Mepsy: The Appliance & Equipment Climate Impact Calculator

Mepsy is CLASP's digital tool to model the impacts of energy and carbon reduction policies. Pre-loaded with data from 162 countries, it supports analysis and prioritization for the most energy-intensive appliances and equipment.

Launch Mepsy

Analyze efficiency policy options for space heating equipment, ACs, refrigerators, motors, fans, and televisions

woman working on computer

For efficiency policy practitioners, accurate data and predictive models provide insight into how policy decisions translate to real-world impacts

Setting policies and achieving their benefits requires accurate, actionable data. Mepsy’s dynamic, user-friendly interface guides researchers and policymakers in identifying efficiency policy opportunities and analyzing their energy and carbon impacts.

  • Choose a country or region, product, and expected effective date to calculate policy benefits through 2030
  • Use pre-loaded data from CLASP research and other sources, or enter your own data
  • Download calculation results as a CSV file for further use

Mepsy calculates product energy use according to a “bottom-up” accounting approach which factors in the number of appliances in use in a country, the energy performance of representative products, the climate-intensity of the local power grid, and other variables to analyze the electricity use, carbon dioxide emissions, and consumer energy costs associated with a given policy scenario.

The tool supports policy analysis for space heating equipment, air conditioners, refrigerators, fans, motors, and televisions. Coming soon: lighting, residential water heaters, distribution transformers, and refrigerated display cases.

Explore global and national policy scenarios

Compare major global carbon emitters or select a country for regional analysis to explore a range of business-as-usual and efficiency policy scenarios for energy use, carbon dioxide emissions, and the number of appliances in use

See the CO2 reductions, energy use, and number of appliances in use under business-as-usual or efficiency policy scenarios

Select a country to project the results of efficiency policy choices there and compare it with other countries in the region. Explore at the country level using the map interface, or dive deeper in the data for a single country.

Mepsy input view interface

Use pre-loaded data or input your own

The Mepsy model is based on a bottom-up stock accounting method that incorporates country-specific data on appliance energy use, markets, economic indicators and other policy factors

Data for Mepsy is drawn from several market research firms and other public and private data sources

Wherever possible, Mepsy references precise stock, sales, and energy performance data from recent CLASP in-country market studies, or country-level estimates from reputable market research firms. Where country-level data for a particular product are not available, calculations are based on estimates from regional or global averages, accounting for differences in country population, economics, or climate as relevant to a particular appliance. Future and past shipments are extrapolated based on recent trends.

Mepsy output screen

View model outputs by country

At the country level, view customer-level policy impacts such as appliance lifecycle costs, as well as national-level changes to energy use, carbon dioxide emissions, and the number of appliances in use as a result of the chosen policy scenario

Mepsy's calculation methodology has been used for decades to evaluate efficiency policy options

The model inputs and results can be downloaded as a data file to support further analysis offline.

For more information, see this Introduction-to-Mepsy or watch our webinar below.

For user instructions see the Mepsy Quick-Start Guide.

To explore the model documentation see the Mepsy Methodology and Assumptions.

More questions about Mepsy? Contact us.


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