What WattCarbon supplies with your data
Your meter readings alone cannot produce an M&V result. To turn energy into avoided carbon and into money, the measurement also needs to know what the grid was doing, what the weather was, and what you pay for energy. WattCarbon fetches all of that for you. You never supply it, and you do not need an account with any of the providers below.
What you supply
Section titled “What you supply”- Your assets: what the project is, where it is, and when it started.
- Your meter readings, or a connection to the provider that holds them.
What WattCarbon fetches for you
Section titled “What WattCarbon fetches for you”Hourly grid carbon intensity
Section titled “Hourly grid carbon intensity”The carbon result depends on how dirty the grid was in each hour, at your location. WattCarbon fetches two signals:
| Signal | Source |
|---|---|
| Marginal emissions, by grid region | WattTime |
| Average emissions, by balancing authority | EIA |
The two answer different questions. Marginal emissions describe the generator that responds to a change in load. Average emissions describe the whole mix. Both come back as hourly series.
Weather
Section titled “Weather”A building’s baseline must be weather-normalized, or a warm winter reads as a saving. WattCarbon fetches the weather history for each asset’s coordinates. Each asset records the source it used:
| Source | Resolution | Coverage |
|---|---|---|
| NASA POWER (MERRA-2) | about 55 km | global |
| Open-Meteo ERA5-Land | about 11 km | global |
| Open-Meteo HRRR | about 3 km | United States |
Tariffs and energy prices
Section titled “Tariffs and energy prices”The cost result needs the price you pay, not an average price. WattCarbon matches your location to the utility rate plans published in the OpenEI Utility Rate Database, and takes state and national energy prices from EIA.
The facts derived from your address
Section titled “The facts derived from your address”You give an address. WattCarbon derives the coordinates, the time zone, and the grid region and balancing authority the asset sits in. Every series above is fetched for those derived values, so an address is enough to start.
Your meter data is the exception
Section titled “Your meter data is the exception”WattCarbon always fetches the data on this page. Your meter readings are different, and what happens depends on your setup:
- If you connect a data provider, WattCarbon pulls your readings on a schedule.
- If your meters are manual, you send the readings yourself, by upload or through the API. Nothing is pulled for you, and nothing is due on a given day.
A manual meter whose data ends in the past is not a broken feed. It is waiting for your next upload.