Working Out Your Own Solar Savings
Most solar calculators are lead capture forms with a number attached. Here is how to do the estimate yourself, with the four figures that actually determine it.
To estimate solar savings, take your annual electricity usage in kilowatt hours from twelve months of bills, multiply by your all-in rate per kWh, and that is your maximum annual saving if solar offsets your entire consumption. Adjust down for the share your roof can realistically cover.
The four numbers that matter
Your annual kilowatt hours
On your bill, not estimated. Add twelve months, because summer and winter differ sharply in New York. This is the single most important figure and most people have never looked at it.
Your all-in rate per kilowatt hour
Divide your total annual bill by your annual kWh. This gives the real rate including delivery charges, which is considerably higher than the supply rate quoted on the front of the bill. Delivery is the part solar offsets too.
The share your roof can realistically offset
Rarely 100%. Shading, orientation and available area all cut it. A good installer models this properly rather than assuming full offset.
What happens to your rate over twenty years
Electricity prices have historically risen. Modest assumed escalation is reasonable; an aggressive one inflates the answer, and that is the lever most online calculators pull.
The arithmetic
Annual usage multiplied by your all-in rate gives what you currently spend. Multiply that by the share your system is expected to offset and you have your estimated annual saving. Compare that against the net system cost after the NY-Sun rebate and the state tax credit, and you have a simple payback period.
That is a deliberately crude model. It ignores rate escalation, panel degradation of roughly half a percent a year, and the Customer Benefit Contribution charge. It is still far more honest than most calculators, because it does not assume anything flattering.
Why online calculators overstate
Assumed full offset
Modelling 100% offset when shading and roof area make that impossible.
Aggressive rate escalation
Assuming electricity prices rise faster than they historically have compounds hard over twenty years.
Ignoring degradation
Panels lose output slowly. Over twenty five years it is not nothing.
Omitting fixed charges
You stay connected to the grid and keep paying the CBC and standing charges.
Stale incentive assumptions
Many still include a federal residential credit that no longer exists.
What a proper estimate needs
A real production estimate uses your address, your roof geometry, measured shading across the year and your actual usage profile. That is what a site assessment produces and what no web form can.
The arithmetic above is for sanity checking. If an installer's projection is far above what your own numbers suggest, ask which assumption is doing the work.
Questions people ask about this
It is on your utility bill in kilowatt hours. Add twelve consecutive months rather than multiplying one month by twelve, because New York usage swings significantly between summer and winter.
Total annual bill divided by total annual kWh. It includes delivery charges, which the headline supply rate does not, and it is the correct figure to use because solar offsets delivery too.
Rarely. You stay grid connected and keep paying fixed charges including the Customer Benefit Contribution. Most systems are sized to offset a large share of consumption rather than all of it.
Usually assumed offset percentage or rate escalation. Neither is necessarily wrong, but both should be stated rather than buried. Ask which assumptions produce the difference.
Yes, slowly. Most manufacturers warrant something in the region of 80 to 90 percent of original output at year 25. A projection that ignores degradation is optimistic.
How to check any solar contractor
This is a new site with no customer reviews, so we are not going to show you any. What we can do is tell you exactly what to verify about whoever contacts you, and where to look it up. That applies to the installer we refer you to and to every other quote you get.
NABCEP certification
The North American Board of Certified Energy Practitioners is the industry standard credential for solar installers. It certifies the individual professional who holds it, not the company, so a firm advertising it may have one certified person and twenty who are not.
How to check. Ask which named individual holds it, then search that name in the directory.
Search the NABCEP directoryNYSERDA participation
Registration in the state's NY-Sun programme. This one is not a nice to have: the New York State incentive is only available through an approved contractor, so using an unregistered installer forfeits it. Some also hold the Quality Solar Installer designation, which requires at least 12 NY-Sun projects in the past year and an average of 4 out of 5 on NYSERDA's own field inspections.
How to check. Search the company name in NYSERDA's list before you sign anything.
Check NYSERDA's contractor listLicensing and insurance
Appropriate electrical licensing for the work, plus general liability and workers compensation cover. A contractor without workers compensation can leave you personally exposed if someone is injured on your roof.
How to check. Ask for certificates of insurance naming you, and check the licence with your town or county before work starts. Do not accept a policy number alone.
Local experience
Interconnection is where most New York solar timelines slip, and it is handled very differently by Con Edison, National Grid, NYSEG, RG&E and PSEG Long Island. Permitting varies again by town.
How to check. Ask how many systems they have energised on your specific utility in the past year, and for two addresses in your county you can drive past.
NY Solar Finder is operated by RBR Growth Consulting. We are not a solar installer, we hold no industry certification, and we do not guarantee the credentials of the company that contacts you. We name these standards, and link to the bodies that issue them, so that you can check that company yourself before you sign anything.
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