On August 1st, I set up a Solar CITIES display table at an event called “The Climate Crisis is Not Neutral,” hosted by Indigenous People’s Day Philadelphia. I spoke with many people throughout the day who were interested in our small-scale biodigesters as a way for individuals and communities to break free from the fossil fuel system. One was a teacher at a school in Bronx, New York City, who asked for information about our biodigester designs, safety, and price list. Then, their head of school replied with some further questions. They cited a NYC statute, Local Law 97, that they said “prohibits any type of heating and cooling that isn’t electrified. I would imagine there is a lobby that is trying to get an exception for biodigesters … but right now, one is not allowed to create heating and cooling with methane.”
One of Solar CITIES’ top priorities is biogas education, especially in K-12 schools, where there is practically no mention of biogas or anaerobic digestion in most school curricula in the USA. We have already helped install several micro-digesters in New York City, including in schools and community gardens. If it is illegal to install a small-scale biodigester in a New York City school, we would definitely want to be aware of that! So, I spent some time looking into the statutes, and here is what I found. (Disclaimer: I am not a lawyer!)
Local Law 97 (“Greenhouse Gas Emissions Reduction”) went into effect in NYC in 2024. The purpose of this law is to bring large building carbon emissions to zero by 2050. The law covers most buildings larger than 25,000 square feet, and provides a formula for these buildings to calculate their annual carbon emissions to ensure they are decreasing over time. What does LL 97 say about methane, biomethane, and/or biogas?
- LL 97 provides a value for calculating carbon emissions from natural gas: 0.00005311 tCO2e per kbtu. So the use of methane in NYC buildings is not prohibited, but rather regulated.
- A related section, 1 RCNY §103-14, has even more values for calculating carbon emissions from other types of fuels, including biofuels. However, biofuels as defined here only includes biodiesel and renewable diesel, not renewable natural gas (i.e. biomethane) or biogas. On an FAQ sheet related to 1 RCNY 103-14, the first question asks about RNG: “Will LL 97 provide for the use of renewable natural gas as a path towards reducing building emissions?” The city’s response is that “more guidance will be provided in the future.” There’s also a website where you can look up your building’s LL 97 status, and ask questions directly to the City, at https://accelerator.nyc/building-directory
- Based on this information, I think it is safe to say that Local Law 97 does not prohibit the use of methane, including biogas, in NYC buildings. On the contrary, it provides a way for building owners to calculate their carbon footprint based on their use of fossil methane, and also acknowledges that the city still has to figure out its carbon calculus for biogas, which the FAQ sheet suggests could actually reduce a building’s emissions profile rather than increasing it.
In the course of my research, I also learned about another NYC Local Law that could affect Solar CITIES’ educational goals: LL 154 (“Building Electrification”). This law is more directly relevant to installing new micro-digesters, because it “prohibits the on-site combustion of fuels that emit more than 25 kg CO2/MMBtu in new construction.” But upon closer inspection, this law does not prohibit the installation of Solar CITIES-style micro-digesters, for several reasons. Here’s why:
- LL 154 applies only to construction permits for new buildings, or to renovations that increase an existing building’s square footage by 110% or more, requiring a new certificate of occupancy. A Solar CITIES micro-digester is not a new building, nor would it increase an existing building’s square footage by 110%, and therefore should not require any construction permits or revised certificates of occupancy. In fact, according to NY state law, biodigesters that accept only waste generated on-site are exempt from NY Department of Environmental Conservation permitting requirements.
- LL 154 also contains an exception for “a device that contains no connection to a building’s gas supply line or fuel oil piping system, is used on an intermittent basis, and is not used to supply a building with heat or hot water.” Therefore, a standalone micro-digester, not connected to a building’s gas supply line, attached to a cooking stove (or lamp or generator) that is used intermittently, and does not supply heat or hot water to the building, is not affected by LL 154.
- Finally, LL 154 also contains an exemption for laboratories. “Exceptions under this law include specific spaces within buildings in which fossil fuels are necessary for manufacturing, laboratories, laundromats, hospitals, commercial kitchens, and emergency or standby power.” The law doesn’t mention schools specifically, and there is room to debate whether or not a biodigester constitutes a “necessary” use, but the law itself does not ban biogas or even methane outright – there are lots of exceptions.
Based on my research, I feel confident that a 1-cubic meter biodigester, using only on-site generated waste, not connected to the building’s main gas supply line, used with an intermittent device such as a stove, as part of a school’s science laboratory, should be perfectly legal under NYC and NY state laws. However, I’m not a lawyer, so anyone with more specialized knowledge of these rules’ enforcement, please feel free to correct me!