require that those farms are restricted to indoor facilities, according to the report.

Also, while Prop. 64 prevents local governments from prohibiting marijuana growth for personal use, local authorities are able to require that any such cultivation is done indoors.

Still, it’s unclear if local jurisdictions are aware of the energy consumption implications of their decisions, the report says.

Some potential recommendations discussed during the CPUC’s workshop include that the CPUC share energy-use information with local governments so they can make fully informed decisions when crafting land-use policies for the pot industry.

Also, growers could be required to submit energy-use projections before they are allowed to begin farming, a requirement already in place for growers in Oregon.

While there isn’t much energy-use or environmental-impact data currently available for the new industry, CalCannabis is working on a report that will evaluate potential impacts and possible ways to mitigate those impacts.

That report should be ready by the end of this year.

The CPUC’s workshop didn’t make any policy recommendations but suggested that the state work with the representatives from the cannabis industry, state agencies, utility companies and local governments to form a “Cannabis Working Group” in order to explore, for example, a special energy tariff for pot growers, similar to what’s already in effect for the state’s wider agricultural industry.