Can Displaying Energy Usage In Real Time Reduce

Published Date: 02 Nov 2017

Introduction

This section of the paper focuses on the findings and discussions of the data obtained, the findings for this study were obtained before, during and after as the research was conducted at the building. This section focuses on the quantitative and qualitative data. The quantitative data identifies and discusses the amount of energy consumed by the buildings occupants while the qualitative data discusses the occupant’s thoughts and opinions towards energy. The primary objective of this chapter was to identify the research the questions, analyse the data, present and discuss the data. The section discusses the four main research questions which were administered by the researcher.

Can displaying energy usage in real time reduce energy consumption?

This question in the paper is undoubtedly the most important question as the paper was structured around the different ways in which energy reduction can be achieved.

Monitoring Process

To answer this research question as accurately as possible a monitoring station was constructed purely to monitor the occupant’s energy consumption. The occupants of the building were unaware as to when the monitoring process took place this was to ensure that normal activities would be conducted as usual. The monitoring process was conducted over a two week period in order to achieve enough data to analyse the occupant’s energy usage. The research was carried in two phases, each phase consisted of monitoring energy consumption and displaying energy consumption for a period of two weeks respectively. The monitoring phase started on Monday the 11th of March and concluded on Sunday the 24th of March. The results below were obtained in the first phase over the two week monitoring period.

Monitoring

Date & Time

Value (kWh)

Day

11/03/2013

13.77

Monday

12/03/2013

17.77

Tuesday

13/03/2013

15.47

Wednesday

14/03/2013

11.46

Thursday

15/03/2013

15.07

Friday

16/03/2013

11.47

Saturday

17/03/2013

11.63

Sunday

18/03/2013

16.80

Monday

19/03/2013

10.17

Tuesday

20/03/2013

15.73

Wednesday

21/03/2013

10.76

Thursday

22/03/2013

15.11

Friday

23/03/2013

13.13

Saturday

24/03/2013

8.59

Sunday

The table above shows the data that was attained throughout the two weeks of the monitoring process. The table shows how much energy was used on a daily basis. The data is in numerical format and is hard to visualise so to gain a better understanding of the energy consumption a bar chart was constructed in Microsoft Excel.

The bar chart above shows the data that was collected over the two week period of monitoring the buildings energy consumption. The bar chart compares the different days in relation to energy consumption. It is clear to see from the bar chart that there is no repetitive data between any of the days this ensures that the occupants had no input with regards to the data that was collected. The total energy that was consumed over the two week monitoring period amounted to 187.01 kilo watt hours (kWh) with a daily average on 13.35 kWh.

Displaying Process

Displaying the energy consumption of the buildings occupants was also conducted over a two week period. The occupants of the building were able to view energy usage in real time at any time of the day through the (HMI) that was configured. The table below shows the data that was collected over the two week period of the displaying process.

Displaying

Date & Time

Value (kWh)

Day

25/03/2013

15.80

Monday

26/03/2013

12.88

Tuesday

27/03/2013

12.01

Wednesday

28/03/2013

3.68

Thursday

29/03/2013

12.76

Friday

30/03/2013

11.18

Saturday

31/03/2013

10.64

Sunday

01/04/2013

9.81

Monday

02/04/2013

8.22

Tuesday

03/04/2013

9.18

Wednesday

04/04/2013

14.67

Thursday

05/04/2013

10.46

Friday

23/03/2013

10.44

Saturday

24/03/2013

10.80

Sunday

The data above shows how much energy was used on a daily basis. Again the data is in numerical format and is hard to visualise so to gain a better understanding of the energy consumption this was also constructed in Microsoft Excel.

The bar chart above resembles the data that was attained from the two week period of displaying energy usage. The bar chart above compares the different days in relation to the energy consumption. However there was very little energy consumed on Thursday the 28th of March this was due to the building being unoccupied for the day due to unforeseen circumstances which was out of control of the researcher. The total energy consumed over the two week displaying period amounted to 152.60 kWh with a daily average of 10.90 kWh.

While the energy over the four weeks was logged, it was logged with respect to monitoring and displaying. The first two weeks of data was monitored to gather information regarding the energy consumption of the buildings occupants. The amount of energy consumed within the two weeks of monitoring period amounted to 187.01 kWh. While the third and fourth week was displaying energy consumption in real time and amounted to 152.60 kWh of energy being consumed. These results show a significant reduction in energy consumption with a reduction of 18.4%.

The graph above compares the two sets of data that was collected, the red line represents the energy used while the system was monitoring and the green line represents the system displaying energy usage. The energy reduction from monitoring to displaying is 34.41 kWh. This shows that by displaying the energy consumption in real time there has been an energy reduction of 18.4%.

However as a result of the building being unoccupied for one day during the displaying period energy consumption would have increased slightly. In reality the figure for energy consumption would have been around 159.82 kWh. This figure was attained by substituting the unoccupied day with the daily average consumption of 10.90 kWh. This would have brought the total energy reduction over the two week period to 27.19 kWh, resulting in an energy reduction of 14.5%. Darby (2006) agrees with this and notes that smart meter technologies, which provide real time feedback on energy consumption, can help to reduce 5 to 10% of energy usage.

It is important to note the Hawthorn Effect as this phenomenon can occur when observing or studying people’s behaviour. A common problem with the Hawthorn Effect is that subjects may behave different because they know that they are being observed or studied. Although these savings are welcomed it is important to keep practicing these techniques as the Fallback effect can slowly come into effect, Wilthe & Ling (1995) define the Fallback effect as

‘the phenomenon in which newness of a change causes people to react, but then that reaction diminishes as the newness wears off’

There are also another number of factors to take into consideration. As the monitoring phase was carried out first, outdoor temperatures may have been lower, however this was not the case as outdoor temperatures were logged throughout the monitoring and displaying process and proved to have no significant effect on the data. The graph below compares the two sets of values, the monitoring temperature steadily increased over the first week but then declined going into the second week. This was the opposite for the displaying period as the temperature was slowly decreasing in the first week but while entering the second week the temperature started to rise again. These values would not have made any significant impact on the results so to speak as one week of high temperatures in then compensated for one week of low temperatures in both cases.

This was also the case with daylight levels as Greenwich Mean Time (GMT) was moved forward by one hour which resulted in more daylight hours per day, however this proved to have no effect on the data that was obtained throughout the displaying period.

Can the heating controls of an existing heating system be improved to reduce energy consumption?

The main objective of this question was to identify if retro fitting new energy efficient heating controls to an existing heating system can reduce energy consumption. This study was carried out at the building discussed in the previous question. The heating system at the building in question consists on of an oil fired boiler fuelled by kerosene. The existing heating controls of the building consisted of a one zone Sunvic select 107 XLS time clock which controls the radiators and hot water but not individually and a boiler thermostat which is set to a value of 75°C, the occupants of the building rarely use the time clock to program the heating as the occupants prefer to control the heating independently. Consultation with the manufacturer of the boiler revealed that the efficiency of the boiler from new was approximately 70%, however over the years this would have slowly declined, as the boiler was installed 10 years ago it is estimated that the efficiency of the boiler is currently operating at 58%. The figure below shows the type of controls that are installed at present.

While the heating system was in its original state, with the original heating controls controlling the boiler, the external temperatures were also monitored. The graph above represents the daily average temperatures throughout the two week monitoring with basic controls. At the start of week one average daily temperature’s started to increase however it started to decline on the fourth day and then continued to decline until day seven. At the start of week two the temperature started to increase and fluctuated throughout the duration of week two.

The graph above represents the heating load and the internal temperature of the building. The red line indicates the heating load while the green line indicates the internal temperature of the building. Monitoring of the heating system with existing controls was conducted over a two week period. The graph displays the data that was collected over a three hour period, the reason why the energy consumption was only monitored over a three hours was that it is easier to interpret and that the time clock that is currently installed is limited to an operating time of three hours before it has to switched back on manually. Prior to switching on the boiler the operating or base load of the building was currently at 14 watts. When the boiler was switched on the electrical load increased instantaneously which increased the electrical load to 99 watts. The boiler was switched on at approximately 6.15pm and continued to run for a further hour and thirteen minutes which indicated that the return temperature of the water in the system was up at 75°C. The energy consumption over this period was fluctuating between 99 and 107 watts. When the thermostat of the boiler reached the predetermined level of 75°C the boiler then operated between 60 and 61 watts for a period of 2-3 minutes. This delay indicated that the temperature of the water had dropped below the temperature of the thermostat. Due to the temperature difference the boiler then operates again for a further twelve minutes this process continues on for the duration of the three hour cycle as the graph indicates. As the boiler is cycling the temperature within the building is represented by the green line is directly proportional to the sequence of the boiler therefore as the boiler turns on the temperature within the building starts to increase and likewise for when the boiler turn off. The total energy that was consumed over the three hour period was 1.805 kWh.

The graph above represents the daily average temperatures throughout the two week controlling period with new energy efficient controls. At the start of week one the temperature was decreasing until the third day and then started to increase again on the fourth. The temperature then declined on the eighth day and then continued to rise until day twelve where the temperature dropped and then increased for the duration of the week.

The graph above represents the heating load and the internal temperature of the building. The green line indicates the heating load, while the red line indicates the internal temperature of the building. The monitoring and controlling of the heating system with new energy efficient heating controls was conducted over a two week period. The graph displays data that was collected over a three hour period this is due to the same reasons as discussed earlier. The electrical load of the buildings was at 14 watts before switching the boiler switched on. The boiler reacted in the same way as before with the basic controls when the boiler started. When the boiler was switched on the electrical load increased instantaneously which increased the electrical load to 99 watts. The boiler switched on automatically at approximately 6.15pm and continued to run for a further hour and twenty three minutes. The energy consumption over this period was fluctuating between 99 and 108 watts resulting in a minute increase compared to the basic controls. The new heating controls installed have effectively kept the heating system on for approximately ten minutes longer on the boilers first cycle. As a result of the boiler cycling for longer the boiler operated between 59 and 66 watts for a longer period of time, ten minutes which results in an increase of approximately seven minutes when compared with the standard controls. The boiler then started again and continued to run for another eleven minutes. The boiler then starts to repeats this process for the remainder of the three hour cycle as the graph indicates. As the boiler is cycling the temperature within the building is represented by the red line. The red temperature line is more constant than the heating with no controls as it doesn’t drop and remains constant throughout the three hour cycle. The total energy that was consumed over the three hour period was 1.707 kWh.

The graph above compares the different external temperatures that were obtained over the four week period. Week one and two of the monitoring period is represented by the red line. The first week starts of good but gradually declines entering into week two. The green line represents the monitoring and controlling process, week three starts of relatively bad as the temperature seems to be decreasing as the week progresses. However, entering the fourth and final week the temperature starts to increase approaching the end of the monitoring and controlling process. By investigating the graph above it is clear that the monitoring process external temperature is increasing but declines as the two weeks come to an end, this can also be said for the monitoring and controlling process but in fact it is the opposite way the external temperature is decreasing as the week progresses but then starts to increase as the monitoring and controlling process comes to an end.

When the two systems are compared in relation to their energy consumption, the system with no controls fitted causes the boiler to cycle more often than compared to the system when the heating controls are installed. The internal temperature of the building varied throughout the cycling when the system had not controls fitted, whereas this was the opposite when the heating controls were fitted, the internal temperature of the building was constant throughout the three hour period. These controls that were installed are essentially working as a weather compensator as occupants of the building will not notice external temperatures. This is achieved by the temperature difference between internal and external temperature, if the temperature difference exceeds the set value the heating system will automatically start to run to compensate for the temperature difference. Taking all these considerations into account and comparing the data that was attained the difference between no controls and energy efficient controls amounted to an energy reduction of 5.16%. Danfoss (2010) claim that energy reduction through weather compensators can be between 10% and 40%. This proved not to be as accurately as expected however it did reduce energy consumption by a fraction of the estimated value.

What are the opportunities and constraints that consumers face in reducing energy consumption after completing an energy audit?

There are many opportunities that consumers face when an energy audit has been completed. It was found that there is four different types of energy audits, walk through audit, utility cost analysis, standard audit, a detailed energy audit and can examine the following sources, electricity, gas, oil and water. The sources examined will depend on the type of building which is being audited. An energy audit may be conducted internally if sufficient expertise is available within the organisation otherwise an independent expert energy consultant can be sourced externally to provide additional assistance in providing possible recommendations. While carrying out the research for this study a number of opportunities were identified they are as follows, optimisation of contracts with the energy supplier, replacing existing electromagnetic ballasts with electronic ballasts, replace indoor fluorescents with more efficient T8 lamps, replace high pressure sodium lamps with more efficient lamps, install motion or passive infrared sensors in unoccupied areas, install controls for projectors or screens, install new efficient heating controls, install variable speed drives on motors and install banks of capacitors to provide power factor correction.

While carrying out the research in this area there was also a number of constraints that were found that can constrain and impede consumers in reducing their energy consumption. They are as follows, financial constraints, limitation of appliance, limitations of the buildings infrastructure, lack of information regarding energy efficiency of appliances, lack of incentives, motivation and commitment.

In a recent energy audit carried out by Gomes et al (2010) some of the opportunities that have been previous mentioned were recommended and a cost benefit analysis was carried out on the possible recommendations. The cost benefit analysis took into account investment costs, maintenance costs, cost per kWh of energy and payback period. After taking all of these issues into consideration the initial investment would amount to €17,572. This investment would reduce energy consumption by an estimated 31,000 kWh per annum and could potentially save €4,000 per annum. Continuous

However there is more to just implementing the recommendations for a successful energy audit. As Ryan (2008) found that an energy audit should follow the 5 stage continuous improvement cycle. A continuous improvement cycle is an ongoing effort to improve products, services, processes and energy efficiency. These efforts can produce incremental imporvements over time. The 5 stage continuous improvement cycle which consists of the following, commit, identify, plan, take action and review.

There are numerous oppurtunties offered to consumers through the process of energy auditing that can contribute to reducing energy consumption. These savings can be achieved by carrying out the possible recommendations where aplicable. Some of the recommedndations previous mentioned can be simply and relatively in expensive where as others can be more difficult to implement and somewhat more expensive. It is good practice to carry out a cost benefit analysis to identify the possible savings that can be achieved by implememnting the reccomendations.

In addition to this there is also contraints that consumers face when trying to reduce energy consuption after an energy audit taking place. The biggest constraint in which consumers and organisations face is the financial cost of trying to implement the reccomendations, or by not having the support and commitment from senior management, to overcome this constraint Kahlenborn et al (2012) found that

"By transferring the Energy Manager to the upper-most management level of the company, you are setting the best example for a successful implementation. For example, the Plant Manager can simultaneously lead the energy management team in the company"

This should have a positive effect on the financial side as the energy manager will hold the most important role within the organisation and could give full financial support to implement the recommendations. Other constraints that can affect this process is the limitation of appliances and the buildings infrastructure, new energy efficient appliances may not be suitable or have not yet been manufactured to replace older appliances and also the buildings infrastructure may require additional construction work to accommodate or support some of the recommendations. A lack of information not being provided to the consumer regarding the efficiency of a new appliance can hinder or influence the consumer to be undecided whether or not to invest in a new product. Lack of incentives provided to the consumer can impede energy savings, consumers should be given more incentives to purchase, install or retro fit energy efficient appliances this could be in the form of a reduction in prices subsidised by the government or government grants. Lack of motivation and commitment can impede energy savings, as both motivation and commitment can be directly linked to the Fallback effect as discussed earlier, as motivation and commitment can slowly diminish over time this is why it so important to follow Ryan’s (2008) 5 stage continuous improvement cycle as two of the stages in the continuous improvement cycle is to review and commit to the programme, in this case it will be the energy audit and will primarely be focusing energy reduction, motivation and commitment from the occupants of the building.

What are the occupant’s thoughts and perceptions regarding energy usage having completed the two questionnaires?

A self-administered questionnaire was given to the occupants and was completed before any other research was conducted at the building, the same questionnaire was also completed after the research was conducted to see if the occupants thought and opinions changed over the course of this study.

Questionnaire prior to the study

The results found that the majority of the occupants found that energy management was not important to them but commented that it would be more important to large energy consumers. Some of the occupants found that energy management was the responsibility of senior management or the buildings proprietor. The questionnaire also revealed that the occupant’s level of awareness on energy was relatively low as none of them can from a technical background. The questionnaire informed the researcher that there was little or no opportunities offered to the occupants to reduce energy consumption while some of the occupants tried to practice energy saving techniques. The questionnaire asked why the occupants should change their behaviour, there was a mixed response to this question some of the occupants answered with benefitting financially and others commented on the environmental impact. The questionnaire also identified that there was no procedures in place to help or influence energy reduction. The questionnaire also asked the occupants what the barriers are in which they face while trying to reduce energy consumption and commented, financially and time. Occupants had little or no motivation in regards to reducing energy consumption. The occupants were asked how this attitude could be reversed and some of the occupants made reference to an energy campaign. The questionnaire also asked what would get people interested, motivated and committed and some commented on having a monthly draws or bonuses if energy targets were reached. Finally the last question on the questionnaire was how or what is the best was of giving feedback regarding energy consumption, all occupants found that the best way to display energy data was graphical instead of numerical as to gain a better understanding of energy use.

Questionnaire after the study

The occupants of the building were presented with the same questionnaire as before to see if their thoughts and opinions have changed over the course of this study. The occupants opinions somewhat changed when data from the questionnaire was analysed, they found that energy management was important and noted that it affects everyone equally not just large consumers. The occupants also went on to say that it was their responsibility for energy management and found that all parties involved in the building should be held accountable. The occupants found that energy awareness levels have increased and all said that they are now practicing energy savings techniques. The occupant’s behaviour stance however did not change and said the main reasons why they would change behaviour were for the following reasons to benefit financially and environmental reasons. The second questionnaire found that there were still no procedures in place to reduce energy but the occupants said that energy signs should be situated around the building to remind staff to turn of appliance when they are finished using them. After participating in the study all four occupants said that motivation and commitment had increased significantly and found that by displaying the energy usage in real time gave them more motivation to try and reduce energy usage even further. The occupants also found that the best way of giving energy feedback was through graphical images such as bar charts as they found that it was easier to interpret.

Conclusion

The section of the paper set out to present an insight to possible answers of the following research question which were administered by the researcher and to provide an oppurtunity to discuss the findings in greater detail to gain a better understanding on the use of energy and the most effective ways of reducing energy consumption.

Can displaying energy usage in real time reduce energy consumption?

Can the heating controls of an existing heating system be improved to reduce energy consumption?

What are the opportunities and constraints that consumers face in reducing energy consumption after completing an energy audit?

What are the occupant’s thoughts and perceptions regarding energy usage having completed the two questionnaires?

The research questions were answered by examining the data that was attained throughout the course of this study. With regards to research question one, the data that was collected over week one and two was compared to the data that was collected over week three and four which enabled the researcher to answer the question. To answer research question two the same approach was taken, the question was answered by comparing the data from week one and two to week three and four. Question three was answered by examining previous studies and researcher was able to identify the opportunities and constraints in which consumer face while trying to reduce energy consumption. The last and final question was answered using qualitative data in which the researcher collected through two questionnaires that were presented to the occupant’s one before the study took place and the other after the study was completed, this enabled the researcher to answer the research question. The next chapter will present these conclusions and will discuss the limitations and the recommendations for the future with regards to reducing energy consumption.