LEED (Leadership in Energy and Environmental Design) is the most established and commonly used green building rating system in the world. It accounts for 32% of green- certified floor space and publicly reports energy efficiency data. We calculated year by year LEED certification rates in six countries (the United States, China, India, Brazil, Germany, and Turkey) and then estimated energy savings in each country each year. We employed the CoBE tool to determine pollutant emissions reductions by country, accounting for transient energy mixes and baseline energy use intensities.
LEED-certified buildings saved $7.5B in energy costs and averted 33MT of CO2, 51 kt of SO2, 38 kt of NOx, and 10 kt of PM2.5 from entering the atmosphere. This amounts to $5.8B in climate and health co-benefits from 2000 to 2016. Climate and health benefits are nearly equivalent to the energy savings for green buildings in the United States, and up to 10 times higher in developing countries, providing an important and previously unquantified societal value.
MacNaughton et al. describes the underlying methods and complete results in the 2018 Journal of Exposure Science & Environmental Epidemiology publication available on this page (and linked here).
The type, size, and location of renewable energy (RE) deployment dramatically affects benefits to climate and health. We assessed the benefits of deploying varying capacities of wind, utility-scale solar photovoltaics (PV), and rooftop solar PV in different regions in the US. Estimates of health and climate benefits per MWh for each RE type and location are shown here.
Total benefits ranged from $2.2 trillion for 3000 MW of wind in the Upper Midwest to $4.2 million for 100 MW of wind in California. Total benefits and highest cost effectiveness for CO2 reduction were generally highest for RE deployment in the Upper Midwest and Great Lakes and Mid-Atlantic US and lowest in California. Health was a substantial portion of total benefits in all regions of the US.
Buonocore et al. describes the underlying methods and complete results in the 2019 Environmental Research Letters publication available on this page (and linked here).
In 2008, Harvard established climate goals for the University based on the best available science to minimize the impacts of climate change from Harvard’s operations. The task force set an ambitious target to reduce greenhouse gas (GHG) emissions by 30% from a 2006 baseline inclusive of growth. Harvard implemented three initiatives: improving the energy efficiency of their buildings, switching their energy source to natural gas, and adding on-site renewable energy.
The combination of these initiatives resulted in significant climate and health benefits. The energy reductions were analyzed using the CoBE tool, which found $44M in climate and health savings over the 10-year period. For each dollar saved in energy costs, another 27 cents were saved in health and climate benefits. We found that the switch to natural gas at the district energy plant played an important role in reducing negative health impacts; despite increases in energy generation at the plant in some years, the health savings from the plant were consistently over $200,000/year because of reductions in PM2.5 and ozone emissions. At the building level, health savings grew gradually over the 10-year period as energy efficiency measures continued to be implemented.
In 2019, New York City passed a policy to reduce the citywide emission footprint by tackling its largest and least efficient energy use sector; buildings. The goal of this bill, also known as climate mobilization act, is to reduce the energy use and emissions from buildings 40% by 2030, and 80% by 2050, relative to the baseline energy use for buildings in 2005.
What if similar progressive energy policies were applied on a larger scale?
We used the CoBE tool to project out the energy savings, health, and climate cobenefits of applying a similar energy policy in a larger region of Middle Atlantic covering states of New York, New Jersey, and Pennsylvania. There are numerous possible pathways to achieve the goal of this policy, each of which having different cobenefits. Here, the projected cumulative cobenefits from 2020 to 2050, under one specific case scenario, is presented.
California is the first state to require all new homes to install solar panels. The code change was brought forth by the California Energy Commission for the 2019 Building Energy Efficiency Standards, Title 24, Part 6, and will take effect January 1, 2020. The solar system must be sized to net the annual electricity usage of the dwelling. The policy is expected to result in a state-wide energy savings of 323 GWh in the first year alone.
What if California’s solar panel requirement policy was implemented on a larger scale?
The CoBE tool was used to estimate the anticipated health and climate cobenefits of the solar requirement in California and throughout a larger region as a potential next step. This regional analysis covers the Pacific census region (Washington, Oregon, California, Alaska, and Hawaii).
MPP is one of the New York State Energy Research and Development Authority (NYSERDA) programs to help residences in multi-unit residential existing and newly constructed buildings in New York State to reduce on-site energy demand and energy consumption in their buildings. This program is a part of NYSERDA mission to advance innovative energy solutions in ways that improve New York State’s economy and environment.
The total energy-saving benefits of the MPP is estimated to be ~$372M (2016 USD) between 2006 and 2018 in NYS. The average return of investment (ROI) period of all renovation projects for NYS homeowners, only based on the energy-saving benefits, is estimated to be approximately 8 years, which would be increased to ~11 years, without MPP funding.
The combined health and climate benefits were estimated ~$73M (2016 USD) for all MPP renovation projects in NYS between 2006 and 2018. Based on both capital and proportion to total benefit, the largest health and climate co-benefits between the renovation categories was belong to the heating, cooling and hot water-related projects.