Combining Sun with ICT to increase solar utilization

 

In Go Green Case Competition, as already mentioned, I and my classmate Annie Chansavang have qualified to the semifinals. Simply said, our idea was to install Solar Water Heater Systems (SWHS) in Baltimore so that a lump-sum energy cost burden as high as 11% of household utility bill would be reduced. In this entry, I would like to elaborate on that and demonstrate how we are going to synthesize ICT with simple solar equipment in order to make more use of solar power.

SWHS simply consists of solar collectors and storage tank. System properties vary depending on whether it is flat plate vs. vacuum tube, active (pressurized) vs. passive (thermosyphon), or open vs. closed loop system. Any system includes one feature from each of the three classifications depending on seasonal characteristics of the place where it is installed. For example, since Baltimore has freezing problem in the Winter and lower solar radiation throughout the year with regard to souther regions, a combination of vacuum tube – active – closed loop systems should be installed for households.

When we look at evolution of these systems, we see that original ones were passive systems that have storage tanks at the top of the collectors in order to create gravitational pressure on water all the way to the taps and at which water is heated through natural thermosyphon from collectors up to the storage tank. Though it is simple system, it enabled people save huge amounts of energy by making use of solar power. Yet, the problem was that you could make use of solar power at peak hours of solar radiation, namely from noon till evening. Since storage tanks were outside, heat isolation was very low. To overcome this problem, it needed storage tanks be installed in the houses and pump be added to the system to circulate the water. However, to make the system work, an  ICT device was needed, which would be digital controller as it is shown in Figure 1. Such a controller has sensors in the storage tank and collectors separately, and starts the pump if temperature in the tank is lower than that of collector. That is to say, it gathers data continuously from these sensors and starts or stops the pump equalize temperature difference. These devices lead to more energy efficient solutions for the customers by better insulation of water and increased storage solar radiation.

In the case competition, our innovation for such a system was to connect the controller to utility companies and laundries in the house. Such an innovation will have positive impacts on energy consumption and production patterns in 2 ways with respect to its connection points:

1 - Laundries: Normally, one cannot fill the laundries with hot water since the laundry itself heats the water until a certain temperature through measuring its thermostats. For example, if laundry needs 45° Celcius in to the sink, you cannot deliver solar heated water in it, since temperature of water in SWHS peaks 97° Celcius in the summer and 58° Celcius in the winter times. You will definitely lead to a breakdown in the laundry and even your clothes will be trash. Therefore, by connecting the laundry and controller, we create data exchange opportunity so that digital controller will measure the temperature of cold and heated water and thus deliver the right temperature mixture to the laundry. Eventually, households will make more use of SWHS. Yet, consumption of solar heated water will be changed since there is another system to feed with the hot water. That is to say, customers will make most use of SWHS when they spread their laundry loads during the week, instead of washing all clothes in one day.

2 - Utility Companies: In our business model, utility companies either sell or lease these systems to the customers. Therefore, they will assume after-sale services. If utility company gains access to the data to be sent from these digital controllers, it will be able to monitor whether there is any defect that causes inefficiency in the system. To accomplish data management, utility company should make use of internet network in order to connect SWHS collectors with company's server that will create a database created from hot water temperature and usage data. Since the main server will monitor all the controller devices, any abnormal temperature decrease will mean to the server software that there is a breakdown in the system so that technicians will step in before there occurs any serious damage to the system - doing so will lead to more customer satisfaction and trust to utility company.Another benefit of receiving data from households will be to determine company's energy production schedule. Besides, by measuring each household's average hot water usage, utility company will both see when it will need to feed-in traditional energy sources to heat water through conventional heater systems as a back up and whether there is any incentive for some households to shift their loads. Other than these, there may exist other opportunities for utility companies, by receiving hot water usage data.

PS: As a last word, I would be more than happy if you pray for us to qualify to the finals in the case competition.