Extreme Weather Events Highlight Need for Resilient Building Systems
A recent powerful storm in the Sierra Nevada, which caused widespread power outages, highlights the growing importance of system resilience in building design. For lighting, this emphasizes the need for robust emergency lighting and control systems, like DALI-2, that can maintain safety and comfort during grid instability. Architects specifying for climate resilience are increasingly focused on backup power compatibility and fail-safe operations.
- The DALI-2 standard for emergency lighting, IEC 62386-202, mandates interoperability between manufacturers and automates critical safety checks. It requires devices to perform both quick function tests (checking the battery, lamp, and charging circuit) and full duration tests to ensure they meet their rated emergency operation time, such as one or three hours. These tests can be triggered automatically, and results are logged for compliance verification. - Recent analysis of U.S. power outages between 2018 and 2020 revealed that 73% of counties experienced a severe weather event and a power outage on the same day. Hurricanes are most likely to cause an outage, but heavy rain is associated with the highest number of total outages nationwide. This data underscores the increasing strain on a grid also adapting to the decommissioning of nuclear plants like San Onofre and Diablo Canyon in California. - The WELL Building Standard v2's circadian lighting feature (L03) specifies light levels in "Equivalent Melanopic Lux" (EML) to support human health. The standard calls for at least 150 EML measured vertically at eye level for four hours a day, which has been shown to improve sleep quality, mood, and alertness by stimulating melanopsin photoreceptors in the eye. - Circular economy principles are being integrated into luminaire design through modularity and "design for disassembly". This approach, highlighted in publications like *arc magazine*, focuses on creating products with easily replaceable and upgradable components, such as LED modules and drivers, extending the product lifecycle and reducing waste. - The new DALI+ specification brings the DALI protocol to wireless, IP-based networks using Thread, a low-power mesh networking technology. This allows for greater scalability and seamless integration with other building automation systems like BACnet and KNX over a shared IP network. - DALI+ with Thread will enable interoperability between new wireless devices and existing DALI-2 wired installations through the use of a bridge. This allows for phased upgrades and retrofitting of buildings without requiring a complete system overhaul. - The North American Reliability Corporation (NERC) has highlighted that a lack of transmission capacity between grid regions threatens reliability during extreme weather. During Winter Storm Fern in late 2024, for example, insufficient transmission prevented affordable wind power in Kansas and Oklahoma from reaching neighboring states where electricity prices spiked to nearly $2,000 per megawatt-hour.
