Frequently Asked Questions
Almost everything you want to know has been asked before.
Solar Water Heating — Cost & Value
Is a solar water heater a good investment?
Often yes. In sunny or moderate climates, a well-sized system can trim 50–80% of water-heating energy and recover its net cost within a typical 5–10 years when incentives apply.
What does a home system usually cost?
Turnkey installs commonly land in the mid-thousands (several thousand dollars) before credits or rebates; local incentives and the 30% U.S. federal tax credit can reduce that substantially.
Why do savings vary so much by home?
Sun exposure, hot-water usage, backup fuel price, and system type (passive vs active) drive the math. Shade or very low usage stretches payback; high usage and good solar access shorten it.
Will energy prices affect ROI?
Yes—higher electricity or gas rates improve returns because your solar output displaces more expensive energy over time.
How Systems Work (In Plain English)
How does a solar water heater actually heat water?
Roof collectors warm a circulating fluid; that heat moves into a storage tank through a heat exchanger (or directly in some designs). A conventional heater remains as backup.
What’s the difference between passive and active systems?
Passive models use natural thermosiphon flow—simple and low-maintenance. Active systems use a small pump and controller—more flexible, better for cold regions, and easier to place the tank indoors.
Do I still need my existing water heater?
Keep it. Solar provides most of the heat across the year, while your existing unit guarantees target temperature during cloudy spells or peak demand.
Winter, Clouds & Night
Will it work in freezing weather?
Yes—if designed for it. Indirect glycol loops or drainback designs prevent freeze damage and keep harvesting winter sun.
What happens on cloudy days?
Output drops, but active systems with quality collectors still preheat water. Your backup tops up to setpoint automatically.
Does anything happen at night?
Collection stops; a well-insulated tank stores heat, and the backup heater maintains comfort if the tank cools.
Collectors — Flat Plate vs Evacuated Tubes
Which collector type should I pick?
Flat plates are cost-effective for warm/sunny areas. Evacuated tubes shine in cold, windy, or cloudy conditions due to superior insulation.
Is roof space a factor?
Yes—tubes can deliver more winter heat per area; flat plates are broader panels that may integrate more flush with the roof.
Pools, RVs & Off-Grid
Can solar get my pool to comfortable temps?
Absolutely. Unglazed polymer panels sized to 50–100% of pool surface area commonly add 5–10°F (more with covers); evacuated tubes help in colder climates.
Are there portable options for camping or vans?
Yes—solar shower bags, evacuated-tube kettles, and compact thermosiphon kits provide small-volume hot water without grid power; many travelers pair them with a propane or 12V backup.
Will RV roof space or weight be an issue?
Plan carefully. Keep collectors compact, minimize tank size/weight, and protect against freezing when traveling in cold regions.
Maintenance, Lifespan & Reliability
How much upkeep is required?
Light maintenance. Annually check glazing, piping insulation, valves, and pump operation. Keep collectors clean.
What about antifreeze loops?
Test and refresh propylene glycol every few years to maintain freeze protection and pH, and monitor loop pressure.
How long do systems last?
Collectors often run 20–30 years. Pumps/controllers commonly 10–15 years. Tanks can exceed a decade with anode replacement and periodic flushing.
Common issues I can prevent?
Dusty glazing, failed check valves, degraded insulation, old glycol, or a tired pump. Small fixes keep performance high.
Buying Checklist — Quick Hits
How do I know my site is suitable?
Look for largely unshaded south-facing roof (or ground rack), solid structure, and space for a solar tank or a two-tank preheat configuration.
What certifications or paperwork matter?
Favor SRCC/OG-100 collectors and OG-300 systems (or regional equivalents) to qualify for incentives and to ensure tested performance.
One-tank or two-tank setup?
Two-tank (solar preheat ? conventional heater) maximizes solar fraction; single-tank combos save space but can limit capture.
Any installer must-asks?
Request multiple quotes with specs, warranties, freeze strategy, expected solar fraction, and service plan. Set the backup thermostat slightly below the solar target so solar does the heavy lifting.