marcel-sk / eleclib

Off-grid planning utility

Purpose

To create a python utility to simplify electrical and off-grid load calculations.
I find myself writing short scripts to run various calculations quite frequently and figured I should create something more versatile and reusable that could help others interested in off-grid power solutions! Currently only the household load calculator is functional- see Module household

This will eventually include:

• conductor sizing
• household load calculation
• solar, wind, and hydro considerations
• battery sizing
• pricing
• ... unfinished list ...

Module household

Class Household

You can create a Household object in order to call various accessors and reporter methods. The Household class will hold a list of appliances which will each contribute to the total load as well as information about the building, number of occupants and location.

Getting Started

The easiest way to get started is to create a Household object without supplying any arguments and then populating the relevant values through interactive command prompts:

from electriclib.household import Household
myHouse = Household()
myHouse.prompt_for_args()

Alternatively you can set it up programmatically, by supplying many or all of the input arguments (shown below), with the unsupplied arguments being set to default values. These inputs include a list of appliances which can be either a list of strings or Appliance type objects.

myHouse = Household(square_footage=4000,
     R_roof=40,
     R_walls=18,
     occupants=4,
     appliances=['oven', 'lights', 'pump'])

Finally the Household object can be used to get load information as follows:

myHouse.get_consumption() #daily average in watts
myHouse.get_peak_current() #peak current (Amps)

These values can be used directly for determining the service size needed.

init(self,**kwargs):

param	default	description
square_footage	6000	Int- total household square footage
R_roof	30	INT- 0 to 100 Average R-value of the roof default is from building code for Ontario as of 2021
R_walls	24	INT- 0 to 100 Average R-value of the walls. default is from building code for Ontario as of 2021
off_grid	False	Bool- is the house off-grid in the sense of not being connected to a municipal power grid.
occupants	3	Int- 0 to 100. Number of permanent occupants. Used to determine water usage, lighting, etc.
appliances	["heater", "water heater", "fridge", "lights", "pump", "oven"]	list of str or Apliance specifying which appliances are in the household.

Public Methods:

prompt_for_args()
Starts the command prompts to specify the Household parameters.

get_peak_current()
Returns the peak current in Amps. This is often needed in sizing panels, main lines, and off grid components like batteries and fuses.

get_power_consumption()
Returns power usage in watt hours. You can use this with peak=True and timespan=1, to get the peak daily value which is a useful number in calculating off grid requirements like battery capacity and power production from solar, wind, or hydro.

Inputs	Default	Required	Description
days	1	False	Int- number of days. Defaults to a daily power usage (1) but can be set to 30 to get monthly (typical billing cycle) or 365 for yearly power usage.
peak	False	False	Bool- wether to give us the peak value (True) or the average. Default is the average.

get_recommendations()
Returns recommendations for reducing power consumption. It can suggest things like switching an appliance to 12V from 120V if it is more efficient (off-grid fridge).

str()
Built-in str() function is implemented for Household as well as Appliances for convenient file or command-line display of current settings

print(str(myHouse))

report()
Generates a report so that the info can be used and viewed later. Supports only the xlsx and txt format at the moment.

Inputs	Default	Required	Description
file_path	"./report.xlsx"	True	String- File path for the generated report. Only supports .xlsx and .txt at the moment.

...More

See appliances/README.md for details on Appliance classes and their use as standalones.

TODO

• finish report() method
• implement docstrings and generate documentation
• use annotations consistently to make inputs more evident
• should I use args, and kwargs in appliances? this way I could look at what has been supplied and separate into concise constructor blocks...