By Aminu Owonikoko
The threat of global warming, together with international agreements like the Kyoto Protocol on sustainable/renewable development, has led to significant interest in the potential of using sustainable energy as a source of power in various buildings such as Solar Energy/Power and Biomass Heating/Bioenergy. This has resulted in rethinking in building construction supply chain industry. Amongst relevant declarations, the United Kingdom (UK) government made a commitment to ensure that 10% of energy production would be from renewable/sustainable sources by 2010 and would progressively increase to 15% by 2020 and beyond. This is a tremendous task and it is definitely affecting the building construction supply chain industry both locally and globally. A concerted effort is therefore required from academia, industry, the general public and the government to achieve these targets. However, Africa and UK cannot act alone to tackle the climatic issues that affect the building construction supply chain, and therefore, international collaborations are required especially with the foreign suppliers of building construction materials. Thus, designing and constructing Near Zero Energy Buildings (NZEB) embedded with ‘SMART’ Structural Health Monitoring (SHM) technology are not only important but necessary. A building which produces or emits energy through sustainable routes as much as it uses from the Grid is known as Near Zero Energy Buildings while Structural Health Monitoring technology is a way of monitoring and evaluating structural health using smart sensors.
Near Zero Energy Buildings (NZEB) project analyses current design practices especially for high integrity and safety critical structures made from composite materials such as building roofing and column. The capabilities of Structural Health Monitoring (SHM) technologies to provide dependable and continuous structural diagnosis and prognosis will be investigated and aligned with structural design cases. The research will involve propose stage and test hypothesis for new structural design principles that preserve the damage tolerance and fail safe nature of current design but incorporating ‘smart’ SHM features as a design variable. New concepts will arise at the point where SHM and structural design converge. The novelty of this work gives excellent prospects for high profile publications and dissemination in conferences.
The work will comprise theoretical investigation of structural design processes especially with respect to building structures and composite materials. Experimental test cases incorporating SHM technologies will also be realised and demonstrated based on new approaches to design that realise advantages in terms of weight, complexity and performance. Furthermore, application ofTheory of Inventive Problem Solving (TRIZ) will be integrated into the project because of its benefits such as segmentation or segregation and extraction.
Net Zero Energy Buildings (NZEB) Concepts
The following NZEB concepts have been identified from the work of Pless, S., and Torcellini, P., 2010:
1. Connection of Grid
2. Switching of Fuel
3. Renewable/Sustainable Energy Credits
4. Options for Energy Supply and Demand
1. Connection of Grid
In concept, NZEB generates excess energy than it employs annually and discharges excess Sustainable Energy generation to the utility (such as district hot water system and electricity grid) to control the energy employed. A utility connection is permitted for energy balances for NZEB. Based on assumption, on-site generation excess can be sent to the grid to be wholly employed.
2. Switching of Fuel
The definition of NZEB enables renewable/sustainable electricity generation to offset different fossil/traditional energy employs. E.g. natural gas energy employ can be offset with excess wind energy or solar energy (i.e. photovoltaic-PV) transferred to the grid; the offset level is calculated by the energy employ accounting method.
3. Renewable/Sustainable Energy Credits
Various Sustainable/Renewable Energy projects are not fully sponsored via the marketing of renewable energy credits (RECs). Though this is a pertinent financial tool, once the RECs are sold and then bought by another person, the project cannot claim the advantages of the renewable energy generated on site for the usefulness of NZEB classification. RECs are not resold in other different utility purchase models.
4. Options for Energy Supply and Demand
Many supply angles of renewable energy production technologies are available for NZEB. Examples of renewable energy production technologies are solar energy (i.e. photovoltaic-PV), geothermal energy, wind, biofuels/bioenergy and hydroelectricity. Renewable energy demand angle and efficiency measures combine methods that save energy but are not commercialised. These cannot be included in the supply angle balance for achieving an NZEB. Examples of demand angle renewable energy and energy efficiency methods consist of day lighting, solar heating, domestic solar water heaters and solar ventilation air preheaters. Renewable energy guiding principles in NZEB are formulated to minimise the movements of energy from production route to final usage and generate maintenance in the residential and commercial buildings environments:
· Reduce the total environmental influence by recommending building designs that are energy-efficient, utilization of renewable energy, and minimising conversion, transportation and transmission losses.
· Renewable energy technology must be available over the life duration of the residential and commercial buildings.
· Must have high repeatable/consistency data potential for future NZEB.
Figure 2: Example of Net Zero Energy Building (NZEB) Concept (Bjorn Berggren and Monika Hall, 2013)
References:
[1] Berggren, B., and Hall, M., (2013) “LCE analysis of buildings – Taking the step towards Net Zero Energy Buildings”.
[2] Ren, H., Chen X., and Chen, Y. (2017) “Structural Health Monitoring and Influence on Current Maintenance”. Reliability Based Aircraft Maintenance Optimization and Applications Aerospace Engineering 2017, Pages 173-184.
