Future load planning worksheet for homes expecting more AC use or EV charging
Your electricity bill today tells only half the story. If you are building a new home, renovating a villa, or simply planning ahead for your family, the loads you will run five years from now will look nothing like the loads you run today. A second air conditioner, a home EV charger, a larger water heater: each one reshapes your demand profile. Sizing a solar system around current consumption alone is the single most expensive planning mistake we see Indian homeowners make. This future load planning worksheet helps you size solar for the home you are growing into, not just the home you have right now.
TL;DR - Summary
- Why plan for future loads? - Solar is a 25 year asset. If you size it only for today's bill, adding an AC or EV charger later may push you back onto expensive grid power, erasing savings you expected.
- What loads matter most? - Inverter ACs (1 to 1.5 kW each) and Level 2 home EV chargers (2.5 to 3.3 kW) are the two biggest demand additions Indian urban households face over the next five to seven years.
- How does the worksheet work? - List every current and planned appliance, assign wattage and daily hours, total the kWh, then add a buffer of 15 to 20 percent. The result is your target system size in kW.
- What system sizes cover future loads? - A 5 kW system typically handles two ACs and standard appliances. A 7 kW system adds headroom for EV charging. Both qualify for PM Surya Ghar subsidy (capped at ₹78,000 for 3 kW and above).
- How we help with future sizing: - Our engineers run a site visit within two days of booking, model your current and projected loads, and recommend the system size that fits your roof, your budget, and your five year plan.
Why today's bill misleads you
Most solar quotes start with a simple question: what is your monthly electricity bill? That number captures what you consume right now. It does not capture the second AC you plan to install when summers get worse. It does not capture the EV you expect to buy within three to four years.
India's residential AC penetration is still below 15 percent nationally, but in urban metros it is climbing fast. EV registrations in India crossed 1.5 million in 2025. Both trends point in one direction: household electricity demand will rise, not fall.
A solar system lasts 25 to 30 years. If you undersize it by even 1.5 to 2 kW, you will buy that shortfall from the grid at slab rates that only increase over time. Planning for future loads is not speculation. It is basic financial hygiene for a multi decade investment.
The future load planning worksheet
Use this worksheet to map your current and expected appliances, estimate daily energy consumption, and arrive at a target system size. The table below walks through a realistic example for a 3 BHK villa household planning to add one AC and one EV charger within five years.
| Appliance | Wattage (W) | Daily hours | Daily kWh | Status |
|---|---|---|---|---|
| Refrigerator | 150 | 24 | 3.6 | Current |
| Washing machine | 500 | 1 | 0.5 | Current |
| Television and router | 120 | 6 | 0.72 | Current |
| Lights and fans (whole house) | 300 | 8 | 2.4 | Current |
| Inverter AC 1 (1.5 ton) | 1200 | 8 | 9.6 | Current |
| Inverter AC 2 (1 ton, planned) | 900 | 6 | 5.4 | Planned, year 2 |
| EV charger Level 2 (planned) | 3300 | 3 | 9.9 | Planned, year 3 to 4 |
| Water heater (geyser) | 2000 | 0.5 | 1.0 | Current |
| Total daily kWh | 33.12 | |||
| Buffer (20%) | 6.62 | |||
| Adjusted daily kWh | 39.74 | |||
To convert daily kWh into a system size, divide the adjusted daily figure by average peak sun hours for your city. Most Indian metros receive 4.5 to 5.5 peak sun hours. Using 5 hours: 39.74 divided by 5 equals roughly 7.9 kW. A 7 kW system with net metering would cover this household comfortably, with some surplus exported to the grid.
If the same household removes the EV charger from the plan, the adjusted daily kWh drops to about 28 kWh, pointing to a 5 kW to 6 kW system. That is still larger than what a bill based quote would suggest if the family currently runs only one AC.
How to fill in your own worksheet
Start by listing every appliance you use today. Write down its rated wattage (check the label or product manual) and how many hours you run it on a typical day. Multiply wattage by hours, then divide by 1,000 to get daily kWh.
Next, add the appliances you expect to add within five years. Be specific. “Another AC” is vague. “1 ton inverter AC in the second bedroom, running 6 hours a day in summer” is useful. For an EV charger, assume a Level 2 unit drawing 3.3 kW and charging for 2 to 4 hours per session, depending on your expected daily driving distance.
Sum all daily kWh values. Add a buffer of 15 to 20 percent to account for seasonal variation, panel degradation over time, and days with lower sunlight. Divide the buffered total by your city's average peak sun hours. The result is your recommended minimum system size in kW.
AC and EV: the two loads that change everything
Air conditioning and EV charging deserve special attention because they are the two fastest growing residential loads in urban India.
Air conditioners on solar
A modern 1.5 ton inverter AC draws about 1 to 1.2 kW at steady state. Running it 8 hours a day adds roughly 8 to 10 kWh to your daily consumption. Two ACs can add 14 to 18 kWh. A household that currently runs one AC and plans to add a second should size the solar system for both from day one.
Can solar run an AC at home? Yes. An on grid system of 3 kW or above can support one inverter AC alongside standard household appliances. For two ACs, a 5 kW system is the practical minimum. We recommend 5 kW for households with two ACs and moderate other loads.
EV charging on solar
A typical home Level 2 EV charger draws 3.3 kW. Charging for 3 hours daily adds about 10 kWh. That is equivalent to adding another AC to your load profile. If you plan to buy an EV within the next three to five years, factor this load into your solar sizing now.
A 7 kW system can handle two ACs, standard appliances, and daily EV charging for most urban commute distances. Systems in this size typically run from ₹2.9 lakh to ₹3.6 lakh for a 6 kW setup, and scale upward for 7 kW and above. PM Surya Ghar subsidy applies up to ₹78,000 for systems of 3 kW and above, reducing the effective cost significantly.
Decision matrix: matching system size to future loads
The table below maps common household profiles to recommended system sizes, factoring in both current and planned loads.
| Household profile | Current loads | Planned additions (5 years) | Recommended system size | Approx. monthly generation |
|---|---|---|---|---|
| 1 to 2 BHK, small family | Fridge, TV, washing machine, 1 AC | None or 1 small AC | 3 kW | 360 units |
| 2 to 3 BHK villa, growing family | Standard appliances, 1 AC | 1 additional AC | 5 kW | 600 units |
| 3 to 4 BHK villa, high consumption | Standard appliances, 2 ACs | EV charger | 7 kW | 1,050 units |
| Premium villa, energy independence goal | Multiple ACs, pump, geyser | EV charger, additional AC | 7 kW or above | 1,050+ units |
These figures assume average Indian metro solar irradiance. Actual generation varies by city, roof orientation, shading, and panel quality. Our engineers model these variables during the technical site visit, which happens within two days of booking.
Common sizing mistakes to avoid
The first mistake is sizing purely on current bill. We covered this above. The second mistake is ignoring seasonal variation. Summer AC usage can double your consumption compared to winter. Size for your peak season, not your average.
The third mistake is forgetting panel degradation. Even high quality panels lose about 0.5 percent efficiency per year. Over 25 years, that compounds. The 15 to 20 percent buffer in the worksheet accounts for this.
The fourth mistake is assuming you can easily expand later. Adding panels after installation is possible but not always simple. Roof space may be limited. Inverter capacity may need upgrading. Net metering paperwork may need resubmission. It is almost always cheaper and simpler to size correctly from the start.
How we approach future load planning
We do not hand you a quote based on your last electricity bill. Our process starts with a technical site visit by an engineer within two days of booking. During that visit, we assess your roof area, orientation, shading, and structural readiness. We also discuss your household's growth plan: planned ACs, EV purchase timeline, family size changes, and any renovation that might affect electrical loads.
Based on this conversation, we model both your current and projected consumption. We then recommend a system size that fits your roof, your budget, and your five year demand trajectory. If a string inverter is the right fit for your roof, we recommend that, even though micro inverters carry a higher price. Our recommendations follow the roof, not the margin.
Every system we install comes with our Arkashield generation guarantee. If the system underperforms, we pay back at ₹7 per unit of shortfall. That guarantee only works if the system is sized correctly from the start, which is why we take future load planning seriously.
Financing is available through 12 month no cost EMI, fully interest free. Longer tenure options are available through bank and NBFC partners at prevailing market rates. Installation itself takes 24 to 48 hours after the site visit and design finalization.
If you are building a new home, renovating a villa, or simply planning for the next decade of your family's energy needs, start with the worksheet above. Then talk to us. We will turn your future load estimate into a system design that holds up for 25 years, not just the first summer.
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