More solar faster, predicts New England grid operator

New England will likely see even more solar photovoltaic energy projects over the next decade than was previously projected, according to the latest draft forecast by the operator of New England's electric grid.

Solar photovoltaic panels on the roof of a Massachusetts home.

To help plan for future needs, grid operator ISO New England, Inc. is developing an updated forecast of solar photovoltaic project development in New England.  In 2014, ISO New England developed its first multistate forecast of PV capacity growth.  It based its 2014 PV forecast heavily on development goals articulated as policies in the six New England states.

ISO New England is now updating that forecast for 2015.  Its draft 2015 Solar PV Forecast, released on February 27, notes that PV development is happening more rapidly than was previously projected.  Using updated historical data, it acknowledges that through 2014, 40% more solar capacity was developed in the region than it previously estimated.  As a result of this faster-than-expected growth, the draft now predicts a higher level of cumulative photovoltaic project development through 2023.

Perhaps more significantly for the solar boom, ISO-NE's draft 2015 forecast also frontloads more new project capacity into 2015 and 2016, while decreasing the amount predicted to be newly developed in later years.  While last year's forecast also predicts more incremental solar capacity will be developed in each of the next three years than in later years, the frontloading is more prominent in the draft 2015 forecast.

The draft 2015 forecast projects that 2,138.8 megawatts of solar photovoltaic projects will be developed in New England by 2024.  This capacity is stated as an alternating current nameplate rating, even though photovoltaic cells essentially generate direct current electricity.  The study derates direct current capacity to alternating current with an 83% array-to-inverter ratio, so this implies an even higher number of megawatts if stated as direct current capacity, as most solar projects are described.

The draft 2015 forecast projects that these solar photovoltaic projects will give rise to a summer seasonal claimed capability of 748.6 megawatts.

ISO New England did not include in its draft 2015 PV forecast any update to its forecast of how much energy these projects would produce.  Instead it suggests that it must first finalize its forecast of installed photovoltaic capacity, and can then estimate the energy production associated with the forecast.  The report does repeat 2014's forecast of energy as illustrative, keeping in mind that actual amounts of energy generated from solar photovoltaic capacity in New England will likely be higher if capacity forecasts are revised upward as is proposed in this draft.

The 2015 draft PV report is now under review by ISO New England's Distributed Generation Forecast Working Group.  That group next meets on April 14, where the final draft forecast will be presented.