National Grid published a recent report stating that the natural gas company could meet 25 percent of its customers’ needs with renewable gas generated from biomass sources.
According to the study commissioned by National Grid, the company can meet a quarter of its demand in Connecticut, New York, New Hampshire and Massachusetts, excluding natural gas used to generate electricity, equivalent to the cooking and heating demands for 2.2 million homes. That represents 16 percent of total demand, according to the company.
Renewable gas, also known as bio-methane, is pipeline quality gas derived from biomass that is fully interchangeable with natural gas.
Produced mainly via anaerobic digestion (AD) or thermal gasification (TG), renewable gas, can be implemented easily and is a cost-effective solution to reduce GHG emissions, according to National Grid.
Currently, most producers, such as the landfill-to-energy project in which Google recently invested, either flare the raw gas or utilize it in a generator to produce
electricity. This raw gas, commonly referred to as “biogas,” is composed of roughly 50 to 60 percent methane and 40 to 50 percent carbon dioxide (CO2). Flaring the gas converts methane to CO2 thereby reducing the GHG effect by a factor of 20.
By collecting, conditioning and injecting a high percentage of the available methane into the natural gas network, customers can directly use the gas in their existing natural gas appliances and other end-use applications.
National Grid said renewable gas reduces GHG emissions by fuel substitution, essentially switching from a fossil fuel to a renewable fuel. Using renewable fuel represents the recycling of carbon already circulating in the environment, and using fossil fuel represents new emissions of carbon that was previously trapped geologically under the surface of the earth.
The capital investment required to deliver renewable gas across the four states is estimated to be approximately $7 billion, which compares well with the cost of delivering other large-scale renewable projects such as solar or wind, according to the company.
Renewable gas production plants are estimated to reduce carbon dioxide emissions by approximately 16 million tons per year, as well as additional GHG benefits of avoided methane that is released into the atmosphere. National Grid said government support will be the most critical factor in delivering renewable gas.
The report urges public policymakers to offer incentives for renewable gas comparable to those currently available for renewable electricity. Renewable electricity incentives have led to a proliferation of power generation projects at landfills, waste water treatment plants and some farms, but using this gas to produce pipeline quality gas is a more efficient way to utilize the energy, according to National Grid.
Some individual companies have already begun implementing the technology at their facilities. Spoetzl Brewery, for example, said it plans to add a $3 million biogas generation and wastewater treatment facility at its historic facility in Shiner, Texas. The renewable energy plant is expected to reduce the facility’s carbon emissions by more than 500 metric tons annually and eliminate 85 percent of the treatable waste components in the brewery’s wastewater.