20 Free Energy Calculators: Solar, EV & Rate Tools on SolarCostData — 2026 Energy Cost, Savings & Tax-Credit Calculators

2026 Solar Savings Calculator: Payback at $0 Credit

Fri, 25 Sep 2026 00:43:41 +0300

Most solar calculators still quietly subtract a 30% federal credit, and most assume every kilowatt-hour you generate is worth full retail. For a 2026 buyer in a net-billing state, both assumptions are wrong, and together they can make payback look the better part of a decade shorter than it will be.

This one prices what you would actually get. Enter your numbers:

Average monthly electric bill ($) Quick-fill your state's EIA average rate Your electricity rate (¢ per kWh) — 17¢ = EIA 2025 annual US average (July 2026 monthly: 18.31¢); check your bill

What your utility pays for exported power

Average Electric Bill by House Size Calculator

Fri, 25 Sep 2026 00:43:41 +0300

“Is my electric bill normal?” has an honest, checkable half-answer: what homes your size, heated your way, actually averaged in the government’s own survey — priced at your state’s current rate.

House size (sq ft) State Primary heating

What changes if… House size 1,800 sq ft

Secondary control over the same field. The URL keeps your scenario.

Solar Lease vs Buy Calculator: Cash, Loan & PPA

Sat, 19 Sep 2026 19:20:15 +0300

Most “solar financing” calculators quietly assume the option that pays their referral. This one doesn’t take referrals, so it just shows you the math — including the two costs the sales pitch skips: the dealer fee hidden in low-rate loans and the escalator hidden in leases.

All-cash system price ($) — the honest baseline from a quote

Loan APR (%) Loan term (years) Loan dealer fee (%) — ~20% on teaser rates Lease start ($/mo) Lease escalator (%/yr) Discount rate (%/yr) — what your money would otherwise earn

Pay cash (you own it)—

Loan, present value (you own it)—

Lease, present value (you don't own it)—

Undiscounted cash out the door—

—

All three are compared in present value at your discount rate, because $24,000 today and $24,000 spread over 25 years are not the same money. Comparing a lump sum against undiscounted future payments makes cash look best almost by construction. Loan principal = cash price + dealer fee, amortized at your APR. Lease payments compound by the escalator. A lease's pass-through of the §48E credit is not modeled — price real quotes. Estimate, not a quote.

How to read it

Three numbers, one honest comparison:

Solar Tax Credit Eligibility Checker

Sat, 19 Sep 2026 19:20:15 +0300

The question has a hard, date-shaped answer now — and much of the internet still gives you 2025’s. Three inputs settle yours.

When was (or will) the system be placed in service? How is it paid for? What is being installed?

Your federal credit: —

This is a screening aid, not tax advice. Confirm your own position with a tax professional and the IRS instructions for the relevant year — edge cases (main-home rules, prior carryforwards, business use of the home) are exactly what a screener cannot see.

How Much Do Christmas Lights Cost to Run? Electricity Calculator

Fri, 25 Sep 2026 00:43:41 +0300

Holiday lights are a watts × hours question with one twist: the wattage is printed on the box, and it differs by a factor of five or more between LED and incandescent strings of the same length. The calculator takes your string count and package wattage; the table shows typical displays at the default schedule.

Mini-light strings (100 bulbs each) Watts per mini string — package rating; ~7 W LED, ~40 W incandescent C9 / C7 strings (25 bulbs each) Watts per C9 string — ~2.5 W LED, ~175 W incandescent Other lit decorations, total watts — inflatables, projectors, net lights Hours lit per night Nights in the season Quick-fill your state's EIA average rate Your electricity rate (¢ per kWh) — 17¢ = EIA 2025 annual US average (July 2026 monthly: 18.31¢)

Season cost: —

Total load: —

Per night: —

Energy for the season: —

Watts ÷ 1,000 × hours × nights × rate. Package wattages are typical ratings — check your box. Estimate, not a quote.

What changes if… Electricity rates move

The slider nudges the rate field above; the URL keeps your scenario.

Generator Fuel Cost Calculator: Gas, Propane, Diesel per Hour

Sat, 19 Sep 2026 19:20:15 +0300

Generator sizing pages tell you what it can run; this one tells you what running it costs. Three prices come from EIA and are refreshed automatically; the one number you supply is your generator’s fuel consumption at the load you actually carry.

Fuel Fuel price ($ per gallon) — prefilled from EIA; use your pump or delivery price Fuel use at your load (gallons per hour) — from your generator's manual at the load you run; not measured here Hours run per day — 8 h Days Compare: grid electricity for the same load (¢/kWh, optional) — and the kW the generator is carrying Load carried (kW)

Fuel cost per hour: —

Per day: —

For the outage / trip: —

Gallons needed: —

Same kWh from the grid would cost: —

Cost = gallons per hour × price × hours × days. Gallons per hour comes from your manual at your load; the table below shows the arithmetic for common consumption rates. Estimate, not a quote.

## Fuel cost per hour and per day at EIA prices | Consumption at your load | Gasoline $4.319/gal — per hour / per 8-h day | Propane $2.44/gal — per hour / per 8-h day | Diesel $6.285/gal — per hour / per 8-h day | |---|---|---|---| | 0.25 gal/h | $1.08 / $8.64 | $0.61 / $4.88 | $1.57 / $12.57 | | 0.5 gal/h | $2.16 / $17.28 | $1.22 / $9.76 | $3.14 / $25.14 | | 0.75 gal/h | $3.24 / $25.91 | $1.83 / $14.64 | $4.71 / $37.71 | | 1 gal/h | $4.32 / $34.55 | $2.44 / $19.52 | $6.29 / $50.28 | | 1.5 gal/h | $6.48 / $51.83 | $3.66 / $29.28 | $9.43 / $75.42 | | 2 gal/h | $8.64 / $69.10 | $4.88 / $39.04 | $12.57 / $100.56 | {caption="Generator fuel cost per hour and per 8-hour day by consumption rate, at EIA national gasoline, propane and diesel prices"} Prices: gasoline and diesel are EIA's weekly US retail averages for the week of 2026-09-14; propane is EIA's STEO national residential forecast for the coming winter (delivered residential propane — a cylinder exchange is priced differently). The consumption column is a parameter, not a claim about any model: read yours off the manual's fuel-consumption line at the load you actually run, and remember that half load usually burns well under half the full-load figure.

What's Your Electricity Rate? Find It by ZIP Code

Sat, 19 Sep 2026 19:20:15 +0300

“What’s my electricity rate?” has two honest answers: the one on your bill, and a defensible average for your utility. This page gets you the second in three clicks — and never pretends it’s the first.

Your ZIP code

Why Is Your Electric Bill So High? Bill Jump Calculator

Fri, 25 Sep 2026 00:43:41 +0300

A bill increase is arithmetic before it’s anything else: dollars this month minus dollars last month is some number, and that number came from somewhere. This tool works backward from your two bills to find where.

Last month's bill ($) This month's bill ($) State

Advanced — kWh from the bills, billing months, heating and cooling on this meter

Last month's kWh — optional, from the bill; unlocks bill-derived rates This month's kWh — optional Billing months — the two months the bills cover Heating on this meter Cooling

Your increase: —

Weather: —

Rate change: —

Usage (behavior): —

Will Time-of-Use Pricing Cut Your Bill? Free Simulator

Sat, 19 Sep 2026 19:20:15 +0300

Time-of-use pitches always show the cheap overnight price. The honest question is arithmetic: your usage, split between the peak window and everything else, priced both ways. This simulator does exactly that — with tariff figures read from the utilities’ own sheets, and a break-even share that tells you how much shifting would actually flip the answer.

Your utility — 14 large utilities preset from their own tariff sheets; anyone else: pick “My utility isn’t listed”

$2.04 a Day for a Space Heater: Electricity Cost Calculator

Sat, 26 Sep 2026 10:27:58 +0300

Most “cost to run X” answers give you one national number. This one uses your wattage, your hours, and your rate — so the figure is actually yours. Pick an appliance or type any wattage:

Appliance — sets a typical wattage & run-time you can edit Power draw (watts) Hours used per day Days used per month — 30 for everyday, fewer for seasonal Quick-fill your state's EIA average rate Your electricity rate (¢ per kWh) — 17¢ = EIA 2025 annual US average (July 2026 monthly: 18.31¢); check your bill

Energy used: — per day

Cost per hour: —

Cost per day: —

Cost per month: —

Cost per year: —

Energy cost only (watts ÷ 1,000 × hours × rate). Everyday use is billed as a full 365-day year rather than 12 × 30 days. Your bill also has fixed fees, taxes and delivery charges. Estimate, not a quote.

What changes if… Electricity rates move

Secondary control: the slider nudges the rate field above (numeric input stays the precise, primary way in). The URL keeps your scenario.

EV vs Gas: What Do You Really Save Driving Electric?

Fri, 25 Sep 2026 00:43:41 +0300

The $7,500 federal EV credit is gone for 2026 buyers (it ended September 30, 2025). That makes the running-cost math more important than ever — so this compares what you’ll actually spend on fuel, using your numbers:

Miles driven per year — US average ≈ 12,000–13,500 EV efficiency (miles per kWh) — typical 3–4; SUVs/trucks lower Quick-fill your state's EIA average rate Your electricity rate (¢ per kWh) — 17¢ = EIA 2025 annual US average (July 2026 monthly: 18.31¢) Gas car fuel economy (MPG) — US average ≈ 28 Gas price ($ per gallon)

Advanced — public charging share and price, cold-weather months, inflation

Share of charging done in public (%) — DC fast charging costs far more than home Public charging rate (¢ per kWh) — commonly 40–60¢; some networks bill per minute Cold-weather months per year — EV efficiency drops 20–40% in freezing conditions Annual fuel and electricity inflation (%) — applied to the 5- and 10-year figures

EV cost to fuel: — per year

Gas cost to fuel: — per year

You save with the EV: — per year

Cost per mile — EV: — · Gas: —

5-year fuel savings: —

10-year fuel savings: —

Energy and fuel cost only. Blends home and public charging at your chosen split, applies a 30% winter efficiency penalty across the cold months you set, and compounds the 5- and 10-year figures at your inflation rate. Excludes purchase price, insurance, maintenance and depreciation — an EV typically costs more to insure and less to maintain. Federal EV credit = $0 in 2026. Estimate, not a quote.

What changes if… Electricity rates move

Secondary control: the slider nudges the rate field above (numeric input stays the precise, primary way in). The URL keeps your scenario.

Tesla Supercharger vs Home Charging: Cost Compared

Sat, 19 Sep 2026 19:20:15 +0300

Supercharger pricing is a per-station fact, not a national one — so this page refuses to guess it, and instead does exact arithmetic on the number in your app.

Your EV State (home rate) — or type your own below Home rate (¢/kWh) Supercharger price ($/kWh) — from your Tesla app, for the station you'd use; no honest default exists

What changes if… Miles per year on Superchargers 2,000 mi

Scales the annual-dollar line; the per-mile comparison doesn't depend on it. The URL keeps your scenario.

EV on a Time-of-Use Rate: The Whole-Home Net Calculator

Fri, 25 Sep 2026 00:43:41 +0300

Want the quick version first? The time-of-use rate simulator answers the flat-vs-TOU question in three inputs with real utility tariffs — this page is the deep end, with cold weather, fast charging and the whole house’s exposure.

Cheap overnight charging is the headline of every time-of-use pitch. The fine print is that the rate applies to your entire meter: the same plan that charges the car at 23¢ overnight bills the house at 54¢ between 4 and 9pm on PG&E’s EV plan, and at nearly 30¢ on Georgia Power’s. The car is the reason you switch; the house decides whether the switch pays.

What Size Heat Pump Do You Need? Free Sizing Estimator

Sat, 19 Sep 2026 19:20:15 +0300

Square footage and climate zone are the two numbers everyone already has — this tool turns them into a published, cited bracket and nothing more.

Conditioned floor area (sq ft) State — sets your predominant DOE/IECC climate zone

What changes if… Floor area

Secondary control over the same field; the numeric input stays the precise way in. The URL keeps your scenario.

What Temperature Should You Switch Off Your Heat Pump?

Sat, 19 Sep 2026 19:20:15 +0300

A heat pump and a furnace deliver the same thing — heat — at costs that cross somewhere on the thermometer. This tool finds where, for your prices and a named, NEEP-listed machine.

State — fills EIA rate defaults Heat pump — NEEP-listed cold-climate models Electricity price (¢/kWh) Natural gas price ($/therm) Furnace AFUE (%) Last winter's gas use (therms, optional) — from your bills; unlocks the annual $ split

What changes if… Electricity price ×1.0 Gas price ×1.0

Sliders scale the two prices to test sensitivity; the numeric fields stay the precise inputs. The URL keeps your scenario.

Is Your Heat Pump Working Right? Free Performance Check

Sat, 19 Sep 2026 19:20:15 +0300

A new heat pump changes the electric bill by definition — the question is whether it changed it the way its own rating sheet says it should. This check answers that with physics, not vibes.

Monthly kWh before the heat pump Monthly kWh after Your unit — or the closest NEEP-listed model State + month — sets the default mean outdoor temp (65°F − HDD/day)

What changes if… Mean outdoor temperature that month

Defaults from regional degree-days; drag if you know your month ran colder or milder. The URL keeps your scenario.

Heat Pump vs Furnace Cost Calculator 2026: Yearly Savings

Fri, 25 Sep 2026 00:43:41 +0300

The federal heat-pump credit ended after 2025, so the decision now rests on running cost — which depends entirely on your fuel prices. This compares them using your numbers:

Current heating fuel — loads typical price & efficiency you can edit What you spend on heating per year ($) Fuel price ($/therm) Current system efficiency (%) — gas ~92, oil ~85, resistance 100 Quick-fill your state's EIA average rate Your electricity rate (¢ per kWh) — 17¢ = EIA 2025 annual US average (July 2026 monthly: 18.31¢)

— optional preset from the Sept 2026 STEO (residential, Oct–Mar simple average): electricity 18.2¢/kWh, natural gas ≈$1.36/therm, propane $2.44/gal, heating oil $5.30/gal. Your own bill beats any national average.

What Outdoor Temp Should Your Dual-Fuel System Switch?

Sat, 19 Sep 2026 19:20:15 +0300

A dual-fuel system has one setting that decides most of what it costs to run: the outdoor temperature at which it stops using the heat pump and starts using the furnace. Set it too high and you burn expensive fuel while the heat pump was still winning. Set it too low and you run the heat pump into weather where gas was cheaper.

That crossover is not a fixed number. It moves with your fuel prices, and it depends on how your particular heat pump behaves in the cold — which is why a single seasonal efficiency figure cannot answer it.

Home Battery Payback: Buy vs Third-Party-Owned Calculator (2026)

Sat, 19 Sep 2026 19:20:15 +0300

A home battery earns its keep two ways that have nothing to do with each other. One is arbitrage: buy cheap, use at peak, pocket the spread. The other is backup: the lights stay on when the grid drops. Almost every calculator online mashes those into a single “savings” figure, which hides the only question that matters — which one is actually paying for this thing?

The distinction is not academic. A battery in a full-retail net metering state earns close to nothing on arbitrage and might still be worth every dollar if you lose power six times a winter. A battery under NEM 3.0 in a suburb that never goes dark is the opposite: pure arithmetic, no insurance. Same hardware, completely different purchase.

Home Battery Payback: Who Still Gets the 30% Credit?

Sat, 19 Sep 2026 19:20:15 +0300

Nearly every battery calculator online still quietly subtracts a 30% federal credit. For a 2026 purchase that line is simply wrong, and it makes payback look years shorter than it is.

The confusing part is that 30% does still exist — just not for you, if you’re the one buying. Pick how you’d actually get the battery and the tool prices that route honestly:

How would you get the battery?

Usable battery capacity (kWh) — Powerwall 3 ≈ 13.5 kWh Energy you shift per day (kWh) — capped by the battery: capacity × depth of discharge × round-trip efficiency Usable depth of discharge (%) — most packs reserve some capacity; 90% is typical Round-trip efficiency (%) — energy lost charging and discharging; ~90% is typical Full cycles per year — 365 assumes solar refills it every single day; winter and cloud make ~300 realistic

How Many Solar Panels Do I Need? Calculator for Any US State

Sat, 19 Sep 2026 19:20:15 +0300

Bigger isn’t better in 2026 — right-size to your actual usage. Enter your numbers:

How do you want to enter usage? Average monthly electric bill ($) Your electricity rate (¢ per kWh) Sun in your area

Estimated system size: —

Number of panels (~400 W): —

Roof area needed: — — includes setbacks

Assumes ~400 W panels at about 21.5 sq ft each, plus roughly 40% extra roof for fire setbacks, walkways and obstructions — so the area shown is roof needed, not panel area. Estimate only; a site assessment refines it.

What changes if… Electricity rates move

Secondary control: the slider nudges the rate field above (numeric input stays the precise, primary way in). The URL keeps your scenario.

Should You Go Solar in 2026? 4-Question Reality Check

Sat, 19 Sep 2026 19:20:15 +0300

Most “is solar right for you?” tools are lead forms in disguise — answer a few questions, hand over your phone number, get called by installers. This one isn’t. Four questions, an honest verdict, no contact details. Then, if the answer is promising, you take it to the numbers.