Gestión y representación del Fondo y de los titulares de los Bonos

packet instructions that recommends 2-3 minutes of boiling. All these aspects of the cooking experience were noted during the trials and marked on the coding scheme, and subsequent questions followed the observations as demonstrated on the table above.

4.5.1 Questionnaire

The second phase of the interview comprised a questionnaire with 20 questions. Participants were asked about their previous knowledge about cooking and where they get information about how to cook. A rating scale ranging from 1 (not important) to 5 (totally important) was used to understand how participants rate the quality of the final meal, the time it takes to prepare, the complexity of the preparation, the amount of electricity used, how many pans and lids they are using, and the nutritional facts when cooking. These items were suggested during a pilot study and were included in the questionnaire in order to understand how people choose their meals, the cooking procedure and how their preferences can affect the energy consumption. A widely used questionnaire to measure ecological awareness was also used. An exploratory phase of the questionnaire asked their awareness of energy saving techniques, their likelihood to adopt recommended energy saving techniques, and what would be good ways to present them with these techniques. The final phase of the interview comprised revealing the electricity usage during the test, discussions about these figures and a discussion about preferences on how to cook noodles regarding consistency, amount of water and seasoning.

4.6 Energy saving techniques

To select the adequate conservation techniques presented here six topics were taken in consideration, according to those demonstrated by Booth (1996):

• Potential for impact on the problem – if performing each of these energy saving techniques, will the energy use be reduced? The energy monitoring proved that it is possible to reduce the electricity use drastically comparing to the amount used by the participants from this study. For graphs and analysis, see the item 4.8 (Results) below.

• Existence of approximations to the ideal behaviour – Are students’ performance similar to ideal behaviours? It was observed that sometimes participants performed the proposed techniques, indicating that there are approximations between actual and ideal behaviours (4.8.3 - Qualitative data, below).

Chapter 4: First Study – Understanding cooking behaviours – 4.6: Energy saving techniques

• Positive consequences – Will the participant have positive consequences, either observable or perceived, by performing the suggested techniques? Other than energy saving, one observable advantage of following the proposed techniques is a quicker cooking process, which was reported to have high importance among the participants (item 4.8.6.1 - Importance scale, below).

• Compatibility with cultural norms or current practices – Are these techniques compatible with current acceptable practices? Energy saving and sustainability are highly positive concepts, and most participants demonstrated having positive ecological worldview as verified by the New Ecological Paradigm scale, described below (item 4.8.6.2 - New Ecological Paradigm evaluation). However, the importance of energy use during cooking was rated as having a rather low score (item 4.8.6.1 - Importance scale, below).

• Costs – Will participants have to pay, in terms of time, energy, money or materials? No financial cost is involved in the proposed techniques, and is possible to save time during the process. Furthermore, it can save the students money when they have to pay for their own bills.

• Complexity – Do these techniques require more thinking or training? A higher level of concentration and effort is needed to cook following the energy saving techniques.

Prior to the user observation study, a series of experiments took place to simulate the cooking process and understand appliance behaviours with the ultimate goal of finding the most efficient way to cook the same food. The electricity monitor was used to understand the energy usage (and consequently heat produced) per hob and per temperature mark. Figure 10 illustrates the results of these individual measurements. It is possible to see that the small hob at the front uses more energy than the similar one located at the back only when on mark 6. It happens because it is equipped with a ‘fast heat element’ (Beko 2006, Beko 2011). This hob was quicker to heat up but can incur in extra energy use, unless the user controls the heat input as described below.

Chapter 4: First Study – Understanding cooking behaviours – 4.6: Energy saving techniques

Figure 10 - Energy use per hob for each control mark

Figure 11 shows the time and the internal temperature of a pan with its lid containing 200 ml of water on the small hob at the front. This data was recorded every 30 seconds using an electronic thermometer with its tip in the water. It was possible to switch the heat source off even before the water had started to boil. 2 minutes and 40 seconds were enough to keep the water boiling for about 4 extra minutes, enough time to cook noodles thoroughly. It is possible to turn the hob off even before the water temperature reaches the boiling point and still have heat to cook for a few minutes. The hob was left on for less than 3 minutes and it produced heat enough to keep the water boiling for about 4 minutes. Since water stays at a maximum 100° C no matter how much energy is put in, the source of heat should be controlled to avoid waste. The water temperature could even be below 100º C and still cook pasta (McGee, 2004), resulting in further savings but it can increase cooking time slightly (Das et al., 2006).

Chapter 4: First Study – Understanding cooking behaviours – 4.6: Energy saving techniques

Figure 11 - Time on and water temperature

Previous research helped during the process of selecting the energy saving techniques for cooking used during this research. The comprehensive literature review performed by Probert and Newborough (1985) presents numerous recommendations on how to manage cooking equipment and utensils more efficiently, focusing on fundamental principles such as thermal performance for energy conservation. The user manual for the specific cooker used during this research was also consulted to understand its characteristics (Beko 2006). This information was added to techniques to reduce the energy use to prepare food that involves boiling (Das, Subramanian et al. 2006), define the efficient temperature needed to cook pasta (Potter, Ruhlman 2010, McGee 2004) and find the ideal volumes, utensils and appliance settings to improve the efficiency of cooking (Oberascher, Stamminger et al. 2011). Data from a pilot study with four participants were also used in order to understand behaviours and evaluate which ones would be investigated further.

The following set of energy saving techniques was constructed with information from the literature review, the on-site experiments performed by the researcher and the pilot study. They had the purpose of finding the most efficient cooking process and could be applied to single meals that involve boiling:

• Read and follow the packet instructions: Reading and following the packet instructions, where the amount of water and the length of the cooking are stated, could guarantee low energy usage. It is important to adopt measurements of quantities of the constituents for a meal instead of rough estimates “because the latter often lead to both energy and food wastages” (Probert, Newborough 1985).

Chapter 4: First Study – Understanding cooking behaviours – 4.6: Energy saving techniques

• Keep track of time: Too long a cooking time can compromise the quality of food and also influence the energy consumption.

• Measure the amount of water: Not measuring the amount of water can result in participants having to heat more water and consequently increasing the energy use since more energy is needed to heat more water (Oberascher, Stamminger et al. 2011). • Do not boil water in the kettle: Boiling water in the kettle and pouring this water in the

pan is a common practice, as reported during the pilot study. Kettles can provide hot water fairly quickly, but in certain circumstances can increase the amount of energy necessary to cook noodles. This happens mainly because cooking instant noodles requires just 200 ml of water, and the kettle found in the students’ kitchen has a minimum mark of 500 ml, resulting in boiling more water than needed. Kettles are still the most efficient way of heating water comparing to a pan or a microwave oven (Oberascher, Stamminger et al. 2011) when just hot water is needed, for example when making tea.

• Use the smallest pan: To increase the energy efficiency and reduce cooking time, a small pan should be used. As this experiment involved cooking one single packet of instant noodles, a small pan would be enough to fit the contents. Smaller pans need less energy to heat because they have small mass and consequently smaller thermal inertia. Furthermore, cooking single noodles in small pans guarantees that the water will cover the noodles better than bigger pans.

• Choose a small hob: A small hob is more indicated for cooking single noodles: it fits the pan and avoids wasting heat to the air (Beko 2006).

• Use the lid: By using a lid it is possible to maintain the heat inside and make the cooking process quicker. Previous research has shown that simply using lids on saucepans can make the energy consumption three to five times lower (cited in  Wade, Hinnells et al. 1995, Brundrett, Poultney 1979).

• Reduce the heat when the water is boiling: The hobs used during this experiment consist of a heating element inside a solid metal plate. This hob heats up by its embedded electrical-resistance elements and then transfers heat to the base of the pan. Due to the cast-iron plates, it has a high thermal inertia. This type of hob usually needs to be energised in advance in order to attain its operational temperature (Newborough, Probert et al. 1990). For this reason, a few minutes are necessary for the hob to heat and then transfer the heat to the pan, and it also takes a longer time to cool down. The remaining heat on the hob indicates that the heat source could be turned down when the pan is hot enough (or even turned completely off, as explained below) in order to save energy.

Chapter 4: First Study – Understanding cooking behaviours – 4.7: Data analysis

• Turn off the heat a few minutes before the end of the cooking time: For short cooking processes, the accumulated heat might be enough to carry on cooking without the need for any extra heat input. It is possible to reduce energy use by more careful time planning, switching “the appliance off before the end of the actual period of use” (Wood, Newborough 2007), applying what can be called “time frugality”.

Each of these techniques are analysed below, together with participants’ explanations for whether they performed it or not (item 4.8.3 - Qualitative data). After developing a set of energy saving techniques, the researcher cooked the same food to determine the minimum amount of electricity necessary. This figure was used as the baseline against which the energy consumption of the participants performing the same task was compared. The energy efficient cooking techniques identified by the researcher were not communicated to the participants until they had finished cooking but were used during data analysis to evaluate each participant’s cooking behaviours.

4.7 Data analysis

Different data types were gathered to help understanding user behaviours. These data included demographic information from the participants and extra information including course, department and year. When participants started the task, video images were collected and checklists containing the code scheme were completed by the researcher. Another important measurement consisted of the energy data at the start and end of the process, read from the energy monitor. Importance scales and attitude measurement surveys were filled in by the participants. Interviews also provided a wide range of information for this study, as described below.

The results from this observation study and semi-structured interview comprised different data sets which required different methods of analysis. First, the demographic details, data from the energy monitor and the closed ended questions that comprised quantitative data were input to a computational system through a customized Microsoft Access entry form. Gathering this information in a database allowed deep analysis and cross-comparison of data to better understand and visualize the results. Microsoft Excel was used to perform calculations and draw graphs as can be seen on the Results below.

The second phase of the data analysis involved dealing with video and audio recordings from the user observation study and interviews. These files were imported into the QSR International NVivo software. This application allows qualitative data examination, and was