As a civilization, we are on the cusp of a transformation from a centralized to a distributed energy generation network that will redefine the built environment. The urban fabric of communities has a critical role to play in this transformation as architecture will need to accommodate large-scale renewable energy generation systems. This might seem far away, but current commitments established to help create a sustainable future, like the Architecture 2030 Challenge, will usher in this profound shift in a few years.
By David Mead
Most projects will require the integration of multiple renewable technologies that can work together to meet a building’s energy needs. As an industry we need to collectively understand which renewable systems work best for projects to achieve net-zero on-site energy. Architects have the opportunity – some might say ‘responsibility’ – to be in the vanguard of this new movement.
The architectural industry at the moment is focused mostly on efficiency improvements but this is a short-sighted focus. Efficiency limits are already starting to be reached by high-performance buildings. Though there is still room to improve, this will only get buildings part of the way to achieving net-zero energy. Even the most efficient buildings in the world require large renewable energy systems to truly be sustainable.
LEED has accustomed the industry to low threshold goals, such as 1% of on-site energy coming from renewables. This is typical in buildings that have one wind turbine or a few PV panels on their facades acting as symbols of sustainability. But to be truly sustainable we need 100% of the energy to come from renewables and architectural teams need to help owners understand how to make this possible.
CURRENT PUBLIC POLICY
Public policy is currently moving the profession towards higher energy efficiency through building codes while net-zero goals have mostly been voluntary efforts by public and private organizations. As a profession we have adopted the Architecture 2030 challenge [including the RAIC, AIA, ASHRAE and others].
Civic organization and cities across North America have also adopted the 2030 Challenge including the US Conference of Mayors, Vancouver and Seattle to name a few. Seattle has gone the additional step to establish a 2030 district in its downtown i , aiming to dramatically reduce emissions for existing and new buildings within the established district. In the US, seven states have adopted the 2030 challenge for new buildings that receive state funding. California and Washington State require all residential and commercial construction to meet the requirements. No known Canadian provinces or territories have adopted the 2030 Challenge to date.
The RAIC has published Canadian example projects that are considered the best energy-efficient commercial buildings in Canada to help promote the 2030 Challenge. Three example projects that have on-site renewable energy are:
Jim Pattison Centre of Excellence in Sustainable Building Technologies and Renewable Energy Conservation – Penticton, BC
Abondance Montréal – Le Soleil – Montreal, Quebec
Joggins Fossil Centre – Joggins, Nova Scotia
The chart [figure 1 in the thumbnails] compares their respective baselines and expected energy performance. Note that only the Abondance Montreal – Le Soleil project is currently expected to produce as much energy on-site as it consumes. These example projects show that large on-site energy generation is possible in Canada through energy reductions and on-site energy production.
ARCHITECTURE 2030 POLICY IMPACTS ON BUILDING CODE
Cities that have committed on to the 2030 Challenge requirements will start changing building codes to meet its requirements. This will include progressive improvements every five years. The 70% reduction threshold set in 2015 is when renewable energy systems will often be necessary to hit the target. In these cities, buildings designed and built in less than two years will need to start integrating large on-site energy generation systems.
But how much on-site energy will be required? The Challenge only allows for 20% of the renewable energy to come from off-site. Please go to the online article to see a graph that shows the requirements based on EUI consumption reductions of 20 kWh/m2/yr every five years.
Note how starting in 2015, renewable energy is necessary to meet the 2030 target. In this example, about 14% of the energy needs to be renewable, which could be part of an off-site purchase agreement. Starting in 2020, however, the project will require 33% of its energy from renewable sources. The architectural industry is currently accustomed to buildings meeting the requirements without the need for renewables, but this will change in 2015 with progressively larger changes moving forward.
According to the 2030 Challenge, in 2020 it will no longer be possible to only purchase renewable energy, and by 2030 the majority of the energy must be generated on-site. The assumption is that projects can attain a 60% or greater EUI reduction through energy efficiency measures. If consumption is not reduced, greater portions of renewable energy will be required to offset the difference.
SOLAR ENERGY POTENTIAL
The world receives over 10,000 times the amount of energy from the sun that humans use every year ii . We only need to harness a fraction of 1% to meet all of our energy needs. It is the most plentiful energy resource on the planet and we currently only capture a small percentage of it. This is even true in northern climates.
For example, take potential outputs from solar energy in the Toronto climate for three buildings – one, three and eight storeys with scaled areas from 1,000 to 16,000m2 – all with an EUI of 100 ekWh/m2/yr. Included in the on-site renewable generation calculation is the electrical output for 20% efficient photovoltaic panels on the roof at a 35° slope and facades with 50% coverage on all but the north. The one-storey building can meet almost all of its energy needs with a rooftop PV array, while the 16,000m2 building can only meet about 12% of its consumption. Once a building is this tall the south, east and west facades become more important for their renewable output than the roof. It is important to understand how transformative this is. Projects need to start covering almost all of their roof areas and large portions of facades with photovoltaic panels [PV] or solar hot water [SHW]. Many buildings will require additional site PV arrays to achieve net-zero energy. This will transform the aesthetic of buildings.
There are a number of buildings that are already responding to this form follows function in regards to on-site energy production. An excellent example is the net-zero NREL SF building in Golden, Colorado where the building roof and massing were designed to respond naturally to the solar capabilities of the site. This building needed additional solar panels in the site to achieve net zero as the roof services alone weren’t enough to meet all of its energy needs. Toyo Ito’s solar powered stadium in Taiwan is another interesting project where the entire roof structure of the stadium is optimized for the 8,844 solar panels integrated in it. The entire structural module of the stadium is setup to support the renewable energy system.
GETTING TO NET-ZERO WITH LARGE BUILDINGS
Large-scale renewable systems must be employed on buildings to meet these commitments. Solar energy is the most complementary system for buildings, as rooftops and facades are natural collection areas. Other renewables can be more challenging to properly integrate with buildings, as every site has different on-site energy generation potentials.
Any project can achieve net-zero energy on-site if a client and design team work together to achieve it. The following chart shows an overview of renewable potentials for different scaled buildings. Other renewable technologies that work with large buildings need to be coordinated in the design process with renewable energy site assessments.
These are used to establish the energy generation potentials of a site. Complementary technologies include biogas fuel cells and co-gen, wind turbines, waste heat recovery, solar hot water, run of river and biomass heating. Architectural teams need to start thinking about how to combine the appropriate technologies based on the available resources for any site. For the full version and quiz of this CEU article, visit www.sabmagazine-education.info
Formerly with Perkins+Will Canada, David Mead is a Building Performance Specialist with WSP Built Ecology in San Francisco.
Tags: 2030 Challenge, ARCHITECTURE 2030 POLICY IMPACTS ON BUILDING CODE, CONTINUING EDUCATION UNIT ARTICLE, David Mead, EUI consumption reductions, Large-scale renewable systems, on-site energy, Perkins+Will Canada, RAIC, sustainable architecture and building, WSP Built Ecology
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