The Carbon Neutral Islands Project website Island Updates was introduced a couple of weeks ago
and it looked to me like they could do with some help fleshing out their Community Climate Action Plans particularly as regards electrification and renewables and so I’ve started with the example of Islay.
Installing 8 × 7MW or 9 × 6.2MW wind turbines at the top of the hills, capacity factors of up to 69% are possible (see Global Wind Atlas) but only 49% CF is needed to yield 240 GWh per year of electricity – equivalent to Islay’s energy mix in 2022.
Wind, solar, storage and back-up system designer
Row C configuration text page.Peak Demand Power: 28.6 MW
Daily Usage of Energy: 429 MWh
Wind Power Capacity: 56 MW
Wind Capacity Factor: 49%
Wind energy per day (average): 659 MWh (= ~240GWh/year)
Storage Energy Capacity: 549 MWh
Back-up power: 8.57 MW (Bowmore generator)
Grid system components specification
- 8 × ~7MW or 9 × ~6MW onshore wind turbines – high wind, class IEC I or II, 50-year extreme gust over 3 seconds 59.5m/s (133mph), 50-year extreme wind over 10 minutes 42.5m/s (95.1mph) or more or equivalent high wind survivability if class IEC S.
- Currently investigating the following makes & models as regards high wind performance and survivability. No definitive recommendation as yet.
- Vestas EnVentus V150-6.0MW 9 × 6.0MW = 54MW
- Siemens Gamesa SG 6.6-155 8 × 6.6MW = 52.8MW but
- Enercon E-175 EP5 9 × 6MW = 54MW
- Sited on the tops of hills & mountains, building new roads where necessary to get cranes and components on site for turbine erection and connection
- 580MWh / 29MW for 20 hours, pumped hydro storage scheme (probably built near Beinn Bhànn). Spinning reserve operation for grid inertia support and off-grid frequency stability.
- 33kV new wind farm and island legacy power transmission lines
- 11kV legacy and additional power lines as required
District and domestic power & heat
- choose options to suit according to preference
- heat pumps
- solar panels
- green hydrogen electrolysis & fuel cells
- legacy boilers / fireplaces burning biomass / biofuels
- thermal energy storage
- batteries
I’d be happy to further flesh out the details of any of this which may be of interest to the Islay community and where it fits in with their respective Community Climate Action Plan.
See Islay Energy Trust & Islay Energy Community Benefit Society
Energy
Islay’s energy use includes electricity provided by the grid as well as solid and liquid fuels used to heat buildings and power industry. Islay’s total energy consumption is approximately 240 GWh per year of which over 80% is supplied from imported fossil fuels, and 17% is grid supplied electricity.
Less than 1% of Islay’s energy demand is met by locally generated renewable electricity.
Decarbonising Islay will almost certainly require more electricity – such as for air-source heat pumps, electric and hybrid transportation, or even electrolysis for hydrogen production. As such, improvements to Islay’s electricity supply are essential.
The CNI project is aiming to install a small solar array to complement the existing community wind turbine. But this will only scratch the surface of Islay’s energy needs and bigger changes to our energy infrastructure are needed.
Islay’s legacy 330kW Enercon Wind turbine is underpowered by a factor of 170. It would take 170 of those legacy small wind turbines to power and heat the island – if there was even space for 170 such turbines to operate properly without interfering with each other, which I doubt.
A much better solution is for the Scottish and UK Governments to invest in eight modern 7MW turbines and the pumped hydro scheme I have advised here. This solution would allow Islay to go off grid, end fossil fuel use and make some money exporting island renewable energy surpluses to the grid!
I’d welcome any of the other Carbon Neutral Island Project people getting in touch with me for free advice – Community Energy Scotland and the islands of Barra & Vatersay, Cumbrae, Hoy & Walls, Islay, Raasay and Yell.
See also – BARRA & VATERSAY: Carbon Neutral Island
Scottish Scientist 
2 thoughts on “ISLAY: Carbon Neutral Island”