Our plans for a community owned power system for Sark.
What’s the plan for the new power system?
The new system will be island-owned and run on an open book
basis to provide power to the island at a fair and sustainable cost.
The new system will replace or substantially upgrade Sark’s
current system including the generation system and the
distribution network up to and including the connections and
metering for each building on the island.
It will provide a safe, reliable and low carbon energy supply for the island. It will be scalable to meet future needs, including a future where heating, cooking and transport are electricity-based.
What options are being considered?
The design phase looked at 2 options for the generation system: a diesel-based system which will be cheaper to build but more expensive to run and a renewables-based system which will be more expensive to build but cheaper to run. Either way, the distribution system needs replacing or substantially upgrading.
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The design work for both the distribution and generation system has been done in a way that that it can form the basis of a complete replacement system or a staged partial or full upgrade.
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Generation system (at Les Laches)
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3 x 350 kVA diesel generators (in noise reducing containers) providing 100% back-up (or basis of transitional diesel only system).
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A new power station building next to the abattoir to house the generators, workshop and low voltage distribution boards.
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2 x 225kW (30m tower and 29m diameter rotor) Vestas V29 refurbished wind turbines.
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510 kWp solar farm (1 field / half an acre – east/west layout)
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750kWh storage capacity battery (8 hours of current night time loads) in fire safe 10ft shipping containers.
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‘Micro gird’ control management system.
Distribution system
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Designed to follow the existing network so can be implemented as a complete replacement system or staged upgrade.
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Able to manage diesel and/or renewables-based generation.
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Will run at 6.6kV (as per current system) with cables able to run at 11kV if required in future.
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Designed to meet demand range from current demand of 90 – 400kVA to max demand of 2,500kVA (with ability to scale above that if and when needed).
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Scalable to future needs where cooking, heating and transport are electricity based.
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Built and maintained to Guernsey standards.
- Low voltage network replaced up to individual properties (excluding upgrades required to property).
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If feasible, a control and billing system to enable low cost ‘heat
tariff’ for hot water and storage heating when there is a surplus of wind or solar.
The design phase reports can be viewed here:
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New Energy Centre design report
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Visualisation of proposed wind turbines (14MB)
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What will the new system cost?
The design phase estimate for a complete replacement renewables-based generation and distribution system and associated development costs is around £10.6million. We will not know the extent of the upgrade required, and therefore the cost, until Sark has ownership of its energy infrastructure.
The generation system needs replacing, which could be done in stages. Parts of the distribution system may be usable, which could significantly reduce costs.
Whilst a diesel only system will be cheaper to build, in the long-run it is likely the cost of electricity will be higher than for a renewables-based system due to the ongoing cost of fuel.
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Whether the generation system is diesel or renewables-based, the distribution network still needs to be replaced or substantially upgraded. The distribution network replacement makes up over 60% of the estimated cost of a full replacement system if required.
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Investment will only go ahead if affordable without a significant increase in electricity bills.
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Where will the new power hub be located?
The proposed location for the wind turbines is in island-owned fields at Les Laches above Creux Harbour with the solar array nearby, as shown below.
The diesel generators and batteries will be housed in a new
agricultural-type building near to the abattoir.
Loan or bond for 100% of build cost
Sark People 100% own
Design & build contractors
Sark Power energy grid & generation
Operations contractors
Electricity supply at fair & open book cost
What does ‘Island owned’ mean?
If the replacement system goes ahead, it will be owned by a new Sark community enterprise – ‘Sark Community Power’.
Sark Community Power will not be a subsidiary of Chief Pleas like Sark Shipping. It will be owned by the people of Sark and will have its community purpose and governance established in its articles of association.
The electricity price will be set on an open book basis at the price required to cover running and finance costs and build up sufficient cash-flow, unplanned maintenance and system replacement reserves. The company will hold an annual general meeting and publish its audited accounts each year. It will continue to operate under the review of the Sark Electricity Price Commissioner who will provide independent oversight of the consumer price set.
Ownership
£1 ‘1 member 1 vote’ shares for island residents.
How much energy does Sark use?
Annual demand for electricity in Sark was recorded by Sark Electricity Limited (SEL) at 1,865,000kWh approximately ten years ago. Since then, it has reduced to around 1,500,000kWh due to a number of hotels closing and some houses and a hotel going ‘off-grid’. High electricity prices are also likely to be suppressing demand.
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Electricity demand is likely to increase in future with:
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The re-opening of currently closed hotels.
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Increased affordability of power (if unit price reduced).
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A shift from bottled gas to electricity for cooking – this could increase annual demand by up to 300,000kWh.
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A shift from oil to electricity for heating – this could increase annual demand by up to 4,000,000kWh.
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A shift to electricity for transport. If Sark’s tractors go electric, that could increase electricity demand by around 500,000kWh per year.
Could Sark be more energy efficient?
Due to the high cost of energy, most Sark households are frugal with their energy consumption. Many of Sark’s buildings are very poorly insulated and we could make our energy go further and have warmer, healthier homes if our buildings were more energy efficient.
As well as addressing the urgent need for a replacement power system, Sark needs a long-term energy strategy to plan for the shift to low carbon heating and transport and making our buildings as energy efficient as possible.
How are we going to raise the capital?
The design phase estimated costs for a complete replacement renewables-based system are around £10.6million. We will not know the extent of the upgrade required, and therefore the cost, until Sark has ownership of its energy infrastructure. The generation system needs replacing, which could be done in stages. Parts of the distribution system may be usable, which could significantly reduce costs.
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A new or substantially upgraded power system will be big investment for Sark. However, there are community-owned energy projects in the UK, financed through community shares/bonds, public sector investment and debt finance which are larger. CfR CIC, which is supporting the finance strategy, has managed the financing of community-owned energy projects with a total capital value of over £70million.
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The objective is to raise the capital from grants and debt-based sources so that the island can retain ownership and control of the system. Investment will only go ahead if affordable without a significant increase in electricity bills.
Electricity price implications
The current system has been declared past it’s serviceable life and in parts dangerous. Sark needs a replacement power system. Continuing indefinitely with the current system is not an option.
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If the build costs and/or finance costs are too high for the replacement system to deliver power at affordable prices with commercial investment, we will need to secure grants or low cost government finance. We will explore these options anyway as, even at current rates, electricity prices on Sark are twice the rate on Guernsey and the power system is critical infrastructure.
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The electricity price for the new system will depend on the build cost, finance costs and likely increases in electricity consumption (e.g. as households shift from bottled gas to electricity for cooking). The electricity price on Sark is regulated and Sark Community Power would have to set prices in accordance with the Sark Electricity Price Control Orders.
Design and Build Contactors
Generation with:
Distribution grid with:
Management with:
