Brief for Simple Gas & Electric Cost Calculation Software
It is difficult to work out accurately the cost of domestic Gas and Electric in the UK. The problem is that bills are quarterly and based on estimated readings. The purpose of this application is to allow domestic Gas and Electric users to be able to calculate the daily/weekly/monthly cost of the Gas & Electric used by entering Meter Readings and Billing Rates. The user should be able to enter multiple readings, which should build up a history.
The main difference between this and the bill data is that these will be actual readings and not [url removed, login to view] user would enter a start and end date for the required costs and should then be able to see the Daily/Weekly/Monthly and cost for the period entered. The start date would always be after the first meter reading.
The difficult area is how to take into account that the required data period may cover several meter readings and changes of Tarif. I would guess that the program needs to calculate the daily rate for each day and then store this on a per day basis. You could then work out how many days at what rate give the answer. There is probably a more elegant way of doing this but this is on the limit of my knowledge!!
Inputs: (By User)
Meter Reading Gas & Date Meter Reading Electric & Date Cost per KWh Electric for first X units used Cost per KWh Electric for units used after first X Cost per KWh Gas for first X units used Cost per KWh Gas for units used after first X Volume Conversion Factor (VCF) currently 1.0226400 taken from Bill Calorific Value (CV) currently 39.3521 taken from Bill Note the formula to convert the Gas Meter Reading (Cubic Meters) to the billing Value (kilo Watt hour KWh) is simply Meter Reading in Cubic Meters X Volume Conversion Factor X Calorific Value divided by 3.6. The formula for Electric is just Kwh Reading X Billing rate.
Outputs: (Displayed on Screen)
Digital (numerical) and graphical display of Gas & Electric usage selectable for daily/Weekly & Monthly: Additional Information: There is a complication in that the suppliers typically charge a rate for the first X units used and then reduce the rate. This will need to be taken into account in the calculations.
The application should be able to accommodate Monthly and Quarterly Billing.
The principle of “Keep it Simple” should be applied.
Password protection should be provided (single common password OK)
Context Help should be built into all input points (Pop up on Hover?)
The software should be in a standalone EXE File. Platform recommendations are requested.