The global warming potentialof the HFC most widely used in is 3,140 times that of CO2, the most common greenhouse gas (2007 IPCC assessment for HFC-227ea). In contrast, the GWP of Novec 1230 fluid is just one (1). Further, Novec 1230 fluid has an atmospheric lifetime of only five days, compared with about 30 years for HFCs. The environmental profile of HFCs was unacceptable for Iberdrola in the environmentally conscious energy sector.
In fact, the high global warming potential and atmospheric persistence of HFCs are already leading to significant pressure to reduce their emissions.
The first steps toward this can already be seen in the F-Gas Regulations that have recently been introduced in Europe. While these regulations stop short of banning the use of HFCs, they do impose requirements specific to HFCs for technician training, inspections, leak testing and reporting.
Measures addressing the use of HFCs are also being drafted in the USA. An early action identified under the California Global Warming Solutions Act of 2006 includes a consideration that, beginning in 2012, all new in California must use an agent with a global warming potential below a minimum threshold level.
The California Air Resources Board (CARB) proposal reflects the regulators’ concern that, while emissions from this sector are currently low, installations of such fire suppression systems are growing quickly and the emission potential of this ever growing installed base represents a significant future liability. The only meaningful way to limit this future liability is to reduce the use of HFCs.
These issues were important to Iberdrola. If restrictions on the use of HFCs were introduced in the future, it would almost certainly mean that a fire suppression system based on a high GWP HFC agent would either have to be replaced in its entirety, or at the very least, substantially modified. This is an unacceptable proposition for such a large and important new infrastructure project, especially as the new substations would be expected to have a lifetime of decades.
Further, making major changes to the fire protection systems in the substations would be an expensive and difficult undertaking given their underground location. The work would be further complicated by the need to guarantee continuity of power to consumers.
In contrast, the 3M Company is so confident in the environmental characteristics of Novec 1230 fluid that it offers its unique Blue SkySM warranty. This guarantees that if Novec 1230 fluid is banned from or restricted in use as a clean extinguishing agent based on ODP or GWP during the next 20 years, the company will refund the cost of the fluid.
In addition, unlike CO2, Novec 1230 fluid has a wide margin of safety for use in occupied areas, which makes it safe to use, even if engineers are working in a substation when a discharge takes place.
“Margin of safety” reflects the difference between the design concentrations necessary to put out a fire and the threshold concentration recognized by approval bodies as suitable for use in occupied spaces. In a typical application, Novec 1230 fluid is used at a concentration of about 5%, but it is acceptable for use up to 10%. Therefore, its safety margin is about double, which is the largest margin of safety for any chemical Halon replacement.
Another important benefit of a system using Novec 1230 fluid is that it requires little space for storage. It is a liquid at room temperature, although it rapidly forms a gas when it is discharged through properly designed nozzles. This provides significant benefits to customers, because, as a liquid, Novec 1230 fluid can be shipped and stored in non-pressurized containers. It also means that installations can be more easily recharged by a liquid transfer. Such on-site refilling allows systems to be back online and operational within short period of time, often within 24 hours.
There are two final factors favoring the selection of Novec 1230 fluid for the Iberdrola application. These factors derive from the fact that Novec 1230 fluid is completely inert and electrically non-conductive. This means that discharge of the agent will not damage the equipment in a space protected by a system using Novec 1230 fluid, nor will it carry the risk of causing electrical short circuits.
Presented with the multiple benefits of Novec 1230 fluid, backed by the reassurance of the unique Blue Sky warranty, Iberdrola decided that it was the only clean extinguishing agent that would meet its requirements in terms of both extinguishing and environmental performance.
As a result, fire protection systems using Novec 1230 fluid have now been installed in all eight of the new Madrid substations that have been completed, and Novec 1230 fluid has been specified for the remaining nine systems. Similar systems using Novec 1230 fluid are also now being used at many other Iberdrola locations throughout Spain.