Current Energy Usage: Collect information on current electricity consumption from utility bills.
Appliance Ratings: Identify the wattage or energy rating of appliances and devices in your home.
Energy Rates: Know the cost of energy per unit (e.g., kWh) from your electricity provider.
Creating an energy-saving calculator for homes involves calculating potential savings from various energy-efficient upgrades or changes in usage patterns.
Here’s how you can create one:
Save-Energy-methods in homes
Identify Areas of Energy Consumption:
Lighting: Energy consumption from different types of bulbs (e.g., incandescent, LED, CFL).
Heating/Cooling: Energy used by HVAC systems, water heaters, and insulation efficiency.
Appliances: Energy usage of major appliances like refrigerators, washing machines, ovens, etc.
Electronics: Usage of computers, televisions, and other electronic devices.
Water Heating: Efficiency of water heaters and potential savings from alternatives like solar water heaters.
3. Calculation Formulas:
Lighting Savings:
Savings per bulb = (Wattage of current bulb−Wattage of LED/CFL bulb)/ 100
Heating/Cooling Savings:
 Savings=(Current energy consumption−Energy consumption after upgrade)×Cost per kWh
Appliance Savings: Savings per appliance=(Wattage of old appliance−Wattage of new appliance1000)×Hours used per day ×Days per year × Cost per kWh
Water Heating: Savings=(Current water heating cost−Cost with energy-efficient water heater)/100
Save-Energy-At-Home tips in homes
Implement a Spreadsheet or App:
Spreadsheet: Use Excel or Google Sheets to create an interactive calculator where users can input their data.
App: Develop or use existing mobile apps that allow users to input data and calculate savings.
5. Include Additional Factors:
Insulation Improvements: Calculate savings from better insulation in walls, roofs, and windows.
Smart Thermostats: Factor in savings from using smart thermostats that optimize heating/cooling.
6. Provide Recommendations:
Suggest specific upgrades based on the savings potential.
Offer a comparison of costs versus savings over time to justify investments.
Energy Efficiency formula
Solar Water Heater Energy Calculation
Calculating the energy savings from a solar water heater involves comparing the energy used by a conventional water heater with the energy contribution from the solar water heater. Here’s a step-by-step guide on how to do it:
Determine the Hot Water Demand
Daily Hot Water Usage (in liters)
Estimate the average amount of hot water used per day (e.g., 100 liters).
Temperature Rise Required: Calculate the temperature increase needed to heat the water (e.g., from 20°C to 60°C, a rise of 40°C).
Calculate Energy Required by a Conventional Heater:
The energy needed to heat water can be calculated using the formula
Energy (kWh) = Volume of Water (liters) ×Temperature Rise (°C)times 4.18 kJ/kg°C/3600
 where:
(4.18 (kJ/kg°C}\) is the specific heat capacity of water.  The result is divided by 3600 to convert from joules to kilowatt-hours (kWh).
Example Calculation:
Daily hot water usage: 100 liters
Temperature rise: 40°C
Energy = 100*40*4.18/ 3600} = 4.644 {kWh per day
Energy Saving from solar power
Estimate Solar Contribution
Solar Fraction:
This is the portion of the energy required that is provided by the solar water heater.
It depends on the system’s efficiency and the local solar insolation (the amount of solar radiation received per square meter).
System Efficiency:Â Solar water heaters typically have an efficiency of 50-70%.
Local Solar Insolation: Find the average solar insolation for your location (measured in kWh/m²/day). This can vary by location and season.
Example Calculation:*
Assume solar insolation: 5 kWh/m²/day
Solar water heater efficiency: 60%
Solar panel area: 2 m²
Energy contribution by solar heater:
 Solar Energy Contribution = Solar Insolation ×Panel Area ×Efficiency
Solar Energy Contribution= 5×2 ×0.6 = 6 kWh per day
If the demand is 4.644 kWh, the solar heater can fully cover this requirement, and any excess would be wasted or stored (if storage is available).
Calculate Energy Savings:
Savings per Day:** If the solar water heater fully meets the hot water demand:
Daily Savings} = Energy Required by Conventional Heater – Energy Provided by Solar Heater
 If the solar contribution exceeds the demand, the savings equal the energy required by the conventional heater.
