Integrating offshore wind into PJM will require billions in new transmission spending, either with radial lines from wind farms to shore or something like the Atlantic Wind Connection, a proposed a 300-mile transmission “backbone” off the coast from New Jersey to Virginia. Lines on shore also will have to be upgraded or built.

What projects will be built, and how much they will cost, will depend on how much generation is added and where it is brought onshore.

PJM has conducted studies of offshore wind in its last three annual Regional Transmission Expansion Plans (RTEP).  The studies looked at integrating various amounts of offshore wind in addition to its current 18,000 MW of nameplate onshore wind.

Among the potential projects are the Atlantic Wind Connection, which backers say could circumvent transmission congestion in New Jersey on hours when wind power is not generated.

In addition, a study released in January found that injecting up to 10,000 MW of wind in Virginia and North Carolina would require $1 to $2 billion in transmission upgrades.

2010 Conceptual Study

The 2010 RTEP included a “conceptual” study on the impact of importing 10 GW, 20 GW and 30 GW of wind off the Delaware, Maryland and New Jersey coasts. Equal amounts were modeled at four injection points in New Jersey, on the Delmarva Peninsula and in Virginia.

The study found that 10 GW both “unloaded” higher cost generation and increased generation east of PJM’s major west-to-east constraints, resulting in a 5.5% load payment decrease compared to the base scenario with no offshore wind.

Doubling wind to 20 GW increased load payment savings to only 7.5%, as the added volume caused constraints near offshore injection points that limited deliverability. Boosting generation to 30 GW produced virtually the same results as the 20 GW scenario.

2011 RPS Scenario Study

In 2011, the Organization of PJM States (OPSI) asked PJM to study how the system would respond if all states met their Renewable Portfolio Standards (RPS) with land based and offshore resources within the RTO.

One scenario that assumed 4 GW of offshore wind found that high levels of Midwest onshore wind would cause heavy congestion in western PJM, with 19 thermal overloads, most on 345-kV lines. Increasing offshore wind to 20 GW caused congestion in Eastern MAAC, with 53 violations, all but four of them on 230-kV lines.

PJM planners modeled two transmission overlays that solved the reliability violations and improved wind deliverability. The overlays allowed each state to meet their RPS goals – albeit not solely with in-state resources. Thus wind-poor states would need to obtain rights to renewables from states with excess wind.

The overlays reduced congestion costs to $6.6 billion (from $8.8 billion) in the 4 GW scenario and to $6.7 billion (from $7.4 billion) in the 20GW scenario. That compares with $5 billion in congestion under the base case without overlays or offshore wind. The analysis did not estimate the cost of the overlays.

2012 RPS Scenario Study

The recently-released 2012 RTEP furthered the RPS analysis, this time including energy deliveries from outside PJM. The 2012 study also included a request from Maryland and Delaware to examine the reliability and cost impacts of new transmission to deliver offshore wind such as the Atlantic Wind Connection (AWC).

Three scenarios were developed using a 2027 starting point base case. Two of scenarios assumed 36 GW of nameplate wind capacity and 7 GW of solar capacity would be available within PJM to meet state targets. The third scenario assumed 21 GW of wind and 7 GW of solar capacity within PJM, with 40 percent of remaining state RPS targets satisfied by wind imported from outside the RTO.

The study found onshore wind from the west faced transmission limits, primarily on 345 kV lines and above, while offshore wind was primarily constrained by 230 kV and above transmission. The study used PJM’s generator deliverability test to identify flowgates limiting deliverability at peak demand. PJM also identified conditions under which wind might be curtailed during light loads.

North Carolina Wind Integration Study

In January, PJM released the results of a study that estimated injecting up to 10,000 MW of wind at a substation in southeast Virginia and two substations in North Carolina would require $1 to $2 billion in transmission upgrades. The study was done jointly with the North Carolina Transmission Planning Collaborative (NCTPC), which includes the Progress Energy Carolinas (PEC) and Duke Energy Carolinas (DEC) balancing areas.

It looked at how the systems would perform at off-peak load conditions when wind is typically strongest.

The study looked at injections of:

• 1,000, 2,000 MW and 4,500 MW at PJM’s Landstown 230 kV substation;
• 1,000 MW to 3,500 MW at PEC’s Morehead City 230 kV substation area; and
• 1,000 MW to 2,000 MW in PEC’s Southport 230 kV substation area.

It found that Landstown could accept up to 2,000 MW without major upgrades but that imports of more than 4,500 MW would require a new 500 kV substation in addition to upgrades to the 500 kV 230 kV network.

Progress Energy Carolina’s injection points required upgrades in all scenarios.

Although as much as 6,000 MW of the power would sink in PJM, no more than $349 million of the transmission improvements would be within the RTO’s footprint.

It’s unclear how the cost would be allocated under FERC’s new Order 1000 rules, but PJM loads seen as benefiting would likely have to assume a share of the North Carolina cost to get the transmission built.