Scottish and Southern Electricity Networks (SSEN) has used ‘Constraint Managed Zones’ (CMZ) to save customers £230,000 and avoid 2,450 tonnes of CO2 emissions on the Isle of Islay.
The company said that this was an “important milestone”, showing that low-carbon technology can support system security in an economically viable manner.
CMZ are a smart systems approach designed to help manage the network when there is planned maintenance, a job that previously would have been done by embedded or mobile diesel generation. The CMZ can also be used during fault scenarios as well.
On the Isle of Islay, constraint was managed using the Inver hydro scheme on the neighbouring island of Jura. The scheme’s 2MW of installed capacity could meet 40% of the average local load, and during a recent fault scenario provided nearly 5GWh of renewable energy.
Stewart Reid, head of future networks at SSEN welcomed the announcement saying that the proliferation of low carbon technologies was creating opportunities to “take a low-carbon approach to addressing network constraint”.
“Managing our energy system in a smarter way helps decarbonisation efforts in a cost-effective manner for the communities we serve.
“Through utilising the CMZ we have managed to avoid the carbon emissions equivalent of taking 971 cars off the road for a year, or enough to power half a million homes for a week. Our ambition is now to increase CMZ usage across both our distribution areas, to deliver cost savings and significant carbon reductions.”
CMZ contracts form a key part of SSEN’s flexibility drive, helping to balance low or zero carbon generation in an effort to transition to net zero.
John Lithgow, managing director of Inver Hydro, added that: “The CMZ has been a great success, ensuring we made a significant contribution to keeping the islands’ lights on over the winter with low-carbon generation. It clearly demonstrates the role of embedded generation like small hydro in delivering the integrated energy networks solutions of the future.”