With renewables, intermittency is a problem

Combo wind-hydro approach makes sense

Progress continues in the New England clean energy revolution: Massachusetts, Connecticut, and Rhode Island recently announced their intention to negotiate seven power contracts with wind and solar developers selected through an unusual three-state bidding process.

The contracts will hold the potential for 452 megawatts of renewable energy, but because wind and solar projects can generate energy about 30 percent of the time, the projects will produce on average 135 megawatts of renewable energy, which is less than 1 percent of New England power demand. While the new power will be a welcome addition to the New England grid, the intermittent nature of this energy raises critical questions going forward for clean energy procurement.

While New England begins to embrace a new wave of clean energy, some energy experts emphasize that intermittency with solar and wind is going to be an increasingly difficult and costly problem. Solar energy requires battery storage if it is going to be used at night, adding a new layer of undetermined costs. The selection of these 10 wind and solar projects will provide an invaluable test case for the ultimate price of the energy.

Among the innovations that weren’t selected in this round of competition was the Vermont Green Line project, a joint effort of Anbaric working with National Grid and Citizens Energy. We proposed a 400 megawatt project that would bring zero and low-carbon energy into the New England grid 24 hours per day. We teamed up with wind developer Invenergy and hydro producer Hydro Quebec and offered what we called the wind and hydro response. When the wind blows, Invenergy’s Bull Run project in upstate New York would access a new transmission project (called the Vermont Green Line), and when the wind doesn’t blow (roughly two-thirds of the time) Hydro Quebec would flow its hydropower over the line.

The Vermont Green Line’s wind and hydro combination provides something the 10 selected projects didn’t offer: continual and reliable clean power 24 hours a day. It links New England with two other markets that already have a huge amount of clean energy and will develop more in the future: New York and Quebec. As coal and nuclear plants in New England close, the wind and hydro combination provides as comprehensive a replacement for “baseload” power as the renewables sector can offer.

The selection of the wind and solar projects solved one problem — we need more renewable energy — but it didn’t solve another: We still need firm and reliable energy. Firm clean energy is more valuable to our grid because it avoids the need for costly backup sources, stabilizes wholesale prices, and mitigates environmental compliance costs. Batteries are gradually making the intermittent energy continual, but we’re not yet at the stage where batteries hooked up to wind and solar farms are sufficient to replace coal and nuclear plants.

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So, welcome as the news is about the procurement of 400 megawatts of “passive” solar and wind power, it won’t be sufficient. That’s why there will be additional procurements of renewable clean energy in New England. We expect that proposals for firm, continual renewable energy like the wind and hydro solution will be needed — and upcoming requests for proposals should be structured to recognize the value of reliable renewables.

Ed Krapels is CEO of Anbaric, an electricity transmission development firm.