27th June 2017

Why not generate power locally? (John Tulloch)

The proposed new Lerwick Power Station at Rova Head was, at least, 50 percent bigger than necessary. It had double the capacity (120MW) of the latest 60MW subsea cable proposal which itself exceeds Shetland’s peak winter demand by about a third. The projected cost of the new power station was therefore excessive and it is little wonder Ofgem balked at the idea.

Q1. Why was the new Lerwick Power Station design so excessively over-sized?

Q2. What would be the cost of a ‘no-frills’, 70MW power station at Rova Head, instead of 120MW?

Q3 What would be the cost of a ‘no frills’, 70MW power station sited at Sullom Voe with upgraded (underground) transmission lines to Lerwick?

Subsea cable connections to Orkney and the Western Isles already existed when the former North of Scotland Hydro-Electric Board was privatised in 1991. By the mid 1990s, its successor company, Scottish Hydro-Electric, keen to cut costs, considered connecting Shetland to the Mainland grid by subsea cable and rejected the idea due to excessive cost.

That assessment was based on the power station using heavy diesel fuel, as now, versus importing cheap coal or gas-fired energy via a grid link. However, a new power station would now use very cheap gas – less than a third the cost of diesel fuel – from Total’s Laggan-Tormore gas field, in which SSE holds a 20 per cent stake, via Sullom Gas Plant.

Gas would cost a fraction of imported mainland renewable energy (Scottish coal power stations have all closed). So there would seem less incentive now than in the 1990s to install a subsea grid connection.

Furthermore, local generation would avoid substantial power losses associated with the very long transmission distance and AC-DC conversion in the proposed subsea cable link.

Finally:

Q4. What will be the capital cost of this proposed Caithness-Shetland subsea grid connection?

John Tulloch

Lyndon,

Arrochar.

7 comments

  1. Thomas Leask

    Sub sea cable is all fine and well until some poor fishing vessel dregs it up or severs it. Then the whole island is up a creek athoot a paddle.

    Reply
  2. James J Paton

    Mr Tulloch may be surprise to hear me praise him. His excellent questions, which due to a privatised industry, may never get answers, due to ‘commercial sensitivities’?

    I maintain that Shetland needs to look first and foremost at energy conservation, then at long- term sustainable energy production from a mix of sources.

    For me a key question, if gas is to be the ‘solution’, what happens when the gas runs out? Also how does Shetland off-set it’s CO2 emissions? Is carbon-capture in empty oil-wells a possibility?

    Although against the scale, and proximity to housing of the Viking Energy and related interconnector proposal, irrespective of Charitable Trust investment, now a non-starter?

    Additionally Shetland needs to work out and accept, that it’s energy costs will always be much higher, unless Government or a large corporate producer is prepared to subsidise with profits made on the UK mainland.

    It is a great irony with oil and gas production ‘on site’, although there were/are many reasons why the Council or an energy provider could not do a deal. I recall BP/Terminal partnership saying they could not guarantee supply. The Terminal power station has had only one, but quite a long, breakdown of production, (1980’s) when diesel had to be transported in.

    Ultimately I believe the Shetland community needs to take ownership of its own energy needs and provision. A tall order?

    Reply
    • Ali Inkster

      The gas west of Shetland will outlast any power station built to consume it.

      Reply
  3. Gordon Simpson

    With the technologies available, being installed around the world as we speak (type – whatever) I believe we could be self sufficient in power with little or no need for a gas turbine.
    Tesla provide (sell) large battery banks that can regulate the ups and downs of power generated from renewable sources. It wouldn’t take much calculation to find a level that provides for all, and allows for seasonal changes.
    The only reason they are determined to get an undersea cable here is to harvest our renewable energy source, to meet their own targets, to put the ugly turbines (hundreds of them) as far away from their own backyards as possible, to comply with international promises made no matter what the inefficiencies. Need I rant more?

    Reply
    • John Tulloch

      Thanks to JJP and GS for comments:

      Technology aplenty is, indeed, available. Sadly, it’s eye-wateringly expensive and consumers must pay.

      Onshore wind is the cheapest, practical, renewable energy. Utilities are forced to take it at 9p/kWh. Marine energy is even more expensive than offshore wind (12p/kWh), and also cannot provide constant supply. Energy storage is needed.

      The US National Renewable Energy Laboratory (2015) estimated utility-scale lithium ion batteries cost $300/kWh. That means a battery to supply Shetland for one winter day would cost around £140 million – on top of the cost of the renewable energy plant whose own cost would far exceed a gas power station.

      A 70 MW gas-fired plant should cost much less than the 120MW, Rova Head proposal (£200 million) and the marginal cost of the electricity should be no more than about 2p/kWh, to which must be added overheads like staff, maintenance, rent, etc., which benefit the local community.

      Gas supplies running out is a red herring. The cable or power station will last 20-30 years. Gas will remain plentiful long after that.

      Presently unaffordable solutions should be considered when they are needed or become economic, not before.

      Reply
  4. John Tulloch

    Peel Energy has two wind farm projects going through planning permission, Mossy Hill (49.9MW), roughly between the Brig a’ Fitch and Gulberwick and Beaw Field, Burravoe, Yell.

    The proposed cable could cater for either, but not both, of these wind farms.

    Beaw Field has the disadvantage of needing transmission lines, including a submarine cable across Yell Sound, to connect to the cable terminal at Lerwick. Mossy Hill, a couple of mies away, will have no problem.

    What wonderful luck for Peel Energy that a grid connection is coming to Lerwick at the very moment they came up with their Mossy Hill idea?

    Reply
  5. John Tulloch

    £millions per year will be lost to the Shetland economy if this grid connection goes ahead.

    It is by no means clear that this is the “most economic solution to Shetland’s future energy needs.”

    Reply

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