Burying High Voltage Lines

RETA has conducted significant research on burying high voltage power lines. We have studied the literature on the matter, and have met with underground cable experts from around the world. Several underground cable experts from Europacable have attended public and private meetings organized by RETA. We arranged for underground cable experts to meet with the Alberta Minister of Energy, other Alberta Members of the Legislative Assembly, as well as Alberta Energy staff, to explain how the undergrounding technology has advanced in recent years and how the costs have come down.

RETA has prepared a Fact Sheet on burying high voltage power lines, and references on the subject are included in our comprehensive reference list.

In summary, when compared with overhead or above-ground lines, buried high voltage power lines:

1. eliminate the electrical field through shielding and significantly reduce the magnetic field through phase cancellation,
2. reduce the negative health impacts of overhead line electromagnetic fields (EMFs) to almost zero,
3. eliminate the negative health impacts of the overhead line corona effect,
4. are safer because they can’t electrocute people or animals,
5. eliminate EMFs and stray voltage that negatively affect livestock,
6. do not negatively impact agricultural crop production,
7. are safer because towers and lines can’t fall over in wind or ice storms,
8. are not affected by solar storms,
9. are safer because helicopters and fixed-wing aircraft can’t crash into them,
10. do not cause nearby pipeline corrosion or hazardous induced currents in pipelines,
11. do not lower adjacent property values,
12. are not an eyesore,
13. do not buzz or hum,
14. do not negatively affect tourism,
15. do not kill thousands of birds annually through collision,
16. are more reliable,
17. have lower maintenance costs,
18. are more efficient and have lower transmission loss costs, and
19. can be buried for almost the same capital cost as overhead lines.

With regard to the cost of burying high voltage power lines, based on RETA’s research, expert testimony provided at the AUC hearing on the proposed Heartland Transmission Project, and many discussions with underground cable experts in Europe:

• The capital cost of burying these lines is not 4 to 20 times the cost of building overhead lines, as suggested by the Alberta Electric System Operator (AESO), Alberta Energy and transmission facility owners in Alberta (e.g., AltaLink, ATCO Electric, EPCOR).

• For example, expert testimony at the April and May 2011 Heartland AUC hearing indicates that the capital cost of a partially buried Heartland double circuit 500 kilovolt line (i.e., 20 of 66 kilometres would be buried) is only about 15% higher than AltaLink’s and EPCOR’s $580 million estimated cost of an entirely above-ground Heartland line. This is a rounding error within the electricity transmission industry, and well within AltaLink’s and EPCOR’s Heartland Transmission Project contingency budget.

• Maintenance costs of buried high voltage power lines are substantially lower than for overhead lines, and this is because underground lines are not subject to tornadoes and other high wind storms, ice storms, general weather deterioration, birds colliding with lines and knocking the power out, etc. For example, the 40-kilometre 500kV line buried in Tokyo in 2000 has had zero maintenance issues.

• Transmission loss (electricity to heat) costs are anywhere from 50% to 67% lower for buried than for overhead lines. This can add up substantially over the 60-year life of a line. In Alberta, the one-year transmission loss costs were estimated by AESO at $220 million in 2009.

When you combine the capital, maintenance and transmission loss costs over the 60-year life of a high voltage power line, and add the health and property devaluation costs of overhead lines,  buried lines cost much less than overhead lines.