This is essentially the cost of the national gas grid.
- Residential: 9.57 £M/PJ investment cost. 0.001 £M/PJ variable operating cost. pg 14 code SRNGA Chapter 4 Markal06 cites source for costs; US EPA (2005)
- Industrial: 7.98 £M/PJ investment cost. 0.001 £M/PJ variable operating cost. pg 13 code SINGA Chapter 4 Markal06 cites source for costs; US EPA (2005)
|* Electricity: 7.98||£M/PJ Investment cost. 0.001 £M/PJ variable operating cost. pg 12 code SENGA cites source for costs: US EPA(2005)|
US EPA (2005) US Regional MARKAL model documentation, Office of Research and Development, US Environmental Protection Agency, www.epa.gov/appcdwww/apb/globalchange
These are American numbers. It would be good to cross-check with National Grid data.
- Lump all gas demand together
- Assume the numbers above are per PJ of average flow, and that the scaling that has been done to peak demand remains unchanged.
- Use +/-50% of the residential range for high and low range, use 35th centile between low and high costs for "Default" figure.
- Assume a 30 year life
- Should perhaps work out the size of the gas pipe based on peak demand so benefit from insulation?
- The Markal capital value looks much to high compared with the UK National Grid regulated asset values of £4.5bn for the gas transmission network and £7bn for the bit they own (perhaps half)http://www.nationalgrid.com/annualreports/2010/operating-and-financial-review/gas-distribution/about-gas-distribution.html.
- The ratio of capital to operating cost looks wrong, compared with national grid. It may be that a lot of the capital replacement in this calculation is actually operating cost in National Grid figures.
- These ofgem documents have gas distribution costs 
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