User Stories

An important aspect of designing a system is to put yourself in the place of a user of the system.  What is important user may be different than what is important to a designer.  With that respect, you must always keep your users in mind because they are ultimately the ones who will be impacted the most by the design.

For the Solar Decathlon, it is important to always keep the goal of the competition in mind which is to design, build, and operate a solar powered house that is cost-effective, energy-efficent, and attractive.  Here are some problems I hope to address while developing some software for the competition.

Maintenance of the system

Since the house must be solar powered, it is important to maintain system and to make sure that you are getting the most out of each component.  As a user, you may not be thinking about what condition your battery is in as it wears over time.  This feature is already provided by laptops, which warn the user when power levels are low or to get their battery serviced.

While keeping a watch on your battery's condition it would also be a smart idea to keep track of the condition of the solar cells themselves.  You could measure the condition of the cells with the ratio Amount of Energy Trasfered / Amount of UV Radiation Exposed.  While this info may not be exciting to the user, it is a very simple measurement that can be taken to provide the user with the information needed to maintain their house properly.  While on the idea of panel condition, solar cells degrade at a slow rate (about 20% over 25 years), and it may not necessarily to monitor the output of each individual cell, but rather to see which cells are actually functioning.  Since the solar encasing for the house is designed to go around the house, as opposed to conventional solar panels that sit on top of the roof, they may be more prone to physical damage as opposed to wear over time.

The aquaponics system seems to be another integral part of teamhawai‘i's house.  I believe monitoring the water conditions would be a crucial aspect to the competition.  For aquaponics there are three major fields you want to monitor: water temperature, pH levels, and electrical conductivity.  By providing the user with this data, they can respond to problems with their system before problems scale out of control.

Apart from the solar energy and aquaponic system, the two water tanks play another important role in the house by both providing water and storage for grey-water, as well as providing some heating capabilities to the house with the latent energy that is absorbed and released by the heat-insulating material that is contained within the tanks.  So it goes without saying that monitoring temperature and water levels would be important to the user.  But what does it mean to provide these readings to the user?  The user shouldn't have to do any calculations of their own when they try to take a warm shower or want to cool down the internal temperature of the house.  So why not implement a system that uses these data values to help the user manage their energy consumption?  A graph projecting future power levels based on tasks that the house is providing wouldn't be too far of a stretch.

Attractiveness

After all the maintenance systems are established we can get into the fun things that would make any user want to buy the house.  One that I thought of applied to the aquaponics system.  Keeping a mini database of the current plants being grown, and of the fish that are in the tank would be a nice educational touch to the system as a whole.  Like a mini aquarium / plant nursery that could display info on the organisms that are part of the system.

We want a system that is easy to manage.  Computers that are incorporated (i.e. display panels) to the structure of the house would be a nice touch to provide user ease of use.  And like most technologies today, having mobile devices (i.e. smart phones) would have to be essential.  These technologies could allow the user to manage the house at a few simple clicks, whether at home or not.  For example setting the temperature of the house on your way home from work.

Finding a way to network your house in a way that services are aware of each other is another important feature I think that should be incorporated into a 'smart house'.  What I mean is, I would like the systems to communicate with each other.  The first thing I can think of is say you want to turn down the temperature of the house, but doing so would cause you to exceed the amount of energy that has been generated because of other tasks that are being preformed around the house.  It may be possible for the house to arrange task priorities, and to maybe turn down energy usage in some areas where it's not as important in order to delegate power for the new task.

I believe the air conditioning system should also be smart.  There should probably be some software that can keep the house at a certain set temperature in the most efficient way possible.  Taking readings from both internal and external ambient air temperatures as well as humidity levels would be essential.  Based on these readings the system could pump out air at certain times to keep the system cool without the user having to worry about it.