Plan Solar for a Future EV, Pool or HVAC Change: A Load Worksheet

Start with a dated baseline and a decision status

Use a complete twelve-month kWh record for the home, noting vacancies, estimated bills and unusual use. Keep electricity quantities separate from bill dollars. Describe the household and equipment represented by those months so a reviewer can tell whether a future change is already partly included. If an EV was charged for six months, adding a full year of EV use to the unadjusted total would double-count part of it.

For each planned item, record whether it is committed, provisional or deferred, plus the expected start month. Keep vendor information or measured records alongside the assumption. A vehicle ordered for next month and a possible pool two years away should not be treated as equally certain.

Estimate home EV charging from the driving plan

Record annual miles, the share of charging expected at home and the vehicle’s energy-use basis. DOE’s Alternative Fuels Data Center describes vehicle efficiency in kWh per 100 miles and emphasizes the role of driving needs in home charging. [2] Ask whether the efficiency figure includes charging losses; do not add an unexplained loss allowance twice.

Hypothetical example: 12,000 annual miles × 80% home-charging share × 0.30 kWh per mile measured at the wall equals 2,880 kWh per year at home. The wall-energy assumption already includes charging losses for this example. It is not a forecast for a particular vehicle, climate or driver. Battery capacity and charger nameplate power are not substitutes for annual driving energy.

Calculate pool and HVAC changes as differences

For a genuinely new pool pump, document its operating power at the planned settings and its seasonal schedule. A simple hypothetical case of 0.8 kW for four hours a day over 200 days uses 640 kWh. Actual variable-speed operation can differ, and a pool heater is a separate load. Do not reuse the pump example as a forecast for the complete pool system.

For replacement equipment, compare new use with the old use already in the baseline. Adding the full consumption of a replacement air conditioner would count both the old and new equipment. Request a supported estimate reflecting the home, equipment and operating conditions; a nameplate rating alone is not an annual-use prediction. If reliable evidence is missing, label a range or leave the item unresolved.

Show scenarios without confusing energy and capacity

A worksheet can keep three columns: measured current use, committed changes and optional changes. Suppose a hypothetical home uses 14,000 kWh annually, adds the 2,880 kWh EV case, and has a documented efficiency change estimated to reduce use by 1,000 kWh. The committed scenario is 15,880 kWh. Adding the separate 640 kWh pool-pump case would make an optional scenario of 16,520 kWh.

These examples explain arithmetic, not expected savings or a recommended system size. Annual kWh does not determine simultaneous electrical demand, service capacity or outage runtime. A qualified electrician must assess charging capacity separately; AFDC specifically identifies that professional review. [2] Charging time and utility terms also affect bills even when annual energy is unchanged.

Agree on the design case and a later review trigger

Ask the proposal to name the chosen scenario, each included change and the supporting assumptions. Confirm how the production estimate compares with that energy target and what remains subject to site and utility review. Do not silently include every optional appliance just to make a larger array appear necessary. Keep a separate date for revisiting deferred projects.

When plans change, update the worksheet first and request a revised design comparison. More panels can change modeled production and offset, but they do not automatically establish proportional bill savings or utility approval. The first Origin conversation can identify the planned changes and supported project scope for the address. Share detailed bills and equipment records through an agreed private channel, not as account credentials in a callback note.

Primary sources

1. U.S. Department of Energy: Homeowner’s Guide to Solar

   Checked October 20, 2026 for efficiency and household-energy considerations only. No tax-credit, current-price or payback claim is taken from this page.

2. Alternative Fuels Data Center: Charging Electric Vehicles at Home

   Checked October 20, 2026 for vehicle energy-use units, driving and charging needs, and qualified electrical-capacity review. All worksheet numbers here are explicitly hypothetical, not quoted utility rates or equipment forecasts.

Planning examples and questions are Origin’s editorial guidance, not a property-specific diagnosis, engineering design, tax determination or promise of savings. Manufacturer and utility references do not imply an affiliation with Origin.

Related guidance

• Prepare the historical electricity-use file
• Compare kW capacity and kWh energy
• Plan the separate home-charging installation