A company based in Southern California, CTC Global Corporation, is doing something about this. In 2005, CTC Global introduced a new bare overhead conductor type known as ACCC that is not only capable of delivering twice the power of a conventional conductor, it also does so with a fraction of the electrical losses of conventional wires. CTC Global’s ACCC conductor’s ability to double the capacity of existing corridors can not only mitigate grid congestion (effectively reducing the cost of delivered power), it can also enable newly developed sources of clean energy to be connected to the improved grid and deliver power to a growing customer base. Line loss reductions provided by CTC Global’s ACCC conductor not only serve to reduce fuel consumption and associated emissions, they also free up generation capacity that is otherwise wasted (An example is provided below).
In the early 1900’s most new power lines were made with copper wires. The demand for copper during WWII curtailed the use of copper so aluminum was used as an alternative. Aluminum is a good conductor, but relatively weak, so aluminum wires were reinforced with a steel core strands to accommodate longer spans on larger power corridors. The product “Aluminum Conductor Steel Reinforced” (ACSR) has been the standard ever since. While ACSR was a good alternative to copper, it has the propensity to sag under heavy electrical load conditions. As conductors carry increased levels of electrical current the electrical resistance of the wires causes them to heat up. Their relatively high coefficient of thermal expansion allows the wires to expand and sag. Sag is often the primary cause of electrical power outages which is quite dangerous and horrifically expensive. Recall the economic losses associated with the major east coast blackout of 2003 was estimated at nearly $10 billion dollars.
To mitigate thermal sag, CTC Global developed a hybrid carbon fiber core that offers a very low coefficient of thermal expansion. CTC Global’s composite ACCC core is also twice as strong as steel and about 70 percent lighter. These factors help minimize project costs and environmental impact on new lines. Because the composite core is so much lighter than steel, it also allows the use of higher quality aluminum and a 28 percent added quantity without a weight or diameter penalty. This not only serves to carry added current, it also reduces line losses by 25 to 40 percent or more.
Figure 1 – Conventional steel reinforced ACSR & CTC Global’s modern composite core ACCC conductor
In December of 2015, American Electric Power (AEP) used CTC Global’s new “Aluminum Conductor Composite Core” ACCC conductor to increase the capacity of 240 circuit miles of an existing ACSR line in Texas. A 100 mile section of that line is presented for comparative purposes:
- CTC Global’s ACCC conductor increased line capacity by 75% with 625 amp emergency reserve
- CTC Global’s ACCC conductor reduced line losses by 30%
- The use of CTC Global’s ACCC conductor saves 300,606 MWh / year (=$19.2M @$0.06 / kWh) (per 100 miles)
- Emission reductions saves ~200,000 Metric Tons CO2 / year (~2,000 metric tons per mile)
- The use of ACCC equates to removing 42,000 cars from the road (1 car = 4.75 metric tons / year)
- Line loss reduction also freed up over 40 MW of generation capacity (cost estimate = $50M+)
- The cost of CTC Global’s ACCC conductor was $12.7M per 100 circuit miles (600 linear miles of ACCC conductor)
The numbers presented above are based on a power flow ‘load factor’ of 62%. CO2 emission reductions are based on the US national average of all combined sources of generation (1,342 pounds per MWh).
While the cost of labor obviously added to the overall project cost, a majority of the existing structures were retained and utilized due to CTC Global’s ACCC conductor technology. Only a handful of rusted structures had to be reinforced or replaced. The ACCC project was also completed while the line remained energized, which was the largest live line reconductoring project undertaken thus far. This project is one example of over 400 similar projects completed in more than 40 countries worldwide with CTC Global’s ACCC conductor.
The chart below demonstrates that it is far less expensive to conserve energy using CTC Global’s ACCC conductor than it is to generate it. The data is based on information provided by the US DOE Energy Information Administration (EIA). As plans to develop new sources of generation are considered, it is very critical to consider the means by which the power is delivered. Here too lies great opportunity for investment return.
Figure 2 – Relative ROI for Reducing Carbon Emissions (Metric Ton Savings per $1 million dollars) using CTC Global’s ACCC conductor
As various means are considered to promote the development of a low carbon energy future, efficiency will continue to play an important role. In the case of deploying high-capacity, highly-efficient ACCC conductors this represents a “no regrets” opportunity. Further, the development of transmission and distribution assets generally offer excellent return for investors, don’t need to be subsidized, and offer desperately needed solutions not only to help reduce anthropomorphic impacts on climate change, but also substantially help underdeveloped nations grow their economies. Without access to affordable and reliable energy, no country can fully realize it’s potential. We need electricity to pump water to grow crops, support waste treatment and water purification facilities and generally compete in a global economy. CTC Global’s ACCC conductor can help substantially.
Figure 3 – 120KV ACCC Conductor Muntanda Lake Crossing Katanga Region, Kolwezi, Congo
Figure 4 – Over 400 ACCC Conductor Installations Worldwide
by Jim Clyde
Vice President Business Development
CTC Global Corporation