Cost Analysis - xante8088/kasa-monitor GitHub Wiki

Cost Analysis

Understanding and optimizing your electricity costs with Kasa Monitor.

Cost Calculation Basics

How Costs Are Calculated

Basic Formula:
Cost = Energy (kWh) × Rate ($/kWh)

With Time-of-Use:
Cost = Σ(Energy in Period × Rate for Period)

With Tiered Rates:
Cost = Σ(Energy in Tier × Rate for Tier)

Factors Affecting Cost

Energy Consumption (kWh)
Rate Structure (Simple/TOU/Tiered)
Time of Use (Peak/Off-peak)
Demand Charges (Commercial)
Taxes & Fees (Additional charges)

Rate Structures

Simple Rate

Flat rate per kWh:

Type: Simple
Rate: $0.12/kWh
Example: 100 kWh × $0.12 = $12.00

Time-of-Use (TOU)

Different rates by time:

Peak (6 AM - 10 PM): $0.15/kWh
Off-Peak (10 PM - 6 AM): $0.08/kWh
Example:
  Day: 60 kWh × $0.15 = $9.00
  Night: 40 kWh × $0.08 = $3.20
  Total: $12.20

Tiered/Block Rates

Rates change with usage:

Tier 1 (0-500 kWh): $0.10/kWh
Tier 2 (501-1000 kWh): $0.12/kWh
Tier 3 (1000+ kWh): $0.15/kWh
Example (750 kWh):
  First 500: 500 × $0.10 = $50.00
  Next 250: 250 × $0.12 = $30.00
  Total: $80.00

Demand Charges

Peak demand pricing (commercial):

Energy Charge: $0.08/kWh
Demand Charge: $15/kW peak
Example:
  Energy: 1000 kWh × $0.08 = $80
  Peak Demand: 5 kW × $15 = $75
  Total: $155

Dashboard Cost Display

Cost Summary Widget

Located at top of dashboard:

┌─────────────────────────────┐
│ Today: $2.45 ↑ 12%         │
│ MTD: $45.67                 │
│ Projected: $92.34           │
│ Budget: $100 (OK)           │
└─────────────────────────────┘

Device Cost Cards

Each device shows:

Today's Cost: Running total
Monthly Cost: Month-to-date
Cost/Hour: Current rate
% of Total: Proportion of bill

Cost Trends Graph

Visual representation showing:

Daily cost bars
7-day moving average
Month-over-month comparison
Budget line (if set)

Detailed Cost Analysis

By Device

Ranked list of cost contributors:

Rank	Device	Monthly	% Total	Trend
1	AC Unit	$28.45	31.2%	↑ 5%
2	Water Heater	$18.20	20.0%	→ 0%
3	Refrigerator	$12.15	13.3%	↓ 2%
4	TV/Entertainment	$9.80	10.8%	↑ 8%

By Time Period

Cost breakdown by time:

Morning (6 AM - 12 PM): $15.20 (25%)
Afternoon (12 PM - 6 PM): $24.50 (40%)
Evening (6 PM - 12 AM): $18.30 (30%)
Night (12 AM - 6 AM): $3.05 (5%)

By Category

Group devices by type:

Lighting:        $8.50 (14%)
Heating/Cooling: $28.45 (47%)
Appliances:      $15.20 (25%)
Electronics:     $8.52 (14%)

Budget Management

Setting Budgets

Configure budget alerts:

Monthly Budget: Total spending limit
Daily Budget: Daily average target
Device Budgets: Per-device limits
Category Budgets: Group limits

Budget Tracking

Monitor budget status:

Monthly Budget: $100
Current Spend: $67.89
Remaining: $32.11
Days Left: 12
Projected: $95.45 ✓

Budget Alerts

Configure notifications:

50% of budget reached
75% of budget reached
90% of budget reached
Budget exceeded
Unusual spike detected

Cost Optimization

Identify High-Cost Devices

Find expensive devices:

Sort by cost: Highest first
Cost per hour: Expensive when on
Always-on cost: Baseline expense
Efficiency ratio: Cost per function

Time-Shifting Opportunities

Move usage to cheaper periods:

Current Schedule:
  Dishwasher: 6 PM (Peak) - $0.45/run
  
Optimized Schedule:
  Dishwasher: 11 PM (Off-peak) - $0.24/run
  
Annual Savings: $76.65

Peak Shaving

Reduce peak usage:

Current Peak: 5.2 kW
Target Peak: 4.0 kW
Actions:
  - Stagger AC cycles
  - Delay water heater
  - Schedule pool pump
Savings: $18/month demand charge

Device Replacement ROI

Calculate upgrade savings:

Old Device: 150W bulb
  Annual Cost: $19.71
  
New Device: 15W LED
  Annual Cost: $1.97
  Purchase Price: $8.00
  
Payback Period: 5.4 months
10-Year Savings: $169.40

Reports & Insights

Daily Cost Report

Date: January 15, 2024
━━━━━━━━━━━━━━━━━━━━
Morning:    $0.82
Afternoon:  $1.15
Evening:    $0.95
Night:      $0.18
━━━━━━━━━━━━━━━━━━━━
Total:      $3.10

Top Devices:
1. AC Unit: $1.20
2. Kitchen: $0.65
3. Office: $0.45

Monthly Cost Report

Comprehensive monthly analysis:

Total cost with breakdown
Daily average and trends
Comparison to previous months
Device rankings
Optimization opportunities
Budget performance

Annual Summary

Year-end analysis includes:

Monthly cost chart
Seasonal patterns
Year-over-year comparison
Total savings achieved
Device lifecycle costs

Advanced Analytics

Cost Forecasting

Predict future costs:

# Based on:
- Historical patterns
- Weather forecast
- Seasonal trends
- Rate changes

Next Month Estimate: $92.34 ± $5.20

What-If Analysis

Model different scenarios:

Scenario 1: Add solar panels
  Monthly Savings: $45
  ROI Period: 7 years

Scenario 2: Switch to TOU rates
  Monthly Change: -$8 (savings)
  Best if shift 30% to off-peak

Scenario 3: Upgrade appliances
  Monthly Savings: $22
  Investment: $2,400

Comparative Analysis

Compare costs:

vs. Previous period
vs. Similar homes
vs. Utility average
vs. Seasonal baseline

Utility Bill Validation

Compare with Utility

Verify accuracy:

Utility Bill: $124.56
Kasa Monitor: $121.89
Difference: $2.67 (2.1%)

Common differences:
- Meter reading dates
- Taxes and fees
- Rounding differences

Reconciliation

Match utility charges:

Export monthly data
Align billing periods
Add taxes/fees
Compare totals
Investigate discrepancies

Cost Saving Tips

Quick Wins

Immediate savings:

Eliminate phantom loads: $5-10/month
Adjust thermostat 2°: $10-15/month
Use timers/schedules: $8-12/month
LED replacements: $15-20/month

Medium-Term

3-6 month projects:

Smart thermostat: $20-30/month
Efficient appliances: $25-40/month
Insulation upgrades: $30-50/month
Solar consideration: $50-100/month

Behavioral Changes

Habit modifications:

Turn off when leaving
Batch similar tasks
Use natural light
Maintain equipment
Monitor regularly

Export & Integration

Export Options

Format	Contents	Use Case
CSV	Raw cost data	Spreadsheet analysis
PDF	Formatted report	Sharing/filing
Excel	Charts & graphs	Detailed analysis
JSON	Structured data	API integration

Integration

Connect with:

Accounting Software: QuickBooks, Xero
Spreadsheets: Google Sheets, Excel
Utilities: Some utility APIs
Smart Home: Home Assistant

API Access

Get Cost Summary

curl -H "Authorization: Bearer $TOKEN" \
  "http://localhost:5272/api/costs?start_date=2024-01-01"

Get Device Costs

curl -H "Authorization: Bearer $TOKEN" \
  "http://localhost:5272/api/device/192.168.1.100/stats"

Export Cost Report

curl -H "Authorization: Bearer $TOKEN" \
  "http://localhost:5272/api/costs/export?format=pdf" \
  -o cost-report.pdf

Troubleshooting

Incorrect Costs

Verify rate configuration
Check time zone settings
Confirm billing period
Validate energy readings

Missing Cost Data

Ensure rates are configured
Check device monitoring
Verify database storage
Review calculation logs

Budget Alert Issues

Check alert settings
Verify email configuration
Test notification system
Review threshold values

Best Practices

Regular Review: Weekly cost check
Update Rates: When utility changes
Set Budgets: Monthly targets
Track Savings: Document improvements
Validate: Compare with bills

Electricity Rates - Rate configuration
Energy Monitoring - Consumption tracking
Dashboard Overview - Cost displays
Reports - Detailed reporting

Getting Help

FAQ - Common questions
Support
Community

Document Version: 1.0.0
Last Updated: 2025-08-20
Review Status: Current
Change Summary: Initial version tracking added