Smart Grid GR2 Designs

Bob launches the Smart Grid application from his tablet. He notices from the consumption bar at the left side of the screen that the energy cost in the past 24 hours is very high - $18 - considerably higher than the average. He then uses the chart at the right side of the screen to find out that the consumption was the highest from 11AM to 2PM. He clicks on the Devices button at the bottom of the screen to navigate to the Devices view, trying to find out why.

Pros:
The consumption bar intuitively provides information comparing today’s consumption to the historical records. It uses the metaphor of a thermometer or other similar scaling devices.

The bar chart is a common way to break down data in different time periods, so it’s easy to learn.

The radio button that allows user to select data on consumption or on cost basis is also easy to learn.

Cons:
Using different tabs for daily, weekly, and monthly data is inconsistent with most applications. A user might expect to get different types of presentation on different tabs, although they are the same with only different time scales. Putting them on one page and using radio buttons for selecting time frame would be a better approach.
The consumption bar shows cost, while the chart shows power consumption. It is inconsistent.

Pros:
The consumption bar allows user to efficiently compare today’s data with historical data, and quickly detects any anomalies.

The chart presents much data efficiently in a small space, and yet makes anomalies stand out in a comparison way. If it further supports swiping to change time frame, it would be more efficient.

The radio button to select consumption verses cost allows quick switch between different kinds of useful information.

Cons:
The screen does not provide information on per device basis. Finding out which device causes problems requires user to dig into other screens, and thus inefficient.

Browsing the chart to a specific date and time is also inefficient. Adding a Calendar widget would remedy the problem.
It’s also not easy to compare same time period, say 1PM-6PM of different days.

Pros:
There is generally no safety issue. If user chooses a wrong button, for example, he or she can quickly switch back. If navigates to a wrong page inadvertently, he or she can also quickly browse back.

Cons:
If user goes to another time frame in the chart by swiping, it could be difficult for him or her to get back. Adding a “Back to Today” button would fix the problem.

If user navigates back and forth between different screens, inadvertently or not, the selection he or she made needs to persist.

In the Devices view, Bob can see the Floor Plan tab, which presents all the devices in his residence in graphics, grouped by areas as he arranged when he first setup the application. Today however he wants to see what devices consume most power, so he clicks the By Consumptions tab.

Pros:
The floor plan naturally maps the devices as they are in the real world, and thus is easy to learn.

Using graphics for devices is also intuitive and helps learnability. Adding words or tooltip around the icons helps make information more precise.

Cons:
The device icon should not be just a static image. Clicking on it should allow user to go to the corresponding control page of the device, or view detailed energy information of the device.

*Pros:*Using graphics is more efficient than words for user to glance all the devices.

Cons:
The floor plan may not scale well to large facilities, for example, a factory. More hierarchies, and zooming capabilities would be needed in that case.
When more devices are available in one place, for example, the basement, they may not fit into the space available. This is another scalability concern with this interface.

*Pros:*Using the screen has no safety issue. If user inadvertently navigates to another screen, he or she can quickly come back.

*Cons:*Using the screen has no issue. Designing the screen at the first place would need to consider safety, but it’s not in the scope of this project

In this screen, Bob can see all his devices in a tree view, along with their consumptions in the time period that Bob has chosen at the left side of the screen. Today, he chooses 11AM to 2PM. The screen also lists the top five power consuming devices. The top of the list is the central air conditioner. Clicking on the device brings him to its control screen.

*Pros:*The interface uses radio buttons, a tree view, and a table to presents perspective information. All offer standard affordance.

If user selects a different time range, the device tree view and the consumption table immediately updates their perspective data, providing immediate feedback.

*Cons:*It’s not easy to do various kinds of comparisons in this UI. For example, user can’t compare a specific device’s data on different days.

*Pros:*The device tree view allows user to tailor it according to the task on hand, by collapsing or expanding parts accordingly. This makes it efficient to retrieve information.

The Top Consumer table allows user to quickly find out which devices consume most power in a given time.

The radio buttons for time rage selection allows user efficiently see data in different time range without navigating to other screens.

Cons:
It doesn’t provide search capability. If user forgets where a device is, drilling down the tree to find it wastes time.
Individually select start time and end time using the widget provided could be inefficient.

In this page, he adjusts the cool setpoint of his home from 65 degree to 75 degree by clicking the up buttons at right side, and the dial at the left side provides immediate visual feedback. After he is done, he clicks the OK button.

Bob is curious about the price information now. So he clicks the Prices button at the navigation bar at the bottom of the screen. The Prices screen provides a chart on how much the market will pay for the power that consumer sells, broken down by hours. For comparison purposes, the chart also provides the highest and lowest records in the past. The right side of the screen provides the estimated extra power that his generators provide during the same period of time. Noticing the price from 12PM to 4PM is very good, and he has extra power, so he decides to sell some. So he clicks the Transactions button at the navigation bar

In the Transaction page, Bob selects the time, power source, and the amount of power he wants to sell. The Smart Grid application calculates the profit for him. After inputs the correct information, he clicks the Sell button. At the right side of the screen, the Pending Transaction table lists all the pending transactions. Bob can see the transaction he just made is listed there. He can select one or more transactions to cancel if he wants to, but that’s not the plan today. Thinking he can make $10 back, Bob is satisfied, and closes the application.