Overview
From AMEE
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What does AMEE do?
The idea of AMEE is that you create a front end web page which takes data from a user - a member of the public, or a company employee - and then you send that data to AMEE. AMEE serves two main purposes: it stores the data in a profile and it performs calculations to return an amount of carbon dioxide emitted. You can then display this information to your user on the web page.
For example, a user might tell you that they drive 1000 km in a large, diesel car every month. AMEE would store than information and then return a value telling you that this emits 264.5 kgCO2 per month.
If your CSR manager or PR team need a summary of AMEE, have a look at http://blog.co2.dgen.net/?page_id=17
Why use AMEE?
The data contained in AMEE represents the nett result of an enormous effort in research and development to ensure that it is correct and the assumptions behind it have been thought through and documented.
The other reason to use AMEE is that the data will be kept up to date. Data such as gas and electricity prices can change from month to month. Also, the data for consumer goods, such as computers and cars, will change as technologies advance. If you were to hard code such data into your application, you would need to keep track of these changes and update your application regularly. Using AMEE, this will all be taken care of automatically.
Profile items
A profile item contains information on a particular aspect of a user's lifestyle and also calculates the amount of carbon dioxide that this emits. For example, when the user tells you that they drive a large, diesel car, you can create a profile item and select "large" for the "size" choice and "diesel" for the "fuel" choice. When they tell you they drive 1000 km per month, then you set the profile item value called "distanceKmPerMonth" to 1000.
Once a profile item is created in this way, you can retrieve the kgCO2 per month value at any time in the future. You can also retrieve the choices and values stored in the profile item, so you can display this information to your user when they return to the page at some time in the future.
Profile items can have their values altered, can be deleted and can have a "Valid from" date attached to them. AMEE allows you to track the history of a profile. So, for example, one month a user might tell you they drove 1000 km, then after being alarmed/ashamed/embarrassed at that month's profile, they might take the bus more next month and so tell you that they only drove 300 km. The profile history lets you display this information back to the user, along with consequent reductions (or increases) in carbon dioxide emission.
Data items
Data items contain the raw data that is used to calculate the carbon dioxide emissions in profile items. When developing an application that uses AMEE, you will usually only need to work with profile items. However, it is useful to look at data items if you want to understand what the data means, what assumptions lie behind it and what you need to ask your user. In fact, documenting these aspects is the main purpose of this wiki,
Algorithms
An algorithm is used to calculate the emitted kgCO2 per month of a profile item using the associated data item.
For example, there is a data item for a large, diesel car with a value of 0.230 kgCO2/km. If such a car is driven 1000 km per month, then the amount returned by the profile item is calculated like this:
1.15 x 0.230 x 1000 = 264.5 kgCO2 per month
The reason why the 1.15 is used and the definition of a "large, diesel" car, can be found by reading the wiki page on cars, which is this page: Car_generic
Most algorithms involve multiplying a user supplied value, e.g. km travelled, by a data item value, e.g. kgCO2 per km. However, some algorithms are more complex and can reference other data items. For example, the kettle data item has a value for typical household kettle usage of 23.5 kWh of electricity per year. The algorithm for its profile item looks like this:
23.5 x electricityFactor / 12
where electricityFactor will depend on other profile items. For example, if the user has told us they are in the UK (recorded in the profile item in the metadata category) then the UK electricityFactor of 0.527 kgCO2/kWh will be used.
