The size of the fixed charge itself
Set by your utility and your tariff, not by you. Moving from $15 to $40 takes the untouchable share of the bill from 10.3% to 27.6% and the 25-year total from $4,500 to $12,000.
HyreSolar tools
What Your Utility Charges Before You Use Anything
The part of the bill that arrives whether you generate or not.
Every residential electricity bill has a floor. Before a single kilowatt-hour is counted, most utilities levy a fixed charge — a customer charge, a basic service charge, a meter charge — and solar does not reduce it by a cent. This tool works out how large yours is, what share of the bill it represents, and where your bill actually lands after solar.
What this returns at the defaults
On a $145 monthly bill covering 900 kWh with a $15 fixed charge, the fixed portion is 10.3% of the bill. A 90% offset of the variable half saves $117/mo and floors the bill at $28/mo — never zero. Raise the fixed charge to $40 and it becomes 27.6% of the bill and $12,000 over 25 years, an amount solar cannot touch no matter how large the array.
Last updated . Data as of 5 September 2026.
Bill floor model
Three numbers off one electricity bill. No rate table involved.
— Bill floors at
— Fixed charge is
— Rate solar can displace
— Blended rate
— Monthly saving
— Fixed charge over the horizon
Models the printed fixed charge only. Minimum bills and demand charges would raise your real floor.
Your own bill is the source. HyreSolar publishes no per-utility rate table and does not sell systems.
How to read your floor
The number that matters is not the fixed charge, it is the share. Fifteen dollars is trivial against a $260 bill and substantial against an $80 one. This is the sense in which fixed charges are regressive: at our defaults the same $15 charge is 5.8% of a high user's bill and 18.8% of a low user's. The household with the least to spend gets the least protection from generating its own power.
Your bill after solar floors at the fixed charge, not at zero. Any proposal projecting a $0 bill is either ignoring the fixed charge, assuming credits that offset it, or wrong. Run 100% offset in the calculator and watch the floor stay put — that is the arithmetic, not a pessimistic assumption.
The variable rate is what solar actually competes against. Strip the fixed charge out and the remaining cents per kilowatt-hour is the rate your array is displacing. It is always lower than the blended rate, which is why a payback estimate built on the blended figure is slightly optimistic.
Under 10% of the billA modest customer charge. Worth knowing about, unlikely to change a decision. Your bill will still not reach zero.
10% to 20%The ordinary range. Large enough that a proposal projecting a zero bill is overstating, and large enough to notice in a payback calculation.
Above 20%A substantial fixed component, common on low-usage accounts and on tariffs that have shifted cost recovery away from volumetric charges. Check whether your utility offers an alternative residential tariff before sizing an array.
How to use this calculator
Every input below is a number you can find, not one you have to guess. This is where each one comes from.
- 01
Find the fixed charge on your bill
It is a printed line, not something to estimate. Names vary: customer charge, basic service charge, service availability charge, meter charge, or basic charge.
Where to find it The itemised section of your electricity bill, usually near the top of the charges list and usually the same amount every month regardless of usage. That constancy is how you identify it if the naming is unclear.
- 02
Enter the total bill amount
The full amount due, including delivery, supply, taxes and riders. Not the supply line alone.
Where to find it The amount due box. Use a recent ordinary month rather than a seasonal peak or trough.
- 03
Enter the kilowatt-hours that bill covered
From the same bill as the amount. Mixing a bill total from one month with usage from another produces a meaningless rate.
Where to find it The usage section, usually shown as kWh this period alongside a comparison to last year.
- 04
Set the offset you expect
The share of your consumption the array is designed to cover. This is a design figure from the proposal, not a guess.
Where to find it Your proposal, usually stated as an offset percentage or as annual production against annual usage. If it says 100%, note that this still does not zero the bill.
- 05
Read the floor first
It is the answer to the question most homeowners actually have: what will my bill be after solar. The floor is where it lands in a month when the array covers everything it was designed to cover.
Where to find it Nowhere on your paperwork — this is the output. Compare it against any bill figure your proposal projects.
- 06
Check the 25-year total last
It puts the fixed charge in the same units as the system price. A charge that looks trivial monthly can be a meaningful fraction of what the array cost.
Where to find it Compare it against your installed price. At $40/month it is $12,000, which is a substantial share of a residential system.
How this calculator works
Split the bill
Total minus the fixed charge is the variable portion. That split is the whole basis of the tool.
Compute both rates
Blended rate is the whole bill over the whole kWh. Variable rate strips the fixed charge out first. Solar competes against the second.
Apply the offset to the variable half only
Generating power reduces consumption charges. It does not reduce a charge levied for being connected.
Report the floor and the lifetime total
What the bill lands at, and what the fixed charge alone costs across the system life.
The formula, in full
variable bill = total − fixed. blended rate = total ÷ kWh. variable rate = variable bill ÷ kWh. monthly saving = variable bill × offset. bill floor = total − monthly saving. lifetime fixed = fixed × 12 × years.
A worked example, start to finish
An ordinary residential account: $145 a month covering 900 kWh, carrying a $15 basic service charge, with a solar proposal designed for a 90% offset.
Inputs
- Monthly bill
- $145
- Consumption
- 900 kWh
- Fixed charge
- $15
- Blended rate
- 16.11 ¢/kWh
- Variable rate after stripping the fixed charge
- 14.44 ¢/kWh
- Designed offset
- 90%
- Monthly saving on the variable half
- $117
Result
$28/mo floor, $4,500 fixed over 25 years
The array reaches $117 of a $145 bill. The remaining $28 is the $15 fixed charge plus the 10% of consumption the design does not cover. Note the two rates: a payback model using the 16.11¢ blended rate assumes the array displaces electricity at that price, but it can only displace the 14.44¢ variable rate — about 10% less value per kilowatt-hour than the blended figure implies. Over 25 years the fixed charge alone is $4,500.
How the answer moves
The same $145 / 900 kWh account, one input changed at a time. Every figure is computed by the calculator on this page.
| Change | Fixed share | Blended rate | Variable rate | Monthly saving | Bill floor | 25-yr fixed |
|---|---|---|---|---|---|---|
| Base case$15 fixed, $145 bill, 900 kWh, 90% offset | 10.3% | 16.11¢ | 14.44¢ | $117/mo | $28/mo | $4,500 |
| No fixed charge at all | 0.0% | 16.11¢ | 16.11¢ | $131/mo | $15/mo | $0 |
| $25 fixed charge | 17.2% | 16.11¢ | 13.33¢ | $108/mo | $37/mo | $7,500 |
| $40 fixed charge | 27.6% | 16.11¢ | 11.67¢ | $95/mo | $51/mo | $12,000 |
| 100% offset instead of 90% | 10.3% | 16.11¢ | 14.44¢ | $130/mo | $15/mo | $4,500 |
| 70% offset instead of 90% | 10.3% | 16.11¢ | 14.44¢ | $91/mo | $54/mo | $4,500 |
| Low user: 400 kWh, $80 bill | 18.8% | 20.00¢ | 16.25¢ | $59/mo | $22/mo | $4,500 |
| High user: 1,800 kWh, $260 bill | 5.8% | 14.44¢ | 13.61¢ | $221/mo | $40/mo | $4,500 |
Two rows carry the argument. The 100% offset row still floors at $15/mo — the fixed charge survives a design that covers every kilowatt-hour the house uses. And the last two rows show the same $15 charge landing as 18.8% of a low user’s bill and 5.8% of a high user’s: an identical charge, nearly triple the burden, falling hardest on the household with the smallest bill.
What moves this number most
Ranked. A proposal can change any of these without saying anything untrue, so these are the inputs to check first.
How much electricity you use
The other half of the share calculation, and the reason the same charge is regressive. A fixed charge is a larger fraction of a small bill by construction.
Whether an alternative tariff exists
Many utilities offer more than one residential rate, and they do not always weight fixed and volumetric charges the same way. This is worth asking about before sizing an array, not after.
The offset the array is designed for
Changes the saving but never the floor. This is the point most often misunderstood — a bigger array reduces the variable half toward zero and leaves the fixed charge exactly where it was.
What is deliberately absent
Minimum bills, demand charges, non-bypassable charges, net metering successor tariff fees, standby charges, and taxes calculated on the total. Several of these behave like fixed charges and would raise your real floor further. This tool models the printed fixed charge only.
Common mistakes with this calculation
Believing a proposal that projects a zero bill
Unless your utility has no fixed charge, or credits exceed it, the bill cannot reach zero. Run 100% offset above and watch the floor hold at the fixed charge. If a proposal shows $0, ask what happened to the customer charge.
Using the blended rate in a payback model
The blended rate includes money the array cannot displace. It overstates the value of each generated kilowatt-hour, modestly but systematically. The variable rate is the honest input.
Confusing the fixed charge with delivery charges
They are different. Delivery is largely volumetric and solar does reduce it — our own measurement puts delivery at 53.2% of the residential bill. The fixed charge is the flat line that does not move with usage at all.
Reading one seasonal bill and generalising
The fixed charge is the same every month, but the share it represents swings with usage. Take an ordinary month, or better, run a summer and a winter bill and look at both.
Assuming the charge cannot change
Utilities file to change fixed charges, and the direction of travel in many jurisdictions has been upward. A charge modelled at today’s level over 25 years is a floor on the estimate, not a ceiling.
Downsizing the array because of the fixed charge
The fixed charge is unaffected by array size in either direction. It is a reason to adjust expectations about the final bill, not a reason to change the design.
Important: this is a planning estimate
- Not a lookup. HyreSolar publishes no per-utility fixed-charge table — the figure comes off your bill, where it is printed every month.
- Models the printed fixed charge only. Minimum bills, demand charges, non-bypassable charges, standby charges and successor-tariff fees are not included and would raise your real floor.
- Assumes solar reduces the variable portion in proportion to the offset. Under net billing or a buyback tariff the relationship is weaker than that.
- Taxes calculated as a percentage of the total are treated as part of the bill, not separated out.
- The 25-year total holds today’s fixed charge constant. Utilities file to change these, and recent movement in many jurisdictions has been upward.
Questions this calculator answers
What is a utility fixed charge?
A flat monthly amount charged for being connected to the grid, independent of how much electricity you use. It appears under names like customer charge, basic service charge, service availability charge or meter charge. The reliable way to identify it is that it is the same every month while your usage changes.
Does solar reduce the fixed charge?
No. Solar reduces consumption, and a fixed charge is not levied on consumption. This is why a bill after solar floors at the fixed charge rather than at zero — and why a proposal projecting a $0 bill has either omitted it or is assuming credits large enough to swallow it.
Why does this tool not look up my utility?
Because a credible per-utility table requires the OpenEI Utility Rate Database, which needs an API key we do not hold, and we will not ship a rate table we cannot retrieve or re-verify. This site already applies that rule to state electricity rates, where only figures with a named EIA vintage are published. Your own bill carries the number, printed, every month, and it is more current than any table we could build.
My bill has no line called fixed charge. What do I enter?
Look for the charge that is identical on two consecutive bills with different usage. That constancy identifies it regardless of the name. If every line moves with usage, your tariff may genuinely have no fixed charge — enter zero and the tool will tell you your bill can, in principle, approach zero.
Are fixed charges regressive?
As a share of the bill, arithmetically yes. Our scenario table holds the charge at $15 and changes only usage: it lands as 18.8% of a 400 kWh household’s bill and 5.8% of an 1,800 kWh household’s. That is a statement about the arithmetic of a flat fee, not a claim about any utility’s intent, and the policy arguments on both sides sit outside what this tool can settle.
Should I use the blended rate or the variable rate in a payback calculation?
The variable rate, if you want a strict answer. The blended rate includes money the array cannot displace, so it credits each generated kilowatt-hour with slightly more value than it earns. At our defaults the difference is 16.11¢ against 14.44¢ — about 10%, which is enough to matter across 25 years.
Can I avoid the fixed charge by disconnecting from the grid?
Only by going genuinely off-grid, which is a different project with different economics, different equipment and different risks. For a grid-tied system the charge is the price of the connection you are still using at night and in winter. See off-grid versus grid-tied.
Will my fixed charge go up?
It can, through a rate case at your regulator. We are not going to predict yours, and the 25-year total above deliberately holds it flat — which makes that figure a floor rather than a forecast. If your utility has a pending rate filing, the fixed charge is one of the lines worth reading.
Does a battery help with the fixed charge?
No more than the array does. A battery raises self-consumption, which reduces the variable half further, but the fixed charge is untouched by both. If a battery proposal projects a lower bill than the array alone, check that the difference is coming from consumption and not from an assumption about the fixed charge.
The research behind these numbers
Every assumption in this calculator is argued from primary sources somewhere in our research library. These are the pages that matter for this one.
- Your first bill after solar Our own measurement across 14.7 million customers: delivery is 53.2% of the residential bill. The companion piece to this tool.
- Solar savings calculator Model the variable half. Enter the variable rate from this tool rather than the blended one for a stricter estimate.
- Solar payback calculator Same point: the rate you enter there should be the rate solar can actually displace.
- Net metering, net billing and buyback What happens to exported kilowatt-hours, and whether credits can reach a fixed charge at all.
- Electricity bills by state Where your bill sits, computed from EIA-861.
- If net metering ends The tariff changes that tend to arrive alongside rising fixed charges.
- Time-of-use rates and solar The other tariff structure that decides what your generation is worth.
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Want a more accurate estimate for your home?
Actual results depend on roof, usage, utility rules and a real proposal. Matching is still being built. The form is an enquiry, not a dispatch line.
Written and audited by
HyreSolar Research
Primary-source research, data analysis and fact checking
We are a research desk, not a sales floor. We read the statute, the tariff, the code section, the federal filing or the manufacturer data sheet ourselves, and we publish the figure with the document it came from and the date we retrieved it. Where a number cannot be traced to a primary source, we publish the shorter page and say what we could not verify. That rule has cost us whole sections, and it is the reason the rest can be trusted.
- 160
- primary sources read and cited
- 220
- figures with a retrieval date
- 115
- federal and state government sources
- 66
- researched pages published
How this desk works
- Primary sources only. Statutes from the legislature’s own publishing system, federal data from the agency that collects it, code text from the adopted edition, manufacturer claims from the data sheet. We do not cite an article that cites a source; we go and read the source.
- Every figure carries its provenance. A named document and the date we retrieved it, so you can check it and so you know how old it is. Retrieval dates are not decoration: an EIA rate from May is a different fact from an EIA rate from August.
- We publish what we could not verify. Every research page carries a section naming the things we tried to establish and could not, and why. A paywalled standard, a state website that refused the request, a manufacturer that publishes no figure at all.
- We separate measurement from modelling from our own reasoning, and label which is which on the page. A laboratory measurement, an assumption inside a modelling tool and our own inference are three different kinds of claim and they are never presented as one.
- We do not sell solar, and we take no payment for placement, ranking or a favourable mention. Nobody buys a position on this site.
Data as of 5 September 2026. Authorship on this site is organisational: the analysis belongs to the desk rather than to a named individual, and we do not publish credentials we do not hold. Our editorial policy sets out how we source, date and correct what we publish.
Data and sources
- Electric Power Monthly, Table 5.6.A (U.S. Energy Information Administration, retrieved 2026-08-06. Source for the national residential average rate used elsewhere on this site. Provides the blended-rate context, not fixed charges, which EIA does not publish per utility at this granularity.)
- Your first bill after solar (HyreSolar Research Desk, retrieved 2026-09-05. Our own analysis across 14.7 million customers, source for delivery representing 53.2% of the residential bill and for the distinction between delivery charges and fixed charges.)
- Utility Rate Database (URDB) (NREL / OpenEI, retrieved 2026-09-05. The dataset a per-utility lookup would require. Named here for transparency about why this page is a calculator rather than a lookup; access requires an API key we do not currently hold.)