The 30% ITC is the whole game (for now)
The Inflation Reduction Act extended the Residential Clean Energy Credit at 30% through 2032, with a step-down to 26% in 2033 and 22% in 2034. Recent political signaling has put this on the table for early repeal or accelerated phase-out — if you're 'maybe' on solar, the 30% credit is the most valuable variable in the entire calculation. A $30k system gets $9k back as a dollar-for-dollar federal tax credit (NOT a deduction). It's non-refundable but can be carried forward to future years.
Why batteries are mandatory in NEM 3.0 California
California's NEM 3.0 (April 2023+) slashed export credits from full retail (~$0.30/kWh) to avoided-cost (~$0.05/kWh). This made exporting solar to the grid almost worthless. The economic response: install enough battery to store daytime production and discharge it during the 4–9 PM peak when YOU would otherwise be buying at $0.45–$0.55/kWh. The battery essentially recaptures the value the utility stopped paying for. Without battery, NEM 3.0 solar payback stretches to 15–20+ years.
Where batteries DON'T pay back
If your utility has 1:1 net metering (full retail credit) and no TOU rate structure, a battery is a luxury, not an investment. Florida, much of the Southeast, and small munis often fit this. In those cases, every kWh you export is worth the same as a kWh you self-consume, so storing it provides no arbitrage. Resilience (backup during outages) may still justify it, but call that an insurance cost, not an investment.
SREC and state stacking
Massachusetts (SMART), New Jersey (TREC/SREC-II), Maryland, and DC pay solar owners per-kWh production incentives on top of federal ITC, often $50–$300/MWh for 10–15 years. In MA, the SMART program can pay $4,000–$9,000 over the contract life on top of bill savings. Always check dsireusa.org for your zip code before assuming national-average payback math applies.
- • MA SMART program: 10-yr payments, $0.05–$0.40/kWh
- • NJ TREC: 15-yr factor-based payments
- • NY-Sun: declining-block rebate
- • IL Adjustable Block Program: lump-sum SREC purchase
Real-world sizing rules of thumb
System size: aim for 80–110% of annual consumption — over-sizing past 110% is wasted in most NEM-haircut markets. Battery size: 10–15 kWh covers most evening peak shifting; 20+ kWh only justified if you want whole-home backup during outages. Inverter: oversize string inverter or pick microinverters if you have shading; this affects production by 5–15%.
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Read the guideFAQ
Can I claim the ITC if I lease?
No. The ITC goes to the OWNER of the system. Lease and PPA arrangements transfer the credit to the leasing company (who builds it into their pricing). Always model loan vs cash purchase vs lease — leases typically deliver 30–50% less lifetime savings to the homeowner.
What if I don't have enough tax liability to use the full ITC?
The credit is non-refundable but can be carried FORWARD to future tax years until used. If you owe $4k in federal tax and your credit is $9k, you'd use $4k year one and carry $5k forward. Retirees with low income may take 3–5 years to fully consume it.
Does solar increase my property tax?
Most states (CA, NY, FL, AZ, MA, NJ, and ~30 others) exclude solar from property tax reassessment. Always confirm with your county assessor — a handful of states have no exemption.
How long do panels and batteries last?
Panels: 25-year linear performance warranty (80% production at year 25); typical degradation 0.4–0.6%/yr. Lithium batteries: 10-year warranty, 70–80% capacity retention at year 10. Plan for one battery replacement during a 25-year solar system life.
What's the difference between NEM 1.0, 2.0, and 3.0?
NEM 1.0/2.0: full retail credit for exports (best). NEM 3.0 (CA only currently): avoided-cost credit ~$0.05/kWh — 80% less. Other states are watching CA and may follow.
Is the cheapest installer the best deal?
Not always. Look for in-house installation (not subcontracted), at least 10 years of operating history, NABCEP-certified installers, and a workmanship warranty matching the panel warranty. Cheap installers go out of business and your 25-year warranty walks with them.
How does the ITC interact with state incentives?
Federal ITC is calculated on cost AFTER state rebates in some states (CA SGIP) and BEFORE in others (most). MA SMART payments are taxable federal income. Run the order-of-operations with a tax preparer the year you install.
What about hail or hurricane risk?
Modern panels are tested to 1-inch hail at 50 mph; homeowners insurance covers replacement. Add an endorsement and confirm replacement-cost coverage. Premiums typically rise $5–$15/mo for a residential system.
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