21-0309 Combustion-based District Emergency Energy

QUESTION

The project’s objective is to become a community that solely relies on solar powered energy, operating year-round in a pollution free manner. As a development, our aim is to provide all energy needs through photovoltaics and store enough energy to allow an off-grid lifestyle.

The community is divided into 4 sectors, infrastructure, community owned buildings, community developed buildings (under private ownership) and private land for residential development. Community owned buildings and community developed buildings will be designed according to Living Building Challenge standards and will produce 105% of the energy they consume. Residential developments on private land will be encouraged, but not required to, obtain Living Building Challenge certification.

Excess energy produced by LBC certified development will be stored for its use during low solar radiance periods, including night. Any excess will be sent towards infrastructure and if possible, towards private housing. A solar farm will produce further energy with storage points located throughout the community.

In Mexico, laws forbid the community from returning energy to the grid. If done so, we would be acting as an energy company, which we are not and it would be considered against the law. For this reason, excess energy produced at the LBC level will be shared at the LCC level for infrastructure and private housing that in need of further energy beyond their production.

Our goal is to be a fully off grid community, storing energy needs at a building and community level. However, we would like to request an exception towards the use of fuel based (propane or natural gas) energy production for emergency use. As per the requirements of I-06 Net Positive Energy, a community is required to store one week of the critical and emergency services. Due to the sharing of energy at a community scale the amount of energy required for emergency storage becomes highly inefficient as most of the energy would be used on a regular basis.

Living Building Challenge 4.0 Handbook page 184 contains exception EC-014 Emergency Power Systems which states:

If programmatic needs, basic project function, or code requirements mandate the inclusion of an emergency power system beyond that required by the Imperative, the use of battery backup power is encouraged. If backup needs exceed the capacity of the required battery, and sufficient battery power is not immediately feasible, diesel or equivalent (e.g., propane or LPG systems) backup generators may be used if the generator:

Is not included in the project’s strategy for operation and any use during the 12-month performance period is offset through the project’s renewable energy generation; and

Does not impact adjacent properties through noxious emissions or noise.

In this case we would like to amend the exception EC-014 to exclude the word “beyond” in its description. The emergency services will not be part of the 12-month performance period as the purpose is to have a one week backup in case of any emergency, electric network failure, solar panel damage or any unforeseen event that might affect the photovoltaic system.

Given the project’s location, the emergency plant will be located away from adjacent properties, avoiding any impact from noxious emissions and noise.

ANSWER

The Institute is creating the new LCC exception LCC I06 E3 03/2021 Use of Combustion Emergency Power at the District Scale, which requires pre-approval. The project team will need to provide the additional information identified in the request to use the exception about the community’s critical emergency services, the back-up system sizing and measures to ensure its will be limited only to support those uses during emergencies.

LCC I06 E3 03/2021 Use of Combustion Emergency Power at the District Scale

An Exception to this Imperative’s prohibition on the use of combustion energy within the community may be granted on a case-by-case basis, for communities that can demonstrate that community-wide emergency battery power sufficient to meet all emergency needs is not immediately feasible and that the combustion-based emergency power is sized for, and used exclusively by, the community’s emergency services.

All other Imperative requirements must still be met.

To use this Exception, project teams must submit a request to support.lcc@living-future.org for preapproval. The Exception request must include a narrative explaining why a non-combustion-based source of emergency power is not viable, and identifying the community’s critical emergency services along with strategies both to ensure that the system is sized and configured to provide only those services on an emergency basis, and to prevent its use outside of emergency conditions.

If fuel storage tanks for emergency power pose a negative impact due to significant danger related to density or other factors (e.g., projects located in Transects L5 or L6), the project team may include a hard-piped natural gas service to the emergency power system, if the gas service:

Is not connected to the project’s primary energy systems;
Is sized exclusively for the emergency power system; and
Includes a dedicated utility meter to account for any emergency use during the 12-month performance period.
Propane-based emergency backup boilers are acceptable in harsh climates or for non-grid-tied projects.

Documentation Requirements

At Master Plan submittal:

The information required in the request to use the exception, or if already approved, the alternative path and compliance strategy explained within the Master Plan narrative and use of the exception referenced.
Calculations of community emergency power loads, itemized by service.
Diagram showing power generation and distribution through the site, as well as the location and method of fuel storage.

At Certification:

Technical documentation of any actual use of emergency backup power during the performance period, including:
Dates, times, and reasons for emergency power use,
Emergency Services supported by backup power,
Amount of backup power used (by kW hours),
Documentation showing that the generator is sized only to support emergency needs and is not included in the project’s strategy for operation,
As-built schematic of Diagram showing power generation and distribution through the site, as well as the location and method of fuel storage.
Documentation showing that any generator use for back-up power during the 12-month performance period is offset through the project’s renewable energy generation.
Documentation showing that the generator does not impact adjacent properties through noxious emissions or noise per LCC I15 Universal Access to Nature.