Energy Musings - ISO-NE's Future Plans - 2

This is the second article about ISO-NE's report about the challenges and opportunities for a clean energy transition. We look at decarbonization and offshore wind. Both face problems.

This is our second article discussing conclusions from ISO-NE’s recent report on Economic Planning for the Clean Energy Transition (EPCET).  Our first article – Decarbonizing New England’s Power Will Be Expensive – discussed the key points of the study which were highlighted in an ISO-NE blog and a Utility Dive article.  The conclusion was that renewables would not be able to achieve the region’s decarbonization target. 

Renewables Cannot Meet New England’s Power Needs 

In this article, we focus on the EPCET report’s analysis that identified challenges and opportunities in reaching the region’s decarbonization goal.  The conclusion is that it is going to be difficult and expensive. To accomplish 

We also examine the use of offshore wind to achieve the decarbonization goal.  Offshore wind is a popular solution embraced by regulators and politicians in the region but with little recognition of its potential impact on New England’s coastal waters. 

ISO-NE has modeled the transition from hydrocarbon energy to renewable power for the New England grid over 2022-2050.  The modeling involves adjusting the power resource mix by retiring existing generation capacity and replacing it with wind, solar, and batteries each year.  The daily hourly power needs can be matched against the available power supply while granting preference to renewables over hydrocarbon power. 

By 2050, ISO-NE cannot achieve 100% decarbonization with renewables only.

As the chart shows, in the changing power supply mix, the daily volume of carbon emissions is reduced over time.  The pace of the reduction reflects the seasonal power needs of the ISO-NE grid, given government plans to “electrify everything.”  By 2040, spring will be mostly decarbonized because seasonal electricity demand is low and wind and solar power supplies are high.  Although this scenario should also be replicated in fall, the history of the region’s weather is that there are more high-temperature days during those fall months than during spring.  However, wind and solar output are not as strong in the fall as in spring. 

By 2050, the transition in grid resources leaves the region with numerous days (indicated in red in the chart) during winter when hydrocarbon power will be needed to avoid blackouts.  During winter days, there are fewer hours of sun, thus less solar output.  Although wind is stronger during winter, the loss of solar output will tax battery storage capacity, exhausting it, which adds greater demand to the grid to recharge the batteries before they can be reused. 

Interestingly, the decarbonization study concluded that February is at greater risk of renewable power failure than December.  That is despite December having three more days than February.  Regardless, the problem highlights why dispatchable hydrocarbon power will be required to ensure sufficient power for these days. 

The decarbonization modeling involved testing the grid’s capability of meeting 100% of its needs using only renewable power.  The supply mix is tested against the New England weather experienced yearly in 2000-2020.  The following chart shows the outcome for all spring and fall months, summer, all the winter months, and the months of May and December, all for 2040, 2045, and 2050.  The decarbonization percentages are measured against 2022 levels. 

How the ISO-NE grid may be decarbonized using renewables.

Footnote to the table: December’s emissions are higher than February’s due to December’s three additional days, although stretches of low solar and wind production coupled with depleted energy storage (conditions that drive more carbon emissions) generally occur more frequently in modeling for February. 

When we examine 2040 results, the spring and fall months reach 88% decarbonization.  All summer months are 75% decarbonized, which is almost 50% greater decarbonization achieved than during all winter months. 

By 2045, all spring, fall, and summer months are decarbonized between 94% and 97%.  However, winter months are decarbonized less than three-quarters of the time.  The sharpest contrast is between May and December where the former is 100% decarbonized but the latter reaches only 59%. 

The problem is that by 2050, when the grid is supposed to be 100% decarbonized, all winter months achieve that level 95% of the time.  That is because December is decarbonized only 90% of the time.  All the hours not decarbonized in December equate to three full days.  While the hours are distributed over the 31 days of December, there are times when the number of hours exceeds the capacity not only of wind and solar but also the capacity of the typical 4-hour and 8-hour battery backups. 

In that case, blackouts will occur unless hydrocarbon-generated power is utilized.  An additional challenge comes from the depleted batteries that must be recharged to be available the next time the power supply is short.  That means the grid has a larger load until the batteries are recharged.  That may be fine if there is a surplus of renewable power, but if not, even greater amounts of dispatchable power will be needed. 

Decarbonization is limited by the physical reality that as the grid adds more renewable energy, the incremental power additions decline in their deliverability.  This is true for batteries, also.  The EPCET report presented graphics showing this reality.  The first set of graphics shows the power contribution from adding additional offshore wind, onshore wind, and solar power. 

Additional renewable capacity yields progressively less output. 

Offshore wind has a much higher capacity factor (actual output relative to nameplate capacity) than onshore wind.  Both show rapid declines over the years as additional capacity is added.  When one compares offshore wind’s initial output with onshore wind, it becomes clear why New England states favor the former over the latter.  Besides, the lack of land to host onshore wind turbines makes offshore wind more attractive.  Both wind resources have higher capacity factors than solar. 

Batteries have similar output profiles.  As shown in the following chart, the 4-hour battery output is greater than the 8-hour battery but its decline rate is much steeper as additional capacity is added. 

Batteries face similar declining output profiles with greater capacity.

Interestingly, the EPCET report did not provide a contribution chart for the 100-hour battery.  However, it was included in another chart and discussion about the levelized cost of carbon removal for each of the clean energy resources.  The cost of each renewable energy resource is estimated based on the cost of removing one ton of CO2. 

The 100-hour battery is projected to be the cheapest way to address carbon emissions.  

The levelized cost of carbon removal shows the 100-hour battery as the most cost-effective renewable resource in 2050.  Not only is it cheaper than the 4-hour and 8-hour batteries, but it is cheaper than wind or solar power.  The 100-hour battery cost in 2030 is considerably more expensive than the 4-hour or the 8-hour battery.  However, it is projected to become the cheapest battery option by 2050.  There is an assumption that this battery will experience a dramatic cost-efficiency improvement after 2030.  However, it remains non-competitive with the shorter-lived battery options until 2050.  Will that dramatic cost-improvement assumption materialize?  If not, this battery option may remain more expensive than the shorter-lived batteries.  That could significantly alter the 2050 rankings of these renewable energy resources. 

Interestingly, outside of the 100-hour battery, every renewable energy resource becomes significantly more expensive in 2050.  Both 4-hour and 8-hour batteries become increasingly more expensive in 2040 and 2045, too.  The ramp-up of the cost of solar during 2040-2050 is dramatic.  This chart raises serious questions about the financial impact of following a path towards a 100% renewable energy grid, given the declining contribution from the additional capacity added in the later years. 

The solar cost curve also raises questions about whether people realize that after 2035 this resource faces an upward cost curve.  That should be a red flag warning signifying the need for greater investigation of whether solar’s rapid buildout in New England should be tempered sooner than the 2030s. 

Offshore Wind As A Solution

A week ago, Massachusetts selected 2,678 megawatts (MW) of offshore wind power from three projects that bid earlier this year in the state’s solicitation for up to 3,600 MW of offshore wind.  According to Massachusetts Governor Maura Healey, “Simply put, we are going big.”  There is no doubt about that. 

The state’s Energy and Environmental Affairs Secretary Rebecca Tepper laid out the case for offshore wind.  "Offshore wind is our future and it's vital that we build that future today.”  She said, "The reality is, we need more power.  Offshore wind will bring stability to Massachusetts at a critical time, and is the keystone of our clean energy transition.  Combined with solar, hydropower, storage, Massachusetts' future promises stability and reliability as our economy continues to grow." 

The clean energy transition is dictated by the state’s law mandating a minimum 50% reduction in its 1990 emissions by 2030.  The reduction will ramp up to at least 75% by 2040 and at least 85% by 2050.  This requirement is similar to policies in the other five New England states and was the impetus for the ISO-NE EPCET report. 

As part of the study, ISO-NE modeled the offshore wind acreage required in 2050 to decarbonize the grid based on three scenarios.  They are based on different offshore wind densities.  The process involved creating the 34,000 MW of offshore wind capacity deemed necessary to achieve the decarbonization goal using the various wind densities. 

Only high-density offshore wind achieves decarbonization without greater acreage. 

According to the modeling, unless offshore wind has high density, there is insufficient acreage currently available in lease areas to meet the decarbonization goal.  At the time of the study, New England had an offshore wind build-out of 800 megawatts (MW), which we assume was the Vineyard Wind project. 

The modeling calculated the space for offshore wind needed to meet the 2050 decarbonization target based on three wind densities.  Wind energy density is determined by MW per acre.  The high-density amount is based on the MW per acre for the region’s most-dense approved offshore wind project or 0.0196 MW/acre.  Likewise, the low-density scenario reflects the MW per acre for the region’s least-dense approved offshore project or 0.0048 MW per acre.  The medium-density scenario represents an output of 0.0100 MW/acre. 

The chart shows that the high-density offshore model calls for wind turbines to be located on 1,750,000 acres of coastal waters.  That represents 2,734 square miles of offshore waters.  That is the equivalent of a 10-mile wide stretch of turbines extending the entire Rhode Island and Massachusetts coastlines. 

The medium-density model requires 3,450,000 acres or 5,390 square miles of wind turbines.  Interestingly, it would need 500,000 acres more than all the acreage currently available.  To install the necessary wind turbines, developers would need a 10-mile swath of acreage extending the entire length of the New England coastline except for New Hampshire’s 13 miles.  This swath would extend from the Connecticut/New York border to the tip of Maine’s border with Canada.  The acreage not currently available is the equivalent of a 20-mile-wide strip extending the entire coast of Rhode Island. 

The low-density scenario calls for using all the available offshore acreage for lease, representing 2,950,000 acres plus 4,200,000 additional acres not currently available.  To provide the power, wind turbines would be located in a 20-mile-wide stretch extending the entire 1,120-mile New England coastline.  The additional lease acres needed represent a 10-mile swath for slightly more than the length of the New England coastline. 

The proponents of offshore wind object to the characterization of what is happening to the waters of New England as “industrialization.”  However, considering the areal extent of the wind turbines needed to meet the three decarbonization scenarios, it is impossible to view the outcome as anything less than industrialization. 

Not only would there be a forest of wind turbines, but there also would be a high level of vessel activity to maintain and repair the structures.  Along with the turbine forest, there would be shipping and flight safety issues from radar interference and a significant disruption of the region’s fishing businesses.  Lastly, these wind turbines would be located amid the most active whale migration, feeding, and birthing areas of North America.  There would be unknown consequences for the populations of these endangered marine mammals. 

Let’s add some perspective to the amount of coastal waters that will need to have wind turbines to achieve the decarbonization of New England’s grid.  The map of New England gives us that perspective.  Imagine a 20-mile-wide swath of coastal waters extending the entire length of the five coastal states.  This is what it would take to achieve decarbonization using a low-density offshore wind system. 

New England’s coastline will become a forest of offshore wind turbines. 

When one examines the New England map, the island due south of Rhode Island is Block Island, home to the nation’s first offshore wind farm installed in 2016.  The 5-turbine, 30-MW wind farm was designed to be a test for a larger project targeted for Long Island.  Block Island lies nine miles south of the Rhode Island coastline.  Thus, when we highlight a 10-mile swath of wind turbines, it would occupy all the space between the coast and Block Island and extend slightly beyond the island. 

Moving up the coast, the next island is Martha’s Vineyard, seven miles from the Massachusetts coast.  The third island is Nantucket, some 30 miles south of Cape Cod.  The distances these three islands are from the coast provide a visual perspective on the amount of coastal waters to be filled with wind turbines to meet the region’s decarbonization goal. 

In several examples, we cited, the wind turbine swath extends from the southern tip of Connecticut through Long Island Sound, along the coasts of Rhode Island and Massachusetts, and up to the Canadian border.  The logistical challenge is that beyond Cape Cod, water depths become too great for the bottom-supported wind turbine structures used in the current wind farms.  Installing wind turbines off the coast of Maine requires that they float, adding to the complexity of wind farms and increasing their cost and the price of the electricity they will produce. 

Expensive offshore wind becomes a significant challenge for New England in reaching its decarbonization goal.  The challenge was illustrated earlier with graphs showing how adding additional units of renewable energy leads to them producing less power.  This is a problem when trying to decarbonize the remaining hours of the year when dispatchable fossil fuel-burning facilities are meeting the power needs of the grid.  It is why ISO-NE says that dispatchable fossil fuel generation assets will become more valuable as we near 2050. 

Throughout the decarbonization study, we learned of the limitations of renewable energy sources for accomplishing the task.  Decarbonizing the ISO-NE grid using renewables will require that they be massively overbuilt, adding to the cost of the effort.  The diminishing output from the additional renewable capacity creates problems that will inflate the price of the region’s electricity for ratepayers.  We have yet to see any effort by the region’s utilities to educate consumers concerning the plans being considered and what they will cost.  This is an educational effort that needs to be undertaken before consumers are handed the bill.