Renewable Energy and Interdependencies: Six Council Properties
Approach and uncertainty: What is the general approach that you will take to reduce carbon emissions associated with the issue that you are looking at and what sources of uncertainty are likely to be important?
The six council properties being constructed by regeneration specialist St. Modwen are situated on a brownfield site that was a former oil refinery and production site used by British Petroleum and represent an ambitious project that is intended to create a sustainable community for about 10,000 residents that can serve as a model for like-minded communities around the world (Evans 2011). The site will ultimately include 4,000 homes, four schools, various businesses, office premises as well as a cricket pitch (Evans 2011). According to Evans, "The project will take 25 years, but should leave behind a fully-formed community where people can live, work, educate their children and relax" (2011, p. 8).
The general approach that will be used to reduce carbon emissions in the six council properties will be a three-fold approach that involves (a) designing more efficient building systems including the use of renewable energy and passive energy systems; (b) orienting all council property buildings to maximize the efficiency of passive energy systems; and, (c) using more efficient construction methods and earth-friendly and human-healthy construction materials (Hirokawa 2009; Pacione 2009).
The main source of uncertainty involved in these initiatives, though, is that there may be a tradeoff involved with some modern environmentally harmful building materials that can introduce toxic substances into buildings, making the need for identification and selection of human-healthy construction materials of paramount importance. Other potentially important sources of uncertainty will include determining which construction methods produce fewer carbon emissions and ensuring that building contractors subscribe to these methods because of inexperience, a lack of appropriate equipment or because these methods may be more expensive; identifying optimally efficient building systems will also likely be challenging because of the rapidity with which new systems are being developed and introduced.
Specific actions and cost-benefit analysis: Identify specific actions that you could implement, and consider in simple terms their cost and effectiveness. Conduct a simple cost-benefit analysis of your carbon reduction actions.
Based on the three general approaches described above, the following cost-benefit analysis is provided:
Designing more efficient building systems including the use of renewable energy and passive energy systems.
This is perhaps the most valuable initiative in terms of carbon emission reductions, and it can provide cost savings and several other benefits as well. In this regard, Rudden (2010) advises that, "Green building energy savings result primarily from reduced energy purchases and secondarily from reduced peak energy demand. Investing in clean, renewable energy technology also hedges against uncertain energy supplies, rising utilities costs, and more stringent carbon emissions limits" (p. 6). Passive energy systems offer a number of other advantages as well. For example, Davey (1999) emphasizes that, "Buildings that rely on passive energy are more agreeable to be in than ones that use masses of plant. They are not prone to the sick building syndrome (nor to getting plagues in the cooling systems). They offer the opportunity for individuals to have much more control over their immediate environments: people can even open the windows" (p. 5).
At present, most passive energy systems are characterized by the three essential elements set forth in Table 1 below:
Three Essential Elements of Passive Energy Systems
Although not strictly necessary, passive energy buildings usually have a boxy exterior shape that makes it easier to maintain a good thermal envelope.
Efficient heat recovery.
Passive energy alternatives user ventilation systems that draw a continuous supply of fresh air. Incoming air passes through heat exchangers that reclaim the energy in outgoing warm air. If necessary, incoming air can also be passed through underground ducts to pick up geothermal energy.
Passive solar heating
Southern-facing, unobstructed windows with triple low- emissivity glazing and superinsulated frames capture and retain more solar energy than they let out.
Source: Stein 2008
Although passive energy systems typically involve slightly higher initial construction costs (between 5% and 7%), the savings that are realized over the long-term make their integration into new building construction feasible as depicted in Figure 1 below.
Figure 1. Breakdown of operational costs: Current average vs. passive construction
Source: Stein 2008
Beyond the long-term cost savings that can be achieved using passive energy systems, there are some other desirable outcomes that can be realized as well, including the following:
A. Passive energy systems are more sustainable than active energy systems because passive systems use far fewer natural resources to build and maintain.
B. Passive energy systems do not rely so heavily upon gas for heating or coolants for air conditioning.
C. Passive energy systems are designed so that they can take natural energy from the sun to heat a building and use specific design principles to cool a building.
D. Passive energy systems are also cheaper than active systems because they are less susceptible to malfunction since they rely completely upon nature, rather than using mechanical equipment to produce energy (Passive energy 2011).
Orienting all council property buildings to maximize the efficiency of passive energy systems.
While this approach would appear to be a cost-effective and straightforward method to optimize passive energy systems, there may be some trade-offs involved that will adversely affect the aesthetics and maintenance of the project (Punter 2010; Baird 2001). Moreover, the hilly nature of the Coed Darcy building site may impede optimal building positioning (Evans 2011).
Using more efficient construction methods and earth-friendly and human-healthy construction materials.
As noted above, although this approach stands to reduce overall carbon emissions, there may be a trade-off involved in the increased costs of the alternative construction methods. In this regard, Halliday emphasizes that, "It is important to understand the type of construction, the materials used and the probable impact of any proposed changes. Furthermore, many modern building techniques are incompatible with traditional methods and can have adverse repercussions if applied" (2009, p. 5). Likewise, the demand for energy-efficient housing has been met with the increased use of construction methods that are intended to reduce energy waste and create carefully controlled indoor environments (Petronella, Thomas, Stone, Goldblum & Brooks 2005).
As a result, modern construction projects are characterized by a reduction in fresh air flow from outside that can create potentially harmful concentrations of noxious substances in the indoor air (Petronella et al. 2005). This point is also made by Halliday (2009) who emphasizes, "New buildings are designed to more stringent energy standards than traditional buildings with increasing standards of insulation imposed through the latter part of the 20th century, and more recently increasing focus on the need for air tightness" (p. 5). Poor indoor air quality and so-called "sick building syndrome" has been associated with a wide range of human healthcare problems, including respiratory infection, chronic obstructive pulmonary disease, respiratory tract cancers, tuberculosis, cataracts, and asthma (Brown 2003).
Benchmarking: Using the Code for Sustainable Homes, how will you benchmark the performance of your proposals, what levels of performance do you think should be achieved and why?
The use of benchmarking is congruent with best industry practices that require something to be measured in order to improve it (Mason, Chang and Griffin 2005). According to Vancelette, "Benchmarking is the use of comparative process performance metrics to establish performance goals. It is usually used in conjunction with the identification and application of best process practices. In fact, benchmarking is often automatically assumed to include the best practice methods" (2002, p. 21). The benchmarking of the above-described proposals will be based on the Code for Sustainable Homes (hereinafter "the Code"), introduced in England in 2006, which is a voluntary standard that is intended to improve the overall sustainability of new housing construction (Rozee 2008). According to Punter, the Code "will have a significant impact on building layouts and landscape, the design of public and private space, and on building facades, fenestration and materials" (2010, p. 344).
The Code evaluates the sustainability of new construction by measuring nine design categories that provide a total construction package rating (Rozee 2008). The design categories are as follows: (a) energy and CO2 emissions; (b) water; (c) materials; (d) surface water run-off; (e) waste; (f) pollution; (g) health and well-being; (h) management; and (i) ecology (Rozee 2008). In February 2008, the Government subsequently established the assessment process and the performance standards required by the Code (Rozee 2008). The levels of performance deemed most suitable for the six council projects will be based on the overall goals of the Code. In this regard, the overall goal of the Code is to continuously reduce carbon emissions from domestic and non-domestic buildings through a three-stage tightening of the Building Regulations as follows:
A. 25 per cent reduction in emissions by 2010;
B. 44 per cent by 2013; and,
C. 100 per cent by 2016 in England (Punter 2010).
Interdependencies: Identify how your choices and actions could either…