Solar panels in Charleston, SC: cost, incentives, and quotes

Charleston sits in Charleston County on the South Carolina coast, served primarily by Dominion Energy South Carolina (the utility formerly known as SCE&G before Dominion\u2019s 2019 acquisition). South Carolina has built one of the strongest solar policy frameworks in the southeastern US, anchored by a 25% state income tax credit that\u2019s among the most generous in the country. Combined with 1:1 retail-rate net metering under the 2019 Energy Freedom Act and the standard sales/property tax exemptions, Charleston solar economics hold up well even after the federal residential tax credit ended in December 2025. The hurricane-zone engineering adds modest cost but not enough to break the math.

Why solar makes financial sense in Charleston

Charleston averages 4.5\u20135.2 peak sun hours per day, comparable to most of the Mid-Atlantic but with longer growing seasons that produce stronger summer output. DESC residential rates run around 13\u201314 cents per kilowatt-hour, below the national average. The moderate rates are partially offset by the strong state-level incentive structure and full 1:1 net metering.

The 25% state tax credit is the standout feature. On a $20,000 system, the total potential state credit is $5,000, claimed at up to $3,500 per year over multiple tax years until the full credit is used (consult a qualified tax advisor about your specific situation). This is meaningfully more generous than most state credits, which typically cap at $1,000 or so. Combined with 1:1 net metering, sales tax exemption, and property tax exemption, Charleston solar economics produce 8\u201311 year payback for most cash-purchase systems in 2026.

The Energy Freedom Act (2019) and net metering

South Carolina\u2019s solar policy framework changed substantially with the Energy Freedom Act (Act 236, 2019), which established net metering for residential systems up to 20 kW, clarified solar leasing and Power Purchase Agreement rules, and set the foundation for the state\u2019s solar market growth. Before 2019, South Carolina was a substantially weaker solar market; since the Act, installed residential capacity has grown roughly tenfold.

Under the current DESC net metering framework:

• Excess solar exports earn credits at the full retail electricity rate
• Credits roll over month to month during the year
• Each November, any remaining unused credits are settled at the avoided cost rate (~2.8\u20133.4 cents/kWh as of 2025)
• Residential systems are capped at 20 kW
• $100 application fee for interconnection

The November true-up is the most consequential design choice for system sizing. Because excess credits convert to avoided cost (a roughly 75% reduction from retail), the math rewards sizing your system to match annual usage closely rather than substantially exceeding it. A reputable Charleston installer designs around the November true-up rather than upselling capacity that gets paid out at avoided cost.

The South Carolina Public Service Commission has been reviewing potential modifications to the net metering framework, so the current rules are worth locking in if you\u2019re considering solar in Charleston. State PSC reviews can result in less favorable terms for new customers while grandfathering existing systems under prior rules.

The 25% state tax credit, in detail

South Carolina\u2019s residential solar tax credit is straightforward in structure but worth understanding in detail because it has both a small annual cap and a long carry-forward period:

• Credit amount: 25% of the total cost of the residential solar installation
• Annual cap: $3,500 per year, or 50% of state tax liability (whichever is less)
• Carry forward: Unused credit carries forward for up to 10 years
• Form: File Form TC-38 with your South Carolina state income tax return
• Stacking: Unaffected by the federal OBBBA changes; continues to apply to systems installed in 2026 and beyond

A worked example: a $24,000 system produces a $6,000 total state credit. Claimed at the $3,500/year cap, it takes two years to use the full credit (assuming sufficient state tax liability to absorb $3,500 each year). For homeowners with limited state tax liability, the carry-forward provision is the key feature; you can capture the full credit over many years.

The 25% credit is also one of the few state credits that materially competes with the federal credit on size. When the federal credit was 30%, South Carolina solar customers were among the few in the country with combined state + federal credits exceeding 50% of system cost. After OBBBA terminated the federal residential credit, the 25% state credit retained its full value, making South Carolina relatively more competitive in 2026 than it was before.

Hurricane-zone engineering (Charleston-specific)

Charleston sits in a high-wind-zone region per the South Carolina Building Code, currently requiring residential structures (and the equipment attached to them) to withstand sustained winds well above 130 mph in many areas. Solar panels and racking installed in Charleston County must meet these wind-load requirements, which means heavier-duty mounting hardware, more attachment points, and engineering review.

A few practical implications. First, expect installation costs in Charleston to run modestly higher than the South Carolina state average because of these requirements. The pricing range above already reflects this. Second, verify your installer is familiar with current South Carolina Building Code requirements for the coastal region. Third, talk to your homeowner\u2019s insurance carrier before installation. Most carriers continue to cover solar as part of the dwelling, but some require notification.

Modern solar panels are remarkably hail-resistant and survive most hurricane wind events when properly installed. The historical failure mode for hurricane damage to residential solar is the mounting, not the panels, which is exactly why the South Carolina Building Code wind-load requirements matter.

The 2026 federal credit reality

The 30% federal residential tax credit (Section 25D) ended December 31, 2025 under the One Big Beautiful Bill Act signed July 4, 2025. For customer-owned solar installed in Charleston in 2026 and beyond, the federal credit is no longer available. The commercial credit (Section 48E) continues for solar leases and PPAs through 2027\u20132030 deadlines.

South Carolina is one of the states where this federal change hurts notably less than average because the 25% state tax credit retains full value, and the 1:1 net metering structure remained intact. The combination kept Charleston payback in the 8\u201311 year range in 2026, while many southeastern states without comparable state programs saw payback push to 13+ years.

Permitting and interconnection in Charleston

Residential solar in Charleston requires permits through the relevant local jurisdiction (City of Charleston, City of North Charleston, City of Mount Pleasant, or Charleston County for unincorporated areas). Each has its own permit process and timeline, with City of Charleston permits typically taking 2\u20134 weeks. The DESC interconnection process runs in parallel and requires the $100 application fee. Total timeline from signed contract to running system typically runs 8\u201312 weeks.

South Carolina does not have a specific Solar Rights Act protecting against HOA restrictions, putting it in the group of about 21 states without explicit statutory protection. Many Charleston neighborhoods are governed by HOAs, particularly in master-planned communities like Daniel Island, I\u2019On, and similar developments. Most approve solar installations with formal architectural review applications, but verify your CC&Rs before assuming approval will be straightforward.

Getting quotes in Charleston

Start by estimating what a system would cost and produce on your specific roof. Our solar calculator uses satellite roof analysis to size a system and estimate output and savings for your Charleston address. Then compare quotes from pre-screened local installers familiar with DESC\u2019s interconnection process, hurricane-zone wind load requirements, and the South Carolina state tax credit application. Ask each installer how they\u2019d size the system around DESC\u2019s November true-up at avoided cost; that\u2019s the design decision that most affects long-term economics in Charleston.