Quick definition
A solar system's sticker price alone doesn't tell you much about whether it's a good value, since a cheap system that produces little energy could easily cost more per kWh than an expensive system that produces a lot. LCOE solves this by adding up every real cost over the system's full lifetime, installation, financing, maintenance, everything, and dividing that total by every kWh the system is expected to generate over that same lifetime.
The result is one clean number: the true cost of each kWh of solar power the system produces, which can be compared directly against a utility's rate or against any other energy source's LCOE.
At a glance: LCOE is the standard metric energy analysts and utilities use to compare wildly different generation sources, from solar to wind to natural gas, on one consistent, apples-to-apples basis.
Why it matters
LCOE is the number that actually made "grid parity" a meaningful, measurable milestone rather than a vague claim. When someone says solar has become cheaper than the grid in most regions, they're really saying solar's LCOE has fallen below the typical retail electricity rate, a precise, calculable comparison rather than an impression. Financial analyst Lazard's 2026 Levelized Cost of Energy+ report put unsubsidized utility-scale solar's LCOE at roughly $40 to $98 per megawatt-hour, up 18% from the year before due to higher capital costs, interest rates, and tariffs, yet still among the cheapest new-build electricity sources available, a reminder that LCOE is a snapshot that moves with financing and equipment costs rather than a fixed number. To see Levelized cost of energy (LCOE) in a real example, the quick financing comparison tool in our Financing section applies it to a working system.
For an individual homeowner, LCOE is a genuinely useful way to compare two different system proposals that look similar on paper but differ in equipment quality, expected lifespan, or financing terms. A cheaper system with a shorter expected lifespan or a higher degradation rate could actually have a higher LCOE, a worse true cost per kWh, than a pricier system built with better components and a longer service life.
It's worth being clear about what LCOE doesn't capture. It's a pure cost-efficiency metric and doesn't factor in a specific homeowner's utility rate, their self-consumption pattern, or available incentives, all of which affect actual savings. LCOE tells you how efficiently a system generates power for its cost; your actual bill savings depend on more than that number alone. The U.S. Energy Information Administration's solar explainer sets out the basics of how solar electricity is produced and what it costs to generate.
Where you'll see this
The levelized cost of energy calculator works out the true LCOE for your specific system based on its cost, expected lifespan, and production estimate.
For a simpler year-by-year view, the cost per kWh produced calculator breaks down what each kWh of solar power is actually costing you at different points in the system's life.
For a business evaluating solar, the commercial solar 25-year TCO calculator extends this same lifetime-cost thinking into a fuller ownership-cost picture over the system's full expected service life.
This term comes up in energy industry cost comparisons, in solar market reports discussing grid parity, and any detailed comparison between two solar proposals with different equipment or financing terms. The Solar Energy Technologies Office sets cost targets for solar electricity and tracks progress toward them.
Frequently asked
Payback period tells you how long it takes for savings to cover the upfront cost. LCOE tells you the true cost per kWh across the system's entire lifetime, which is a more useful number for comparing solar against another energy source on a fair, apples-to-apples basis.
A properly calculated LCOE does, factoring in that a system's output gradually declines each year rather than assuming constant peak output for the system's entire lifespan. Ignoring degradation would understate the true LCOE.
Yes, that's exactly what LCOE is designed for. Because it reduces every energy source down to one comparable cost-per-kWh figure, it's the standard metric energy analysts use to compare wildly different generation technologies on equal footing.
Generally yes for comparing the underlying cost efficiency of different systems or technologies, but a homeowner's actual savings also depend on their specific utility rate and how much of their own production they use directly, which LCOE alone doesn't capture.