This is the second half of my interview with solar pioneer Tom Lane, who was elected to the Solar Hall of Fame in 2006. Part one of the interview is here.
His company, ECS Solar, installs solar electric, hot water and pool heating systems in Florida. He wrote the book “Solar Hot Water: Lessons Learned 1977 to Today”, which some consider the bible of the industry. 
Q- What pitfalls a homeowner should watch out for when buying a solar hot water system?
The biggest thing to be aware of is to make sure the homeowner buys a system with a 100% guarantee against freeze damage. Usually the best type of system is a drain-back system. Fundamentally, there are 2 types of solar heating systems: direct and indirect.
Direct means the water heated in the system is the water that comes out in your shower. That system should only be used in areas that have one freeze or less per year. If you’re in an area that has freezes, you should be using an indirect system, with a heat exchanger. The water that goes through the system is either a drain-back system that drains back when the pop cuts off or you’re circulating a pressurized anti-freeze system.
It’s important that homeowners get a system that’s appropriate for their area and they get a 100% freeze damage guarantee.
Another issue to watch out for is if you have really hard water, depending on the calcium and minerals in your water. That’s another reason to use a heat-exchanger system so your heater system doesn’t get contaminated with mineral buildup. And make sure your heat exchanger is sized properly to handle any problems with water quality.
Q- Any final comments or advice for homeowners?
I would advise people to take advantage of getting a system as soon as possible because the $2000 tax credit may end in Dec 2008. It’s funny, people get all excited about solar electric systems – they’re great and I support them – but you get better energy savings with a $5000 solar hot water system. With the federal and state rebates, it makes it obvious that this is the first thing people should do when going solar.
