Electricity you don’t use
The concept of negawatts was introduced by American environmentalist, author, and energy efficiency expert Amory Lovins, back in 1989. A negawatt is a watt of electricity that is not used because of a conservation measure, and is therefore available for some other use.
For example, if you switch a 60-watt incandescent light for a 7-watt LED light, you have saved 53 watts. So you could say your new lamp has added 53 negawatts to the electrical supply on the grid.
The negawatt was originally intended to show how much cheaper it is to save electricity than to build new electrical generation capacity. Utility companies who see demand increasing over time basically have two choices:
- Increase supply by building new generation capacity or buying new supply from other suppliers, who in turn may need to build new generation capacity
- Reduce demand, either by raising prices or offering conservation incentives.
Utility companies put a price on each megawatt of generating capacity. This price reflects the cost of building the generating capacity (non-renewable electric generation station such as a coal, fossil gas, or nuclear plant, or renewable energy source such as hydroelectric, wind, solar or geothermal) and the price of transmission lines. It does not the cost of generation itself (mainly applicable to non-renewable sources since fuel is required). Generation costs are priced not by megawatt but by megawatt hour.
Lovins saw a negawatt as a measurement that could be used to add conservation as an alternative in the list of choices a utility would face when looking for new sources of power.
For example, suppose a utility company had to find ten megawatts of additional generation capacity to meet peak demand on hot summer days. They could:
- Upgrade an existing generating station, or build a new one
- Allow companies to sell negawatts to the utility during peak periods, meaning they agree to use less electricity to offset peak demand.
Electric utility companies sometimes pay home energy users for the negawatts consumers produce. For example, in 2008 in Ontario, Canada, if you cut your electricity usage by 10% over the previous summer, you got a check from your local utility for a share of the savings the utility realized from not having to generate the electricity or invest in new generation capacity. As well, if you installed a regulator on your air conditioner that let the utility cycle it off and back on for short (15 minute) periods during times of peak demand, you got a discount on your power bill.
It’s helpful to think of your electricty saving actions as a way of producing negawatts. Every negawatt you “produce” by lowering your consumption can help reduce greenhouse gas emissions, and may prevent the construction of new coal, fossil gas or nuclear plants.