Community solar project in Bloomfield. CTEC Solar

Samantha Dynowski’s CT Viewpoint, New England’s grid operator needs to admit gas is unreliable begins with the premise that the region is overly reliant on methane gas for heating and power generation. She proposes that our state must become a champion for less fossil fuel dependence and more renewable energy.

I agree with major aspects of her thesis even if I disagree with various facets of her proposed solution.

New England currently relies on natural gas for about 50% of its electricity generation, up from around 15% just two decades ago. However, the pipeline infrastructure has not kept pace with demand for gas.

There are a host of reasons why this creates potential reliability issues, from natural hazards to major casualty events.

The fundamental issue with natural gas-fired generation is the just-in-time aspect of gas transmission to power stations. To address this, many generating stations now have dual fuel capability with on-site oil storage. However, the total oil storage capacity is limited. We witnessed this shortcoming during the 2017-2018 winter bomb cyclone where the region came very close to running out of fuel.

The problem with transition to an all-renewable energy grid relying mainly on solar photovoltaics and wind is the intermittent nature of these sources. The capacity factor of rooftop solar energy is at best 15% accounting for nighttime, overcast skies, and poor angle of the sun. Even solar energy farms can at best get about 20%. Land-based wind might hit 32%. While the data are not available for off-shore wind, projections are 40 to 45%. That is not good enough. The grid as a system needs to be better than 99.9% reliable.

The reliability of the future energy grid would be dictated by the worst performing periods of renewables, not the best. Publicists at ISO New England and elsewhere like to tout those rare, sunny and breezy spring and fall days when renewables might make-up sizeable fractions of the region’s energy supply. Not mentioned are periods when the sun is down and the wind is not blowing.

On August 16, 2022, at 3 a.m., of the 5,000 megawatts of solar photovoltaics in New England there was zero power generation. Of the 1,500 MW of wind, most of it in central and northern Maine, there was only 12 MW of generation according to ISO NE data. That is less than 1% of wind capacity. In fact, actual wind performance data indicate 20% of the time all the wind generation in New England is less than 20% of capacity, and 10% of the time less than 10% of capacity. It makes no difference if you expand wind generation in the region 10-fold to 15,000 MW, it isn’t enough. You cannot run a modern grid with those kinds of performance.

Some have proposed substantially expanding grid-level battery storage. Until recently, there were less than 50 MW of such capability in the region. One of largest new battery storage facilities is proposed for Gorham, ME, at 175 MW power flow and 350 MW-hours of capacity (i.e., 2 hours of electricity storage).

Let us pre-suppose that it is 2045, we have zero Greenhouse Gas emissions, and a few thousand megawatts of sources including hydro, nuclear, and imports from Canada. On a cold winter’s night with demand of 15,000 to 20,000, and a stagnant air mass with little wind generation, we could easily be short 10,000 MW or more of power generation. To make it through just 12 hours of nighttime, we would need at least 120,000 MWh of battery storage. Do the math: that is the equivalent of 340 facilities like the Gorham battery farm, dispersed around New England, some centralized and much behind-the-meter. I submit that with all the siting issues, environmental impacts, and capital needs, that will never happen.

Yes, renewables such as solar and wind can be a partial solution to our energy needs. But we need more fuel diversification than those sources alone can provide. We will continue to need 24/7 baseload power, whatever forms that might take, including advanced nuclear energy.

Donald A. Dubé is a retired nuclear engineer from Farmington.