Data Centres and Renewable Energy Project
Estimating overall Data Centre costs
We also looked at how the different energy supply options affected the overall costs of building and running this data centre in Shetland. The estimates looked at costs over 3 years - the expected life of the IT equipment (1). The estimates are order of magnitude only but they should provide insights on how the various options compare to each other.
Impact of varying location – Shetland as an example
Different locations were selected depending on the primary energy supply, in order to minimise expensive buried transmission lines. This means that the data centre has to be connected to the main fibre optic cable by two independent routes. The costs of buried fibre optic cable are £56,000 per km, so even with two routes this is less expensive than buried 33kV line which is £186,000 per km.
The sketch map shows the possible locations for the various options. The new fibre optic link to SHEFA will terminate at Lerwick.
- A wind turbine or biomass plant could be located close to Lerwick, so we assumed that a two-route link would be only 5km in total.
- A hydroelectric plant would almost certainly have to be further away, after looking at a contour map we have assumed a total of 30km of fibre otpic cable
- For tidal energy, the nearest location would be at Toft, near Yell Sound, and require around 90km of cable; and for wave, the ebst location is at Sandnes on the W coast, and require around 100km.
Outcomes:
The chart below compares the total costs over 3 years.
- Locating the data centre at a distance from the nearest existing fibre optic connection point can double the capital cost of the entire facility.
- Scaling up in size would increase the IT costs without changing the those for site, infrastructure or connectivity; however, even with 5 times the IT power the difference in connectivity costs will still be significant.
- Overall, the lowest overall cost of for wind with biogas. There is however a limit to how large this data centre could be, as its viability depends on availability of organic waste. It would be worth studying this option in more depth to determine how far this could be scaled up, including with a grid connection.
Assumptions and data sources:
The breakdown of cost elements and their estimates was pieced together from numerous references, suppliers’ quotes and conversations which are detailed in the attached spreadsheet. The starting point was PwC’s study on Iceland as a potential location for data centres (1), modified where better information was available. The main other sources were:
IT costs: Survey of server power and costs for small business applications, from Dell, HP and IBM. These costs turned out to be less relative to the rest than indicated in (1); however this is to be expected as IT costs have come down over the last 4 years.
Site and Infrastructure: Based on the layout outlined in the Data Centre section. Quoted cost for HP-20ft container is from data centre news website (2); much of the remainder based on information from a construction and property consultant, Brian Willshire (3)
Connectivity: Estimates are based on information from Jim Mennie, of Telecosse, a company specialising in voice and data cable installation in the North of Scotland (4)
Operating costs: based on PwC Iceland study (1): assumed 4 IT specialists to staff the centre; and security, maintenance and other service costs are 20% of the total infrastructure capex per year.
A more detailed presentation of assumptions and calculations are in this spreadsheet
References used in this page:
(1) PriceWaterhouse Coopers 2007: Benchmarking Study on Iceland as a Location for Data Centre Activity, May
(2) Datacentreknoweldge: HP Offers 20-Foot Version of POD Container, http://www.datacenterknowledge.com/archives/category/technology/containers/ , accessed 14 March 2010
(3) Brian Willshire, Summers Inman Partnership – personal communication
(4) Jim Mennie, Telecosse – personal communication