Last December, ISO New England, the operator of the region’s bulk power system and wholesale electricity markets, completed a multi-year transition to a new market system that allows generators to submit supply offers on an hourly basis – an enhancement that will help improve power system reliability. On June 29, ISO-NE announced that it had updated and made available its real-time fuel mix charts to show this dynamic power marketplace.
The updated charts appear on the iso-ne.com home page, at ISO Express, and via the ISO to Go mobile app, as well as in the RTO’s Daily Generation by Fuel Type report, and other market reports to reflect this enhanced data, concurrent with the December 2014 market change.
Under the Energy Market Offer Flexibility Project, dual-fuel generators now can submit supply offers that specify the percentage of each fuel they plan to use during the upcoming hour — called “blended offers.” The market changes are designed to give generators the flexibility to represent their cost for each fuel in their supply offers, helping to ensure that – when they must switch fuels – their costs are accurately represented. This provides an incentive for them to perform as needed, according to the RTO.
As an added benefit, the inclusion of blended offers provides better insight into the fuels that dual-fuel units are using – and thus more accurate representation of the amounts of electricity generated by each type of fuel in New England.
Most of the time, dual-fuel units do not submit blended offers; they generally use their least expensive fuel (usually natural gas in gas/oil units). Blended offers are most likely to be made when market or operating conditions warrant the fuel switch. For example, during tight winter conditions, a natural-gas-fired plant may switch to oil if it has insufficient gas supply or if the price of gas becomes higher than oil. The enhanced data would be revealed in the real-time fuel mix chart during these times.