The Green goals
A critical feature of the NCSL is its basis upon renewable energy using cutting-edge but proven viable technologies. The technologies adopted for the project will provide a cost- efficient source of powering the facility but also future-proof the investment and, importantly, make it fully compliant with the climate change targets of the Scottish Government (Climate change - gov.scot (www.gov.scot 2019)). A study by Ramboll, an international engineering consultancy has validated the NCSL’s approach.
The Marine Heat Pump
The key foundation of the project is the marine heat pump which makes use of the energy embodied within the sea by using a heat-exchanger to heat a fluid with a very low boiling point, and in turn transfer to the circulating hot water. Effectively the mechanism is much the same as a standard domestic fridge, but in reverse. This technology enables delivery of the key 'green' energy-source ambitions of the NCSL project whilst being as local as can be - the Moray Firth. A number of examples of this technology currently operate within the UK and internationally; some in much colder environments than Nairn (See: www.orkney.com/life/energy/renewables; www.greenergyexpo.eu/drammen-heat-pump/).
The marine heat pump will be the primary heating source. The electricity required to power the marine heat pump will be derived primarily from Photo-voltaic (PV) panels on the new domed roof to the swimming pool. Alongside these it is planned to install solar-thermal panels which use solar radiation to provide additional hot water. This energy source is not just confined to sunny days, although it will be more abundant then, and has been demonstrated nearby to provide water at up to 80°C.
Air Source Heat Pump
Back-up supporting technologies will be configured from a combination of other validated options. These include an air source heat pump which operates in much the same way as the marine heat pump; the only difference being the energy source of the surrounding air is used instead of the seawater. Such units are highly efficient and typically will return 3 units of output for every unit of energy input.
Ground Source Heat Pump/Geothermal
Another option is the use of a ground source heat pump which has been favourably validated in the range of alternatives assessed so far. Geothermal energy, sourced by drilling down into the old red sandstone bedrock, is yet another possibility subject to a favourable geological survey. Such a system is used in Iceland’s famous Blue Lagoon (www.bluelagoon.com).
A study of the potential use of graphene as the filtration medium for the grey water output from the facilities has been investigated by a study commissioned from Edinburgh University. This research produced encouraging results and furthered the potential for a zero waste project.