Where our numbers come from
Every estimate on Ballpark Lab is built from primary-source data — not other blogs — and we show exactly where each number comes from. Solar and pool costs are data and engineering topics, not medical, legal, or financial advice, so we publish under organizational authorship rather than a single named expert.
Accountability lives in the method, not a bio: a transparent methodology, the cited sources below, visible “last updated” dates, and a real way to reach us with corrections. Ballpark Lab is maintained by the Ballpark Lab Research Team.
Primary sources & what each one feeds
U.S. DOE / EIA
Solar + Pools- Residential retail electricity prices by state ($/kWh)
- Household electricity consumption used to size systems and estimate bills
NREL (National Renewable Energy Laboratory)
Solar- Average daily peak sun hours by state
- PVWatts-style production modeling that turns system size into yearly output
DSIRE (Database of State Incentives for Renewables & Efficiency)
Solar- State-level solar incentives as a fraction of system cost
- Net-metering treatment — how each state credits exported energy
IRS guidance & federal policy (OBBBA)
Solar- Residential federal credit (Section 25D) status — expired 2025-12-31, now $0
- Commercial credit (Section 48/48E) claimed by lease/PPA system owners
Pool & Hot Tub Alliance and industry pricing surveys
Pools- Pool shell, sitework, and feature cost ranges by type (gunite, fiberglass, vinyl)
- Construction and safety standards that shape real-world bids
See the data in action
These sources feed live tools and an open dataset. Every result shows its assumptions, and the methodology spells out each formula in plain English.
Solar data updated June 30, 2026· Pool data updated June 30, 2026