FAQs

  1. What is LEEM?
  2. What is “Environmentally Sensitive Electricity?”
  3. How does LEEM work?
  4. Why does LEEM matter?
  5. By how much can LEEM help reduce emissions?
  6. What locations can use LEEM today?
  7. Which emissions are reported by LEEM?
  8. Why is there a difference between the forecasted and real-time emission intensities?
  9. How can energy managers use LEEM’s day-ahead and real-time emission intensity data?
  10. Who are the people behind LEEM?
  11. What is the difference between air quality and air emissions?
  12. What about Carbon Dioxide Emissions?
  13. What about mercury emissions?
  14. What about NOx, SO2, and Lead Emissions?


What is LEEM?

LEEM, which stands for “Locational Emissions Estimation Methodology,” is a big data emissions estimation product developed by researchers at Wayne State University (WSU). LEEM automatically tracks, organizes, normalizes, analyzes, and reports location-specific, real-time and day-ahead “marginal emissions” – the emissions that are created/deferred by the next unit of electricity consumption/avoidance.

LEEM makes Environmentally Sensitive Electricity possible.

What is “Environmentally Sensitive Electricity?”

Environmentally Sensitive Electricity (ESE) is a new term used reflecting the ability to manage electricity usage based upon the level and types of emissions caused by the generators that are creating that electricity.

How does LEEM work?

LEEM takes your location and uses a sophisticated algorithm to:

  1. Identify the commercial production node (CPN) closest to your location
  2. Use electricity Locational Marginal Pricing (LMP) information provided by the grid’s Independent System Operator to estimate the emissions intensity of the generator types likely to provide electricity both real-time and over the next 24 hour period
  3. Reports out the emission intensity estimates to LEEM users.


Why does LEEM matter?

In 2014, fossil fuel electric generators in the US create 57% of the mercury and 30% of the carbon dioxide (CO2) emitted to the atmosphere. With LEEM, municipalities, businesses, and institutions can now:

  1. Track times when electricity is supplied by high-emission generators
  2. Control how their energy management systems respond to high and even “Peak Emissions” periods
  3. Reduce electricity usage, especially during Peak Emissions.


By how much can LEEM help reduce emissions?

WSU studies suggest that users can reduce emission impacts when LEEM data is used to switch electricity usage from high-intensity to low-intensity periods, and is used to shave electricity usage during high/peak emission periods.

By integrating LEEM emission-intensity data as a new input to your utility’s energy management system, your utility will be able to reduce emissions caused by shedding and shifting electricity consumption for HVAC, pumps, lights, and other electrical draws. We have even evaluated the use of LEEM for electric car chargers and for high energy data centers.

What locations can use LEEM today?

LEEM services electricity users in territories managed by the following three Independent Systems Operators: MISO, PJM, NYISO.

Which emissions are reported by LEEM?

LEEM reports real-time and day-ahead emissions of:

  1. Mercury (Hg)
  2. Carbon Dioxide (CO2)
  3. Nitrogen Oxide (NOx)
  4. Sulfur Dioxide (SO2)
  5. Lead (Pb)


Why is there a difference between the forecasted and real-time emission intensities?

They differ because they are derived from two different data sets provided by the relevant ISO. The forecasted emission intensities are derived from day-ahead marginal pricing information published in hourly increments over a subsequent 24-hour period. Day-ahead data is designed to signal what is projected. The real-time and day-ahead values of LMP may differ significantly, leading to a difference in the predicted day-ahead and real-time emissions.

LEEM’s real-time emission intensity data is derived from information about actual marginal pricing information usually published on a current basis every five minutes. Real-time information is considered as close to “actual” as is possible given the information available.

For the purposes of this competition, and for emission reductions in general, most water utilities will rely on day-ahead emission intensity projections.

How can energy managers use LEEM’s day-ahead and real-time emission intensity data?

Day ahead data can be integrated into proactive energy management system planning, while real-time emission intensity data can be used to make quick and reactive adjustments to energy usage, if desired.

One can also use real-time emission intensity data to calculate an emission “footprint” for a facility that has detailed energy consumption data. LEEM has this capability.

Who are the people behind LEEM?

LEEM is a software technology developed by a team lead by researchers at WSU and funded by the Great Lakes Protection Fund. Energy Emissions Intelligence (E2i) LLC is commercializing the LEEM technology.

What is the difference between air quality and air emissions?

Air quality describes the current state of the ambient air. For example, levels of ozone, smog, or particulate matter that you may be breathing at a given moment are all reflective of air quality. Air quality is influenced by of a large number of factors including air emissions and weather conditions such as temperature, precipitation, and wind speed.

Air emissions represent the actual pollution leaving an emissions source at a given moment in time (for example: the number of pounds of carbon dioxide that are released by a particular coal-fired electricity generation plant). Air emissions from power plants directly impact air quality “downwind” of that power plant.

What about Carbon Dioxide Emissions?

Carbon dioxide (CO2) is the primary source of Greenhouse Gases (GHGs); gases that trap heat in the atmosphere by absorbing and emitting thermal radiation from the sun. Beside CO2, other sources of GHGs include methane (CH4), nitrous oxide (N2O), and fluorinated gases. CO2 is emitted to the atmosphere through both natural processes and human activities.

In the US, an estimated 85% of CO2 emissions are from the combustion of fossil fuels. Of CO2 emissions from the combustion of fossil fuels, more than half is emitted from electricity generation plants that burn coal, natural gas, and oil.

Carbon dioxide enters the atmosphere through the burning of fossil fuels (oil, natural gas, and coal), solid waste, trees and wood products, etc. Carbon dioxide is also removed from the atmosphere (or “sequestered”) when it is absorbed by plants as part of the biological carbon cycle.

CO2 equivalents are calculated based on the Global Warming Potential (GWP) (http://en.wikipedia.org/wiki/Global-warming_potential) of different gases. Global-warming potential (GWP) is a relative measure of how much heat a greenhouse gas traps in the atmosphere compared to how much heat is trapped by CO2.

What about mercury emissions?

Mercury is an element that occurs naturally in the earth's crust. It is found in many types of rocks, including coal. Burning coal releases mercury into the atmosphere, where the mercury can travel great distances and be deposited on land or water. Once there, mercury can be absorbed by plants and animals - and the people that consume them.

In 2014, the EPA estimated that 57% of mercury air emissions came from electricity generation. According to the National Resources Defense Council, there are more than 144 coal-fired power plants in the eight US states that surround the Great Lakes. In 2010, these power plants pumped over 13,000 pounds of mercury into the air, an amount close to 25% of the nation’s mercury emission total. Other sources include natural gas fuels burned for electricity production and gasoline for automobiles. The burning of municipal waste, and fossil fuels for cement manufacturing, steel and other metal processes are also significant sources.

Mercury (Hg) is a well-known environmental toxin. It causes neurological and digestive health problems in the animals and humans that are exposed to it. Even very low concentrations of mercury in water pose a health risk, because mercury undergoes bioaccumulation. A substance that bioaccumulates is taken in by an organism faster than it can be eliminated. Bioaccumulation causes animals that are on top of the food chain to have higher levels of mercury accumulate in their bodies.

Mercury is never removed from the environment, it just moves around. And in the Great Lakes region, mercury released by coal-fired power plants bio-accumulate in both inland waterways and the Great Lakes. The EPA has identified seven species of fish whose average bioaccumulation of mercury exceeds recommended guidelines: Yellow Perch, Lake Trout, Smallmouth bass, Northern Pike, Largemouth bass, and Walleye.

What about NOx, SO2, and Lead Emissions?

NOx, SO2, and lead are other major pollutants emitted by fossil fuel electricity power plants. For more information about these emissions, please go to the Emissions Information tab at the herowayne.com website prepared by the Healthy Urban Waters team at Wayne State University.